March 18, 2013
DENVER ZOO STUDIES BISON IN NEW MEXICO Zoo takes over Conservation Programs of Rio Mora National Wildlife Refuge
Denver Zoo conservation biologists are studying the effects bison have on their ecosystem in northern New Mexico. This is one of several projects the zoo is undertaking as it takes over management of the Rio Mora National Wildlife Refuge, near the small town of Watrous. The zoo's primary goals for Rio Mora are to pursue wildlife conservation and research, restore ecosystems and water flow, disseminate information to like minded individuals in the regions, and provide conservation education.
Staff primarily tests theories on a herd of about 50 bison, which roam most of the grounds in a low-stress environment. Research includes how their grazing influences the local plant and animal life differently from cattle, and how bison's replacement by cows on the Great Plains long ago may have disrupted other species' habitats. For instance, bison seem to graze far and wide and leave a more diverse set of habitats behind for other species than cattle, which typically will graze one area heavily and leave only medium height grass. This can exclude, or even remove, habitat for species that prefer really tall grass or no grass at all.
Early research also indicates bison are useful in restoring grassland from encroaching plant species like juniper trees and yucca bushes, which out-compete grass for moisture, by chewing, ripping and horning them. Previously it was believed that only fire could control those species' intrusion.
Denver Zoo took over management of the Rio Mora National Wildlife Refuge in November 2012. The 5,000 acre property, roughly 80 miles east of Santa Fe, was donated by philanthropist Gene Thaw to the U.S. Fish and Wildlife Service in September 2012 to protect it for conservation purposes. Thaw asked Denver Zoo conservation biologists to manage its programs as they had already been working the property for several years.
Conservation biologists also study a wide array of other wildlife and restore areas where cattle overgrazing contributed to erosion by creating rock walls and meander to creeks to slow water and encourage soil deposition. Staff also shows local ranchers their methods and research as a model.
