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Sunday, August 7, 2011

The Killdeer


Run, stop, hesitate...head bob. Run, stop, hesitate...head bob. 
The killdeer travels at its own peculiar pace. 
 



Although the killdeer is technically a shorebird it can be found far from the ocean in fields, parks, parking lots and pastures and on lawns and golf courses. It forages in such places for grasshoppers, snails, beetles, ants, flies, insect larvae, and worms.

Killdeer breed in summer across the United States and Canada. Northern populations migrate south for the cold months. They can be found in the southern states all year. Their winter range includes Central America and northern South America.

Killdeer (the plural can be killdeer or killdeers) get their common name from their loud piercing cries of kill-deer! kill-deer! Their calls are so loud that they have also been called the chattering plovers and noisy plovers.

Males and females look alike and their plumage is essentially the same year round. They are eight to 11 inches long, grayish brown above, and white below. They have reddish feathers on the rump and two black bands on the chest. The tail ends in a white-tipped black band. They have a white stripe above the eyes and a white bar on the face above the beak. Their bold plumage acts as disruptive camouflage, breaking up the body outline and making the bird surprisingly hard to see when it stands still.

Killdeer make nests on open ground with a view all around and usually near water. They are minimalists. Their nests are just little scrapes in the ground that may be lined with pebbles, grass, wood chips, or debris. A scientific study showed that killdeer prefer light colored nesting material; when scientists removed material from killdeer nests and placed white and black sticks nearby as possible replacement material, the birds overwhelmingly selected white sticks. Killdeer usually make nests on light colored backgrounds like oyster shell piles, pale roof gravel, and even the crushed-limestone boundary lines of sports fields. Building on reflective white substrates may help keep their nests cool, which is a problem for them as they nest in the open without shade from the sun.

The eggs are tan with splotches of brown or black and they can be surprisingly hard to see even though they are in plain sight. One naturalist described finding perfectly camouflaged eggs against a background of trash and broken glass on a rubbish pile. Eggs in nests on sandy gravel and on the tarpaper and stone roof of a racetrack grandstand were equally well concealed.

But nesting in the open is still risky. Killdeer have an active strategy when camouflage fails; they pretend to be injured to draw invaders away. The bird crouches with wings drooping and drags its fanned tail on the ground. It appears to have a broken wing. It cries in apparent distress. It may flap its wings against the ground. Facing away from the intruder, the bird looks over its shoulder while walking away. When the strategy works, the intruder follows in pursuit of what appears to be an easy victim. At a distance from the nest, the killdeer drops its pretense and flies away. While all this goes on, the downy chicks, perhaps as large as a human thumb, lay flat and motionless in the nest with necks outstretched -- lying low and hoping for the best.

Killdeer were once hunted for plumes to decorate ladies' hats, and for eggs, and as food. John James Audubon wrote that although killdeer were sold in the markets year round, they were only really good when they were fattened up in autumn. It became illegal to harm killdeer when they came under the protection of the Migratory Bird Treaty Act of 1918.

That's a couple of food and fashion fads that everyone should be glad to see the end of.

The Killdeer, Charadrius vociferus. 

2 comments:

  1. Nice post. The Killdeer nesting strategy is certainly a fail in places like cemeteries. My wife would routinely come across Killdeer nests while mowing the cemetery. She would stake the nest to avoid running over it. The broken wing routine was a common occurrence. ;)

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  2. Thank you, Scott. It is very thoughtful of your wife to mow around the nests. :) When killdeer tangle with cows or other immediate threats they don't even try the broken wing feint -- they fan their wings and lunge! That sometimes startles the intruders away.

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