Creating 'escape routes' for wildlife

Biological corridors, such as one planned from Panama to Mexico, would let species migrate to safer climates as global warming heats up their old habitats.

By Moises Velasquez-Manoff | Contributor to The Christian Science Monitor

from the June 21, 2007 edition

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Biolley District, Costa Rica - Slightly smaller than West Virginia, Costa Rica is a relatively little country. At its narrowest, it's a mere 74 miles wide. And yet, like much of Central America, it contains an extraordinary diversity of wildlife. The country encompasses mangrove swamp on the coasts, lowland rain forest on the Caribbean coastal plain, drier forest in the foothills of the Pacific slopes, and high-elevation cloud forests on its mountains. Covering only 1/10000th of the world's surface, Costa Rica hosts 1 out of every 20 species on the planet. All of Central America hosts roughly 1 out of every 8 species.

As the globe warms, scientists generally expect ecozones – those habitats defined by a specific temperature and rainfall – to move away from the equator and, in mountainous regions, to move uphill.

In theory, the wildlife accustomed to these habitats would move, too. But in human-dominated and fragmented landscape – and given the speed of predicted climate change – scientists worry that wildlife won't be able to adjust in time. Trapped behind agricultural fields, cities, and highways, many species will simply disappear as the climate warms, they say. One-quarter of Earth's species – plant and animal – could disappear by century's end, according to the latest report by the Intergovernmental Panel on Climate Change.

To improve the situation, scientists propose creating "biological corridors" between wilderness areas – natural spaces that allow wildlife to shift uphill or across latitudes in response to changing climate. In Central America, conservationists dream of a paseo pantera – a panther's path – running from Panama north to Mexico. They call it the Meso-American Biological Corridor.

Facilitating the movement of wildlife isn't a new idea. Scientists have long argued that "corridors" would allow animals like the jaguar, which needs about 15 square miles of territory per individual, space to roam, hunt, and breed. Corridors also prompt the exchange of genes between isolated populations, promoting genetic diversity and avoiding inbreeding. (Unfortunately, they provide little help to animals on top of tropical mountains, which have nowhere to go.)

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