CAN CITIES PROVIDE HABITATS FOR LIVING THINGS?

          When towns and cities are built, the habitats of the living things in the area are destroyed. Gradually, however, other plants and animals find a foothold in the urban environment, while a few of the original species adapt to the new conditions. Even in the largest cities there are parks, gardens and tree-lined roads. Human beings throw away an enormous amount of food, which can provide nourishment for insects, birds and animals.

          Humans are an increasingly urban species. By 2050, somewhere between 60-70% of people will live in cities or other analysis suggests we may have already reached that number worldwide. This provides an opportunity, and a responsibility, to examine the ecological role that expanding urban areas play in supporting biodiversity.

          Despite perceptions of urban areas as devoid of nature, where humans live, so, too, will wildlife. Some creatures lived where our cities were before our arrival, while others have adapted to be synanthropic?residing alongside humans more frequently than others. Many of these species are tolerant of human disturbances or may even favor the built environments that dominate cities. Yet, little attention is paid to the services these animals provide to city dwellers. Before viewing the scavenging coyotes (Canis latrans) in the abandoned lot or the American Crows (Corvus brachyrhynchos) roosting in the park trees as nuisances, consider the value they could be providing the city.

          Urban areas carve up space with roads and development. We know that the resulting habitat fragmentation leads to all kinds of issues for birds, reptiles, amphibians, and mammals that are trying to navigate and breed. In some cases, fragmentation is linked to declines in a variety of wildlife. Roads, in particular, kill many organisms each year. But because these roads create roadkill–an ample food source for scavengers–scavenging species seem to adapt to this fragmentation more easily than other species.

          One study from the UK found that gulls, foxes, magpies, and crows all contributed to cleaner streets by scavenging for roadkill. Birds, active at dawn and through the day, were documented to be quick and efficient scavengers, while foxes and other small mammals were active at night, providing around-the-clock elimination of rotting roadkill from the roads and thru-ways of the city. This is an incredible sanitation service, as anyone who’s encountered decaying roadkill can attest.

          Humans produce waste. Scenes like the one depicted above are all too common. Some urban animals are using this litter as a food source. For example, one study in New York City, comparing food litter removal in medians vs. parks, found arthropods, namely ants, were able to remove 4–6.5 kg (8.8-14 lbs) of food per year in one median. In the same study, vertebrates, such as birds and small mammals were also found to be effective at removing food waste, with a greater diversity of them in parks compared to medians. These animals are providing a critical sanitation service in our cities, while we wish it wasn’t a necessary act, it does keep streets cleaner.

Picture Credit : Google