Not untouched nature: Birds are changing due to climate change

I’ve written before about the idea of an environment or wilderness that is separate from humans. The separation is an artificial construct. We can’t be separate as we depend on nature for everything from food to building supplies to our recreation. Sure, many of our objects are not obviously from nature but the petrochemicals for example that are used to make plastics were once plants and animals. Fine, we depend on nature. But surely there are pockets of nature that remain untouched by humans?

This looks less and less likely. Jirinec and others (2021) have published an analysis of four decades worth of research on resident birds in areas of the Amazonian rainforest that are still intact. What they found shows that human-induced climate change is impacting nature regardless of whether there are humans physically present in an area. The act that the birds were year-round residents is significant because it removes the potential for other areas that the birds might migrate to that could alter the impacts of local changes.

Specifically, Jirinec et al found that the birds who live in these intact forest areas year-round have smaller bodies and longer wings than they used to. Based on their data, the longer and hotter dry seasons are creating evolutionary pressures. The heavier your body is, the more work it is to fly. The more work you have to do, the more energy you need to consume. Therefore, as food availability decreases, birds with smaller bodies are better fit for the environment and natural selection occurs. Natural selection occurs when fitter birds are better able to survive and reproduce, passing their genes on at a higher frequency compared to birds with heavier bodies.

In the big picture, this research shows that the concept of untouched nature is an illusion. Humans are part of natural systems and we have the ability to change these systems significantly. In order to embrace this relationship and respond appropriately we need to change how we picture humans and nature. Fortunately many Indigenous cultures have a much more recipricol relationship if only the rest of us will take the time to listen and learn.

Photo by ncassullo via Pixabay