Recent studies have highlighted the importance of coyote predation on deer fawns, especially in the Southeast. Despite their relatively recent establishment in the Southeast, coyotes have accounted for more than 37% of fawn deaths in multiple studies. Also, coyotes kill adult deer, although their influence on adult deer survival has not been well-documented in the Southeast.
Fawn mortality caused by coyotes adds to other sources of mortality and can cause deer populations to decline. The abundance of coyotes directly influences the number of deer in an area. However, coyote control programs are challenging, cost prohibitive across broad areas, and their success can vary. When coyotes are removed by trapping, hunting, or other causes of death, they are quickly replaced by transient coyotes and coyotes from adjacent areas. Changes in fawn recruitment in response to coyote removal has ranged from undetectable to an estimated 200% increase depending on site and year.
Often, managers can adjust deer harvest by taking fewer does to offset coyote predation. Deer populations are usually managed in units set by state agencies where similar habitats and hunting pressure influence deer populations similarly across the area. Knowledge of coyote populations within these deer management units is essential to make deer management recommendations intended to compensate for reduced fawn survival caused by coyotes.
DNA testing can be used to identify individual animals. Doctoral student Jordan Youngmann is using a technique called fecal genotyping to identify coyotes across South Carolina. Because coyotes tend to defecate on roads and trails, we can collect their feces fairly efficiently by driving roads through coyote habitats. In the laboratory, Jordan extracts the DNA from fecal samples to determine which individual made the scat.
Combining the DNA results with mapping and statistical methods known as spatially explicit capture-recapture models, we can estimate the number of coyotes in an area. Also, by determining the number of coyotes across the landscape using these techniques, we can identify what habitats hold more coyotes.
This project is funded by South Carolina Department of Natural Resources and is being conducted jointly with the U.S. Forest Service Southern Research Station and the Savannah River Ecology Laboratory.
The primary objectives are:
1) Estimate coyote densities across regions in South Carolina
2) Evaluate coyote densities relative to habitats
3) Examine population genetic structure of coyotes across the state. In other words, how do populations of coyotes interact and interbreed.
Although not native to the Southeast, coyotes have become common throughout the region. They now fill the role once occupied by the red wolf. Because they feed on a variety of animals and plants, including deer, their arrival has affected deer population management on some properties. It is important that we learn how to better estimate their abundance and effect on deer populations.
To many observers, this is just a pile of coyote poop. However, to wildlife researchers like Jordan Youngmann, this is a biological journal, which communicates diet selection, genetic identification and population size.