Killdeer: a true tale of nests, eggs, and chicks a-hatching
This past April, Killdeer began appearing on the mudflats around a lake near my home in the oak woodlands south of Yosemite National Park. I had high hopes of photographing their nesting activity and offspring. Following is my account of three pairs mating, five nests, twelve eggs, and seven chicks. It’s complicated, so sit down, relax, and read on.
Killdeer are on constant high alert. They will most likely see you before you see them. You know you’ve been spotted when you hear their alarm calls: shrill, repetitive, and ear piercing. The sound travels a good 1/4 mile. Appropriately, the Latin name given this member of the Plover family is “charadrius vociferus.” Vociferous, indeed.
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As for the common name, what an odd appellation for a bird, don’t you think? 18th century naturalists settled on the name “killdeer” because the bird regularly seems to vocalize that sound (kee dee dee). Listen to the recording below, and see what you think:
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Killdeer typically lay their eggs on the ground, in a shallow depression surrounded by low vegetation. Add a few stones, perhaps, and that’s about it. Because of the color of its plumage, the adult attending the nest blends right in, so much so that you would be hard pressed see it, even if you knew it was there.
It was in mid-May that I discovered my first Killdeer nest. I might have stepped on it while walking down a slope to the water’s edge had one adult not been wildly performing broken wing display.
“Broken wing” is a distraction tactic that some birds exhibit to draw predators away from the nest or their flightless chicks. Feigning injury, Killdeer hobble a short distance, then pause while making a shrill, trilling sound. When the predator comes near, the bird suddenly moves further away, again and again. Once far from the nest, the bird flies off, leaving the predator behind to look for something else to eat. Their flight call seems to say: “Ha, I sure fooled you.” I can attest from personal experience that this behavior is quite effective in dealing with camera-toting predators.
The egg laying had just begun in this first nest, as evidenced by the single egg which I quickly photographed before retreating. You can imagine how pleased I was at my good fortune: at the top of the slope I would have a good vantage point from which to observe ongoing nest activity, and perhaps photograph a brood of 4-6 chicks in about 30 days.
Sadly, that vision was not to be realized. A few days later, I returned to discover the nest had been inadvertently destroyed by human activity. So much for my dream of taking photos of newly hatched Killdeer chicks.
The following week, however, I came upon a second nesting pair. Their nest was off the lakeshore path, in a more secluded area. Nearby was a natural blind behind which I could quietly observe the birds when it came time for the eggs to hatch. I felt more confident about the success of this clutch.
Meanwhile, an unseasonal heat wave moved in. Could the developing embryos survive the unusually warm temperatures? Not to worry. The adults, having dampened their feathers in the lake, took turns standing over the eggs to shade them and keep them cool. On June 2nd, two chicks hatched.
While Killdeer are classified as shorebirds, they are commonly found far from the shore. Grazed fields are often a good place to find them. Imagine the danger that livestock present to these robin-sized birds. Remarkably, Killdeer have developed another distraction behavior called “ungulate display.” Rushing toward the far larger interloper, the bird flaps its wings and takes an aggressive posture. I’m not sure how a cow might react, but I was startled when it happened to me as I came out from behind my blind.
A day later, I returned to photograph the broken egg shells, but there were none to be found; nor could I find any evidence of the nest. Apparently, as a precaution against predators noticing vulnerable, newly-hatched chicks, Killdeer immediately remove the egg shells from the nesting area.
Continuing my walk around the lake, I came upon a third adult pair. With them were two chicks, no more than a few weeks old, foraging the mudflats. Things are looking up, I mused. We now have a tally of four Killdeer chicks foraging the lakeshore.
Since these precocial chicks won’t begin to fly for about 30 days, survival depends upon their ability put distance between themselves and danger. You would be hard pressed to keep up with them, so quickly do their little legs carry them away.
When foraging for insects or other invertebrates, Killdeer move in fits and starts. When they pause, invariably they bob their heads up and down as if they have a bad case of the hiccups. Actually, they are pumping their tail, and the head follows along. It’s a joy to watch them.
Killdeer are high-strung birds. If they’ve spotted you nearby, you may witness a nervous and humorous dance that goes like this: two Killdeer approach each other, and pause to bob their heads; they then pass side by side, only to stop, turn and face each other again, bob their heads, and repeat the process.
Mid-June delivered another surprise: a fourth Killdeer nest. This one contained four eggs. It was located on a large, partially submerged boulder about 50 feet from the shoreline.
Imagine the serendipity of the situation: this nest is on a mini island, the chicks will be safe from land predators, and they won’t be able to run away from me. Perfect.
Killdeer may have from one to three broods per season. Since the location of this nest was quite near to where the very first nest had been, I want to believe that the same Killdeer pair was trying again. I can’t prove it, but that is what intuition tells me. Isn’t that a wonderful thought?
Coincidently, June - July is also molting season for our resident geese and ducks. These hefty birds can’t fly until their flight feathers are replaced, so during this interval they spend much of their time just grooming themselves on shore.
The boulder seemed to have a special attraction to these much larger waterfowl. You know from my Canada Goose article here what that means: up to three pounds of soggy calling cards each day. So much so that I named this new nesting site “Bird Poop Rock.”
Research has shown that 53% of Killdeer eggs are lost to predators. With all the comings and goings on this granite outcropping (geese, ducks, turtles, and grackles), I feared the combination could not end well. Indeed, four days later, that nest, too, was gone. All that remained was bird poop.
Following unlucky birds is not an uplifting endeavor. After the catastrophe at Bird Poop Rock, my interest in Killdeer began to wane. My photographic attention drifted towards the juvenile Green Herons now visiting the lakeshore (that will be a future article).
But wait. If you have been counting, you know from my introduction that one nest, three eggs, and three chicks have yet to be accounted for. It is a happy accounting, so please continue reading.
On August 2nd, at the very location of the first nest I came upon in mid-May, I spotted three Killdeer chicks foraging on the mudflat. Only one adult was present; it was sounding alarm calls and performing broken wing displays like there was no tomorrow. This individual had to be one of the original nesting adults, but this time - on the third try - it had a successful brood.
Newly hatched Killdeer chicks cant’t fly, but they can swim. I know this because the lone adult and three chicks took up residence on a spit of land not far from the shore a few days after hatching. It is fascinating to watch them cautiously dip their feet into the water, and then start to paddle, with neck stretched high as if to keep themselves from sinking.
Killdeer chick swimming to shore.
After about four weeks out of their shells, the chicks began attempts at flight. They stretched and flapped their wings while standing in place. After several attempts, one chick flapped while running, and went airborne for a second or two, just like the Wright Brothers at Kitty Hawk.
And that concludes my account of three adult mating pairs, five nests, twelve eggs, and the seven Killdeer chicks that hatched on the shores of Blue Heron Lake near my home.
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