February 27, 2015
Bird Tracks
Good Natured reader Vanessa Quillinan spotted this birdy “snow angel” last year while snowshoeing at Corron Farm in Campton Township. Judging by the size of the wingspan, as well as other clues at the scene, Vanessa guessed that the print was made by a hawk.
Anyone who’s ever kept a birdfeeder in their yard knows that anything and everything can show up to take advantage of the free offerings. Large mammals, like deer; small mammals, like rodents. And pretty much every critter in between, because in addition to the seed itself there’s often the allure of a warm meal, in the form of small rodents foraging among the “crumbs” on the ground.
Then of course, there are the birds themselves.
Over the past few weeks, as we’ve Good-Naturedly reviewed the tracks and signs of several species of local wildlife, we’ve focused rather exclusively on class Mammalia—the warm-blooded, fur-bearing critters that trot through our yards, climb our trees, and take up residence under our sheds and decks. But birds, too, leave plenty of evidence of their presence, whether it’s seed hulls beneath a feeder (hard to distinguish different species’ marks there); splats on windshields, sidewalks and porch rails (still tough, but getting easier); excavations into hollow trees, and cedar siding (not hard at all); or, as this week’s photo shows, gorgeous wing prints in the snow.
Even though most tracking books focus on mammal tracks and sign, indications of bird activity are all around us. Next time you’re outdoors, keep an eye, or ear, out for:
Tracks: With more than 250 birds known to occur in Kane County, describing the tracks of each would be featherbrained, to say the least. However, there are a couple of neat things you can look for if you happen to see tracks of passerine, or perching, birds in the snow.
These birds leave what is referred to as the “classic” four-toed bird track: three toes that point forward and one that points backward. Many of these species, like blue jays, goldfinches and juncos, hop, and the prints they leave behind are side by side, in pairs.
Some passerines, however, skip instead of hop. These species, which include snow buntings and white-breasted nuthatches, place one foot down, then put the other down slightly ahead of the first.
You have to be pretty dedicated to follow these small tracks and distinguish between the two gaits. But if you do, you’ll gain a sense of satisfaction in knowing the difference. And you also be another step closer to becoming a full-fledged nature nerd. (If you do reach this echelon of eco-geekdom and want to learn more—lots more—an excellent reference is Bird Tracks & Sign, A Guide to North American Species by Mark Elbroch and Eleanor Marks. At 456 pages it’s extremely comprehensive; it’s also the only book I know of that has tackled this topic.)
Songs and calls: Although spring has not yet sprung, some birds are already declaring their territories through song. The other day while I was shoveling I heard the clear, two-note whistle of the black-capped chickadee (“Spring’s here!” supposedly are the words you can apply to this song—ha!).
Farther south, migration already is underway. It won’t be too much longer before we hear the sweet sounds of our familiar summer species like the song sparrow and American robin. (If you are seeing robins now, chances are they are in flocks that have opted to overwinter in our area. You may their calls, which consist of “cucks” and “yeeps” but you’ll have to wait a little longer to hear the melodious “Cheery-up, cheerio” song that signals that mating has begun.)
Then again, we also have one year-round species that has been whooping it up—actually, hooting it up—for weeks. Great-horned owls are in the midst of raising their broods, and their territorial hoots are common night sounds in many area neighborhoods. If you listen closely, you can hear the difference between the male’s low-pitched tones and the female’s higher ones.
One last bird call to pay attention to is the persistent caw-caw-caw of the American crow, as well as the jeers of a group of blue jays. These birds regularly conduct their own neighborhood watch programs and alert others to potential threats. If you track down a group of calling crows or jays, you might be rewarded with the sight of a roosting hawk or owl.
Whitewash and pellets: Speaking of owls, the trees they frequent often are bedecked with a glaze of white. Looking somewhat like white candle wax and fancifully known as whitewash, these markings are the chalky, uric acid components of the bird’s waste. If you find a tree—often a conifer—with whitewash, be sure and scan the ground underneath it for pellets. These oval-shaped blocks contain the fir, bones, claws and other undigestible bits of the owl’s last meal.
(Fun fact: Although owls are the most famous pellet producers, many other bird species, including eagles, hawks, crows and gulls, eject inedible matter in this way too. Because these birds consume diets vastly different from one another, their pellet sizes and contents will vary widely too.)
Nests: I’m always surprised by the number of people who think that birds sleep in their nests year round. Nests as we tend to think of them—round structures made of plant material and sometimes mud—are used by birds only for raising young in spring and summer.
Winter though is a great time to survey the empty nests in your neighborhood to see who your warm-weather residents might be. Each species makes a specific sort of nest, sometimes even using species-specific materials and/or locations. The Peterson Field Guide series includes a volume on bird nests; check it out if you’d like to learn more about these amazing—and easy to find—bird signs.
(Don’t be surprised if you find a winter bird nest occupied by a mouse. These adaptable creatures often build “roofs” over bird nests of species like goldfinches, which tend to build lower to the ground and well within a mouse’s range.)
Piles of feathers: This sign is actually an indication of two bird species—the feathers can help you figure out the prey species, and the pile itself will tell you that either a Cooper’s hawk (certainly the more common species in our area) or sharp-shinned hawk nabbed a meal and plucked it clean before consuming it.
Wing prints: When snow conditions are just right—fluffy or wet, but not crusty—and you’re in the right sort of area—open space, in or near woods–you can sometimes be lucky enough to find the stunning imprints of bird wings. Larger birds can leave these upon takeoff, and raptors often make them when swooping down on prey. If there are other clues like tracks and scat, maybe even telltale fur at the scene, you can tell an entire story of winter survival of the fittest.
Pam Erickson Otto is the manager of nature programs and interpretive services at the Hickory Knolls Discovery Center, a facility of the St. Charles Park District. She can be reached at 630-513-4346 or potto@stcparks.org.