Bison restoration results in increased bird diversity and higher use by deer in prairie riparian areas

Smithsonian Conservation Research Brief:
Bison Restoration results in increased bird diversity and higher use by deer in prairie riparian areas

Temperate grasslands and the species that depend on them are in serious trouble. Bison reintroduction is one way land managers are attempting to restore the ecological health of the Great Plains ecosystem. In a study published today in Frontiers in Ecology and Evolution, Smithsonian ecologists found bison reintroduction has strong positive effects on biodiversity in wetland, or riparian, habitats within temperate grasslands. Together with previous Smithsonian research, this study underscores bison are ideal grazers for restoring bird diversity and ecosystem health in grassland systems.   

Research Paper
Title: “Bison Reintroduction to Mixed-Grass Prairie Is Associated With Increases in Bird Diversity and Cervid Occupancy in Riparian Areas”
Published: Frontiers in Ecology and Evolution
For citations: https://doi.org/10.3389/fevo.2022.821822
Abstract:
In grassland ecosystems, grazing by large herbivores is a highly influential process
that affects biodiversity by modifying the vegetative environment through selective
consumption. Here, we test whether restoration of bison is associated with increased
bird diversity and cervid occupancy in networks of riparian habitat within a temperate
grassland ecosystem, mixed-grass prairie in northcentral Montana, United States.
We used a long time-series of remote sensing imagery to examine changes in
riparian vegetation structure in stream networks within bison and cattle pastures. We
then assessed how vegetation structure influenced diversity of bird communities and
detection rates of mammals in these same riparian networks. We found that percent
cover of woody vegetation, and native grasses and forbs increased more rapidly over
time in bison pastures, and that these changes in vegetation structure were associated
with increased bird diversity and cervid occupancy. In conclusion, bison reintroduction
appears to function as a passive riparian restoration strategy with positive diversity
outcomes for birds and mammals.

Quote from Andy Boyce, lead author and conservation ecologist, Smithsonian’s National Zoo and Conservation Biology Institute’s Migratory Bird Center:  

“We’ve known for some time that bison don’t spend as much time in wetland areas as cattle do, but what we didn’t understand was how this difference was going to influence biodiversity. When we looked at areas where bison were reintroduced, and compared them to similar areas with cattle, we found that the  vegetation along small streams changed in ways that are associated with more diverse bird communities and increased use of these areas by native ungulates like white-tailed deer. Bison reintroduction is resulting in healthier more biodiverse riparian environments, which is great news for tons of other prairie species.”

Authors
Andy J. Boyce (1), Hila Shamon (1), William J. McShea (1)

(1) Smithsonian Conservation Biology Institute

About the Smithsonian’s National Zoo and Conservation Biology Institute  
The Smithsonian’s National Zoo and Conservation Biology Institute (SNZCBI) leads the Smithsonian’s global effort to save species, better understand ecosystems and train future generations of conservationists. Its two campuses are home to more than 2,000 animals, including some of the world’s most critically endangered species. Always free of charge, the Zoo’s 163-acre park in the heart of Washington, D.C. features animals representing 360 species and is a popular destination for children and families. At the Conservation Biology Institute’s 3,200-acre campus in Virginia, breeding and veterinary research on   species providing critical data for the management of animals in human care and valuable insights for conservation of wild populations. SNZCBI’s staff and scientists work in D.C., Virginia and with partners at field sites across the United States and in more than 30 countries to save species and conserve native habitat. SNZCBI is a long-standing accredited member of the Association of Zoos & Aquariums.