We are currently in the midst of the sixth global extinction crises and many species around the world are disappearing. Amphibians are no exception. Specifically, amphibians are one of the vertebrate groups that are worst hit with over 30% of species currently threatened around the world. So what are the causes of global amphibian decline? And which are the most vulnerable species?
It is well documented that the primary cause of amphibian decline is habitat destruction and fragmentation. Recently, however, disease and climate change have emerged as major threats to amphibian populations around the world.
The Environmental Futures Research Institute is working with the Griffith Climate Change Response Program to look at how amphibians are likely to respond to climate change. One of the projects is looking specifically at mountain-top endemic rainforest frogs from mid-eastern Australia. These are frogs that live only on mountain-tops and are at high risk of extinction due to climate change. Changes in species distribution due to climate change have been reported, with the general trend of shifts towards the poles and higher elevations. This is because as mountain temperatures rise this frog species could be forced beyond the limit of its distribution into extinction.
Examining this issue is not simple task, and there is a lot of research to do in order to assess how a frog is likely to respond to climate change. This requires a lot of filed work to find out where the frogs occur. For my PhD research spent a lot of time in the field searching for tiny frogs, a very rare mountain-top rainforest endemic species.
Once I found these frogs I then needed to determine why and where they occur. Firstly, I had to make sure that we actually detected this frog specie. Hence, it was very important to determine the detectability and the probability of finding a frog. Secondly, The next I determined the environmental conditions which allow the frogs to survive. This involved determining the maximum and minimum temperatures at which a frog can survive. I did this by undertaking extensive experimental field laboratory tests. Thirdly, I determined the actual temperature of the environment in which the frogs occurred by setting up field temperature loggers. I also monitored rainfall for behavioural influences.
Once I characterised the frogs thermal environment I was able to determine the likely response to climate change. Studying these rare mountain-top endemics frogs can give us a good idea of how other species are likely to respond to climate change. So it appears as though the mountain-top endemics will be pushed off the top of the mountain and we need to do everything we can to mitigate climate change.