Both common and rare animals fluctuate in number in a time of global change

Climate change is going to have a huge effect on biodiversity. We tend to think that some species are more resilient than others because they are simply not endangered. However, a new study from the University of Edinburgh found that common animals and rare animals both fluctuate in number in a time of accelerating global change.

Previously we thought that the Hawksbill sea turtle is more likely to be endangered than red deers, but now we cannot be sure. Image credit: DRVIP93 via Wikimedia (CC BY-SA 4.0)

This study included more than 2,000 species and nearly 10,000 animal populations. Scientists analysed data collected between 1970 and 2014. They wanted to see how changing conditions affect biodiversity and which species are more vulnerable than others. Most importantly, they wanted to see whether common animals fluctuate in number differently than rare animals. Scientists found that 67 % of species in the research period didn’t exhibit any change in number, while 18 % increased and 15 % decreased. Amphibian populations declined while birds, mammals and reptiles experienced increases.

What does this mean? Well, up until now scientists concentrated their conservation efforts in endangered animals. This study shows that this might not be an ideal approach, because common animals are just as likely to suffer from changing global conditions. They may go from common to rare very quickly. Obviously, however, scientists do know that animals from smaller populations are facing a greater danger of extinction. It is just because both common and rare animals are as likely to fluctuate in number as global conditions change. Scientists are particularly worried about amphibians, because their populations are more likely to decline.

Those species that do well in human-modified landscapes are more likely to increase in population. Also, those that humans are actively protecting – our efforts are yielding results. Scientists are emphasising the importance of data in subjects like this. Dr Isla Myers-Smith, co-author of the study, said: “Only as we bring together data from around the world, can we begin to really understand how global change is influencing the biodiversity of our planet. The original idea for this study stemmed from a fourth year undergraduate class at the University of Edinburgh”.

This study could alter the ways we go about conservation. We have to focus on more species, not just the ones that are already in danger. It is very important to understand how changing conditions are affecting different animals. Only in this way we can achieve truly great results and predict how changing global conditions are going to reshape natural biodiversity.


Source: University of Edinburgh

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