Todd Burras: This shorebird employs tricks to avoid predators and people
Low water levels in local rivers, creeks and wetlands might not provide ideal habitat conditions for ducks and geese, but they do present an opportune invitation to a number of local shorebirds.
Earlier this week while visiting the wetlands on the west side of Ada Hayden Heritage Park in Ames, I noted several species taking advantage of the shallow water and surrounding mudflats. There was a great blue heron probing the mud and water presumably for frogs, salamanders or any vulnerable small carp that might venture too close to the edge of the rapidly diminishing pool.
At the same time, a spotted sandpiper could be seen teetering back and forth with its tale bobbing up and down as it searched for small invertebrates, such as mayflies, as well as grasshoppers, worms and beetles. Meanwhile, a pair of greater yellowlegs took a less frenetic approach to hunting for similar menu items by standing still and surveying their surroundings for short periods of time before striding slowly away and taking up to new posts.
All of this was the backdrop to the exploits of a host of killdeer swooping over the water and combing the water’s edge in search of food. Unlike the birds with which they shared the shrinking pool of water, the killdeer were predictably and unabashedly noisy as they sought to stuff their tiny tummies with snails, beetles, worms and aquatic insect larvae.
Watching the antics of the dozen or more killdeer reminded me of a close encounter with a nesting pair I had with my daughter, Elizabeth, a few years ago. It was a Sunday morning, and we were walking next to a parking lot on a sidewalk with a stone-covered border on one side when Elizabeth said, “Dad, what’s wrong with that bird?”
Just a few feet in front of us, a killdeer began flopping about on the walkway like a mortally injured gamebird shortly before gasping its final breath. With wings akimbo, the brown-and-white-colored bird with black neck bands indeed looked as if it was on its last leg, literally and figuratively.
It quickly struck me, however, as I looked up from the bird to see the concern on Elizabeth’s face that this wasn’t a struggle over pending death but rather a ruse on the bird’s part to preserve life. Or, as the case was, future lives.
Unlike most shorebirds, killdeer spend more time away from water than near it and are comfortable living and nesting in proximity to people. As a result, they frequently come in contact with humans and have developed adaptations to protect themselves and their offspring.
In its encounter with Elizabeth and me, the animated bird was simply doing what any killdeer parent does when it or its young are confronted with danger: feigning injury. Like some other species, killdeer will perform a broken-wing impression in an effort to draw attention away from its nest of eggs or its young. In this case, the killdeer was trying to divert our attention away from its nest — a simple depression in the rocks — and its contents: four tan eggs with dark markings.
It’s easy to be both impressed and amused by the antics of killdeer. They ardently utilize both vocal and theatrical expression to draw the attention of people or potential predators to themselves and then lead them on a wild chase away from their nest or offspring. Once they sense they have created a safe distance between the intruder and whatever they are protecting, the adult killdeer miraculously recovers from its “injury” and flies even further away, often with the predator in pursuit.
While many shorebird species, such as redknots and golden plovers, are long-distance migrants, killdeer can be year-round residents or partial migrators. The most widespread of all North American plover species, killdeer arrive locally in early spring and stick around to raise one or two clutches of young during the summer before flying south for the winter in late October or November.
Killdeer are considered a “leapfrog” migrant as they will pass over suitable winter habitat in the southern U.S. and Mexico, which offer year-round homes to nonmigratory populations of killdeer, and head instead to Central America and northern South America. Come spring, they’ll repeat the process, again skipping over suitable nesting habitat in the southern U.S. and Pacific Coast in order to return to nesting grounds in the northern U.S., including Alaska, and all across the prairie and maritime provinces of Canada.
The next time you see a boisterous bird dragging its wing and frantically calling “kill-deer, kill-deer,” don’t take the bait. Instead, carefully look around for a nest of well-camouflaged eggs or, if you’re fortunate, a small clutch of fledglings that look like stilted dandelions going to seed. They’re puffy, quick as lightning and as cute of a creature as you’ll ever set eyes on.
Todd Burras can be reached at firstname.lastname@example.org.