Tuesday, May 5, 2015

Killdeer

Last Saturday, Erika and I visited a plant nursery in nearby Carver County. The large, dirt parking lot was a madhouse of frenzied gardeners. As we searched for a spot to park, I noticed a Killdeer running along the shoulder of the lot, and giving a classic Killdeer broken wing act. While Erika explored the nursery, I returned to the investigate the bird.
I quickly discovered the Killdeer brooding four eggs (the typical number for this species). The nest, called a scrape (since there is not much to it), was only a couple of feet from the parked cars. The Killdeer showed no fear, and even threatened me if I got too close. Both male and female Killdeer build their scape and often build more than one, much in the fashion of House Wrens that build dummy nests.  Both Killdeer sexes incubate the eggs.
Initially the scrape is a bare depression in the ground. As the season progresses, however, Killdeer  add “rocks, bits of shell, weed stems, or other material” (Jackson and Jackson 2000). These authors report that the birds often collect white objects (shells, crayfish parts, cigarette filters, gravel, plastic, plaster) or build their scrape on white ground. One nest even contained bits of human bones. Apparently the Killdeer try to create a mottled background so that their eggs are better camouflaged. By the end of incubation, the amount of white material can be substantial—nests with over 1500 pebbles have been reported, and the scrape is sometimes raised two or three centimeters (Jackson and Jackson 2000).

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