Perhaps their mothers have become more adept at hiding them – or maybe a warm winter and early spring staggered their arrival.
Evidence continues to mount, however, that the coyote, whose numbers have mushroomed in the past decade, is the primary culprit.
Just last week, at Yuchi Wildlife Management Area in Burke County, a friend noticed something odd protruding from a dried lump of coyote scat.
At first glance, the enameled, triangular objects – smaller than a fingernail – looked like shark’s teeth from a windswept beach.
Instead, they turned out to be a pair of tiny hooves from a newborn fawn – the coyote’s favorite early summer food.
From some perspectives, the spread of the resilient and reviled Canis latrans might help control overpopulations of deer. Many areas, however, might see depleted whitetail numbers.
U.S. Forest Service research biologist John Kilgo has been studying coyote-fawn predation at Savannah River Site since 2006, with sobering conclusions.
Using radio collars, DNA and other modern tools, his team concluded – in studies from 2006 to 2009 – that coyotes are killing at least 37 percent of newborn fawns, and most likely as many as 80 percent, based on the ones studied at SRS.
In a peer-reviewed article scheduled for publication in August in the Journal of Wildlife Management, Kilgo and co-authors including S.C. Department of Natural Resources deer and turkey project leader Charles Ruth share the latest observations about the coyote’s future impact on whitetails in the Southeast.
The bottom line, they say, is that if coyote predation on fawns is as high as studies say it is, the current hunter harvest levels appear unsustainable. Thus, wildlife agencies might have to amend seasons or bag limits to compensate for the number of deer killed as fawns.
“The effects of coyote predation on recruitment should be considered when setting harvest goals, regardless of whether local deer population size is currently above or below desired levels, because coyotes can substantially reduce fawn recruitment,” the article said.
At Savannah River Site, coyotes have succeeded in affecting deer populations that were immune from change by other factors.
“During the pre-coyote period, predation by bobcats, disease, malnutrition, and doubtless many other mortality factors operated in the SRS population without excessively depressing recruitment,” the authors said. “Our data demonstrate that coyote predation on neonates can be substantial in the Southeast.”
Excessively high deer populations could be reduced rapidly by coyote predation, the article said. “Conversely, in populations below desired levels, harvest reductions, particularly among females, may be necessary to offset losses to predation.”
At SRS, for example, female deer harvest averaged 636 deer per year from 1990–2004, the period of the coyote’s population establishment and growth.
“During 2005–2008, harvest was intentionally reduced to an average of 161 females per year. This 75 percent reduction in annual harvest, apparently necessary to offset the 77 percent mortality we observed among neonates, halted the decline and resulted in a more stable population trend. Such adjustments in deer harvest management may be necessary in many areas across the region.”
What’s next in the quest to better define the relationship between coyotes and our whitetails?
Kilgo and his fellow scientists is nearing the end of another three-year study focusing – from 2010 to 2012 – on how the removal of coyotes from a particular area alters fawn survival. The data from those studies is expected to be available in the next year or so.