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The predicted increasing hardening in Flanders causes an increase in habitat fragmentation.

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In Belgium 25 to 75 % of the species are at risk of decreasing in numbers. Many causes are responsible for this decline, for example degradation and fragmentation of habitats, pollution of the soil, water and air, building...
The climate change puts the biodiversity under more pressure. Native species have the choice between adapting, migrating or extinction. In the meanwhile new non-native species emerse and develop massively at the cost of indigenous species.

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In ons land loopt 25 à 75 % van de soorten het risico zeer sterk in aantal af te nemen. Daarvoor zijn veel oorzaken verantwoordelijk, zoals de aantasting van hun leefgebieden door versnippering, bebouwing, de vervuiling van de bodem, het water en de lucht, enz.

De klimaatveranderingen zetten de biodiversiteit verder onder druk: de inheemse soorten hebben de keuze tussen zich aanpassen of migreren en... uitsterven. Intussen verschijnen er nieuwe soorten die zich soms massaal en ten koste van de inheemse soorten ontwikkelen.

Sinds 2004 is er een alarmerende achteruitgang vastgesteld van het tweestippelig lieveheersbeestje. Dit is te wijten aan de introducie, in de jaren 90, van het Aziatische lieveheersbeestje als biologisch bestrijdingsmiddel. Deze soort voedt zich wel degelijk met bladluizen maar valt ook onze inheemse lieveheersbeestjes aan en eet hun nakomelingen. (Bron: BelgaImage)

Veranderende interacties tussen soorten

Door de stijging van de temperatuur doen bepaalde voorjaarsverschijnselen zich vroeger voor, zoals het ontluiken van de bloemknoppen (5 tot 15 dagen vroeger dan 50 jaar geleden), en bepaalde najaarsverschijnselen later, zoals de verkleuring van de bladeren. Die fenologische veranderingen verstoren de interacties tussen de soorten.

Neem bijvoorbeeld de bonte vliegenvanger. De aankomstdatum van deze trekvogel evolueert trager dan de periode waarin het voornaamste voedsel voor zijn jongen (de beukenrups) voorkomt. De laatste 20 jaar is de vliegenvanger steeds vroeger teruggekomen van zijn overwinteringsgebieden in Afrika, maar niet vroeg genoeg om van de voedselpiek te kunnen profiteren. Het gevolg is dat de populatie bonte vliegenvangers sterk begint terug te lopen in België.

(Bron: BelgaImage)

Sommige soorten vestigen zich in onze streken

De wetenschappers zien ook veranderingen in de verspreidingsgebieden door het feit dat veel thermofiele (warmteminnende) soorten naar het noorden verhuizen. De laatste decennia zijn in België namelijk steeds meer soorten verschenen die in warme gematigde klimaten thuishoren: zuidelijke libellen (zoals de vuurlibel), spinnen (wespspin, afkomstig uit het Middellandse-Zeebekken), vogels (Europese bijeneter, een soort uit het zuiden die tegenwoordig ook in België broedt) en muggen (die tropische ziekten zoals het West-Nijlvirus kunnen overbrengen), enz. Sommige schadelijke soorten hebben voordeel van de effecten van de klimaatverandering (verspreiding van teken, processierupsen, enz.).

In Wallonië heeft men door de opeenvolging van warme en droge zomers gedurende meerdere jaren zeven zuiderse soorten libellen steeds vaker kunnen waarnemen. Hetzelfde geldt voor andere zuiderse insectensoorten zoals sprinkhanen, krekels, vlinders enz.

Deze grafiek toont de evolutie van de observatiefrequentie in Wallonië en Brussel van de 7 soorten die het grondgebied het meest hebben gekoloniseerd in de jaren '80 en '90. De groene lijn geeft de gemiddelde jaartemperatuur door de jaren heen weer. (Bron: Libellenwerkgroep Gomphus Wallonië-Brussel - 2009)

Spinnenonderzoek in de Antwerpse binnenstad door de gebroeders Van Keer heeft aangetoond dat er momenteel een aantal soorten voorkomen, zoals de witrugzakspin, die oorspronkelijk een meer zuiderse verspreiding kenden. Alles wijst erop dat ze op eigen kracht naar Antwerpen afgezakt zijn, en er overleven. Bovendien werden er buitenshuis ook soorten aangetroffen die bij ons normaal gezien alleen binnenshuis voorkomen. Dit alles wijst volgens de arachnologen (spinnenspecialisten) duidelijk op een geleidelijke opwarming van het klimaat."

In de Noordzee veroveren meer zuiderse soorten zoals de sardien en de ansjovis een plaats omdat de temperatuur van het water is gestegen.

... en andere soorten trekken weg

Bepaalde inheemse soorten verlaten onze streken, zoals bijvoorbeeld de kabeljauw, die naar het noorden trekt op zoek naar kouder water.

Bij talrijke andere soorten overstijgt het tempo van de klimaatverandering hun migratiecapaciteit, vooral wanneer hun bewegingen beperkt worden door het versnipperde landschap of wanneer de soorten geen aangepaste habitats kunnen vinden. Sommige vogelsoorten (zoals de keep of de barmsijs) dreigen in de toekomst uit Vlaanderen te verdwijnen, als gevolg van de toegenomen temperatuur tijdens de voortplantingsperiode.

Het Brussels Hoofdstedelijk Gewest heeft in het Zoniënwoud een onderzoek verricht om de invloed van klimaatveranderingen op verschillende bossoorten te evalueren. Dit onderzoek heeft aangetoond dat de verwachte milieuomstandigheden in de toekomst niet gunstig zullen zijn voor de groei van de beuken. De beroemde "beukenkathedraal" is dus in gevaar en zou wel eens voorgoed kunnen verdwijnen.

Meer info :

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In ons land loopt 25 à 75% van de soorten het risico zeer sterk in aantal af te nemen. Daarvoor zijn veel oorzaken verantwoordelijk, zoals de aantasting van hun leefgebieden door versnippering, bebouwing, de vervuiling van de bodem, het water en de lucht, enz.

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Current status and predicted impact of climate change on forest production and biogeochemistry in the temperate oceanic European zone: review and prospects for Belgium as a case study

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Current status and predicted impact of climate change on forest production and biogeochemistry in the temperate oceanic European zone: review and prospects for Belgium as a case study

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Results show that Belgian forests are mainly young forests, very productive and have a high capacity for carbon storage. Major negative deviations in vitality were observed in the 1990s (storms) and as a result of disturbances in the last decade for sensitive species such as poplar and beech. Thanks to high atmospheric deposition and soil fertilization (as a result of the former land use), the nutrient supply of the Belgian forests will probably be able to be maintained in the future, despite the expected increase in productivity as a result of an increase in atmospheric CO2 concentrations in the coming years. . However, in the long term, such an increase in production is likely to be limited by a shortage of nutrients at poor sites and by drought for vulnerable species such as beech and Norway spruce. Drought situations are likely to increase in the future, but negative effects are expected for a limited number of tree species. The potential effects of storms, outbreaks of insects and fungi must be carefully examined, while forest fires should in principle be less of a concern for Belgium.

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Current status and predicted impact of climate change on forest production and biogeochemistry in the temperate oceanic European zone: review and prospects for Belgium as a case study | Ecopedia

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Dit artikel presenteert de huidige status van de productie van het bosecosysteem en de te verwachten effecten van klimaatverandering voor België. Resultaten tonen aan dat Belgische bossen voornamelijk jonge bossen zijn, zeer productief en een hoge capaciteit voor koolstofopslag kennen.

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www.klimaat.vmm.be

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Species 1 - Northern crested newt (Triturus cristatus)

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Species 1 - Northern crested newt (Triturus cristatus)

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The Northern crested newt mainly occupies small-scale landscapes with a high diversity of biotope types. The breeding sites are cattle drinking pools, bomb pits, cut river arms, small ponds, clay grooves, relatively nutrient-rich fens or other puddles with stagnant, relatively nutrient-rich water with a virtually neutral pH (see, for example, habitat type 3150). Crested newts are frequently found in areas with groups of closely spaced water bodies. The puddles are preferably little or not shaded, relatively deep and / or contain virtually year-round water. The presence of fish has an adverse effect. The presence of water plants is required; alternation between places with dense water vegetation and parts with open water is optimal. The females individually lay the eggs on submerged leaves of water or shore plants. The larvae hatch after about three weeks, and then live in the pond as aquatic predators (predates on tadpoles, worms, insects and insect larvae).
In the period November-March the species hibernates on land. Favorable land biotopes are forests, thickets, orchards, moist and extensively managed meadows, heathland, hedgerows and hedges. The migration from land-to-water biotope and between breeding coils often takes place along hedges, rows of pollard trees, reed beds and field margins with rough herbs.

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De Kamsalamander is de grootste inheemse watersalamander. Vrouwtjes worden tot 18 cm lang, mannetjes blijven iets kleiner (tot 16 cm). De buik is opvallend geel tot oranjerood met een onregelmatig patroon van grote zwarte vlekken. De kop, rug, flanken, staart en bovenzijde van de poten zijn donker- tot roodbruin gekleurd, vaak met zwarte vlekken.

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Species 2 - European nightjar (Caprimulgus europaeus)

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Species 2 - European nightjar (Caprimulgus europaeus)

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The Nightjar is a bird of structurally rich (old) heathlands with a gradual transition to open to semi-open forests on sandy soil with wide sand plains or paths. There is also nesting in cap plains. The nest is always on the ground. In the twilight and at night they hunt on insects such as moths, mosquitoes and beetles, which are caught with a wide open mouth.

The nightjar occupies a special ecological niche of insectivorous birds that hunt during twilight and night. Unlike bats or owls, they hunt only on sight. They therefore have special morphological and physiological adjustments. The diet consists mainly of night-active moths, but also of beetles. Since nightjars are not very selective in their diet, the food composition will depend on the supply. The availability of insects can vary according to biotope type, year, season, temperature and humidity, but also according to the propagation time of the insects.

In addition to the development of large eyes, each eye has a field of view of 180 and each eye can be rotated separately to explore the underlying environment. When opening the mouth, you can look past the beak so that the prey can be caught more accurately. The internal structure of the eyes has also been adjusted. The retina consists of a large number of rods and behind the retina a tapetum lucidum occurs. Other developments in the head focus on the 'processing' of prey. Bristles on the upper beak enlarge the catch area, reduce the escape possibilities for insects and protect the eyes. A highly vascularized palate and the tang hairs on the upper beak would allow to respond quickly to the capture of an insect. A dilated esophagus serves for the storage and rapid channeling of food. The feathers of the nightjar are soft, like with owls, this makes it possible for them to fly noiselessly and to approach prey more easily.

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De Nachtzwaluw is een bruingrijze vogel met ingewikkelde tekening die overdag, met gesloten ogen en perfect gecamoufleerd, zit te rusten op de grond of een dikke tak. Het is een nachtactief dier met een kenmerkend groot oog. Het mannetje heeft sneeuwwitte vlekken op de handpennen en witte staarthoeken. Deze vlekken ontbreken bij het vrouwtje en de onvolwassen vogels. Mannelijke nachtzwaluwen zijn het opvallendst tijdens de baltsvlucht wanneer ze naast een insectachtige zang ook een soort vleugelgeklap laten horen. De dieren vliegen licht en wendbaar: even stijgend, kort biddend, plots snel glijdend en uit het zicht verdwijnend. De zang is ver dragend (vaak tot op één kilometer hoorbaar) en bestaat uit een hard snorren (van dichtbij ratelend), dat met korte tussenpauzes urenlang te horen is, van de late avondschemering tot het ochtendgloren. Door zijn levenswijze en aangepaste camouflage is de Nachtzwaluw overdag uiterst moeilijk waar te nemen.

Het broedareaal omvat heel Europa behalve het uiterste noorden. De Nachtzwaluw is een zomervogel die laat toekomt in het broedgebied (meestal een eind in mei) en in september terugtrekt naar de overwinteringsgebieden in tropisch Afrika. In Vlaanderen broeden naar schatting 500-550 paren, hoofdzakelijk in de Limburgse Kempen. De soort komt er vooral voor op de overgang van grote heidegebieden met dennenbossen. Recent werden geschikte biotopen in de Antwerpse Kempen ook weer bezet. In de relictbiotopen van Oost- en West-Vlaanderen is de soort al ruim één decennium verdwenen, met uitzondering van een recente vestiging te Moerbeke en occasionele meldingen in de kustduinen en in de bossen nabij Beernem.

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Sinds het einde van de 19e eeuw degradeerde en versnipperde het habitat van de Nachtzwaluw in snel tempo. Hierdoor werd zij opgenomen in Bijlage I van de EU- Vogelrichtlijn en de Vlaamse Rode Lijst waar zij ingedeeld worden bij de 'Kwetsbare soorten' die op termijn tot status 'Bedreigd' kunnen overgaan. Met uitzondering van enkele Waalse populaties in Lagland, Spa-Malchamps en Croix-Scaille (totaal 50-60 koppels) treffen we Nachtzwaluwen in België hoofdzakelijk aan op de Kempense zandgronden.

Na een absoluut dieptepunt met 208-281 broedparen in 1980 lijkt zich vandaag een opmars af te tekenen, maar schattingen van de populatiegrootte zijn sterk uiteenlopend. In Limburg wordt het aantal broedparen geschat op 500 in 2002 en 800 koppels in 2008. Het is echter noodzakelijk deze gegevens met uiterste voorzichtigheid te benaderen omdat tellingen gebaseerd zijn op het aantal zangposten in de getelde gebieden, en niet op het werkelijke aantal broedkoppels dat mogelijk lager ligt.

Als gevolg van de intensivering van de houtproductie voor steenkoolmijnen werden vanaf de 19de eeuw ecologisch waardevolle heidegebieden in Bosland beplant. Het huidige bosareaal bestaat hoofdzakelijk uit naaldhout (91%), met Corsicaanse den Pinus nigra var corsicana (59%) en Grove den Pinus sylvestris (35%) als voornaamste soorten. De belangrijkste ecologische waarden in het projectgebied worden toegeschreven aan heide-, ven- en stuifduingebieden en heischrale graslanden. Zij getuigen, samen met de nationaal en- Europees beschermde soorten die dit habitat verkiezen, van het historisch uitgestrekte heidelandschap in Noord-Limburg. Om de instandhouding van de ecologische waarden te garanderen, staat de ontwikkeling van een netwerk van open habitats, gefundeerd op wetenschappelijke kennis over soorten en habitats, hoog op de agenda in Bosland.

Uit de resultaten van onderzoek (bron: Tracing Nature) blijkt dat het leefgebied van de Nachtzwaluw vele malen groter is dan eerst werd gedacht. Zo worden gemiddelde oppervlakten van 100ha gevonden per individu. Hierbij moet rekening gehouden worden met een sterke onderschatting in oppervlakte door de gebruikte analyse. In vergelijking met eerdere schattingen (5ha) is deze 100ha toch een aanzienlijk verschil. Ook de plaats waar Nachtzwaluwen voedsel gaan zoeken is opmerkelijk. Zo blijken zij voedsel te gaan zoeken in de kleinschalige landbouwgebieden rondom de heide- en duingebieden. Deze resultaten hebben uiteraard sterke consequenties voor het beheer voor de Nachtzwaluw.

Bedreiging

Verstoring of vernietiging van de nestplaats, een hoge recreatiedruk, habitatverlies en het gebruik van insecticiden zijn de belangrijkste bedreigingen. De soort verdwijnt wanneer in het broedgebied te veel bomen opschieten.

De combinatie van bomen waar insecten zich ophouden en de aanwezigheid van open, zandige ruimten en onbegroeide plekken die, als gevolg van het warmtehoudend vermogen, vaak insecten aantrekken en dus uitstekende foerageerplaatsen vormen, is essentieel voor het verzekeren van een voldoende groot voedselaanbod. Het beheer van geschikte broedgebieden dient hierop afgestemd te zijn. Vermits de natuurlijke successie van de broedgebieden leidt tot bos, dient dit door menselijk beheer te worden tegengegaan. Op plaatsen waar nogal wat Nachtzwaluwen foerageren, valt een nachtelijk rijverbod op secundaire wegen te overwegen.

Een netwerk met open plekken en variërende overgangen naar ijle bosbestanden is aangewezen om geschikte broedgebieden te creëren. Het is belangrijk dat de overgangen voldoende begroeiing met jonge boompjes en onbegroeide aarde bevatten. Netwerken worden opgebouwd uit kernen en verbindingen. De kernen zijn dan de open plekken o.a. heide-, stuifduin- en vengebieden. Om open gebieden te creëren worden veelal volledige kappingen uitgevoerd, gevolgd door plaggen of chopperen. Hierbij wordt de bovenlaag weggehaald tot op de zandlaag.
Scherpe randsituaties wordt door nachtzwaluwen als ongunstig beschouwd. Beter is dus om bijkomend de aangrenzende bosrand te dunnen zodat natuurlijke verjonging er spontaan kan ontwikkelen.
Open gebieden kunnen als permanent open of halfopen beheerd worden. In het eerste geval is het aangewezen, bij onvoldoende betreding, te frezen of eggen om te verhinderen dat deze plaatsen vergrassen. Halfopen gebieden kunnen beheerd worden door een lichte begrazing. Dit lijkt de meest aangewezen methode om lokale structuur en insectendiversiteit te verhogen (Lensink 1989, Maréchal 1989b). De opslag van geïsoleerde jonge bomen die zo ontstaat, moet niet negatief zijn voor het voorkomen van nachtzwaluwen. Wel dient men enigszins rekening te houden met tijdstip en intensiteit van begrazing.
De brede open wegen met dagzomend zand vormen de verbinding tussen deze kernen. Deze brede, golvende wegen kunnen een dubbele rol vervullen in het open netwerk. Lokaal zullen deze wegen een bijdrage leveren aan de oppervlakte open habitat, en dus broedgelegenheid voor de nachtzwaluw. Op grotere schaal zullen deze wegen als verbindingsgebied dienen waarlangs kleinere diersoorten zich naar geschikte gebiedenkunnen verplaatsen. Naast de ecologische functies kunnen brede wegen belangrijke economische functies vervullen. Als brandweg kunnen zij de verspreiding van vuur verhinderen in droge periodes.
Als exploitatieweg kunnen zij zorgen voor een gemakkelijke toegang tot de gewenste bosbestanden wanneer deze worden ontgonnen.

Om de nachtzwaluwpopulatie op lange termijn in stand te houden, worden vandaag vaak enkel beheerwerken uitgevoerd in broedgebieden. Uit onderzoek blijkt echter dat nachtzwaluwen niet enkel afhankelijk zijn van de gebieden kort bij hun slaap- of broedplaatsen. Vaak zoeken zij tijdens het broedseizoen voedsel op meer dan anderhalve kilometer.Na het broedseizoen legden zij afstanden tot drie kilometer en verder af. Het belang van de voedselgronden wordt dus sterk onderschat, maar hun ligging is ook vaak onbekend. Indien deze voedselgronden verdwijnen door een gebrek aan een aangepast beheer, zullen de dure ingrepen bij de broedplaatsen weinig uithalen. Nachtzwaluwen zouden vooral gaan jagen in de kleinschalige, extensieve landbouwgebieden, nabij waterpartijen en natte heide. Ook in deze gebieden wordt best geopteerd voor een gevarieerd landschap met voldoende uitkijkposten, hagen, opslag en nectarplanten voor insecten.

De Nachtzwaluw is een vogel van structuurrijke (oude) heidegebieden met een geleidelijke overgang naar open tot halfopen bossen op zandgrond met brede zandvlakten of -paden. Er wordt ook genesteld in kapvlaktes. Het nest bevindt zich steeds op de grond. In de schemering en 's nachts wordt er gejaagd op insecten zoals nachtvlinders, muggen en kevers, die met wijd opengesperde bek gevangen worden.

De nachtzwaluwachtigen bezetten een speciale ecologische niche van insectivore vogels die jagen tijdens schemering en nacht. In tegenstelling tot vleermuizen of uilen jagen zij niet met behulp van sonar of geluid, maar enkel op het zicht. Zij beschikken dan ook over speciale morfologische- en fysiologische aanpassingen. Het dieet bestaat vooral uit nachtactieve motten, maar ook uit kevers. Aangezien nachtzwaluwen weinig selectief zijn in hun voeding, zal de voedselsamenstelling afhangen van het aanbod. De beschikbaarheid aan insecten kan variëren volgens biotooptype, jaar, seizoen, temperatuur en vochtigheid, maar ook volgens de voorplantingstijd van de insecten.

Naast de ontwikkeling van grote ogen beschikt ieder oog over een gezichtsveld van 180° en kan ieder oog afzonderlijk gedraaid worden om de achterliggende omgeving te verkennen. Bij het openen van de bek kan er langs de snavel gekeken worden waardoor de prooi nauwkeuriger gevangen kan worden. Ook de interne structuur van de ogen is aangepast. Het netvlies bestaat uit een groot aantal staafjes en achter het netvlies komt een tapetum lucidum voor. Andere ontwikkelingen in de kopstreek focussen zich op de 'verwerking' van prooien. Tasthaartjes op de bovensnavel vergroten het vangoppervlak, verkleinen de ontsnappingsmogelijkheden voor insecten en beschermen de ogen. Een sterk doorbloed gehemelte en de tastharen op de bovensnavel zouden toelaten snel te reageren bij de vangst van een insect. Een verwijde slokdarm dient voor de opslag en snelle kanalisatie van voedsel. De veren van de nachtzwaluw zijn zacht, zoals bij uilen, dit maakt het voor hen mogelijk geruisloos te vliegen en prooien makkelijker te naderen.

Tijdens onderzoek (bron: Tracing Nature) werd in 2012 voor de eerste keer integraal onderzoek gedaan naar de voedselbeschikbaarheid van Nachtzwaluwen. Hierbij werd in verschillende biotopen de beschikbaarheid van voedsel gemeten. Ook werd bij gevangen Nachtzwaluwen de aanwezigheid van prooien in de bek nagegaan. Dit onderzoek kwam tot stand dankzij de hulp van twee studenten van de Universiteit Hasselt, die dit project als hun eindwerk Bachelor Biologie vervullen, en LIKONA.

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De Nachtzwaluw is een bruingrijze vogel met ingewikkelde tekening die overdag, met gesloten ogen en perfect gecamoufleerd, zit te rusten op de grond of een dikke tak. Het is een nachtactief dier met een kenmerkend groot oog. Het mannetje heeft sneeuwwitte vlekken op de handpennen en witte staarthoeken.

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Species 1 - Little Egret (Egretta garzetta)

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Species 1 - Little Egret (Egretta garzetta)

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The Little Egret is a species of very open terrain. The preference is mainly for mud flats, marshes and lagoons, preferably surrounded by alluvial forests consisting of willows and other tree species or low bushes. Other areas with shallow water are also eligible. It is a daytime active bird that feeds on fish, amphibians, insects and snails in shallow water. In the evening they fly with their kind to a shared sleeping place. The nest is made in the trees, usually in colonies between other heron species.

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De Kleine zilverreiger is een middelgrote, volledig witte, slanke reiger met smalle zwartachtige snavel, zwarte poten en kenmerkende heldergele tenen. In zomerkleed zijn er twee lange kruinveren aan het achterhoofd en sierveren op de rug.

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Species 2 - Great white egret (Ardea alba)

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Species 2 - Great white egret (Ardea alba)

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The favorite breeding and foraging biotopes of this colony bird are reed marshes, alluvial forests and shoreline zones of large shallow lakes and ponds, preferably with reed beds and some shrubs or trees. The food consists of fish, amphibians, small mammals and water insects. Foraging mainly takes place in ditches, along banks and on flooded grasslands. The three-spined stickleback is at the top of the menu. The nest is built on over-old reeds, sometimes also in willows.

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De Grote zilverreiger is een zeer grote, geheel hagelwitte reiger, bijna even groot als de Blauwe reiger, maar iets sierlijker, met langere poten en zeer lange hals. Hij verschilt van de Kleine zilverreiger door de langzamere en statigere vlucht, relatief langere poten die in vlucht ver uitsteken en donkere tenen.

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* difference in foraging methods : The Little Egret often runs after its prey. The Great Egret is more patient, and will stand still for a long time to wait until prey come nearby; then it spears its prey with its beak.
* the size of prey varies : Little Egret eats prey with a size in between of 1,2 en 15 cm with a preference for prey of ca. 4 cm.

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Bittern (Botaurus stellaris) feeds
on fish, small mammals, fledgling birds, amphibians (mainly frogs), crustaceans and insects (larvae of libellulae).

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Wat eet de roerdomp?

De roerdomp voedt zich vooral met vis, amfibieën (vooral kikkers), kleine zoogdieren (vooral woelmuizen), insecten (vooral libellenlarven) en kleine vogels. De historische achteruitgang van de soort wordt soms in verband gebracht met het verdwijnen van de medicinale bloedzuigers, een belangrijke voedselbron van de roerdomp. De medicinale bloedzuiger ging reeds in het midden van de 19 de eeuw sterk achteruit omdat hij met het oog op aderlatingen massaal verzameld werd. Zo werden rond 1833 vanuit Duitsland 42 miljoen bloedzuigers geëxporteerd naar Frankrijk en 30 miljoen naar de Verenigde Staten.

Waar leeft de roerdomp?

De roerdomp broedt doorgaans in uitgestrekte, structuurrijke rietvelden met meerjarig riet en hier en daar ondiepe plasjes. Hij foerageert vooral in ondiep water in brede rietkragen.

Verspreidingskaart van de roerdomp

Hoe plant de roerdomp zich voort?

De roerdomp broedt van half april tot half mei. Het nest wordt gebouwd door het vrouwtje en bestaat uit een platform van dood riet, vlak boven de waterspiegel. Roerdompen leggen gewoonlijk één legsel per jaar. Het legsel telt meestal 5 tot 6 eieren die worden gelegd met een tussenperiode van twee of drie dagen per ei. Het wijfje bebroedt de eieren ca. 25 dagen en start hiermee van zodra het eerste ei is gelegd. De jongen komen dus niet tegelijk maar om de twee à drie dagen uit. Ook de broedzorg is vooral voor het wijfje. Roerdompen zijn polygaam. Mannetjes kunnen er soms tot vijf vrouwtjes op na houden. Monogame mannetjes nemen een deel van de broedzorg op zich, polygame meestal niet.

Hoe krijg je de roerdomp te zien?

De roerdomp krijg je (in de broedperiode) vaak gemakkelijker te horen dan te zien. De baltsroep van het mannetje draagt erg ver! De beste periode om een 'boemende' roerdomp te horen is van begin april tot begin juni, van 's ochtends (twee uur voor zonsopgang), tot zonsopgang en in zwoele avondschemer. Eens er jongen zijn, kan je de volwassen vogels regelmatig boven de rietvelden zien vliegen, op zoek naar voedsel. In strenge winters, wanneer de meeste plassen zijn dichtgevroren, kan je roerdompen soms spotten langsheen wakken in rietland, behoedzaam schuifelend over het ijs.

Weetjes over de roerdomp

In Vlaanderen moet de roerdomp vroeger een algemene verschijning geweest zijn. In 1454 werd een banket van Filips de Goede opgeluisterd met niet minder dan 400 roerdompen. Op dergelijke banketten dienden vogels niet enkel voor consumptie, maar ook voor de sier. De roerdomp werd als iets exclusiefs gezien en alleen wie van adel was, mocht op deze soort jagen. Er zijn plakkaten uit de 16de eeuw gevonden waarin 'soecken, rooven of raepen van de eiders van putoeren' streng verboden was voor het gewone volk.

Op het werk van de Antwerpse schilders Frans Snyders (1579-1657) en Jan Fyt (1611-1661) komen regelmatig afbeeldingen van roerdompen voor. Zo wordt aannemelijk gemaakt dat de soort in de eerste helft van de 17de eeuw regelmatig langs de Schelde voorkwam. Er bestaat ook een zelfportret van de Hollandse schilder Rembrandt met een dode roerdomp in de hand. Aangezien roerdompen tijdens de eerste helft van de 17de eeuw regelmatig in voorraadkamers afgebeeld worden, bestaat er geen twijfel dat zij gegeten werden.

De Duitse filosoof, theoloog en natuuronderzoeker Albertus Magnus (1193-1280) waarschuwde al vroeg voor de gevaren van de scherpe snavel van de roerdomp. 'Soo blijft hij stille sonder hem te roeren, als oft hij doodt waer en als hij verneemt dat hij aan een strick vast en gevangen is, soo blijft hij even stil staen tot dat de Vogelvanger hem naeder komt en hem toch neemen wil als dan steeckt hij met den neb van sich gelijk een Reyger en verwondet den Vogelvanger seer want sijn neb is hem geheel scherp en spitsich. Soo men dese Vogel bradet soude hij uitermaten wel ruijcken. Sijn bloedt is oock een seer nutbaer Medicijn voor de gene die met de Jicht geplaeght zijn. Dit is de Putoor', aldus Albert Magnus.

Het woord roerdomp kan worden opgesplitst in twee delen. Het eerste deel van het woord 'roer' betekent 'riet', het tweede deel 'domp' kent twee etymologische verklaringen. Een eerste verklaring brengt 'domp' in verband met het doffe geluid dat de vogel in de paringstijd maakt. Een andere verklaring linkt 'domp' aan het werkwoord 'dompen' in de betekenis van 'onderduiken'. Een roerdomp is dan een 'riet-duiker', een vogel die in de rietvelden onderduikt.

Uit een onderzoek van Natuurpunt naar vogels die tegen hoogspanningsleidingen aan vliegen, blijkt dat soorten die 's nachts vliegen een verhoogd risico lopen. Naast o.a. 7 houtsnippen, 1 kerkuil, 5 koperwieken, 1 kramsvogel, 1 kwartel, 4 oehoes, 2 porseleinhoentjes, 2 ransuilen, 5 waterrallen en 1 watersnip (allemaal nachttrekkers) werden ook twee nachtactieve reigers gevonden als draadslachtoffer: 2 woudaapjes en 4 roerdompen.

Natuurpunt en de roerdomp

De roerdomp is één van de ambassadeursoorten van de beste Natuurpunt-gebieden. De soort broedt o.a. in de Maten (Genk), het Wik (Bokrijk), het Hageven (Neerpelt) en het Krabbelshof (Zandhoven). In elk van deze gebieden werden soortgerichte beheermaatregelen uitgevoerd, waar ook vele andere rietvogels hun voordeel kunnen uit halen.

Natuurpunt beheert geschikte leefgebieden en herstelt leefgebieden die ooit verloren zijn gegaan. Natuurpunt dringt er bij Elia, de beheerder van het hoogspanningsleidingsnetwerk in België, op aan om 'zwarte' lijnen te bebakenen, zodat de aanvliegkans voor roerdompen (en andere soorten) aanzienlijk kan worden verlaagd.

Meer weten?

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De roerdomp voedt zich vooral met vis, amfibieën (vooral kikkers), kleine zoogdieren (vooral woelmuizen), insecten (vooral libellenlarven) en kleine vogels. De historische achteruitgang van de soort wordt soms in verband gebracht met het verdwijnen van de medicinale bloedzuigers, een belangrijke voedselbron van de roerdomp.

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The Eurasian bittern or great bittern (Botaurus stellaris) is a wading bird.
The bittern usually breeds in extensive, structure-rich reed beds with perennial reeds and here and there shallow ponds. He mainly forages in shallow water in wide reed collars.
It is a secretive bird, seldom seen in the open as it prefers to skulk in reed beds and thick vegetation near water bodies.
Picture below © François Van Bauwel

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The common roach (Rutilus rutilus) is a fresh and brackish water fish.
The roach is a small fish, often reaching no more than about 35 cm; maximum length is 45–50 cm.
The common roach is very adaptable and can be found in any freshwater ecosystem, ranging from small ponds to the largest rivers and lakes. It will feed at any depth, although its preferred food sources tend to be in shallower water.

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Daubenton's bat (Myotis daubentonii) is insectivorous and uses echolocation to find prey and orient itself at night.
Daubenton's bat often hunts above water. He owes his name to this. The species lives mainly from shooting moths and flies.

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De watervleermuis paart in de herfst en de winter.Vanaf mei komen de vrouwtjes samen in grote kraamkolonies. In juni en juli werpen ze enkel één jong. De draagtijd is afhankelijk van de weersomstandigheden.

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Daubenton's bat (Myotis daubentonii) - predator

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Daubenton's bat (Myotis daubentonii) - predator

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The Daubenton's bat is a medium-sized species that can be found anywhere in Flanders near the vicinity of water.
Picture below © Karolien Brauns

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The caddisflies, or order Trichoptera, are a group of insects with aquatic larvae and terrestrial adults.
Caddisflies are useful as bioindicators, as they are sensitive to water pollution and are large enough to be assessed in the field.

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Parasitic organism 1 - Mistletoe (Viscum album)

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Parasitic organism 1 - Mistletoe (Viscum album)

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The mistletoe (Viscum album) is an evergreen plant. Viscum album is a hemiparasite on several species of trees, from which it draws water and nutrients.
The most general host in Flanders is undoubtedly the Canada poplar. Mistletoe also grows quite frequently on apple trees. Other hosts are rarer (including hawthorn, maple and robinia). Mistletoe is in our regions mainly bound to calcareous soils, while the hosts appear much wider.
The species can mainly be found in the south of Limburg.

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Parasitic organism 2 - Lousewort (Pedicularis sylvatica)

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Parasitic organism 2 - Lousewort (Pedicularis sylvatica)

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Lousewort  is a species of habitattype 6230 Species-rich Nardus grassland, on siliceous substrates.
The species prefers slightly humous to peaty and loamy, acidic, nutrient-poor sandy soils. The species stands in places with a shallow groundwater table.
The species is a hemiparasite and parasites on the roots of grasses.

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Heidekartelblad is een soort van vochtige en schrale heiden. De soort verkiest licht humeuze tot veenachtige en leemhoudende, zure, voedselarme zandgronden. Daardoor wordt heidekartelblad in het heidelandschap vooral aangetroffen in heischrale graslanden en andere grazige, ijle en lage begroeiingen langs paadjes en in bermen.

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During the last decades, outdoor recreation has become progressively more important, especially in UPA, while biodiversity continues to decline by among others human-induced stress (such as hiking, biking, etc.). Currently, the legal framework to protect ecosystems and ecosystem services is scattered around many laws. In this arena of conflicting demands, careful planning of the area, its infrastructure and activities is needed to sustain the value of UPAs.

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Methods and strategies to monitor and manage human impact on urbanized protected areas (UPA)

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Hasselt University is organizing the second PhD course on the management of urbanized protected areas (UPAs) integrating expertise from different disciplines. Background Monitoring and management of UPA - During the last decades, outdoor recreation...

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The marlpits in Limburg are used by bats as a winter residence. Disturbance by humans have occured by parties, walks, making fire, driving around with vehicles, etc. in the marlpits. Nowadays many marlpits in Limburg have been closed of in protection of the hibernating bats. This has led to an increase in the number of hibernating bats in these specific marlpits.

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De toegang tot de groeven is voornamelijk een probleem op het vlak van de veiligheid. Niet alleen kan men verloren lopen in de groeven (wat ook jaarlijks meerdere personen overkomt), eveneens bestaat er een reëel instortingsgevaar. Het betreden van de groeven dient dus onder begeleiding te gebeuren.

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The Impact of Insecticides and Herbicides on the Biodiversity and Productivity of Aquatic Communities

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The Impact of Insecticides and Herbicides on the Biodiversity and Productivity of Aquatic Communities

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Pesticides are often used in nature management as a solution for invasive species. A researcher investigated the effects on freshwater fauna. The biodiversity declined with 22% when glyfosate is used, by 30% when malathion is used, by 15% when Sevin is used en no effect when 2,4-D is used.
Especially Roundup (glyfosate) eradicated different species of amphibians, reducing de tadpoles diversity by 70%. Therefor is the use of glyfosate in and around water ecosystems advised against.

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The Impact of Insecticides and Herbicides on the Biodiversity and Productivity of Aquatic Communities | Ecopedia

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Pesticiden zoals glyfosaat vormen hoe langer hoe meer een oplossing in het natuurbeheer voor hardnekkige problemen als invasieve exoten. Deze onderzoeker bekeek de effecten van diverse pesticiden op zoetwaterleven. De biodiversiteit bij gebruik van deze producten nam met 22% af in het geval van glyfosaat, 30% bij malathion, 15% bij gebruik van Sevin en geen effect bij 2,4-D werd vastgesteld.

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The lethal impact of the pesticide Roundup on aquatic and terrestrial amphibians

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The lethal impact of the pesticide Roundup on aquatic and terrestrial amphibians

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A relation between Roundup and the decline of biodiversity of amphibians has been found. 68-86% of young amphibians died when exposed to a thinned solution of Roundup.

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The lethal impact of Roundup on aquatic and terrestrial amphibians | Ecopedia

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In een gelijkend artikel was de relatie tussen Roundup en de achteruitgang van de biodiversiteit van amfibieën vastgesteld. Met name bij dikkopjes en gebruik van Roundup (een oplossing met glyfosaat, een herbicide) bij de commercieel aangeraden dosissen. De auteur ging een stap verder en ging na of ook de amfibieën in landfase schade ondervinden bij gebruik van Roundup.

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The Belgian Forum on Invasive Species gathers scientific information on presence, distribution, auto-ecology, adverse impacts and management of invasive alien species. It regularly updates a reference list of exotic species in Belgium and is responsible for the elaboration of a black list gathering species with a strong detrimental impact on biodiversity.

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The Belgian Forum on Invasive Species gathers scientific information on presence, distribution, auto-ecology, adverse impacts and management of invasive alien species. It regularly updates a reference list of exotic species in Belgium and is responsible for the elaboration of a black list gathering species with a strong detrimental impact on biodiversity.

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Preventing and fighting invasive species is becoming more and more important in nature management in Flanders.

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* impacts of landuse by agriculture and urbanization
* impacts of the use of pesticides
* impacts of the changing climate
* impacts of human-induced stress, such as disturbance by noise, temperature shift, presence of humans, recreation
* impacts due to the introduction of invasive species
* ....

For more detailed information I refer to Theme 3 : Threats to biodiversity in a changing climate

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Biotic characteristics - biodiversity and nature areas

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Biotic characteristics - biodiversity and nature areas

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According to latest data gathered by Statistics Belgium (reference year 2011), 40.467 species have been identified so far in Belgium. There are probably around 15.000 additional species present, but these have yet to be discovered. A little less than two-thirds of the known species are animals, the rest being plants, micro-organisms and fungi. Insects, like in elsewhere in the world, are by far the most numerous.

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Biodiversity in Belgium | Convention on Biological Diversity

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The (semi-)natural habitats currently found in Belgium are the legacy of agricultural practices developed since the Neolithic, when large forest areas on the most fertile soils were cleared for farming. The modern landscape combines cultivated fields, pastures, heathlands and forests, interspersed by densely urbanised and industrialised areas.

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40% of the surface of protected nature in Flanders is located in Limburg. About 90% of all the Flemish plants and animals are present in Limburg. Above all many rare and threatened Flemish species can only be found in province Limburg

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Maar liefst 40 % van de oppervlakte Vlaamse beschermde natuur ligt in Limburg. Van alle Vlaamse planten- en diersoorten komt 90 % in Limburg voor. Bovendien komen heel wat zeldzame en bedreigde Vlaamse soorten enkel in Limburg voor! Limburg...

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The invasive Corbicula species (Bivalvia, Corbiculidae) and...

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Lien T.H. Nguyen, Niels De Pauw Laboratory of Environmental Toxicology and Aquatic Ecology, Department of Applied Ecology and Environmental Biology Ghent University J. Plateaustraat 22 B-9000 Ghent, Belgium Belg. J. Zaal. Jrg. 132, nr. 1 (2002):...

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Biotic characteristics - species and habitats

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Biotic characteristics - species and habitats

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Biodiversity hotspots and endemic species

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Biodiversity hotspots and endemic species

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There are no biodiversity hotspots and no endemic species in province Limburg.

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Several nature reserves are located in Limburg. Recognized nature reserves, Flemish nature reserves and Forest reserves can be distinguished.
These nature reserves mostly overlap with the Natura 2000 network and the VEN and IVON areas.

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In Belgium are 9 Ramsar sites present, but none of them are located in the province of Limburg.

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Flemish Ecological Network (VEN) and Integral Interweaving and Support Network (IVON)

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Flemish Ecological Network (VEN) and Integral Interweaving and Support Network (IVON)

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The VEN and IVON areas are protected nature areas in Flanders.
The VEN and IVON consists of "big unites of nature", 'big unites of nature in development" and "nature interweaving areas". Together they form an ecological network, consisting of stepping stones for protected species.

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Natura 2000 is a European network of core breeding and resting sites for rare and threatened species, and some rare natural habitat types which are protected in their own right.
The aim of the network is to ensure the long-term survival of Europe's most valuable and threatened species and habitats, listed under both the Birds Directive and the Habitats Directive.
In the figure below you can observe the areas protected by the Birds directive and the habitats directive in Limburg.

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The map below shows the regions that are effectively and possibly sensitive to flooding.

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The main 2 rivers in Limburg are the Meuse in the West and the Demer in te East.

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In limburg are 2 large river basins, namely of the Meuse in the west and the Scheldt in the east. The sub-basins of the rivers Demer and Nete are part of the basin of the Scheldt.

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The province of Limburg is located in the Flemish region of Belgium.
Belgian Limburg is situated between the provinces Vlaams-Brabant, Antwerpen and Luik of Belgium and the provinces Noord-Brabant and Limburg of the Netherlands.
The town of Voeren is separated from the rest of Belgian Limburg by the provinces Luik and Dutch Limburg.

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Soil use consists of agricultural, natural, habitated and industrial areas.

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In the province of Limburg the following soil types can be found : sandy soil, loam soil, clay soil, sandy loam soil, rocky loam soil, drift dunes, colluvial soil, alluvial soil, bogland

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The height model for Limburg shows that this region is rather plane. The heigt varies between 18 and 287,5 m above sea level (highest point in Voeren). In the south of Limburg there are hills present, but no mountains or volcanoes can be found in this regione.

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Many species on the IUCN red list of Flanders can be found in Limburg, for instance :

Hylo arborea (critically endangered),
Rana arvalis (vulnerable),
Coronella austriaca (endangered),
Sterna hirundo (vulnerable), Botaurus stellaris (critically endangered),
Circus aeruginosus (endangered)
Neomys fodiens (endangered),
Muscardinus avellanarius (critically endangered),
Myotis bechsteinii (endangered),
Myotis myotis (critically endangered),
Sympetrum depressiusculum (vulnerable),
Leucorrhinia pectoralis (critically endangered),
Lucanus cervus (endangered),
Maculinea alcon (endangered),
Misgurnus fossilis (critically endangered),
Lampetra planeri (vulnerable),
Liparis loeselii (critically endangered),
Luronium natans (vulnerable),
...
https://www.inbo.be/en/search-flanders-red-lists
Picture of the european tree frog below © Hugo Willockx

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Species of the habitat and bird directive

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Species of the habitat and bird directive

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Species of the Bird and Habitat directive present in Limburg are for instance :
Myotis bechsteinii,
Myotis myotis,
Hylo arborea,
Rana arvalis,
Coronella austriaca,
Sterna hirundo,
Botaurus stellaris,
Luscinia svecica,
Liparis loeselii,
Luronium natans,
...

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Answer : "3. The wolves were brought in because the increased elk population was overgrazing the deciduous, woody species such as aspen and cottonwood."

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Habitattypes of the Habitat directive in Flanders

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Habitattypes of the Habitat directive in Flanders

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Habitattypes present in Limburg are for instance :
2330 Inland dunes with open Corynephorus and Agrostis grasslands
4030 European dry heaths
6410   Molinia meadows on calcareous, peaty or clayey-silt-laden soils (Molinion caeruleae)
7110 Active raised bogs
9130 Asperulo-Fagetum beech forests
...

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The increasing urbanization and the intensification of agriculture have an impact on ecosystems and their services. If our society wants to use the ecosystems and their services to the full, it must protect them and preserve them.

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Landgebruiksveranderingen waarderen in Vlaanderen (Natuurrapport - Aan de slag met ecosysteemdiensten Hfdst 4) | Ecopedia

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De toenemende verstedelijking en de intensivering van de landbouw hebben een impact op ecosystemen en hun diensten. Wil onze samenleving de ecosystemen en hun diensten ten volle benutten, dan moet ze die beschermen en in stand houden. In dit hoofdstuk stellen we een methode voor om de veranderingen in landgebruik te waarderen en zo meer duurzame beslissingen te kunnen nemen over landgebruik.

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Many species on the IUCN red list of Flanders can be found in Limburg, for instance :

Hylo arborea (critically endangered),
Rana arvalis (vulnerable),
Coronella austriaca (endangered),
Sterna hirundo (vulnerable), Botaurus stellaris (critically endangered),
Circus aeruginosus (endangered)
Neomys fodiens (endangered),
Muscardinus avellanarius (critically endangered),
Myotis bechsteinii (endangered),
Myotis myotis (critically endangered),
Sympetrum depressiusculum (vulnerable),
Leucorrhinia pectoralis (critically endangered),
Lucanus cervus (endangered),
Maculinea alcon (endangered),
Misgurnus fossilis (critically endangered),
Lampetra planeri (vulnerable),
Liparis loeselii (critically endangered),
Luronium natans (vulnerable),
...
https://www.inbo.be/en/search-flanders-red-lists
Picture of the Bechstein's bat below © Karolien Brauns

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European badgers have suffered in the past of extermination, hunting and poaching.

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De das is onze grootste inheemse marterachtige. Door zijn erg gedrongen lichaamsbouw werd vroeger gedacht, dat de das tot de familie van de beren behoorde. Grote ondergrondse burchten kunnen duiden op zijn aanwezigheid.

Hoe kan je de das herkennen?

Van kop tot romp kan een das 70 tot 80 cm worden, zijn staart is kort en meet 12 tot 20 cm. Een das heeft een schouderhoogte van zo'n 30 cm. Mannetjes zijn groter dan vrouwtjes.

De das heeft een erg herkenbare vachttekening; de kop heeft opvallende zwart-witte banden en de oren zijn zwart met een witte rand. De bovenzijde van zijn rug is grijs, de buikzijde en de poten zijn zwart.

Met zijn wigvormige lichaam, kleine kop en lange snuit is de das goed aangepast aan het leven in de gangen van zijn ondergrondse burcht. Met zijn korte, sterke poten en stevige nagels kan hij goed graven.

Wat eet de das?

Dassen zijn omnivoren en eten dus vrijwel alles. Tijdelijke en verschillende voedselbronnen zorgen ervoor dat de das het hele jaar door voedsel vindt. Regenwormen, kevers, rupsen en larven staan op het menu. Naargelang het seizoen, is de das verlekkerd op kersen, pruimen en andere vruchten, die van de bomen vallen. Gras, graan en maïs lusten ze ook en wanneer ze toevallig jonge muizen of vogeleieren vinden, smullen ze hier beslist van.

Waar leeft de das?

De das komt bijna in geheel Europa en grote zones van Azië voor. Een gevarieerd landschap, met bossen en grasvelden, vormt de ideale biotoop voor hen. Of een das zich ergens permanent zal vestigen, hangt af van de aanwezigheid van goede voedselgronden.

Dassen zijn 's nachts actief en vertoeven voor het grootste gedeelte van de dag in hun ondergrondse burchten. Hun leefgebied moet dus ook geschikt zijn om burchten te graven of al bestaande, verlaten burchten bevatten. Een dassenburcht gaat vaak generaties mee en wordt meerdere malen uitgebreid. Een dergelijke burcht heeft verschillende ingangen en meterslange, ondergrondse gangen. Naast meerdere burchten, voorzien dassen ook voldoende speelplekken, krabbomen en latrines in hun territorium.

Verspreidingskaart van de das

Hoe plant de das zich voort?

Per territorium of clan is er een dominant vrouwtje, zij is in principe de enige die jongen krijgt. Een clan bestaat, al naargelang de regio, uit zo'n 3 tot 6 dieren. Er is geen vaste paartijd, het vrouwtje kan het hele jaar door paren. De bevruchte eicellen blijven evenwel in kiemrust tot december. Pas daarna ontwikkelen de eicellen zich verder en in februari worden er 2 tot 3 blinde en bijna kale jongen geboren. De jongen verlaten na 8 tot 9 weken de burcht om de omgeving te verkennen en hun moeder te vergezellen op haar voedselzoektochten. Vanaf juni durven ze er alleen op uit te trekken.

Hoe krijg je de das te zien?

Dassen worden doorheen heel Vlaanderen waargenomen. Door de jacht en het vernielen van dassenburchten is de das in Oost- en West-Vlaanderen zeldzaam, en in Antwerpen en Vlaams-Brabant is hij mogelijk nog zeldzamer. In verschillende zuidelijke delen van Limburg komen ze wel vaak voor. Vrouwtjes krijgen gemiddeld 3 jongen per worp, hierdoor kan de Vlaamse populatie dassen zich snel herstellen. Maar het verkeer eist ook hier zijn tol, een dode das langs de weg is zeker geen uitzondering.

Weetjes over de das

Naargelang het aantal dieren in een clan en de ligging en het gebruik van het territorium, is er een bepaalde structuur waar te nemen. In de hoofdburcht worden de jongen geboren. Nabij de hoofdburcht bevinden zich een aantal bijburchten, deze doen dienst als reserveburchten en zijn dus niet permanent bezet. Verderaf de hoofdburcht kan er zich een 'subsidiary' burcht bevinden. Ook deze burcht is niet permanent bezet, maar kan naargelang het seizoen ingenomen worden, vaak is deze burcht gelegen nabij een tijdelijke voedselbron. Tot slot zijn er nog de vluchtpijpen, verspreid over het hele territorium.

Dassen leven in groep samen, toch gaan ze afzonderlijk op zoek naar voedsel. Het sociale leven beperkt zich tot de burchtsite.

Dassen kunnen tot 16 jaar oud worden. Jammer genoeg is het verkeer een grote bedreiging voor hen en halen ze die leeftijd zelden.

Een das houdt geen winterslaap, tijdens koudere periodes is hij wel minder actief.

Wat kan jij doen voor de das?

Dassen komen steeds meer voor in verstedelijkte gebieden. Jammer genoeg, is het uitgebreide Vlaamse wegennetwerk een grote bedreiging voor de dieren. Dassen komen regelmatig onder de wielen van een auto terecht. Met het project 'Dieren onder de Wielen 2.0' wil Natuurpunt iedereen oproepen om dode dieren langs de weg te melden. Zo kan men de gevaarlijkste wegen voor dieren in kaart brengen.

Ga op zoek naar sporen van de das met de sporenfolder. Heb jij sporen gevonden? Meld het op www.waarnemingen.be

Heb je een dode das of een ander dood dier langs de weg gezien? Ga naar www.dierenonderdewielen.be en meld het.

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De das is onze grootste inheemse marterachtige. Door zijn erg gedrongen lichaamsbouw werd vroeger gedacht, dat de das tot de familie van de beren behoorde. Grote ondergrondse burchten kunnen duiden op zijn aanwezigheid. Van kop tot romp kan een das 70 tot 80 cm worden, zijn staart is kort en meet 12 tot 20 cm.

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The Eurasian beaver (Castor fiber) was nearly hunted to extinction in Europe, both for fur and for castoreum, a secretion from its scent gland believed to have medicinal properties. However, the beaver is now being re-introduced throughout Europe.

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Beavers (genus Castor) are large, semiaquatic rodents of the Northern Hemisphere. There are two existing species: the North American beaver ( Castor canadensis) and the Eurasian beaver ( C. fiber). Beavers are the second-largest living rodents, after capybaras, weighing up to 50 kg (110 lb). They have stout bodies with large heads, long chisel-like incisors, brown or gray fur, hand-like front feet, webbed back feet, and tails that are flat and scaly. The two species differ in skull and tail shape and fur color. Beavers can be found in a number of freshwater habitats, such as rivers, streams, lakes and ponds. They are herbivorous, consuming tree bark, aquatic plants, grasses and sedges.

Beavers build dams and lodges using tree branches, vegetation, rocks and mud; they chew down trees for building material. Dams restrict water flow, and lodges serve as shelters. Their infrastructure creates wetlands used by many other species, and because of their effect on other organisms in the ecosystem, beavers are considered a keystone species. Adult males and females live in monogamous pairs with their offspring. After their first year, the young help their parents repair dams and lodges; older siblings may also help raise newly-born offspring. Beavers hold territories and mark them using scent mounds made of mud, debris, and castoreum-a liquid substance excreted through the beaver's urethra-based castor sacs. Beavers can also recognize their kin by their anal gland secretions and are more likely to tolerate them as neighbors.

Historically, beavers have been hunted for their fur, meat, and castoreum. Castoreum has been used in medicine, perfume, and food flavoring; beaver pelts have been a major driver of the fur trade. Before protections began in the 19th and early 20th centuries, overhunting had nearly exterminated both species. Their populations have since rebounded, and they are listed as species of least concern by the IUCN Red List of mammals. In human culture, the beaver symbolizes industriousness, especially in connection with construction; it is the national animal of Canada.

There are two extant species: the North American beaver ( Castor canadensis) and the Eurasian beaver ( C. fiber). The Eurasian beaver is slightly longer and has a more lengthened skull, triangular nasal cavities (as opposed to the square ones of the North American species), a lighter fur color, and a narrower tail.

Carl Linnaeus coined the genus Castor in 1758; he also coined the specific (species) epithet fiber. German zoologist Heinrich Kuhl coined C. canadensis in 1820. However, they were not confirmed to be separate species until the 1970s, when chromosomal evidence became available. (The Eurasian has 48 chromosomes, while the North American has 40.) Prior to that, many considered them the same species. The difference in chromosome numbers prevents them from interbreeding. Twenty-five subspecies have been classified for C. canadensis, and nine have been classified for C. fiber.

Phylogeny of extant and extinct relatives of modern beavers based on genetics and morphology.

Beavers belong to the rodent suborder Castorimorpha, along with Heteromyidae ( kangaroo rats and kangaroo mice), and the gophers. Modern beavers are the only extant members of the family Castoridae. They originated in North America in the late Eocene and colonized Eurasia via the Bering Land Bridge in the early Oligocene, coinciding with the Grande Coupure, a time of significant changes in animal species around 33million years ago ( myr).

The more basal castorids had several unique features: more complex occlusion between cheek teeth, parallel rows of upper teeth, premolars that were only slightly smaller than molars, the presence of a third set of premolars (P3), a hole in the stapes of the inner ear, a smooth palatine bone (with the palatine opening closer to the rear end of the bone), and a longer snout. More derived castorids have less complex occlusion, upper tooth rows that create a V-shape towards the back, larger second premolars compared to molars, absence of a third premolar set and stapes hole, a more grooved palatine (with the opening shifted towards the front), and reduced incisive foramen. Members of the subfamily Palaeocastorinae appeared in late-Oligocene North America. This group consisted primarily of smaller animals with relatively large front legs, a flattened skull, and a reduced tail-all features of a fossorial (burrowing) lifestyle.

In the early Miocene (about 24 mya), castorids evolved a semiaquatic lifestyle. Members of the subfamily Castoroidinae are considered to be a sister group to modern beavers, and included giants like Castoroides of North America and Trogontherium of Eurasia. Castoroides is estimated to have had a length of 1.9-2.2 m (6.2-7.2 ft) and a weight of 90-125 kg (198-276 lb). Fossils of one genus in Castoroidinae, , have been found near piles of chewed wood, though Dipoides appears to have been an inferior woodcutter compared to Castor. Researchers suggest that modern beavers and Castoroidinae shared a bark-eating common ancestor. Dam and lodge-building likely developed from bark-eating, and allowed beavers to survive in the harsh winters of the subarctic. There is no conclusive evidence for this behavior occurring in non- Castor species.

The genus Castor likely originated in Eurasia. The earliest fossil remains appear to be C. neglectus, found in Germany and dated 12-10 mya. Mitochondrial DNA studies place the common ancestor of the two living species at around 8 mya. The ancestors of the North American beaver would have crossed the Bering Land Bridge around 7.5 mya. Castor may have competed with members of Castoroidinae, which led to niche differentiation. The fossil species C. praefiber was likely an ancestor of the Eurasian beaver. C. californicus from the Early Pleistocene of North America was similar to but larger than the extant North American beaver.

Characteristics

Beavers are the second-largest living rodents, after capybaras. They have a head-body length of 80-120 cm (31-47 in), with a 25-50 cm (9.8-19.7 in) tail, a shoulder height of 30-60 cm (12-24 in), and generally weigh 11-30 kg (24-66 lb), but can be as heavy as 50 kg (110 lb). Males and females are almost identical externally. Their bodies are streamlined like marine mammals and their robust build allows them to pull heavy loads. A beaver coat has 12,000-23,000 hairs/cm ² (77,000-148,000 hairs/in ²) and functions to keep the animal warm, to help it float in water, and to protect it against predators. Guard hairs are 5-6 cm (2.0-2.4 in) long and typically reddish brown, but can range from yellowish brown to nearly black. The underfur is 2-3 cm (0.79-1.18 in) long and dark gray. Beavers molt every summer.

Beavers have large skulls with powerful chewing muscles. They have four chisel-shaped incisors that continue to grow throughout their lives. The incisors are covered in a thick enamel that is colored orange or reddish-brown by iron compounds. The lower incisors have roots that are almost as long as the entire lower jaw. Beavers have one premolar and three molars on all four sides of the jaws, adding up to 20 teeth. The molars have meandering ridges for grinding woody material. The eyes, ears and nostrils are arranged so that they can remain above water while the rest of the body is submerged. The nostrils and ears have valves that close underwater, while nictitating membranes cover the eyes. To protect the larynx and trachea from water flow, the epiglottis is contained within the nasal cavity instead of the throat. In addition, the back of the tongue can rise and create a waterproof seal. A beaver's lips can close behind the incisors, preventing water from entering their mouths as they cut and bite onto things while submerged.

The beaver's front feet are dexterous, allowing them to grasp and manipulate objects and food, as well as dig. The hind feet are larger and have webbing between the toes, and the second innermost toe has a "double nail" used for grooming. Beavers can swim at 8 km/h (5.0 mph); only their webbed hind feet are used to swim, while the front feet fold under the chest. On the surface, the hind limbs thrust one after the other; while underwater, they move at the same time. Beavers are awkward on land but can move quickly when they feel threatened. They can carry objects while walking on their hind legs.

The beaver's distinctive tail has a conical, muscular, hairy base; the remaining two-thirds of the appendage is flat and scaly. The tail has multiple functions: it provides support for the animal when it is upright (such as when chewing down a tree), acts as a rudder when it is swimming, and stores fat for winter. It also has a countercurrent blood vessel system which allows the animal to lose heat in warm temperatures and retain heat in cold temperatures.

The beaver's sex organs are inside the body, and the male's penis has a cartilaginous baculum. They have only one opening, a cloaca, which is used for reproduction, scent-marking, defecation, and urination. The cloaca evolved secondarily, as most mammals have lost this feature, and may reduce the area vulnerable to infection in dirty water. The beaver's intestine is six times longer than its body, and the caecum is double the volume of its stomach. Microorganisms in the caecum allow them to process around 30 percent of the cellulose they eat. A beaver defecates in the water, leaving behind balls of sawdust. Female beavers have four mammary glands; these produce milk with 19 percent fat, a higher fat content than other rodents. Beavers have two pairs of glands: castor sacs, which are part of the urethra, and anal glands. The castor sacs secrete castoreum, a liquid substance used mainly for marking territory. Anal glands produce an oily substance which the beaver uses as a waterproof ointment for its coat. The substance plays a role in individual and family recognition. Anal secretions are darker in females than males among Eurasian beavers, while the reverse is true for the North American species.

Compared to many other rodents, a beaver's brain has a hypothalamus that is much smaller than the cerebrum; this indicates a relatively advanced brain with higher intelligence. The cerebellum is large, allowing the animal to move within a three-dimensional space (such as underwater) similar to tree-climbing squirrels. The neocortex is devoted mainly to touch and hearing. Touch is more advanced in the lips and hands than the whiskers and tail. Vision in the beaver is relatively poor; the beaver eye cannot see as well underwater as an otter. Beavers have a good sense of smell, which they use for detecting land predators and for inspecting scent marks, food, and other individuals.

Beavers can hold their breath for as long as 15 minutes but typically remain underwater for no more than five or six minutes. Dives typically last less than 30 seconds and are usually no more than 1 m (3 ft 3 in) deep. When diving, their heart rate decreases to 60 beats per minute, half its normal pace, and blood flow is directed more towards the brain. A beaver's body also has a high tolerance for carbon dioxide. When surfacing, the animal can replace 75 percent of the air in its lungs in one breath, compared to 15 percent for a human.

Distribution and status

North American beaver in Yellowstone National Park

The IUCN Red List of mammals lists both beaver species as least concern. The North American beaver is widespread throughout most of the United States and Canada and can be found in northern Mexico. The species was introduced to Finland in 1937 (and then spread to northwestern Russia) and to Tierra del Fuego, Patagonia, in 1946. As of 2019, the introduced population of North American beavers in Finland has been moving closer to the habitat of the Eurasian beaver. Historically, the North American beaver was trapped and nearly extirpated because its fur was highly sought after. Protections have allowed the beaver population on the continent to rebound to an estimated 6-12million by the late 20th century; still far lower than the originally estimated 60-400million North American beavers before the fur trade. The introduced population in Tierra del Fuego is estimated at 35,000-50,000 individuals as of 2016.

The Eurasian beaver's range historically included much of Eurasia, but was decimated by hunting by the early 20th century. In Europe, beavers were reduced to fragmented populations, with combined population numbers being estimated at 1,200 individuals for the Rhône of France, the Elbe in Germany, southern Norway, the Neman river and Dnieper Basin in Belarus, and the Voronezh river in Russia. The beaver has since recolonized parts of its former range, aided by conservation policies and reintroductions. Beaver populations now range across western, central, and eastern Europe, and western Russia and the Scandinavian Peninsula. Beginning in 2009, beavers have been successfully reintroduced to parts of Great Britain. In 2020, the total Eurasian beaver population in Europe was estimated at over one million. Small native populations are also present in Mongolia and northwestern China; their numbers were estimated at 150 and 700, respectively, as of 2016. Under New Zealand's Hazardous Substances and New Organisms Act 1996, beavers are classed as a "prohibited new organism" preventing them from being introduced into the country.

Eurasian beavers swimming and foraging

Beavers live in freshwater ecosystems such as rivers, streams, lakes and ponds. Water is the most important part of beaver habitat; they swim and dive in it, and it provides them a refuge from land predators, restricts access to their homes and allows them to move building objects more easily. Beavers prefer slower moving streams, typically with a gradient (steepness) of one percent, though they have been recorded using streams with gradients as high as 15 percent. Beavers are found in wider streams more often than in narrower ones. They also prefer areas with no regular flooding and may abandon a location for years after a significant flood.

Beavers typically select flat landscapes with diverse vegetation close to the water. North American beavers prefer trees being 60 m (200 ft) or less from the water, but will roam several hundred meters to find more. Beavers have also been recorded in mountainous areas. Dispersing beavers will use certain habitats temporarily before finding their ideal home. These include small streams, temporary swamps, ditches, and backyards. These sites lack important resources, so the animals do not stay there permanently. Beavers have increasingly settled at or near human-made environments, including agricultural areas, suburbs, golf courses, and shopping malls.

Beavers have an herbivorous and a generalist diet. During the spring and summer, they mainly feed on herbaceous plant material such as leaves, roots, herbs, ferns, grasses, sedges, water lilies, water shields, rushes, and cattails. During the fall and winter, they eat more bark and cambium of woody plants; tree and shrub species consumed include aspen, birch, oak, dogwood, willow and alder. There is some disagreement about why beavers select specific woody plants; some research has shown that beavers more frequently select species which are more easily digested, while others suggest beavers principally forage based on stem size. Beavers may cache their food for the winter, piling wood in the deepest part of their pond where it cannot be reached by other browsers. This cache is known as a "raft"; when the top becomes frozen, it creates a "cap". The beaver accesses the raft by swimming under the ice. Many populations of Eurasian beaver do not make rafts, but forage on land during winter.

Beavers usually live up to 10 years. Felids, canids, and bears may prey upon them. Beavers are protected from predators when in their lodges, and prefer to stay near water. Parasites of the beaver include the bacteria Francisella tularensis, which causes tularemia; the protozoan Giardia duodenalis, which causes giardiasis (beaver fever); and the beaver beetle and mites of the genus Schizocarpus. They have also been recorded to be infected with the rabies virus.

Infrastructure

Beavers need trees and shrubs to use as building material for dams, which restrict flowing water to create a pond for them to live in, and for lodges, which act as shelters and refuges from predators and the elements. Without such material, beavers dig burrows into a bank to live. Dam construction begins in late summer or early fall, and they repair them whenever needed. Beavers can cut down trees up to 15 cm (5.9 in) wide in less than 50 minutes. Thicker trees, at 25 cm (9.8 in) wide or more, may not fall for hours. When chewing down a tree, beavers switch between biting with the left and right side of the mouth. Tree branches are then cut and carried to their destination with the powerful jaw and neck muscles. Other building materials, like mud and rocks, are held by the forelimbs and tucked between the chin and chest.

Beaver start building dams when they hear running water, and the sound of a leak in a dam triggers them to repair it. To build a dam, beavers stack up relatively long and thick logs between banks and in opposite directions. Heavy rocks keep them stable, and grass is packed between them. Beavers continue to pile on more material until the dam slopes in a direction facing upstream. Dams can range in height from 20 cm (7.9 in) to 3 m (9.8 ft) and can stretch from 0.3 m (1 ft 0 in) to several hundred meters long. Beaver dams are more effective in trapping and slowly leaking water than man-made concrete dams. Lake-dwelling beavers do not need to build dams.

Beavers make two types of lodges: bank lodges and open-water lodges. Bank lodges are burrows dug along the shore and covered in sticks. The more complex freestanding, open-water lodges are built over a platform of piled-up sticks. The lodge is mostly sealed with mud, except for a hole at the top which acts as an air vent. Both types are accessed by underwater entrances. The above-water space inside the lodge is known as the "living chamber", and a "dining area" may exist close to the water entrance. Families routinely clean out old plant material and bring in new material.

North American beavers build more open-water lodges than Eurasian beavers. Beaver lodges built by new settlers are typically small and sloppy. More experienced families can build structures with a height of 2 m (6 ft 7 in) and an above-water diameter of 6 m (20 ft). A lodge sturdy enough to withstand the coming winter can be finished in just two nights. Both lodge types can be present at a beaver site. During the summer, beavers tend to use bank lodges to keep cool. They use open-water lodges during the winter. The air vent provides ventilation, and newly-added carbon dioxide can be cleared in an hour. The lodge remains consistent in oxygen and carbon dioxide levels from season to season.

Beavers in some areas will dig canals connected to their ponds. The canals fill with groundwater and give beavers access and easier transport of resources, as well as allow them to escape predators. These canals can stretch up to 1 m (3 ft 3 in) wide, 0.5 m (1 ft 8 in) deep, and over 0.5 km (0.31 mi) long. It has been hypothesized that beavers' canals are not only transportation routes but an extension of their " central place" around the lodge and/or food cache. As they drag wood across the land, beavers leave behind trails or "slides", which they reuse when moving new material.

Environmental effects

The beaver works as an ecosystem engineer and keystone species, as its activities can have a great impact on the landscape and biodiversity of an area. Aside from humans, few other extant animals appear to do more to shape their environment. When building dams, beavers alter the paths of streams and rivers, allowing for the creation of extensive wetland habitats. In one study, beavers were associated with large increases in open-water areas. When beavers returned to an area, 160% more open water was available during droughts than in previous years, when they were absent. Beaver dams also lead to higher water tables in mineral soil environments and in wetlands such as peatlands. In peatlands particularly, their dams stabilize the constantly changing water levels, leading to greater carbon storage.

Beaver ponds, and the wetlands that succeed them, remove sediments and pollutants from waterways, and can stop the loss of important soils. These ponds can increase the productivity of freshwater ecosystems by accumulating nitrogen in sediments. Beaver activity can affect the temperature of the water; in northern latitudes, ice thaws earlier in the warmer beaver-dammed waters. Beavers may contribute to climate change. In Arctic areas, the floods they create can cause permafrost to thaw, releasing methane into the atmosphere.

As wetlands are formed and riparian habitats are enlarged, aquatic plants colonize the newly-available watery habitat. One study in the Adirondacks found that beaver engineering lead to an increase of more than 33 percent in herbaceous plant diversity along the water's edge. Another study in semiarid eastern Oregon found that the width of riparian vegetation on stream banks increased several-fold as beaver dams watered previously dry terraces adjacent to the stream. Riparian ecosystems in arid areas appear to sustain more plant life when beaver dams are present. Beaver ponds act as a refuge for riverbank plants during wildfires, and provide them with enough moisture to resist such fires. Introduced beavers at Tierra del Fuego have been responsible for destroying the indigenous forest. Unlike trees in North America, many trees in South America cannot grow back after being cut down.

Salmon (Oncorhynchus nerka) jumping a beaver dam

Beaver activity impacts communities of aquatic invertebrates. Damming typically leads to an increase of slow or motionless water species, like dragonflies, oligochaetes, snails, and mussels. This is to the detriment of rapid water species like black flies, stoneflies, and net-spinning caddisflies. Beaver floodings create more dead trees, providing more habitat for terrestrial invertebrates like Drosophila flies and bark beetles, which live and breed in dead wood. The presence of beavers can increase wild salmon and trout populations, and the average size of these fishes. These species use beaver habitats for spawning, overwintering, feeding, and as havens from changes in water flow. The positive effects of beaver dams on fish appear to outweigh the negative effects, such as blocking of migration. Beaver ponds have been shown to be beneficial to frog populations by protecting areas for larvae to mature in warm water. The stable waters of beaver ponds also provide ideal habitat for freshwater turtles.

Beavers help waterfowl by creating increased areas of water. The widening of the riparian zone associated with beaver dams has been shown to increase the abundance and diversity of birds favoring the water's edge, an impact that may be especially important in semi-arid climates. Fish-eating birds use beaver ponds for foraging, and in some areas, certain species appear more frequently at sites where beavers were active than at sites with no beaver activity. In a study of Wyoming streams and rivers, watercourses with beavers had 75 times as many ducks as those without. As trees are drowned by rising beaver impoundments, they become an ideal habitat for woodpeckers, which carve cavities that may be later used by other bird species. Beaver-caused ice thawing in northern latitudes allows Canada geese to nest earlier.

Other semi-aquatic mammals, such as water voles, muskrats, minks, and otters, will shelter in beaver lodges. Beaver modifications to streams in Poland create habitats favorable to bat species that forage at the water surface and "prefer moderate vegetation clutter". Large herbivores, such as some deer species, benefit from beaver activity as they can access vegetation from fallen trees and ponds.

Beavers are mainly nocturnal and crepuscular, and spend the daytime in their shelters. In northern latitudes, beaver activity is decoupled from the 24-hour cycle during the winter, and may last as long as 29 hours. They do not hibernate during winter, and spend much of their time in their lodges.

Family life

The core of beaver social organization is the family, which is composed of an adult male and an adult female in a monogamous pair and their offspring. Beaver families can have as many as ten members; groups about this size require multiple lodges. Mutual grooming and play fighting maintain bonds between family members, and aggression between them is uncommon.

Adult beavers mate with their partners, though partner replacement appears to be common. A beaver that loses its partner will wait for another one to come by. Estrus cycles begin in late December and peak in mid-January. Females may have two to four estrus cycles per season, each lasting 12-24 hours. The pair typically mate in the water and to a lesser extent in the lodge, for half a minute to three minutes.

Up to four young, or kits, are born in spring and summer, after a three or four-month gestation. Newborn beavers are precocial with a full fur coat, and can open their eyes within days of birth. Their mother is the primary caretaker, while their father maintains the territory. Older siblings from a previous litter also play a role.

After they are born, the kits spend their first one to two months in the lodge. Kits suckle for as long as three months, but can eat solid food within their second week and rely on their parents and older siblings to bring it to them. Eventually, beaver kits explore outside the lodge and forage on their own, but may follow an older relative and hold onto their backs. After their first year, young beavers help their families with construction. Beavers sexually mature around 1.5-3 years. They become independent at two years old, but remain with their parents for an extra year or more during times of food shortage, high population density, or drought.

Territories and spacing

Beavers typically disperse from their parental colonies during the spring or when the winter snow melts. They often travel less than 5 km (3.1 mi), but long-distance dispersals are not uncommon when previous colonizers have already exploited local resources. Beavers are able to travel greater distances when free-flowing water is available. Individuals may meet their mates during the dispersal stage, and the pair travel together. It may take them weeks or months to reach their final destination; longer distances may require several years. Beavers establish and defend territories along the banks of their ponds, which may be 1-7 km (0.62-4.35 mi) in length.

Beavers mark their territories by constructing scent mounds made of mud and vegetation, scented with castoreum. Those with many territorial neighbors create more scent mounds. Scent marking increases in spring, during the dispersal of yearlings, to deter interlopers. Beavers are generally intolerant of intruders and fights may result in deep bites to the sides, rump, and tail. They exhibit a behavior known as the " dear enemy effect"; a territory-holder will investigate and become familiar with the scents of its neighbors and react more aggressively to the scents of strangers passing by. Beavers are also more tolerant of individuals that are their kin. They recognize them by using their keen sense of smell to detect differences in the composition of anal gland secretions. Anal gland secretion profiles are more similar among relatives than unrelated individuals.

Communication

Beavers within a family greet each other with whines. Kits will attract the attention of adults with mews, squeaks, and cries. Defensive beavers produce a hissing growl and gnash their teeth. Tail slaps, which involve an animal hitting the water surface with its tail, serve as alarm signals warning other beavers of a potential threat. An adult's tail slap is more successful in alerting others, who will escape into the lodge or deeper water. Juveniles have not yet learned the proper use of a tail slap, and hence are normally ignored. Eurasian beavers have been recorded using a territorial "stick display", which involves individuals holding up a stick and bouncing in shallow water.

Interactions with humans

Grey Owl feeding his beaver

Beavers sometimes come into conflict with humans over land use; individual beavers may be labeled as "nuisance beavers". Beavers can damage crops, timber stocks, roads, ditches, gardens, and pastures via gnawing, eating, digging, and flooding. They occasionally attack humans and domestic pets, particularly when infected with rabies, in defense of their territory, or when they feel threatened. Some of these attacks have been fatal, including at least one human death. Beavers can spread giardiasis ('beaver fever') by infecting surface waters, though outbreaks are more commonly caused by human activity.

Flow devices, like beaver pipes, are used to manage beaver flooding, while fencing and hardware cloth protect trees and shrubs from beaver damage. If necessary, hand tools, heavy equipment, or explosives are used to remove dams. Hunting, trapping, and relocation may be permitted as forms of population control and for removal of individuals. The governments of Argentina and Chile have authorized the trapping of invasive beavers in hopes of eliminating them. The ecological importance of beavers has led to cities like Seattle designing their parks and green spaces to accommodate the animals. The Martinez beavers became famous in the mid-2000s for their role in improving the ecosystem of Alhambra Creek in Martinez, California.

Zoos have displayed beavers since at least the 19th century, though not commonly. In captivity, beavers have been used for entertainment, fur harvesting, and for reintroduction into the wild. Captive beavers require access to water, substrate for digging, and artificial shelters. Archibald Stansfeld "Grey Owl" Belaney pioneered beaver conservation in the early 20th century. Belaney wrote several books, and was first to professionally film beavers in their environment. In 1931, he moved to a log cabin in Prince Albert National Park, where he was the "caretaker of park animals" and raised a beaver pair and their four offspring.

Commercial use

Beavers have been hunted, trapped, and exploited for their fur, meat, and castoreum. Since the animals typically stayed in one place, trappers could easily find them and could kill entire families in a lodge. Many pre-modern people mistakenly thought that castoreum was produced by the testicles or that the castor sacs of the beaver were its testicles, and females were hermaphrodites. Aesop's Fables describes beavers chewing off their testicles to preserve themselves from hunters, which is impossible because a beaver's testicles are internal. This myth persisted for centuries, and was corrected by French physician Guillaume Rondelet in the 1500s. Beavers have historically been hunted and captured using deadfalls, snares, nets, bows and arrows, spears, clubs, firearms, and leg-hold traps. Castoreum was used to lure the animals.

Castoreum was used for a variety of medical purposes; Pliny the Elder promoted it as a treatment for stomach problems, flatulence, seizures, sciatica, vertigo, and epilepsy. He stated it could stop hiccups when mixed with vinegar, toothaches if mixed with oil (by administering into the ear opening on the same side as the tooth), and could be used as an antivenom. The substance has traditionally been prescribed to treat hysteria in women, which was believed to have been caused by a "toxic" womb. Castoreum's properties have been credited to the accumulation of salicylic acid from willow and aspen trees in the beaver's diet, and has a physiological effect comparable to aspirin. Today, the medical use of castoreum has declined and is limited mainly to homeopathy. The substance is also used as an ingredient in perfumes and tinctures, and as a flavouring in food and drinks.

Various Native American groups have historically hunted beavers for food. Beaver meat was advantageous, being more calorie-rich and fattened than other red meats, and the animals remained plump in winter, when they were most hunted. The bones were used to make tools. In medieval Europe, the Catholic Church considered the beaver to be part mammal and part fish, and allowed followers to eat the scaly, fishlike tail on meatless Fridays during Lent. Beaver tails were thus highly-prized in Europe; they were described by French naturalist Pierre Belon as tasting like a "nicely dressed eel".

Beaver pelts were used to make hats; felters would remove the guard hairs. The number of pelts needed depended on the type of hat, with Cavalier and Puritan hats requiring more fur than top hats. In the late 16th century, Europeans began to deal in North American furs due to the lack of taxes or tariffs on the continent and the decline of fur-bearers at home. Beaver pelts caused or contributed to the Beaver Wars, King William's War, and the French and Indian War; the trade made John Jacob Astor and the owners of the North West Company very wealthy. For Europeans in North America, the fur trade was a driver of the exploration and westward exploration on the continent and contact with native peoples, who traded with them. The fur trade peaked between 1860 and 1870, when over 150,000 beaver pelts were purchased annually by the Hudson's Bay Company and fur companies in the United States. The contemporary global fur trade is not as profitable due to conservation, anti-fur and animal rights campaigns.

Beaver sculpture over entrance to the Canadian Parliament Building

The beaver has been used to represent productivity, trade, tradition, masculinity, and respectability. References to the beaver's skills are reflected in everyday language. The English verb "to beaver" means working with great effort and being "as busy as a beaver"; a "beaver intellect" refers to a way of thinking that is slow and honest. The word "beaver" can also be used as a sexual term for the human vulva.

Native American myths emphasize the beaver's skill and industriousness. In the mythology of the Haida, beavers are descended from the Beaver-Woman, who built a dam on a stream next to their cabin while her husband was out hunting and gave birth to the first beavers. In a Cree story, the Great Beaver and its dam caused a world flood. Other tales involve beavers using their tree chewing skills against an enemy. Beavers have been featured as companions in some stories, including a Lakota tale where a young woman flees from her evil husband with the aid of her pet beaver.

Europeans have traditionally thought of beavers as fantastical animals due to their amphibious nature. They depicted them with exaggerated tusk-like teeth, dog- or pig-like bodies, fish tails, and visible testicles. French cartographer Nicolas de Fer illustrated beavers building a dam at Niagara Falls, fantastically depicting them like human builders. Beavers have also appeared in literature such as Dante Alighieri's Divine Comedy and the writings of Athanasius Kircher, who wrote that on Noah's Ark the beavers were housed near a water-filled tub that was also used by mermaids and otters.

The beaver has long been associated with Canada, appearing on the first pictorial postage stamp issued in the Canadian colonies in 1851 as the so-called " Three-Penny Beaver". It was declared the national animal in 1975. The five-cent coin, the coat of arms of the Hudson's Bay Company, and the logos for Parks Canada and Roots Canada use its image. Frank and Gordon are two fictional beavers that appeared in Bell Canada's advertisements between 2005 and 2008. However, the beaver's status as a rodent has made it controversial, and it was not chosen to be on the Arms of Canada in 1921. The beaver has commonly been used to represent Canada in political cartoons, typically to signify it as a friendly but relatively weak nation. In the United States, the beaver is the state animal of New York and Oregon. It is also featured on the coat of arms of the London School of Economics.

References

1. ^ International Commission on Zoological Nomenclature (1922). "Opinion 75. Twenty-Seven Generic Names of Protozoa, Vermes, Pisces, Reptilia and Mammalia Included in the Official List of Zoological Names". Smithsonian Miscellaneous Collections. 73 (1): 35-37.

2. ^ Busher, P.; Hartman, G. (2001). "Beavers". In MacDonald, D. W. (ed.). The Encyclopedia of Mammals (2nd ed.). Oxford University Press. pp. 590-593. ISBN 978-0760719695.

3. ^ Fabre, Pierre-Henri; Hautier, Lionel; Dimitrov, Dimitar; Douzery, Emmanuel J. P. (2012). "A glimpse on the pattern of rodent diversification: a phylogenetic approach". BMC Evolutionary Biology. 12 (88): 88. doi:10.1186/1471-2148-12-88. PMC . PMID 22697210.

4. ^ Doronina, Liliya; Matzke, Andreas; Churakov, Gennady; Stoll, Monika; Huge, Andreas; Schmitz, Jürgen (2017). "The beaver's phylogenetic lineage illuminated by retroposon reads". Scientific Reports. 7 (1): 43562. Bibcode:2017NatSR...743562D. doi:10.1038/srep43562. PMC . PMID 28256552.

5. ^ Swinehart, A. L.; Richards, R. L. (2001). "Paleoecology of Northeast Indiana Wetland Harboring Remains of the Pleistocene Giant Beaver (Castoroides Ohioensis)". Proceedings of the Indiana Academy of Science. 110: 151.

6. ^ Samuels, J. X.; Zancanella, J. (2011). "An early Hemphillian occurrence of Castor (Castoridae) from the Rattlesnake Formation of Oregon". Journal of Paleontology. 85 (5): 930-935. doi:10.1666/11-016.1. S2CID 128866799.

7. ^ Barisone, G.; Argenti, P.; Kotsakis, T. (2006). "Plio-Pleistocene evolution of the genus Castor (Rodentia, Mammalia) in Europe: C. fiber plicidens of Pietrafitta (Perugia, Central Italy)". . 39 (6): 757-770. Bibcode:2006Geobi..39..757B. doi:10.1016/j.geobios.2005.10.004.

8. ^ Baker, B. W.; Hill, E. P. (2003). "Beaver Castor canadensis". In Feldhamer, G. A.; Thompson, B. C.; Chapman, J. A. (eds.). Wild Mammals of North America: Biology, Management, and Conservation (2 ed.). Johns Hopkins University Press. pp. 289-297. ISBN 978-0801874161. OCLC 51969059.

9. ^ Campbell-Palmer, Róisín; Gow, Derek; Needham, Robert; Jones, Simon; Rosell, Frank (2015). The Eurasian Beaver. Pelagic Publishing Ltd. pp. 7-12. ISBN 978-1784270407.

10. ^ Graf, P. M.; Wilson, R. P.; Sanchez, L. C.; Hacklӓnder, K.; Rosell, F. (2017). "Diving behavior in a free‐living, semi‐aquatic herbivore, the Eurasian beaver Castor fiber". Ecology and Evolution. 8 (2): 997-1008. doi:10.1002/ece3.3726. PMC . PMID 29375773.

11. ^ Naiman, Robert J.; Johnston, Carol A.; Kelley, James C. (December 1988). "Alteration of North American Streams by Beaver" (PDF). BioScience. 38 (11): 753-762. doi:10.2307/1310784. JSTOR 1310784. Archived from the original (PDF) on March 4, 2012.

12. ^ "Beaver reintroduction in the UK". Royal Society for the Protection of Birds. Archived from the original on November 6, 2020.

13. ^ "Hazardous Substances and New Organisms Act 2003 - Schedule 2 Prohibited new organisms". New Zealand Government. Archived from the original on November 6, 2020.

14. ^ Mahoney, Michael J.; Stella, John C. (2020). "Stem size selectivity is stronger than species preferences for beaver, a central place forager". Forest Ecology and Management. 475: 118331. doi:10.1016/j.foreco.2020.118331. S2CID 224922775.

15. ^ Grudzinski, Bartosz P.; Cummins, Hays; Vang, Teng Keng (2019). "Beaver canals and their environmental effects". Progress in Physical Geography: Earth and Environment. 44 (2): 189-211. doi:10.1177/0309133319873116. S2CID 204257682.

16. ^ Rosell F; Bozser O; Collen P; Parker H (2005). "Ecological impact of beavers Castor fiber and Castor canadensis and their ability to modify ecosystems". Mammal Review. 35 (3-4): 248-276. doi:10.1111/j.1365-2907.2005.00067.x. hdl:11250/2438080.

17. ^ Burchsted, D.; Daniels, M.; Thorson, R.; Vokoun, J. (2010). "The river discontinuum: applying beaver modifications to baseline conditions for restoration of forested headwaters". BioScience. 60 (11): 908-922. doi:10.1525/bio.2010.60.11.7. S2CID 10070184.

18. ^ Hood, Glynnis A.; Bayley, Suzanne E. (2008). "Beaver (Castor canadensis) mitigate the effects of climate on the area of open water in boreal wetlands in western Canada". Biological Conservation. 141 (2): 556-567. doi:10.1016/j.biocon.2007.12.003. S2CID 84584842.

19. ^ Puttock, A.; Graham, H. A.; Carless, D.; Brazier, R. E. (2018). "Sediment and Nutrient Storage in a Beaver Engineered Wetland". Earth Surface Processes and Landforms. 43 (11): 2358-2370. Bibcode:2018ESPL...43.2358P. doi:10.1002/esp.4398. PMC . PMID 30333676.

20. Bromley, Chantal K.; Hood, Glynnis A. (2013). "Beavers (Castor canadensis) facilitate early access by Canada geese (Branta canadensis) to nesting habitat and areas of open water in Canada's boreal wetlands". Mammalian Biology. 78 (1): 73-77. doi:10.1016/j.mambio.2012.02.009.

21. ^ Jones, B. M.; Tape, K. D.; Clark, J. A.; Nitze, I.; Grosse, G.; Disbrow, J. (2020). "Increase in beaver dams controls surface water and thermokarst dynamics in an Arctic tundra region, Baldwin Peninsula, northwestern Alaska". Environmental Research Letters. 15 (7): 075005. Bibcode:2020ERL....15g5005J. doi:10.1088/1748-9326/ab80f1.

22. ^ Hunt, Kate (June 30, 2020). "Beavers are gnawing away at the Arctic permafrost, and that's bad for the planet". CNN.

23. ^ Wright, J. P.; Jones, C. G.; Flecker, A. S. (2002). "An ecosystem engineer, the beaver, increases species richness at the landscape scale" (PDF). . 132 (1): 96-101. Bibcode:2002Oecol.132...96W. doi:10.1007/s00442-002-0929-1. PMID 28547281. S2CID 5940275. Archived (PDF) from the original on October 9, 2022.

24. ^ Fairfax, E.; Small, E. E. (2018). "Using remote sensing to assess the impact of beaver damming on riparian evapotranspiration in an arid landscape". Ecohydrology. 11 (7): e1993. doi:10.1002/eco.1993. S2CID 134994160.

25. ^ Fairfax, E; Whittle, A. (2020). "Smokey the Beaver: beaver‐dammed riparian corridors stay green during wildfire throughout the western United States". Ecological Applications. 30 (8): e02225. doi:10.1002/eap.2225. PMID 32881199.

26. ^ Saarenmaa, H. (1978). "The occurrence of bark beetles (Col. Scolytidae) in a dead spruce stand flooded by beavers (Castor canadensis Kuhl)". Silva Fennica: 201-216. doi:10.14214/sf.a14857.

27. ^ Kemp, P. S.; Worthington, T. A.; Langford, T. E. L.; Tree, A. R. J.; Gaywood, M. J. (2012). "Qualitative and quantitative effects of reintroduced beavers on stream fish". Fish and Fisheries. 13 (2): 158-181. doi:10.1111/j.1467-2979.2011.00421.x.

28. ^ Cooke, Hilary A.; Zack, Steve (2008). "Influence of Beaver Dam Density on Riparian Areas and Riparian Birds in Shrubsteepe of Wyoming". Western North American Naturalist. 68 (3): 365-373. doi:10.3398/1527-0904(2008)68[365:IOBDDO]2.0.CO;2. S2CID 62833818.

29. Grover, A. M.; Baldassarre, G. A. (1995). "Bird species richness within beaver ponds in south-central New York". Wetlands. 15 (2): 108-118. doi:10.1007/BF03160664. S2CID 13053029.

30. ^ Nummbi, P.; Holopainen, S. (2014). "Whole-community facilitation by beaver: ecosystem engineer increases waterbird diversity". Aquatic Conservation: Marine and Freshwater Ecosystems. 24 (5): 623-633. doi:10.1002/aqc.2437.

31. ^ Mayer, M; Zedrosser, A; Rosell, F (2017). "When to leave: the timing of natal dispersal in a large, monogamous rodent, the Eurasian beaver". Animal Behaviour. 123: 375-382. doi:10.1016/j.anbehav.2016.11.020. S2CID 53183887.

32. ^ Graf, P. M.; Mayer, M.; Zedrosser, A.; Hackländer, K.; Rosell, F. (2016). "Territory size and age explain movement patterns in the Eurasian beaver". Mammalian Biology - Zeitschrift für Säugetierkunde. 81 (6): 587-594. doi:10.1016/j.mambio.2016.07.046.

33. ^ Rosell, Frank; Nolet, Bart A. (1997). "Factors Affecting Scent-Marking Behavior in Eurasian Beaver (Castor fiber)". Journal of Chemical Ecology. 23 (3): 673-689. doi:10.1023/B:JOEC.0000006403.74674.8a. hdl:11250/2438031. S2CID 31782872.

34. ^ Sun, Lixing; Muller-Schwarze, Dietland (1998). "Anal Gland Secretion Codes for Relatedness in the Beaver, Castor canadensis". . 104 (11): 917-927. doi:10.1111/j.1439-0310.1998.tb00041.x.

35. ^ Callahan, M. (April 2005). "Best Management Solutions for Beaver Problems" (PDF). Association of Massachusetts Wetland Scientists: 12-14. Archived (PDF) from the original on October 9, 2022.

36. ^ "Beaver Damage Management" (PDF). US Department of Agriculture. January 2011. Archived (PDF) from the original on October 9, 2022.

37. ^ Bailey, D. R.; Dittbrenner, B. J.; Yocom, K. P. (2018). "Reintegrating the North American beaver (Castor canadensis) in the urban landscape" (PDF). WIREs Water. 6 (1): e1323. doi:10.1002/wat2.1323. S2CID 85513383. Archived (PDF) from the original on October 9, 2022.

38. ^ L. Riley, Ann (2016). Restoring Neighborhood Streams - Planning, Design, and Construction. Washington, DC: Island Press. pp. 177-178. ISBN 978-1610917407.

39. ^ Madsen, Axl (January 30, 2001). John Jacob Astor: America's First Multimillionaire. Wiley. pp. 2, 4, 49, 226-231. ISBN 9780471385035.

40. Francis, Margot (2004). "The Strange Career of the Canadian Beaver: Anthropomorphic Discourses and Imperial History". Journal of Historical Sociology. 17 (2-3): 209-239. doi:10.1111/j.1467-6443.2004.00231.x.

Further reading

External links

# data[].attributes.attachment_link.description
Beavers (genus Castor ) are large, semiaquatic rodents of the Northern Hemisphere. There are two existing species: the North American beaver ( Castor canadensis) and the Eurasian beaver ( C. fiber). Beavers are the second-largest living rodents, after capybaras, weighing up to 50 kg (110 lb).