Wiltz: Whitetail or mule deer? Or both?
In describing our West River deer hunt from November, I wrote about a large buck shot by a fellow hunter that appeared to be a mule deer-whitetail hybrid cross. While he possessed mule deer characteristics, including a black-tipped tail, his antlers were of classic whitetail configuration.
What really perked my interest was the fact that this buck was with a number of mule deer does, and the rut appeared to be in full swing. Might this breeding potential lead to hybrids of varying degree bloodlines? Might these crosses be sterile, like mules?
Reader interest and questions have prompted me to take a harder look at these hybrids. Other than searching the internet and asking South Dakota Department of Game, Fish, and Parks people for information, I contacted the University of Wisconsin School of Veterinary Medicine. Dr. Harry Momont replied that hybridization does occur as chromosome numbers are similar. He said the offspring are rare and that fawn survival is an issue. Andy Lindbloom of GF&P responded to my inquiry, and the internet offered a wealth of information, some with which I don't fully agree.
The internet data stated that the deer usually don't associate, and that overlapping range is uncommon. While I'll agree with the term "usually," over the years I've observed both species sharing habitat on numerous occasions. Concerning overlapping range, both sides of our Missouri River from the Nebraska border to North Dakota are overlapping range, and so are the Black Hills and all of our West River counties.
Relative to this discussion, on last month's Wyoming elk hunt, we traveled State Highway 120 from Cody to Meeteetse during the late afternoon. We observed hundreds of whitetails on the east side of the road, and hundreds of mule deer on the west side of the road. They were 100 percent segregated. In talking to our guide about it, he said it's always like that. There is some truth to the observation that they generally don't associate.
How far east have I seen mule deer? I once saw mule deer on our farm 4 miles east of Parkston and I've also seen mule deer along the county road that runs from Woonsocket to Mount Vernon.
The internet also stated that the ruts of whitetail and mule deer peak at different times, and that the mating rituals differ. I can't speak with authority about mating rituals, but I have witnessed the full-blown rutting activity of both species on the same hunting trip.
I want to talk about hybrid fawn mortality, a point mentioned by both Dr. Momont and the internet data. Supposedly the hybrid deer can't run properly. This would make the fawns vulnerable to predators. In the words of the internet data, "they run like they are inebriated." Why is this? Whitetails run in leaping bounds. Mule deer literally bounce with all four hooves hitting the ground at the same time. It's called "stotting." It makes sense to me that this would be a serious hybrid problem.
Whitetails and mule deer can differ in their coloration, metatarsal glands (outer hind legs), antlers, tails, ears, facial features, and preorbital glands (eyes). A cross will exhibit variations.
Lindbloom stated that the best way to identify a cross, other than genetic testing, is to examine the metatarsal glands. A mule deer's are brown and about 3 to 7 inches long. The whitetail's is about an inch long and surrounded by white hair.
What do I make of this? Hybrids can and do exist, and I've seen a few. My partner, Doug Koupal, nailed one a few years ago in Brule County. The deer was positively weird. I've come to the general conclusion that while we certainly have first-generation crosses, the offspring are most likely sterile, otherwise we would be overrun with hybrids of varying degrees, and our pure strains would be lost forever.
I've also suggested previously that my 2017 West River whitetail buck might have had some mule deer in him because his antlers lacked brow tines. While mule deer often lack brow tines, so can whitetails. I read too much into it. I was completely off base.