In New Mexico canyon, a novel way to prevent roadkill
Lobbied by concerned students, the state created a critter-friendly underpass.
In 2003, a group of New Mexico students began lobbying the state legislature to address collisions between vehicles and wildlife. The Wild Friends program at the University of New Mexico’s Law School in Albuquerque works with classrooms in Grades 4 through 12 to draft legislation on issues students find important. That year, they decided to tackle vehicle-wildlife collisions, a growing problem nationwide.Skip to next paragraph
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“It’s an issue that just about every student in the program has experience with,” says Carolyn Byers, director of Wild Friends. In New Mexico classrooms, stories abound of such encounters, she says.
The Legislature pledged to address the problem. Subsequent analysis of collision data revealed “hot spots” – areas critical to both people and wildlife where a little mitigation could go a long way. Tijeras Canyon, just east of Albuquerque, was one such place. There, on its journey from California to North Carolina, Interstate 40 passes between the Sandia Mountains to the north and the Manzanitas to the south. The canyon, which also contains a creek – a magnet for thirsty animals – is a critical crossing point for wildlife moving between the two wilderness areas.
Now, as a result of the process originally kicked off by students – and subsequent work by citizens’ groups – state agencies have installed fences to guide mule deer, black bears, cougars, and other wildlife through safe passages beneath I-40. So far, the project – completed last year for the relatively modest sum of $750,000 – seems to be working. Before, collisions on I-40 in Tijeras Canyon averaged between 20 and 30 yearly. This year, there have been only three.
The wildlife passage, the first in New Mexico, also tries to address scientists’ broader concern over increasingly fragmented landscapes. To remain healthy, wildlife populations need to maintain gene flow among populations, scientists say. A small isolated population can lead to inbreeding, and limited genetic variation can hinder a population’s ability to adapt to environmental changes over time.
Unfortunately, natural habitat is increasingly fragmented by cities and farms, not to mention crisscrossed by highways. By one estimate, roads alone affect the ecology of 15 to 20 percent of all US land. Safe passages for wildlife – over or under roadways, as well as corridors connecting separate patches of wilderness – may help ease this. They permit wildlife to graze, hunt, and interact over larger areas.
Climate change is another concern. As the climate warms, scientists expect habitats to move toward the poles and, on mountains, upward.
Wildlife suited to these ecological niches will shift as well. Scientists have already observed what they say are climate-induced migrations of plants and animals. With climate putting wildlife on the move, barriers like I-40 could theoretically supply a critical blow to a population or species.
“If you don’t allow for passage of wildlife over large areas,” says Kim Vacariu in Portal, Ariz., “you’re going to exacerbate the extinction crisis that we face right now.” He is the western director for the Wildlands Project, a conservation organization.
The present economic turmoil notwithstanding, the movement to create or preserve connections among wild areas has gained momentum in recent years, especially in the relatively sparsely populated West.
In June, the Western Governors’ Association voted to make wildlife corridors a top priority. Wildlife overpasses – bridges over highways planted with trees and grass to make them more attractive to wildlife – already arch over roads in Canada and Florida. Colorado, Washington State, and Arizona are planning them. Organizations such as the Wildlands Project, meanwhile, are pushing for a north-south wildlife corridor along the “spine of the continent”: a 5,000-mile swath of unbroken wilderness from Mexico to Alaska along the Rockies.