A little girl and her mother are strolling on a quiet trail in Skokie Lagoons when out of nowhere a sizable injured bird appears just ahead on the path. Tugging at her mother’s sleeve, the child urges her mother to do something to come to the rescue. The hobbling bird is calling piteously and trying to fly. It stumbles, it staggers; it looks desperate. Finding it impossible to get closer, the distressed mother’s anxiety peaks when suddenly, miraculously, the bird recovers and flies away! The pair have been taken in by a Killdeer’s “broken-wing act.” This convincing performance tempts possible predators away from the eggs in its very exposed nest on the ground or from its young. Other animals perform variations of this “distraction” act, but for mimicking sheer panic, the Killdeer might win the Oscar.
The Killdeer, Charadrius vociferous, is a medium-sized plover. Plovers are shorebirds with short, straight bills and somewhat rounded bodies and heads. The Killdeer is a shorebird that can be seen without visiting the shore. While often found near water, Killdeer are attracted to human-made habitats such as farm fields, golf courses, sports fields and corporate campuses that have close-cropped grasses, mudflats, dirt or gravel parking lots, driveways, and even flat gravel roofs. For water, a sprinkler will suffice. Their scientific name vociferous aptly reflects earlier common names Chattering Plover and Noisy Plover. The loud and far-carrying “Kill-dee! call, is mostly made in flight, hence today’s common name.
This handsome bird can be easily recognized by its coloration, long legs and gait. As they search for food they run, stop, bob, look around to see what insects (many considered agricultural pests) they have startled up, then run again. The two black breast bands, brown back, white breast and forehead, and brown cap distinguish it from other striped plovers, which have a single breast stripe. Their tails are long and their long pointed wings make for fast flight and easy maneuverability. Male and female look alike; the young hatch with only a single band.
The species is widespread in the Americas, breeding from southeastern Alaska east to Newfoundland down to parts of Central and South America. In the Chicago area, Killdeer are migrants, typically arriving by February or March and leaving by the end of October, although a few may linger into later in the year, staying as long as there is open water. They migrate during day or night, generally traveling in flocks, resting up and feeding on mudflats. They often mix with other shorebirds, and may be the sentinels alerting the group to danger. They are opportunistic feeders, searching on mud or in the shallows for seeds, earthworms, insect larvae, snails, grasshoppers, even small invertebrates such as frogs. They are excellent swimmers.
Killdeer are monogamous and sometimes a migrating pair will be found together on their wintering grounds. It is not uncommon for the pair to return to their same breeding location for several years. Nest building, or more accurately nest scraping, involves a Scrape Ceremony, surprisingly complex considering that the nest is only a shallow depression and doesn’t involve importing materials. The pair may make several “dummy” scrapes before laying eggs. Usually, the male initiates the first scrape, lowering his breast, touching the ground, and using his feet to form a slight depression. The female then lowers her head, approaches the spot, ducks underneath him, and takes over. The male, after tossing some material over his shoulder, stands aside and trills. Then the male approaches the scrape, replaces the female, and begins to scrape. And so it goes, repeatedly, male and female taking turns in what may become a lengthy sequence.
Typically, the female lays four cryptically colored eggs. Incubation lasts for 25 days on average, and the chicks are precocial at hatching. That is, they hatch with eyes open, their bodies covered with fluffy down. Once they are dry after a few hours, they are ready to move off the nest and start pecking for food. (Altricial chicks are helpless, blind and naked at hatching.) A precocial chick will stay in the highly nourishing egg about two weeks longer than an altricial chick. A killdeer egg is about twice as big as a robin egg. Both male and female forage with the young chicks until they can fly when they are just about over a month old.
Sometimes the nests are placed on gravel rooftops, typically on low buildings. This choice causes obvious challenges, especially when there are rooftop parapets that serve as barriers, because the chicks have to be lured by a parent to drop to the ground. One observer watched a successful jump from a seven story building. In another instance, chicks found a rain gutter and slid to the ground in the downspout. However, rooftop nests, with all their issues, may be as good a strategy as ground nesting. One observer of several nests on the grounds of Cranbrook Estate in Bloomfield Hills, Michigan found that “boys on bicycles rode through the nests, crushing the eggs; football players walked on two nests. … Small children took the eggs from one nest, and the remaining nests were also robbed, probably by stray dogs.” Other than accidental humans, opossum, raccoons, snakes, and foxes are ground predators. Birds such as hawks are threats on roof or ground.
In the past, Killdeer were victims of hunting for sport, feathers and food, although whether they made a good meal was a matter of argument and taste. Today, protected by the Migratory Bird Treaty Act of 1918, they are victims of modern environmental problems such as cars, eating insects that have ingested poison, and flying into towers. Beset by human hazards and despite their losses from predators, the population of Killdeer has remained steady over most of the Americas. They can often be seen at the small beach just south of Northwestern University’s lagoon.