The behavioral investigation of coyote depredation on sheep, and its implications for control techniques: A novel approach to a chronic problem.

Idaho NERP Links

Since the pioneer days, coyotes have been killed regularly throughout the western United States because of their depredations on domestic animals. Millions of coyotes in the western United States have been destroyed, yet the coyote problem still persists today. Studies have shown that not all coyotes kill sheep and social status is a key factor of those that do. This study will track the movements and hunting behavior of alpha (dominant), beta (younger adult offspring) and transient (searching for a mate or territory) animals so that more specific control methods may be employed.

Coyote research conducted previously has contributed significantly to our knowledge of the species. However, our understanding of information specific to the depredation of livestock is lacking. It is known that not all coyotes kill sheep and social status is a key factor of those that do. This fact is supported by several studies from Utah and California, showing alpha coyotes (the dominant breeding pair) to be almost exclusively responsible for killing sheep. Furthermore, evidence from a number of studies show that coyotes of alpha status are more difficult to capture within their home-ranges than either beta or transient coyotes, suggesting unique behavior.

A study conducted on the 890 square mile Idaho National Environmental Research Park (NERP) located on the Idaho National Engineering and Environmental Laboratory (INEEL) by Mike Ebinger, Utah State University PhD candidate and Dr. Mike Jaeger, USDA Wildlife Services, plans to continue in a logical progression by building from this key piece of information in two broad objectives:

Investigation of the spatial and behavioral differences of alpha animals from others (betas and transients) and the implications these differences have to the depredation of sheep.
Document the spatial-temporal pattern of coyotes when sheep are killed, including the events leading up to and continuing past the actual predation event. This crucial piece of information of how and when coyotes actually kill sheep has gone unanswered for decades. Until recently, technological restrictions were a justifiable excuse for this knowledge gap. However, the advent of Global Positioning System (GPS) radio-collars now allow for fine-scale spatial-temporal data (every 5 to 15 minutes) to be collected.

Clearly, these two broad objectives of the project have the potential to fundamentally change the body of knowledge surrounding both lethal and non-lethal control, as well as substantially contribute to the understanding of coyote behavioral ecology outside the context of management.


Loading the coyote nets before takeoff. Coyotes were captured with net-guns launched from a helicopter operated by Hawkins and Powers Aviation, Inc.		Unloading the coyotes after a successful flight. Coyotes were muzzled and hobbled for researchers' safety. Coyotes were captured in family groups and returned to the same location after collars were fitted..

Four coyotes were fitted with GPS collars. These collars record the animal’s positions at five-minute intervals from the time of capture until March 10th when the collar automatically drops off the animal and is retrieved by project scientists. Information is then downloaded from the GPS unit providing a detailed map of the animal's movements.		Each of the coyotes was fitted with a radio collar which emit unique frequencies so study animals are individually recognized and tracked during the duration of the study. Thirty coyotes were captured between January 28 - February 2, 2004.

Blood was drawn from each of the captured coyotes. Analysis of the blood will help determine general health of the coyote and DNA material recovered from the blood will show if the coyotes are related to others in the area.		The patterns of wear of a coyote's teeth is used to estimate the animal's age.

Numbered ear tags were placed in each of the coyote's ears for identification purposes - white for females, red for males.		Special thanks to Leif Isaacson of Desert Air Ag in Terreton for the use of his hangar for tagging and collaring coyotes.

Back