The relentless wind on February nights sends skiffs of snow sliding across the rural landscape of Illinois. Average temperatures this time of year dip into the low 20s prior to dawn. For extra balance, a young wild turkey rests its breastbone on the branch of a northern red oak tree where it is spending this windy night perched high above hungry predators that lurk below.
This roosted turkey has not yet had its first birthday, but so far, it has defied the odds. It is still alive. Most research shows that nearly 80% of all turkey nests fail to hatch even one poult. And in successful hatches, only 25% of those birds survive their first 30 days. Right now, winter is the ultimate limiting factor in wildlife biological carrying capacity populations. But before we deal with winter, let’s consider the past nine-month journey this wary bird has already traveled.
In Illinois, the breeding season for wild turkeys is usually April, and hens begin laying eggs. The incubation process then begins, requiring another 28 days of survival from predators, floods, cold weather, and the eggs’ total dependence on the mother hen that spends these days in her drab camouflage colors, sitting constantly on a ground nest. Once hatched, a wild turkey must survive four more weeks without feathers before fledging and being able to fly up to the safety of a roost for the first time. That’s conservatively 50 to 55 days of survival from every hungry raccoon, opossum, snake, and coyote living in the area.
Now, back to February, and the bird is enduring the winter chill on that red oak branch. Wild turkeys are not picky eaters, but every type of food is in short supply as the dark winter drags on. No insects, worms, snails, or frogs are available – and all the easily found nuts, berries, mosses, and seeds have already been eaten.
Biological carrying capacity is defined as an equilibrium between the availability of habitat and the number of animals of a given species that habitat can support over time. If this roosted bird is a hen, it is quite valuable to the future population dynamics of this area. But if it’s a young male, a jake, it is not nearly as valuable. Why? One male turkey can breed with several hens, making the remaining male turkeys rather expendable for future populations. Thus, the male turkeys are legal game for human hunters in April, and harvesting hens in the spring is illegal.
Therefore, the wild turkey in our story today has already survived tremendous odds to get to this point in its life. Hens have a three-year life expectancy and toms have a four-year life – that is, if they get to their first birthday. Our bird has not yet made it through 365 days, and the ones directly ahead will be hard.
Seventy years ago, the wild turkey in Illinois was completely extirpated from our landscape, but now this noble bird of our history has been reestablished throughout the state and is managed quite successfully by the Illinois Department of Natural Resources. It is one of our state’s greatest accomplishments of wildlife conservation, and yet every bird “hangs in the balance” on its own perch on a cold February night.
ABOUT THE BLOG: Naturalist News is a blog by University of Illinois Extension Master Naturalist staff and volunteers who bring you stories highlighting the individuals, places, wildlife, and plants that make this state amazing. Join us each week to learn something new, be inspired and become connected to your own community by recognizing the amazing ways we are all intertwined. Want to get notified when new Naturalist News posts are available? Sign up here!
ABOUT THE AUTHOR: Curt Sinclair is a natural resources and shooting sports 4-H specialist.