Theme 3 & 4 by https://padlet.com/jo_van_egroo/vwbc2cxtox0k Herpetofauna of the Canary Islands en-us 2019-03-26 17:10:46 UTC 2024-06-20 02:44:43 UTC hello@padlet.com The Iberian water frog (Pelophylax perezi) has been introduced in the Canary Islands. It inhabits a wide variety of temporary and permanent waterbodies (pools, streams, ditches, irrigation canals etc.). The terrestrial habitats of the species include forests, Mediterranean-type scrub, agricultural areas, rocky areas, coastal marshes, gardens and urban parks. It breeds in various aquatic habitats, and is able to tolerate some habitat disturbance. Because this frog uses water bodies as shelter from predators, for foraging and as breeding habitat, nitrogen pollution may cause a threat to this species throughout its life cycle. The wide distribution and abundance even in highly eutrophic agricultural habitats means that there may be populations exposed to differing nitrogen concentration, which may cause interpopulational variation in tolerance to eutrophication. The genetic adaptation of the embryos to moderately saline environments helps them to cope with an excess of inorganic nitrogen in the water. jo_van_egroo https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345371231 2019-03-26 17:12:30 UTC https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345371231 Iberian water frog (Pelophylax perezi) jo_van_egroo https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345375058 The West Canaries lizard (Gallotia galloti) is endemic tot he Canary Islands. It is native to Tenerife, La Palma and the smaller islets. This species is common in various open, rocky and shrubland habitats. It is commonly associated with stone walls in cultivated areas. The species is rarer in forested areas, where it may be confined to pathways and other open areas.

The spatiotemporal distribution of this lizard could be explained to a large extent invoking thermoregulatory behavior. They are active in the micro habitats and at times of day that allowed them to minimize variations in the surrounding thermal environment. This behavioral choice of nearly constant microclimates seem to be responsible for a high degree of thermoregulatory precision. 

The circadian activity is clearly unimodal in contrast with the pattern found in most lizards from hot, arid, desertic or semi-desertic regions restrict their activity to relatively short time periods in the early morning and late afternoons, and retreat tot heir burrows at midday. Their activity decrease at midday because even shaded perches are probably warm enough for most lizards. Nevertheless, activity could be maintained, though at lower levels, also at mid day, when lizards shortened the duration of basking periods and restricted their movements to the scarce shaded perches available. Lizards can select basalt walls in which crevices allowed the maintenance of body temperatures enabling them to under take short bursts of surface activity. 
]]> 2019-03-26 17:20:08 UTC https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345375058 West Canaries lizard (Gallotia galloti) jo_van_egroo https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345377470 2019-03-26 17:24:21 UTC https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345377470 All amphibian species on the Canary Islands are introduced. They include stripeless tree frog (Hyla meridionalis), Iberian water frog (Pelophylax perezi) and Sahara frog (Pelophylax saharicus), all belonging to the family of the frogs (Ranidae). The lizards of the Canary Islands belong tot he family of Gekkonidae, Phyllodactylidae, Lacertidae, Dactyloidae and Scincidae. The 4 endemic geckos (genus Tarentola) of the Canary Islands are categorized as not threatened (T.angustimentalis, T.boettgeri, T.delalandii, T. gomerensis). These have the IUCN Red List category of Least Concern (LC). The other gecko species is introduced (Hemidactylus turcicus). The green anole (Anolis carolinensis) is also introduced. The Lacertidae are represented by 8 species of the endemic genus Gallotia. Four 4 species are categorized as Least Concern (LC): G. atlantica, G. caesaris, G. galloti, G. stehlini . There are no major threats to these species. The other 4 species are categorized as Critically Endangered (CR): G.auaritae, G. bravoana, G.intermedia, G.simonyi. The La Palma giant lizard (Gallotia auaritae) is possibly extinct although recent observations suggest that a small remnant population of these lizards is present in northern La Palma. The causes of extinction over much of this species range appear to have been introduced cats, consumption by people, and conversion of land to agricultural use. The current threats to any remaining populations need further investigation. It is not known if the species is present in any protected areas. There is a need to verify the identity of animals recently observed; if these are not individual of Gallotia auaritae, it remains probable that these populations will still be of very high conservation concern. There is an urgent need to secure any remaining populations of giant Gallotia lizards on La Palma, including strict protect of areas of suitable habitat and prevention of collection of animals for non-research purposes. The La Gomera giant lizard (Gallotia bravoana), thought to be long extinct, was rediscovered as a living animal in 1999, and is known only from two separate inaccessible cliffs 2 km apart, close to the Valle Gran Rey, in the west of the island of La Gomera. The species is thought to have once ranged throughout much of La Gomera, and the present range is less than one hectare. The population of this species consists of only 90 wild individuals remaining in the wild. The main threats to this species are predation by feral cats, and rock falls within its restricted range. The species historically declined through overgrazing, hunting, and predation by feral cats and rats. It is present in the Parque Rural de Valle Gran Rey. The species is protected by international legislation. A captive breeding programme has been established on La Gomera, and a species recovery plan is in place. There is a need to control cat populations in the vicinity of the remaining animals. Further surveys are needed on La Gomera within other isolated areas to determine if any more remnant populations of this species persist. The implementation of education programmes for local people has been recommended. The El Hierro giant lizard (Gallotia simonyi) is endemic to the island of El Hierro. The species was once present throughout much of the island and on the small offshore Roque Chico de Salmor. It is currently restricted to the southern end of the Risco de Tibataje, in la Fuga de Gorreta, located between Guinea and the so-called Paso del Pino (an area of about four hectares), with reintroduced populations on the Roque Chico de Salmor, and at Julan and la Dehesa on El Hierro. The population of this species is about 300 to 400 animals in the wild (including re-introduced populations). The major threat to this species is predation by feral cats, and possibly also by dogs and rats. A recovery plan for this species has been developed, and captive-breeding and reintroduction programmes are in place. The species was successfully reintroduced to the Roque Chico de Salmor in 1999, and subsequent reintroductions have taken place at Julan and at la Dehesa. Continued control of feral cats should be resumed to allow population recovery. The Tenerife speckled lizard (Gallotia intermedia) was discovered in 1996 in the Macizo de Teno in the extreme northwest of Tenerife. It is now know from a small area of coastline in the extreme west of the island, and also from Montana de Guaza in the extreme south. It is believed that the species was once widespread throughout much of Tenerife. There are 40 isolated populations along 9 km of coastline, totaling 500 animals. The population at Montana de Guaza is around 100 animals. It is increasing as a result of the control of introduced mammals. The main threat to this species is predation by feral cats and, to a lesser degree, by rats. It is presumed that the historical decline in this species was largely due to predation by cats. Measures to control access by cats to some of the remaining populations, such as fencing, have been implemented. A recovery action plan has been developed for this species. The species may still exist in other inaccessible parts of Tenerife, more field surveys are urgently needed. It occurs in at least one protected area. There are 3 species of skinks. The Gran Canaria skink (Chalcides sexlineatus) and West Canary skink (Chalcides viridanus) are categorized as Least Concern (LC). There are no major threats to these species. The East Canary skink (Chalcides simonyi) is categorized as Endangered (EN). This species is endemic to the islands of Fuerteventura (the central area with an isolated population in the south), Lanzarote (in the north only) and Lobos. It is a rare species. The main threat is fragmentation of populations due to climatic changes (increasing aridity), loss of soil due to erosion. The main population was probably lost in a volcanic eruption in the 18th century. Feral and domestic cats are also a threat. It occurs in some protected areas. The only snake that occurs in the Canary Islands is the California kingsnake (Lampropeltis getula) and is an introduced species. jo_van_egroo https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345443036 The turtles of the Canary Islands are represented by two families: Cheloniidae and Dermochelyidae. The species of the Cheloniidae include the not threatened Green Sea turtle (Chelonia mydas), the vulnerable loggerhead sea turtle (Caretta caretta) and the critically endangered hawksbill sea turtle (Eretmochelys imbricata) and the Kemp’s Ridley sea turtle (Lepidochelys kempii). Most turtles have a circumglobal distrubtion throughout tropical and subtropical waters. All species are highly migratory and use a wide range of broadly separated localities and habitats during their lifetimes. The leatherback sea turtle (Dermochelys coriacea) is a vulnerable highly migratory species that belongs to the Dermochelyidae.  


]]> 2019-03-26 19:44:29 UTC https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345443036 Distribution map of the different Gallotia species on the Canary Islands jo_van_egroo https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345828842 (note: map does not include the possibly extinct species Gallotia auaritae on La Palma)]]> 2019-03-27 17:49:43 UTC https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345828842 Distribution map of Gallotia auaritae on La Palma jo_van_egroo https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345835803 Critically Endangered (CR) - possibly extinct]]> 2019-03-27 18:03:29 UTC https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345835803 Distribution map of Gallotia bravoana on La Gomera jo_van_egroo https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345836338 Critically Endangered (CR)]]> 2019-03-27 18:04:39 UTC https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345836338 Distribution map of Gallotia intermedia on Tenerife jo_van_egroo https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345836542 Critically Endangered (CR)à]]> 2019-03-27 18:05:07 UTC https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345836542 Distribution map of Gallotia simonyi on El Hierro jo_van_egroo https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345836806 Critically Endangered (CR)]]> 2019-03-27 18:05:41 UTC https://padlet.com/jo_van_egroo/vwbc2cxtox0k/wish/345836806