By John Shackford
The Killdeer (Charadrius vociferous) is undoubtedly the best known of any shorebird in North America. The adults are told from other plovers by their two dark bands on the white breast, orange on the rump, and of course the loud cry (vociferous) of “kill-dee”. I like the way Bent (1962, Life histories of North American shore birds), some 55 year ago, began his discussion of this species: “It may be said of the killdeer that it is probably the most widely distributed and best known of all our shore birds…it is not confined to the borders of lakes and of the sea but is found in meadows, pastures, and dry uplands often many miles from water.” Unlike most other shorebirds, it does not have a strict timetable for its migratory pattern. As we know here in Oklahoma, some linger through the winter until their numbers are augmented by a swell of incoming birds in the spring.
Sutton (1967, Oklahoma Birds) gives the earliest date for nesting as 30 March 1957 when four eggs were found in a nest in Marshall County, south-central Oklahoma, so April is a good time to be on the lookout for Killdeer nests in our area. The latest date for nesting, according to Sutton, was 19 September 1918 when a brood was seen “running across a road in Texas County.” The species is double-brooded.
Killdeer nests are found in pastures, the gravel of dirt roadways, and even on buildings; thus they readily will nest in towns, something most other shorebirds will not do. In nesting, there is no effort made to conceal the nest in weeds, as there is in many shorebirds. The Killdeer nest is just a slight depression in open ground, sometimes with a few pebbles or other objects scattered outside the nest several inches. They are known to build several scrapes and then choose one of them for the nest.
Near the nest or with precocial young the Killdeer is famous for its “crippled bird” distraction display. It will drag a wing, spread its tail so the orange rump is flashy; thus the rump and wings are held in an unnatural position. During this “demonstration” they give their loud cries. The object, of course, is to lead the intruder away from nest or young. When the young are out of the nest, which occurs only an hour or two after hatching—as soon as the young’s down is dry—the adult can give a call where all young stop in their tracks and squat down. They are extremely hard to detect after they crouch, so effective is their camouflage—usually—against the background.
One of the fascinating things about Killdeer nesting is that they will nest on the high flat roof of a building that uses gravel as part of the roof waterproofing. Dr. Sutton discussed this fact in his book, Birds Worth Watching (1986). A number of such roof nests have been found and from these, after young are hatched, the young have been seen on the ground. But I do not believe that anyone has figured out exactly how the young get safely from the roof of the building to the ground: do the adults carry them down or do the young leap off the roof on their own and survive? One thing that, on first thought, seems to tilts the answer toward the adults carrying the young at least a little way has to do with the three-foot high “railings” that surround most such rooftops, from where the young could jump. Perhaps the adults only carry the young to the top of the railing. But when I asked my wife Melissa how she thought the young got to the ground, I think she had an interesting thought: at the bottom of the railings of the rooftops there would be some drains or holes for water, after a rainstorm, to escape and she thought the young birds might go through these openings, something no one has considered before, so far as I am aware. In this case the adults would not have to carry the young at all, the young would simply jump from those openings, and then survive the fall to the ground. So aspects of how the Killdeer young get to the ground from building roofs remains something of a mystery, at least for now!