Amphibians and reptiles, being ectothermic species, are strongly connected with their environment. Therefore, they are more directly affected by climatic conditions alternations because of their body temperature depends on the surrounding temperatures (Ockendon et al., 2014). Climate change and global warming are  believed to influence on herps behavior such as offspring sex-ratio (Mazaris et al., 2008), spawning events, activity periods and breeding seasons to name a few (Walther et al., 2002). Although direct evidence between climate change and herpetofauna populations declines has been sparse (Carey & Alexander, 2003). A very large proportion of amphibian species have been identified as particularly vulnerable to .change (Foden et al., 2013) and both amphibian and reptile species will undoubtedly be affected by the occurring climate changes.  Both groups are declining worldwide (IUCN, 2008) and these declines have been partly attributed to climate change (Parmesan & Yohe, 2003; Huey et al., 2010). However, recent studies reported that among the highest importance threats are anthropogenic land-use changes, leading to habitat destruction and fragmentation, and the fatal disease chytridiomycosis (chytrid fungus Batrachochytrium dendrobatidis). Climate change is also an important threat, might interact with chytridiomycosis, environmental pollution, direct exploitation for food, medicine and pet trade, increase in ultraviolet-B irradiation due to anthropogenic ozone depletion, and the spread of invasive species (Blaustein & Kiesecker, 2005; Hof et al., 2011).

 

Here we specifically investigate how climate change affect amphibian and reptile species in three countries: Denmark, Greece, Italy and Pakistan. Three countries (Denmark, Greece, Italy) belong to Palearctic biogeographical realm (Olson et al., 2001) while Pakistan belongs to Indo-Malayan biogeographic realm (Fig.1). Also, the latitudinal zone, the climate and land use history of the three countries is different. Thus, we expect differences on how climate change affects herpetofauna in the three countries. In this report, we analyze the threats and potential benefits that climate changes might provide and look into invasive species, ecological changes and more. 

Fig. 1 Biogeographical realms of the world (Olson et al., 2011)

 

In Greece and Italy, the most frequent response of amphibian and reptile species appears to be the displacement of the distribution according to their ecological requirements. For example, several species might be distributed to northern areas where temperatures that are more suitable will prevail. We expect populations with limited range and / or limited dispersal potential to disappear while other species are expected to be favored from the new climatic conditions settle new areas. The degree of habitat fragmentation, particularly in aquatic environments, is particularly critical for the existence of migratory pathways suitable for amphibian dispersal and therefore is a necessary information for the assessment of vulnerability of all species as well as for the development of conservation plans in the light of the scenarios climate change (Adamopoulou, 2018).

 

In Pakistan, Mr. Rafaqat Masroor, Associate Curator (Herpetology), Pakistan Museum of Natural History was consulted for his expert opinion in this regard. He concluded that: “Reptiles like different gekko genera i.e., Cyrtodactylus, Cyrtopodion (Ground Gekkos), Alsophylax, Mesodactylus (Stone Geckos), Tenuidactylus (Standstone Gekkos) residing in restricted habitats. Thus, average temperatures variation will cause shift species ranges and distributional limits. Temperature may strongly influence amphibian species geographic distribution, so the species’ distribution limits are determined by the extreme temperatures. As a result, species with broad tolerance to thermal regimens should be able to expand their ranges and then colonize new habitats. Although Pakistan endemic and habitat specific species like Nanorana vicina (Murree Hill Frog), Bufo pseudoraddei baturae (Batura Glacier Green Toad) and Scutiger occidentalis (Deosai Toad) populations will be strongly affected by temperature regime shifting. Climate change will cause species migration to higher altitudes and subsequently leads to habitat shrinkage or loss and distribution. It will also effect on their emergence and reproduction in their habitats.

Following this pattern, Greece being a Mediterranean country faces the problem of increased desertification, with its islands being listed as areas of high desertification risk. The islands of the Aegean, areas with intense relief and low vegetation cover face major confrontations. The impacts of these specific changes are expected to influence significantly biodiversity, composition and functionality of ecosystems, soil structure, water reserves and island landscape. The predictions for the island ecosystems are particularly ominous, since climate change is expected to sharpen further the environmental problems already derived from the abandonment of traditional land uses (i.e. cultivation of terraces). These problems include soil erosion and loss of fertile land, as well as increased flammability of vegetation and subsequently high fire risk. The natural island environment will also be subjected to negative impacts, e.g. increase in ecosystem susceptibility and reduction of abundance of species and biodiversity (Karamanos and Voloudakis, 2011). A recent census of the wetlands in the Aegean islands from WWF Hellas recorded 352 wetlands in 51 islands and islets in Aegean apart from Crete, of many types and rich in biodiversity (Vella et al., 2011). The islands of the Aegean Sea host numerous herpetological species (reptiles and amphibians), from highly venomous vipers to the very rare Mediterranean common chameleons (Archipelagos). The wetlands of these islands are key habitats for the conservation of the populations of several hundreds of wetland-dependent vertebrate such as the amphibians: Rana ridibunda, R. cerigensis (endemic to Karpathos), Bufo bufo, Bufo viridis, Hyla arborea; and the reptiles: Mauremys rivulata, Emys orbicularis, Natrix natrix, N. tesselata (Catsadorakis et al., 2007). As such, extreme weather conditions such as increased aridity and desertification will negatively affect micro-habitats especially ponds and isolated biotopes and thus herpetofauna. Lyciasalamandra helverseni which is endemic to three Aegean islands: Karpathos, Saria, and Kasos. exhibit significant local isolations and high degree of inbreeding, mostly due to extensive degradation and habitat destruction, climatic alterations and human activities. As a result, the species is classified as Near Threatened, but on the island of Kasos it is considered as Critically Endangered (Lymberakis et al., 2009).

 

In Italy also the main problem is the drought that seriously affect fresh water and alter habitats. Increasingly often draught events take place in the country, and this is a damage for temporary waters that are reproductive sites for amphibians such as tree frogs (genus Hyla) and the emerald toads (genus Bufo) (Stoch and Naselli-Flores, 2014). or the reptiles of the genus Emys (marsh turtles present in Italy with two species and various subspecies) which can use the temporary waters as reproductive sites. In all these cases, species survival is often guaranteed by metapopulations, which occupy not one but a series of small neighboring basins; species that inhabit ponds isolated or peripheral are generally more in danger of extinction (Stoch & Naselli-Flores, 2014).

 

Pakistan climate is mostly arid subtropical with few rains. In climate change scenario there is considerable variation in the timing of receding of glaciers, which resulted in changing duration and intensity of the monsoon precipitation. This is especially threatening because Indus Basin 50-70% flow mostly depends on the glaciers melt water. Monsoon rains average annual rainfall is not expected to have a significant long-term trend, but is expected to exhibit large inter-annual variability in Pakistan. This precipitation change will effect on population of amphibians because of highly permeable skin, and both aquatic and terrestrial life stages. These attributes make Pakistan’s endemic amphibian fauna very sensitive to changes in temperature and precipitation. 

 

The cold blooded nature of these animals and their semi-permeable skin makes them perfect environmental indicators, especially with regards to climate change and water toxicity. However, according to some particular studies, because reptiles are known to favour warm areas, they might therefore be less severely affected by increasing temperatures or may even benefit from global warming in colder regions (Winter et al., 2016). Furthermore, as studies have shown, the sex of the sea turtle for example is affected by the temperature at which the egg is incubated, so that climate change causes almost most sea turtles (reptiles) to be born females (Jensen et al., 2018). In Greece it is already evident that climate change threatens coastal ecosystems and nesting beaches of sea turtles (Dr. Minotou for WWF). 

 

Also, Fernandez-Chacon et al. (2011) examined the effects of climate variability on the population dynamics of Hermann’s tortoise (Testudo hermanni), a threatened reptile species endemic to the Mediterranean region, to forecast the population responses to the regional climate changes predicted for this area. They showed that a shift to a more arid climate would have negative consequences for population persistence, enhancing juvenile mortality and increasing quasi extinction risk because of a decrease in recruitment. 

It is believed that climate changes and especially warmer temperatures will increase the risk of getting new invasive species in Denmark or provide better circumstances for current ones (www.klimatilpasning.dk). For example, might the red-eared slider (Trachemys scripta elegans) get even better living conditions posing an even larger threat to the native species. The American bullfrog (Lithobates catesbeianus), which so far has not established any populations in Denmark, might also suddenly be able to proliferate in the Danish nature due to climate changes. In Greece, there is one observation for an amphibian alien species which its expanding in the country probably has been driven by climate change (Demertzis & Iliadis, 2017).

In many areas of the world, chytridiomycosis has been spread into native ecosystems via biological invasions caused by alien invasive species, translocations of native species, and the amphibian trade (Cunningham et al., 2005, Fisher & Garner, 2008). Batrachochytrium dendrobatidishas not yet been reported in Pakistan. Although this disease is a major issue of amphibian conservation, patchy distributed surveys will be extremely useful for the early detection of new infections hotspots across wide, poorly investigated areas. Chytrid fungus has unfortunately been reported in a few Danish amphibian species (Martin Nielsen personal observation, unpublished). So far, its presence has not been associated with any mortalities in Denmark but it is likely that the changes induced by climate change might alter the amphibian-fungus relationship and interactions which might lead to reduced fitness and mortalities (Bosch et al., 2006; Rohr & Raffel, 2010).

An amphibian species endemic to the appennic region of Italy, Bombina pachypus is endangered according to IUCN. This is because of multiple threats, like habitat degradation, destruction of reproductive sites but it also emerged from the Environment Ministry of Italy that global warming favors pathogenic agents (Canestrelli et al., 2014). 

Fig. 2 Spatial distribution and pairwise overlap of the three main factors threatening global amphibian biodiversity, projected for the year 2080. a, Climate change and chytridiomycosis. b, Climate change and land-use change. c, Chytridiomycosis and land-use change. Figure has been published at Hof et al. (2011).

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Introduction: Mariana Tsianou 

Results: Sofia Chronopoulou, Ismini Gkourtsouli – Antoniadou, Francesca Graciani, Niovi Hatzinikolaou, Martin Nielsen, Georgios Stamatopoulos, Mariana Tsianou, Mishkat Ullah 

Conclusions: Sofia Chronopoulou, Ismini Gkourtsouli – Antoniadou, Francesca Graciani, Niovi Hatzinikolaou, Martin Nielsen, Georgios Stamatopoulos, Mariana Tsianou, Mishkat Ullah