Climate change is one of the greatest challenges facing animals. The slow process of evolution often prevents them from adapting to a rapidly changing environment. This is especially true for birds, which are sensitive to climate change and depend on seasonality for their breeding and survival.
Recently, a team of scientists from the Netherlands Institute of Ecology conducted a genomic breeding experiment on great tits (Parus major) to assess the possible effects of climate change on this species. Great tits are a model species widely used in scientific research. The study was published in the journal Science Advances.
Scientists decided to study the future of the birds to determine how quickly the species could adapt to climate change. To do this, they accelerated the evolutionary process by artificially selecting genetically early and late birds. They then took the eggs of this population to De Hoge Veluwe National Park to compare their offspring to wild great tits.
The study showed that the earliest birds that were selected to lay eggs in early spring did not lay eggs significantly earlier than wild great tits. Thus, genetic adaptation to earlier egg-laying times proved to be a very slow process. This indicates that climate change is happening too fast for animal evolution.
In addition, climate change can cause serious ecological problems for birds. For example, insectivorous songbirds, such as great tits, depend on insects to feed their young. However, the breeding time of these birds no longer coincides with that of insects. This means that the young birds are missing out on sources of nutrients that normally play an important role in their growth.
Right now, it’s not clear to scientists how much earlier the birds could lay eggs. But they warn that climate change is happening too fast for birds to adapt. In the harshest climate scenarios, they will fall further and further behind.
The effect of climate on animal evolution is masked by density-dependent processes. For example, if eight or nine out of ten chicks die in the first year of life due to predation, lack of food, or competition, climate change may improve the chances of the remaining birds surviving.
Even so, climate change is having a serious impact on wildlife. Birds and other species face problems adapting to new conditions, and their survival and reproduction depend on their ability to evolve quickly.