Cities could be wildlife refuges of the future

With more species going extinct, we must consider the potential of urban environments to serve as refuges for the survivors. Studies show that cities can support, protect, and even evolve wildlife biodiversity, providing opportunities for innovative approaches to conservation.

|
Eric Gay/AP
A young girl chases pigeons and ducks at a park in San Antonio, Texas, Feb. 4. Op-ed contributor Madhusudan Katti writes: 'More conscious green landscape designs in cities can ...help support more...native species diversity.'

Mention the word wildlife to a city dweller and images of animals and birds in remote natural surroundings will probably come to mind – not in an empty parking lot around the corner. But research shows that cities can in fact support wildlife biodiversity, and this can have major implications for conservation efforts.

On a crowded planet, protecting species in their natural habitat is proving increasingly difficult. Humans continue to expand their networks of cities, towns, and farms, leaving few remaining natural animal habitats. By 2030, cities are expected to occupy three times as much land as they did in 2010. With the number of species going extinct on the rise, it is necessary to consider the potential of urban environments to serve as refuges for the survivors.

In 2010, the Convention on Biological Diversity commissioned a new global assessment of the state of biodiversity in urban areas. Their findings, published in the book "Cities and Biodiversity Outlook," which I co-edited, were not entirely bleak. It turns out that cities support biodiversity and provide opportunities for innovative approaches to conservation.

A recent global analysis of urban plant and bird diversity found that cities have lost an average of one-third of the native species found in their surrounding region. While this level is worrying, it is worth noting that two-thirds of the native plant and bird species continue to exist in cities that were never designed with biodiversity protection in mind. In fact, at least 20 percent of the world’s known bird species now occur in urban areas, as do at least 5 percent of the known plant species. More conscious green landscape designs in cities can only help support more of the native species diversity.

While urbanization displaces many species, others have adapted and not only survive but thrive in cities. House sparrows, rock pigeons, starlings, brown rats, and feral house cats are just some examples of species that are ubiquitous in many cities worldwide. More surprisingly, many rarer species are adapting to suburban environments, including San Joaquin Kit Fox of central California.

For many native species, urban habitats may actually be more attractive as refuges. They provide easier and more predictable access to water and food resources, warmer temperatures in the winter, and often fewer predators. Continued breeding can drive the long-term evolution of urban species as they adapt to their new environment.

Species such as the house sparrow have evolved to be strongly dependent on human habitation. And warmer nights and feeding by humans have even changed the migration pathways and geographic ranges of some migratory species. For example, a population of European Blackcap Warblers now winters in suburban southern England instead of Africa.

Noise pollution is another factor influencing urban ecology and affecting the many animals that communicate using sound, such as birds, frogs, and some insects. Birds that have adapted to the urban soundscape show distinct dialects with songs that are simpler, louder, or higher pitched to cut through the background noise. 

San Francisco’s resident White-Crowned Sparrows have changed their tune over the past 30 years as the city has grown noisier, losing some distinct notes of their songs. This may have evolutionary consequences, as dialect formation is often the first step toward speciation. Other studies have found genetic differences between urban and nonurban populations of some species, indicating fairly rapid evolutionary changes.

New wildlife communities are coming together in cities, often with accidental manipulation and active management by humans. These communities can play an important role in both the urban ecosystems and surrounding natural habitats. Urban and suburban gardens, for example, can support important reservoir populations of bees and other pollinators that find it difficult to survive under modern intensive agriculture.

The overall picture is not bleak. Cities can provide new habitats that may be quite different from those in natural ecosystems but can still support a variety of species. Species that evolve under such urban conditions may well represent what the future holds for much of Earth’s biodiversity.

Madhusudan Katti is an associate professor of vertebrate ecology at California State University, Fresno. He studies urban biodiversity and has received funding from the US National Science Foundation, and the National Center for Ecological Analysis and Synthesis (NCEAS). He is a contributor to several chapters in the Cities and Biodiversity Outlook (CBO) scientific synthesis and a lead author of the CBO: Action and Policy.

An earlier version of this article was originally published at The Conversation. Read the original article here.

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Cities could be wildlife refuges of the future
Read this article in
https://www.csmonitor.com/Commentary/Opinion/2014/0213/Cities-could-be-wildlife-refuges-of-the-future
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe