The Wildside: The case of the bird-eating Turkey?
When I worked in central Kansas, biologists puzzled over the mystery of declining numbers of bobwhite quail. Local hunters thought they had the answer-turkeys were eating the quail.
When I worked in southwest Minnesota, turkeys were accused of eating pheasant chicks. Here in Wisconsin, I have had people report that turkeys eat ruffed grouse chicks. Are turkeys rampaging across the countryside, gobbling up any other game birds in their path? Or could there be another explanation?
The first time I looked into the question of turkeys eating poults of other bird species was many years ago, when my uncle asked if turkeys really eat grouse. The study I found online, which was emerging technology at the end of the last century, was very well done. It explained that grouse and turkeys really don’t extensively share habitats.
Grouse prefer early succession habitat, like aspen and alder forests. Turkeys occupy forests with more hardwood species, favoring oaks. I like this explanation, because it uses habitat to explain a change in wildlife use.
An aspen forest attracts and holds grouse, but may not be ideal habitat for turkeys. As aspen forests age, and are not rejuvenated by cutting, they slowly fall apart. Hardwood species invade, possibly maples, basswood and oak. As these species mature, they produce the kind of food and habitat that attracts turkeys, but may not hold as many grouse as the aspen used to years before. The turkeys haven’t eaten the grouse, they have simply followed the habitat; the grouse have moved on to other areas that provide the food and cover they prefer.
This does not completely answer the riddle, however. It is one consideration.
Let’s look at the biology of the birds as well. Turkeys are large birds, and they have a fair amount of variety in their diet. However, probably 90 percent of their diet is plant matter (seeds, fruits, nuts, grass, clover, even aspen buds) and only 10 percent is animal protein (like insects and animals). If they were foraging in the grass and a really small chick ran in front, a turkey might snap at it. However, there is no evidence that turkeys intentionally target chicks or poults. Their beaks are not designed to eat birds or eggs. They don’t have meat-tearing beaks like hawks, eagles, or vultures. They don’t have sharp, chiseled beaks like jays, crows, or ravens. Yet it is not too difficult to find someone who heard a story about a turkey ransacking a grouse nest.
Recently I was walking a private forest with Ruffed Grouse Society biologist Gary Zimmer; we were talking about this very topic. He pointed out that several studies have used motion sensing game cameras set up on bird nests to detect predators. Nest robbers are usually animals like raccoons, skunks, foxes and other small furbearers. Crows and jays probably raid nests as well. I have even seen a couple of studies that showed deer eating eggs and chicks. Turkeys were not detected in the studies that Gary mentioned.
Gary presented an explanation that makes a lot of sense. If a hen grouse successfully hatches her brood, she leads them away from the nest. All that remains is an empty nest with empty egg shells. Birds seek the calcium in egg shells, and will gladly come to the nest to eat these shells-including turkeys. It is possible that these people saw a turkey cleaning up a nest after the hatching is complete, and in fact the birds are safe a good distance away.
Turkeys could possibly eat a young bird or two, but it is likely that they are innocent of the charges that they consume pheasant, quail and grouse chicks. They may just be moving into habitat that has changed enough to suit them. The next question I will address about turkeys-would anyone release rattlesnakes to control their numbers? Hint: the answer is definitely not.
Jeremy Holtz is a wildlife biologist with the Wisconsin DNR and writes a weekly column in the Star Journal. To contact him, call 715-365-8999.