The Three-Minute Outdoorsman: Wild Science from Magnetic Deer to Mumbling Carp

16. Wolves, Coyotes, and Deer

t h e t h r e e - m i n u t e o u t d o o r s m a n 72 are survivors, which might explain why introductions have been so successful. 16 wolves, coyotes, and deer Perspective is a great help in identifying some animals in the wild. For example, if you see a canid (doglike animal), you wonder if it’s a coyote or a wolf. If there’s just one, it can be hard to judge size. Through the years I have heard of reports of lone wolves in my neck of the rural areas of the Twin Cities in midwinter, but my gut feeling is “not likely, but possible.” I think that one would most likely see several wolves, and if they’re around, there would likely be lots of reports. I realize there could be the lone “explorer.” But my guess is that these observers saw a coyote, which can be confusing to identify when alone, at least to those of us not used to making a quick identification of a lone individual (I always forget that the wolf has the tail held out, coyote down). But my attention was caught by a recent scientific article that might shed some light on this issue, one of interest to deer hunters as well. Coyotes are thought to have evolved as a prairie canid that catches primarily small prey. That coyotes in the northeastern United States are larger than coyotes elsewhere has been known for some time. We also know that northeastern coyotes eat a larger proportion of deer than those in the West and, not surprisingly then, do not avoid forested areas where deer hang out. The question is, why are coyotes in the Northeast so much larger than coyotes elsewhere? One possibility is that the environment in the Northeast favors increased size, so that if a western wolf were transplanted and grew up in New York, it would be big too. This is referred to as phenotypic plasticity. To further understand this, imagine you could clone a person and let one clone grow up in Minnesota and one in a third-world country. The clone in Minne- I N T H E W O O D S 73 sota would be bigger in spite of being genetically identical, simply because of better nutrition. Another possibility, which was investigated by Roland Kays (New York State Museum in Albany) and colleagues in an article in Biology Letters, is that the “coyotes” in the Northeast are actually wolf-coyote hybrids, and as result of having genes from the bigger wolves, the “coyotes” are larger than their western counterparts and more likely to prey on deer. They used some standard molecular techniques to determine that a large fraction of northeastern coyotes carry wolf genes. Furthermore, they noted that the skulls of northeastern coyotes are not just larger, they are proportionately larger; in other words, if you took a picture of a western wolf and blew it up 20 percent, the skull would also be 20 percent larger. But in northeastern coyotes, it’s like the skull is 30 percent larger when the rest of the body is only 20 percent larger (these are not exact numbers but for illustration). Kays speculated that the wolflike skulls of northeastern coyotes were “associated with strong bite forces and resistance to the mechanical stresses imposed by large, struggling prey.” Translation: holding on to notyet -dead deer. How did this happen? Reliable records show that western coyotes “invaded” the eastern forests starting in the early 1900s using forest openings created by agriculture. They took a twopronged approach: some went north around the Great Lakes, where they encountered “Great Lakes wolves,” and some took a southern route, through Ohio, where wolves had already been extirpated (driven out). Although coyotes and wolves are supposed to be separate species, meaning they don’t hybridize, many coyotes taking the northern route hybridized with Great Lakes wolves. Today, the pure wolves are gone, and in their place is a population that is a hybrid mixture of wolves and coyotes. So, wolves are gone, but they left behind a genetic legacy—a bigger coyote that eats more deer than its western ancestors. What about the “wolves” seen by my friends near the Twin Cities? Could they be large-bodied, coyote-wolf hybrids? More t h e t h r e e - m i...