By s.e. smith, Networx
There are around 10,000 bird species worldwide, and an estimated 13% of them are threatened with extinction, with human pressures on their habitats being a significant contributing factor to their decline. Birds aren’t just beautiful to look at; they also play a vital role in the natural world, as part of a complex food chain that includes smaller and larger animals dependent on birds as food sources, venues for seed distribution, and more. With vanishing bird species comes growing concern among researchers about the environmental impacts of species loss.
Researchers across the world are studying bird populations to learn more about the specific threats they experience, and what they can do about it. One major area of concern is habitat fragmentation, which Rhiannon L. Crain, PhD, a Project Leader at the Cornell Lab of Ornithology, explains occurs “when large tracts have been subdivided into smaller parcels such that the total habitat area is no longer contiguous; you can think of it like a puzzle where none of the pieces actually touch.”
She noted that you can see the effects of habitat fragmentation for yourself by looking out the window of an airplane. As you soar across farming land, you’ll see the land divided into a variety of tracts, large and small, and those get much denser as you approach suburban and urban areas. The closer you are to a major city, the fewer plants and trees, and that’s an entirely human-created problem.
As human populations settle and spread, looking for more land to develop, they break up the habitat even more. Between cutting large tracts into smaller parcels for development and sale, building up in urban areas, converting open farmland, and installing recreational facilities in formerly pristine areas, humans intrude on the natural environment. They have a tendency to break it up with different types of uses, dividing roads, and other introductions that permanently change the landscape, turning it into a new and unknown world for the animals that formerly inhabited it.
“Just because birds can fly doesn’t mean that every bird can utilize any piece of the puzzle. While some birds are generalists, and can thrive in many different habitats, many require very special environmental conditions in order to successfully feed and breed. It turns out that one of the special conditions required by many birds is large, unbroken tracts of habitat, especially birds of the grasslands and forest interior,” says Dr. Crain.