The robin-sized killdeer likes to hunt bugs on short grass, so they frequently live on golf courses. Some call them “golf course plovers” although their scientific name is Charadrius vociferus, and vociferous they are.
Killdeer pretend to have a broken wing and writhe on the ground, crying, to distract predators who approach their nest. When the predator begins stalking the apparently wounded parent bird, the killdeer leads the predator away from the eggs, and then promptly “recovers” and jets away.
I’ve worked part time at a golf course with killdeer in northwest Oregon for a couple of decades and I have watched them live, love, tend to eggs and young’ns, scold golfers, and pass this mortal coil.
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Every spring, in northwest Oregon, killdeer migrate onto this golf course, fall in love, nurture eggs, and raise little killdeer.
Killdeer nest on hard ground or bark dust, after scratching out a cup-sized depression, with the eggs in plain sight, camouflaged by little more than their mottled markings. They often nest on paths, driveway shoulders, or bark dusted gardens.
I began tracking the killdeer closely in 2008, after discovering them actually nesting inside a sand bunker by the golf green. The greens crew just worked around the nest for a few weeks until the chicks hatched. Baby killdeer are born good to go, catching their own bugs a few hours after birth.
I first wrote about the killdeer in 2013. www.dailykos.com/...
I studied the adult killdeers’ antics to lure predators away from their nests. They seemed mechanical. When you approached to 15 yards, they’d move away from their eggs and display their colored tail feathers. At 10 yards, they’d fan out their “broken wing” and stagger in circles, slowly moving away from the nest, as shown in this Bucket’s first photo. But when you got to a yard from the eggs, the adult might dart back and circle right under your feet.
To find their nest, you walked in the opposite direction they attempted to lead you. Still, the eggs’ coloring made them nearly invisible. (middle of photo below)
I’m sure the hawks and coyotes figured it out, too, that the broken wing dance meant you were near a nest, and if you looked opposite of where the killdeer was going, you’d find the four speckled eggs.
I often found handfuls of killdeer feathers scattered on the grass; evidence of an efficient predator. Killdeer pairs nesting on the golf course declined from 9 to 3 from 2008 to 2013. I blogged about that.
www.dailykos.com/...
In 2014, the killdeer shifted their nests to the southeast corner of the golf course. And they stopped performing the broken wing dance that signaled you were close to their eggs.
When I hunted their nest in 2015, they paused some 20 feet from the likely site they’d used the prior year, and flashed a tail feather or two, but mainly watched me warily from the corners of their eyes.
I’m amazed these golf course killdeer have apparently curtailed or abandoned its polished diversionary display, or paratrepsis as wiki calls it. Observers have noted these tactics for over 100 years. Thus Howard Lacey (1911) "..found a killdeer standing over her eggs with upspread wings and scolding vigorously." birdsbybent.netfirms.com/…
The nicest study of the killdeer’s diversion tactics is at:
sora.unm.edu/…
Wherein Douglas Deane denies the “trick” is a reflex action, “There must be a considerable amount of training and intelligence combined in this trick, as the bird has evolved procedures that vary with the different types of enemy.”
I venture that “my” golf course killdeer have evolved procedures tailored to their immediate predators, and no longer invoke the broken wing dance every time golfers strolled by, even ones searching for golf balls in the grass near their nest.
Every year from 2008-2014 I found 1 or more killdeer nests. In 2015 they ceased the broken wing dance and I haven’t found a nest since then. However, sometimes they issue a “calling all killdeer” cry, and several will flock near me, cursing, and then follow my retreat for a hundred yards.
I saw about 15 killdeer flocking this late autumn, which is about the historic average. There were 23 in 2008 at autumn’s end, and 12 in 2013.
I proffer one more killdeer picture, because I love their bold stripes.
NOW IT’S YOUR TURN
Any vocal birds in your back yard? What have you noted in your area or travels? As usual, please post your observations and general location in your comments. I’ll respond in between working on an endless list of garden chores.
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