Earlier this year the El Paso Zoo (zoo) piloted a Zoo-Park partnership with Big Bend National Park to coordinate efforts to conserve black bear habitat along the Rio Grande. 

Zoo staff members traveled to the park in March as part of a team of 17 park rangers and volunteers tasked with reducing invasive Athel Tamarisk.  Tamarix aphylla, native to Eurasia and Africa, has been in the United States for almost 200 years. Big Bend National Park (BIBE) has been managing T. aphylla since the 1990s. Previous work areas include Gravel Pit and Hot Springs areas of the park.

Why is T. aphylla a problem, and why is treatment necessary?

With populations of the tree growing rapidly, they are beginning to outcompete for resources with important native plant species. The riparian zone of the Rio Grande provides crucial habitat for wildlife and many animals, such as black bears  and mountain lions frequently move through the riparian zone to travel between the United States and Mexico   The yellow-billed cuckoo, a threatened species in the park, is impacted by these invasive trees as well, as it relies on native forest structure for its habitat. With the amount of massive stands of invasive T. aphylla increasing and native plant populations decreasing, the quality of habitat provided by the riparian zone is becoming threatened. These issues sparked the decision to begin management efforts on the tree.

From March 4 – 9 2019, 17 people, including Big Bend National Park employees, volunteers and interns, two members of the Diablos Fire Fighting Crew, and four employees from El Paso Zoo, worked from mile 802 to mile 790 on the Rio Grande (fig. 6).  The team cut over 500 trees and treated 15 acres of riparian habitat. 

Funding was made possible for this partnership when the El Paso Zoo and Big Bend National Park were awarded the $10,000 Winter 2018 America’s Keystone Wildlife Grant (AKW). The grant partners zoos with National Parks and National Wildlife Refuges to help America recover the wildlife legacy lost during the fur trade and westward expansion era of the United States.

The El Paso Zoo is among a small inaugural group of accredited zoos selected that meet certain criteria, including AKW Field Conservation, AKW Citizen Stewardship, Community Engagement, and Sustainability. The zoo successfully worked with Big Bend National Park to create the Black Bear Habitat Improvement in Big Bend National Park Project to apply for the grant.