Urban animals are particularly adaptable
Animals from urban areas cope better with environmental changes than their conspecifics. This adaptability could make them a lifeline for entire species in the face of climate change.
In environments that have been modified by humans, living organisms are exposed to many different stress factors - but they are also better able to adapt to such difficulties. As a result, animals and plants from peri-urban habitats could potentially serve as "rescue populations" in climate change and biodiversity crises. This is the conclusion reached by a working group led by Elizabeta Briski from the GEOMAR Helmholtz Centre for Ocean Research in Kiel based on studies of mussels and amphipods from the Baltic Sea. As the team reports in the scientific journal "Ecology Letters", animals from the Kiel Fjord, which is heavily influenced by humans, tolerate changes in water quality better than their conspecifics from the nearby Schleimünde nature reserve. This suggests that they have already adapted to the increased human impact.
The environment around densely populated cities, where almost 60 per cent of the world's population now live, differs greatly from natural habitats. Animals are exposed to different, new pressures to which they have to adapt. For example, city birds sing louder and at different pitches than their rural counterparts in order to distinguish themselves from human noise. Cities are also heat islands, giving an indication of how animal species cope with higher temperatures. Apparently, however, living organisms not only adapt to changing conditions, but also to the fact that the conditions change more strongly and more frequently. This is suggested by the experiments conducted by Briski's team.
The experts collected specimens of the mussel Mytilus edulis and the amphipods Gammarus locusta and Gammarus salinus from the Kiel Fjord and the Schleim estuary. They then kept the animals in tanks and varied the temperature, salinity and carbon dioxide concentration in ranges that are realistic for the Baltic Sea today and in the future. The team observed the animals over a period of 30 days. In almost all experiments, the individuals from the urban area proved to be less sensitive to changing environmental conditions. This resilience could provide clues as to how living organisms will adapt to changing conditions on Earth in future evolution, the team writes. In addition, such populations could repopulate regions where the species has become extinct due to changing environmental conditions. However, the higher adaptability of these animal species also harbours the risk of them colonising other habitats as invasive species, say the experts according to a press release from GEOMAR.
Originalartikel auf Spektrum.de
Experts from science and research report on the latest findings in their fields – competent, authentic and comprehensible.