Potential spread of cheatgrass (Bromus tectorum) by feral horses (Equus ferus caballus) in Western Colorado

Rangeland Ecology and Management
By: , and 



The invasive grass cheatgrass (Bromus tectorum L.) presents major challenges for land management and habitat conservation in the western United States. Feral horses (Equus ferus caballus) have become overabundant in some areas of the West and can impact fragile semiarid ecosystems. Amid ongoing efforts to control cheatgrass in the Great Basin, we conducted a study to determine if feral horses contribute to the spread of cheatgrass through distribution via their feces. We collected feral horse fecal samples from Little Book Cliffs Herd Management Area in western Colorado in 2014. Fecal samples were dried, and 20 from each of 3 collection sessions were cultivated to examine germination success. Six species germinated from 18 samples (30%; mostly one plant per sample where germination occurred), including cheatgrass from 8% of samples. In a separate study we examined the diet of this same horse population using fecal plant DNA barcoding. Plant species that germinated were rare in the diet and germinated from fewer samples than expected relative to their detection in the diet. Our results suggest that feral horses could be contributing to cheatgrass propagation. Native ungulates and domestic cattle also have this potential. Although management of all large ungulates is necessary to mitigate cheatgrass spread, control of feral horse numbers is particularly necessary.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Potential spread of cheatgrass (Bromus tectorum) by feral horses (Equus ferus caballus) in Western Colorado
Series title Rangeland Ecology and Management
DOI 10.1016/j.rama.2019.02.006
Volume 72
Issue 4
Year Published 2019
Language English
Publisher Elsevier
Contributing office(s) Fort Collins Science Center
Description 5 p.
First page 706
Last page 710
Country United States
State Colorado
City Grand Rapids
Other Geospatial Little Book Cliffs Herd Management Aarea
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