Making Room for Wildlife in an Urbanized World
In the southern Indian state of Karnataka we can find a good example of wildlife – even large predators – living near human settlements. In other regions cities have begun to recognize the value of protecting wildlife even within their own borders. Urbanization does not always need to mean a big threat for nature.
Tigers at your doorstep
In Karnataka you can find beautiful shade coffee plantations, with an understory of coffee plants, and pepper vines — a second cash crop — twining up the trunks of the shade trees. Coffee plantations managed in this fashion, connected to surviving patches of natural forest, provide continuous camouflage for the predators — especially tigers moving through by night; and wildlife conflict is minimal here. Elsewhere, though, the corridor narrows to a thread winding past sprawling villages, and conservationists play a double game, hand-holding to help people live with large predators on their doorsteps, but at the same time legal combat to keep economic interests from nibbling into the wildlife corridor from both sides. This is a microcosm of how wildlife hangs on these days, not just in India, but almost everywhere in the world.
For conservationists, protecting biodiversity has in recent years become much less about securing new protected areas in pristine habitat and more about making room for wildlife on the margins of our own urbanized world. Conservation now often means modifying human landscapes to do double-duty as wildlife habitat — or to continue functioning for wildlife even as humans use them for homes, highways, farms, etc. There is simply no place else for animals to live.
National parks, wildlife refuges, and other protected areas remain essential, especially for species that do not adapt well to human-dominated landscapes. The 168 nations that signed the Convention on Biological Diversity (CBD) have committed themselves to extend protected area coverage to 17% of their land area by 2020. But getting there is difficult. Coverage by national parks and other protected areas has remained stuck for the past few years at about 15% worldwide (much less than E.O. Wilson’s grander vision of “half-Earth” set aside for nature).
Buffer zones and corridors
Research has demonstrated that biodiversity can improve already from wildlife corridors as little as 25 yards wide. Work to improve buffer zones around parks, and to establish corridors on the land between existing protected areas, has flourished.
Since 2 000 the area protected by land trusts in the US has more than doubled, (from 23 million to 56 million acres), according to the Land Trust Alliance. Corridor protection on the grand scale has achieved remarkable results, notably with the 2,000-mile long Yellowstone-to-Yukon Conservation Initiative. It aims to connect protected areas and to ensure safe passage for elk (photo), grizzly bears, and other wildlife across 500,000 square miles of habitat, both public and privately owned.
At the same time, research by Nick Haddad (conservation biologist at the University of Michigan’s W.K. Kellogg Biological Station) has demonstrated substantial improvements in biodiversity from corridors as little as 25 yards in width, well within the range, he says, of “what’s reasonable in urban landscapes.”
Indeed, a new study from northern Botswana has found that elephants traveling from Chobe National Park to the nearby Chobe River will use corridors as small as 10 feet wide to traverse newly urbanized areas.
Cities protecting wildlife
Urban areas now recognize that it’s cheaper to protect clean water by buying up natural habitat both within their own borders and at the source, instead of installing expensive technology to purify it after the fact. Well known is New York City purchasing huge chunks of the Catskills. North Carolina for instance, has protected 500,000 acres of watershed and riverside habitat over the past 20 years — with enormous incidental benefits for wildlife.
Cities have begun to recognize the value of protecting wildlife within their own borders. Singapore, for instance, has increased its natural cover to almost half its land area over the past 30 years, even as its human population has doubled. Its Central Catchment Nature Reserve has become one of the last refuges of the straw-headed bulbul, a bird once common across Southeast Asia. The government also announced plans to create new nature parks as habitat for the critically endangered banded leaf monkey (photo).
Even in the absence of new parks and other habitat, city residents have rallied to their wildlife, sometimes in extraordinary fashion. In Mumbai, development-oriented politicians continue to encourage the destruction of natural habitat, particularly in the Aarey Milk Colony neighborhood abutting the city’s Sanjay Gandhi National Park. But local conservationists, together with the park itself, have launched a pioneering campaign to help densely populated neighborhoods around the park cope with more than 30 free-ranging leopards in their midst.
Los Angeles has turned its mountain lions into urban folk heroes. (The Facebook bio of the lion known as P22 begins: “Hi! I’m LA’s loneliest bachelor. I like to hang out under the Hollywood sign to try and pick up cougars.“
Highway departments have learned that they can save money, reduce their carbon footprint, please tourists, and also help wildlife by converting roadsides and medians from grass to wildflowers. The Federal Highway Administration recently published best management practices for using roadside margins as pollinator habitat — with Florida incidentally saving $1,000 per road mile in mowing costs and Oregon reducing pesticide use by more than 25%.
The idea of making human-dominated landscapes more wildlife-friendly dates back at least to the 1970s, when the anti-lawn movement in the USA proselytized for turning backyards into habitat. But finding ways — large and small — for wildlife to live among us has come to seem dramatically more urgent in recent years. That may be partly because in this century Homo sapiens has become a predominately urban species for the first time in history, with huge projected growth in cities and megacities.
The sharp decline in insects…
Even scientists were stunned in 2017 by the report of a mass insect die-off in Germany. That study found that over a 27-year period, from 1989 to 2016, the population of flying insects at nature reserves across Germany had collapsed, down by 76% overall, and 82% in the peak mid-summer flying season. Most of the likely causes — including habitat fragmentation, deforestation, monoculture farming, and overuse of pesticides — were factors outside the borders of these protected areas. “We appear to be making vast tracts of land inhospitable to most forms of life,” one co-author grimly commented, “and are currently on course for ecological Armageddon.”
…and other animals
That came on the heels of a report (of the National Academy of Sciences) describing a “biological annihilation” in which “as much as 50% of the number of animal individuals that once shared Earth with us are already gone,” with likely “cascading catastrophic effects on ecosystems,” and on economic and social services “vital to sustaining civilization.” In particular, global vertebrate populations — from elephants to amphibians — declined by 58%, with losses likely to reach 67% by 2020. That’s two-thirds of all vertebrate animals on Earth vanished in the lifetime of a person not yet 50.
Changes in human attitudes
In the face of “annihilation” and “Armageddon,” emphasis on tending the margins of our lives can seem marginal. “If the focus is on degraded landscapes – roadside edges, powerline rights of way – you can find examples where these habitats are important to particular species,” says Josh Tewksbury, (conservation biologist at the University of Colorado, Boulder). “But it would be hard to find any evidence that it’s going to make a whit of difference to the big problem. It’s not going to solve 95% of the problem.” Then, as a second thought, he added, “It could be the 95% solution for people and biodiversity,” in the sense that “routinely seeing birds in a city park, or a fox running across a field – or even crossing the street – can have big implications for how people think about the value of nature.”
And changes in human attitudes about nature can have dramatic effects on the ability of wildlife to survive in human-dominated landscapes.
Bringing back wildlife
For instance, persistence of old cultural attitudes is the major reason wolf recovery has struggled in the U.S., despite an abundance of available land. Meanwhile, Europe, one of the most industrialized landscapes on earth, has welcomed the return of wolves even to the fringes of its largest cities — along with brown bears, lynx, bison, and other species. The surprisingly rapid recovery of such species in Europe has led to a call for rewilding to become “a primary component” of long-term biodiversity conservation on degraded landscapes elsewhere — even perhaps everywhere.
But even if having our cities and suburbs as wildlife habitat is probably still a good idea, one danger is that these landscapes may become “ecological sinks” — that is, places where excess individuals from undisturbed habitat can survive, but in the end not increase. Having straw-headed bulbuls in central Singapore does not, for instance, ensure survival of the species. Success with some more visible species may also blind us to broader but less obvious declines in other species. European rewilding, for instance, has not been rewilding for its insect population as we have seen.
Changes in ecosystems
Finally, we know almost nothing about what has been called “these cryptic changes happening” (Meredith Holgerson at Portland State University) as humans occupy and alter a landscape. For her doctoral research she looked at the effects of suburbanisation on wood frogs in 18 ponds in the prosperous Connecticut suburb of Madison. The area around the ponds had developed largely with two-acre zoning, allowing for survival of “pretty good red maple swamps and vernal ponds,”. But chemical analysis of the ponds demonstrated that, along with other changes, the wood frog larvae were getting as much as 70% of their nutrients from materials leaching out of septic systems. “It suggests,” says Holgerson, “that tadpoles and other pond organisms are made up of human waste.”
The consequences of that remain unknown. But it also suggests that we may change the entire nutrient flow of an ecosystem, cause eutrophication, or introduce hormone-disrupting drugs or other chemicals in our waste — and still imagine that we live in a relatively intact habitat.
By Richard Conniff, source Yale Environment 360, january 3, 2018