Blane Klemek: The fascinating aspects of the feet of birds
Like the beaks of birds, the feet of birds can tell you a lot about how a particular species lives its life. Some feet are for swimming, some feet are for clutching and gasping, some feet are for running, and some feet are hardly used at all. Feet can also aid in the identification or the grouping of certain species of birds. Feet, while essential tools for birds, are interesting avian features we can study and learn about.
I remember when I was a little boy too young to go with my Dad on duck hunting trips, when he would bring ducks home after a day in the marsh hunting with friends and relatives. It was the first time in my life that I held a duck in my hands and could examine closely their anatomy. I recall being especially fascinated by their feet as I spread their toes apart and marveled about how the webbing attached to each toe and folded neatly when the toes were drawn together. It was then that I understood how a duck propelled itself across the surface of the water.
Hawks, owls, eagles and falcons, for example, all share several things in common with one another. Not only do birds in these groups prey on other animals, they must first and foremost be able to capture their prey. Special feet enable them to capture and subdue their prey quickly.
Armed with large and powerful feet with toes tipped with long and sharp talons, the weaponry is vital for a raptors’ survival. In the case of owls, once prey is caught and talons dug in, the bird has great difficulty even releasing its grip.
Most birds have four toes, but some have only three. For instance, the ostrich — that large, flightless land bird — has only two toes. Along with long and powerful legs, ostriches are capable of running extremely fast.
Great blue herons, a species of bird often referred to as wading birds, have four toes — three of which are very long. This enables herons and other like species to negotiate soft surfaces often encountered in aquatic environments that these birds typically encounter. Like the wooden snowshoes that we sometimes strap to our own feet, long toes help distribute the heron’s weight over large surface areas.
The northern jacana, a rare shorebird distributed along the Gulf Coast of Texas, Louisiana and Mexico, has perhaps the longest toes in proportion to its body of any living bird. The incredibly long toes and oversized feet are perfectly designed for the habitat this bird enjoys. As though walking on air, jacanas stride effortlessly across floating aquatic vegetation in search for food or to escape predators.
As do most birds, waterfowl such as loons, grebes, ducks, and geese have four toes too. Yet, as already mentioned, another adaptation common amongst these species involves webbing between the three larger toes. The webs of skin that stretches between each of the three long toes helps propel the birds through their watery world. Some species like loons and diving ducks use their webbed feet to not only swim on the surface of the water, but to swim below the surface as well.
Many other birds have webbed feet too. Gulls, terns, penguins, and puffins all have webbed feet. Coots and phalaropes, on the other hand, do not and instead have lobed toes. Just the same, the lobes serve to aid in swimming.
Birds such as ruffed grouse and ptarmigan have special snowshoe-like adaptations of their feet. Ruffed grouse have tiny projections along the toes that enable these birds to easily walk on soft snows and to grip ice-covered branches when feeding or roosting.
Ptarmigans have similar adaptations along with having heavily feathered feet that further aids in walking on snow.
Woodpeckers, creepers, and nuthatches are birds with interesting feet specialized for their particular needs and habits. Most woodpeckers have four toes of similar length and are arranged two in the front and two in the back. The toes of woodpeckers are also tipped with long and sharply curved claws that enable these climbing birds to cascade up and down tree trunks and branches with ease as they search for food and excavate cavities. Nuthatches, which have the habit of negotiating down tree trunks headfirst, have a large claw on the hind toe that essentially keeps them securely attached to the tree.
Even the smallness of feet can suggest a bird’s lifestyle. Swifts are masters of the sky and spend the bulk of their lives flying and capturing insects in mid-air. Having large feet is unnecessary for these birds. Their Latin family name says as much: Apodidae, with “A”, meaning not or without, and “pod” meaning foot.
Almost half of North America’s birds belong to the large order Passeriformes, otherwise known as “perching birds.” These birds include flycatchers, jays and crows, wrens, warblers, blackbirds and sparrows, to name just some. All passerines have feet that are perfectly adapted for perching on thin branches, herbaceous plants, and wires.
Perching birds have three toes in the front and one long toe in the back giving them the ability to grip their perches tightly.
Observing birds can involve a lot more than just recognizing plumage variation, body shape, and behaviors. Seasoned birders will take note of all the physical characteristics in helping them identify birds. Indeed, knowing what makes a particular species of bird different or similar to other species of birds is what it’s all about as we get out and enjoy the great outdoors.
BLANE KLEMEK is a Minnesota DNR wildlife manager. He can be reached at bklemek@ yahoo.com.