Conserving our wild border

The southern border region is one of the most bio-diverse areas in the United States and a crossroads for many carnivores. Today, the area is more widely known for the highly charged border politics involving people than for how those politics may affects the bears, jaguars, mountain lions and other wildlife that make the area home.

For hundreds of years, as national borders have been redrawn by various governments, these species have maintained a natural distribution across the region. A recent study provided insight into the critical role that movement corridors – the paths that wildlife follow to access seasonal resources such as various foods, water and mating opportunities – play in ensuring the persistence of bears and other large carnivores in this region.

The collaborative study, by the Wildlife Conservation Society and federal and state land and wildlife management agency partners, found that bears in the southern United States are more closely related genetically to endangered black bear populations in northern Mexico than to those in central Arizona and New Mexico. These data suggest that bears and other carnivores are likely dependent upon cross-border corridors to travel between the naturally, patchily distributed habitat in the region.

Corridors serve many species and purposes in the border region. Recent evidence suggests that jaguars and ocelots, for example, have begun to return northward from Central America and Mexico to reoccupy their former range in the United States. Other studies indicate that a number of species cross the border when times are tough (such as in drought years) and suitable habitat exists only on “the other side.”

The current debate about whether to continue or expand a border fence out of legitimate national security concerns, combined with changing land-use patterns that have led to increased road-building and urban sprawl in previously wild places, makes a conversation about how all of this will impact wildlife more important than ever.

The study showed that linkages across the border are essential in ensuring that bears and other species have access to habitat and resources, and to keep them from being genetically isolated from other subpopulations. Can we maintain such linkages in the context of a border fence without compromising immigration and national security goals?

The answer is yes, if we plan in advance. The border fence is not a homogeneous structure along its entirety, but is a collage of various fence types. For example, there is pedestrian fencing that generally is near dense human population zones and often represents a complete barrier for wildlife; and there is vehicle fencing, which is generally more permeable to wildlife movement.

There is opportunity for conservation scientists, Homeland Security representatives, land and wildlife management agencies and the engineering community to look at innovative ways to allow animals, but not humans, to cross border barriers. One solution may be a combination of permeable fences combined with intensive remote monitoring at crucial wildlife corridor crossings identified by field data.

The issue of habitat connectivity for wildlife at our borders is an important one and now is an ideal time to tackle this issue. What happens along the southern United States will likely set the precedent for similar fencing/border security activities that have recently been discussed for our northern border with Canada, where a variety of other important species that require large expanses of open land can be found.

Enforcing our immigration laws and protecting U.S. citizens is critical, but do we have to sacrifice wildlife and ecosystems to secure that protection? For years, the governments of Tanzania and Kenya have worked cooperatively to ensure the safe migration of millions of wildebeest and other species from the Serengeti across their shared border. Let us now work with Mexico and Canada to do the same.

Beckmann is a conservationist with the Wildlife Conservation Society’s North America program.


