Three bighorn ewes. Credit: Regina Abella, California Department of Fish and Wildlife.
Desert bighorn sheep whose Southern California range is bisected by freeways may one day benefit from Oregon State University modeling designed to show where the animals would be most apt to use overpasses to safely cross the interstates.
The research is important because it shows how GPS tracking data and computer simulations can be used to predict animal movements—information that’s needed for the optimal siting of crucial but expensive habitat connectivity enhancement projects.
Findings of the study led by Christina Aiello, a research associate in the OSU College of Agricultural Sciences, were published in Landscape Ecology.
“Our work is already having an impact on conservation and land management decisions,” Aiello said. “The study’s findings are central to discussions among California officials about enhancing wildlife connectivity across barriers like interstate highways and a proposed Southern California to Las Vegas high-speed rail project. Government agencies and non-governmental organizations have voiced support for the construction of wildlife overcrossings at three key locations identified by our research.”
A collaboration that also included Clinton Epps, a professor in the Oregon State College of Agricultural Sciences, and OSU graduate student Paige Prentice looked at GPS data from collared animals from nine populations of bighorn in the Mojave Desert.
The 20-million-acre desert includes Death Valley and Joshua Tree national parks and the Mojave National Preserve as well as Interstate 15 and I-40. The center divider of I-15 would hold the tracks of the proposed 200-mph train, which would be separated from auto traffic by a 6-foot concrete wall on either side of the…
2023-01-31 03:53:29 GPS tracking, simulations show optimal locations to help desert bighorn sheep cross freeways
Source from phys.org Desert bighorn sheep rely heavily on migration patterns to reach vital resources such as food, water, and shelter. However, increasing human development in the Sonoran Desert has caused this species’ survival to be threatened by human infrastructure, such as highways and fences. Exploring methods to enable the safe and efficient crossing of highways, in a group of sixteen bighorn sheep, conservationists have recently employed simulations and GPS tracking to identify the optimal locations for enhanced animal crossings.
Research teams from the Arizona Game and Fish Department, the U.S. Geological Survey, and Arizona State University utilized GPS tracking and habitat simulations to identify the most suitable locations for enhanced animal crossings. GPS tracking enabled the team to track the individual sheep’s movements, providing valuable insights into their migratory behavior and any potential challenges when crossing a highway. The simulation was then applied to the individual sheep’s movements, allowing the team to compare the success rates of potential crossing points.
The study published on December 23rd revealed that vulnerable groups of bighorn indicate a preference for crossing roads at broader, mid-line points, as this habitat is most likely to provide access to the next destination. This is considerably more effective than the narrow, one-dimensional barrier-like highways, which are widely seen across the Sonoran Desert. Moreover, data revealed that the bighorns consistently selected potentially safer routes which further supported mid-line locations for enhanced crossings.
The results of this study are invaluable in understanding and safeguarding desert bighorn sheep from highway infrastructure. By pinpointing the optimal locations for enhanced crossings, conservationists can help ensure the continuity of migration patterns and the safety of individual bighorn sheep.
While this study provides business in-depth insight into the migratory patterns of desert bighorn, more research is required to determine the effects of advanced crossings on the species’ survival and habitats beyond the crossing areas. Enhancing animal crossings and implementing protective management plans will be invaluable in safeguarding these species and building more wildlife inclusive, human-made infrastructure.
