Adult Killdeer - Photo: Bob Boekelheide
Killdeer in Our Midst
by Bob Boekelheide
September 2022
On the official Clallam County bird list, the group of birds with the highest number of species is the shorebirds, also known as “waders” in Britain. Shorebirds include plovers, sandpipers, and their myriad relatives, such as oystercatchers, turnstones, curlews, godwits, dowitchers, and many more. An amazing total of 48 shorebird species have been recorded in Clallam County, about one-eighth of the total 396 species of birds currently on the Clallam list.
Equally interesting to me, out of all these 48 shorebird species only four regularly nest in Clallam County. Can you name the four shorebird species that nest every year in Clallam County?
The other 44 species of shorebirds recorded in Clallam County are migrants, nesting mostly in the Arctic, taiga forests, or inland prairies, then showing up here during migration. A few of these migrant species stay for the winter, like Black-bellied Plovers and Dunlin, but most do not. Some shorebird species on the Clallam list do not even nest in North America, like Curlew Sandpiper and Little Stint, both of which nest in Asia and rarely show up in North America. Fully a third of all the shorebird species on the Clallam list could be considered “rare,” not seen every year.
Okay, here are the four shorebird species that nest every year in Clallam County: Black Oystercatcher, Killdeer, Wilson’s Snipe, and Spotted Sandpiper. Denny Van Horn once found Greater Yellowlegs with chicks by the Quillayute River, but that is the only breeding record we know for yellowlegs in Clallam County. Consequently, I’m sticking with only four regularly-nesting shorebird species.
Of the four nesting species, probably the best known by most birders is the pugnacious Killdeer. Killdeer are vocal plovers with spunky attitudes that place their cryptic nests in gravelly areas, then defend their territories with shrill calls and broken-wing displays. They are easily recognized by two bold stripes across their white neck and breast. Despite these striking markings, they also blend in very well with the landscape, until they start making noise. They are a common nesting bird throughout the Puget Sound region, as well as over most of North America from central Mexico to central Canada.
Adult Killdeer in August. Notice that its long flight feathers are darker and unworn in contrast to the frayed edges of its wing coverts, showing that this bird is carrying out its “pre-basic molt” at the end of the nesting season. Photo by Bob Boekelheide
Even though Killdeer are present in Clallam County throughout the year, their number vary by season. This is evident from data collected by OPAS volunteers during the Three Crabs Restoration Project, where we counted birds on the shores of Dungeness Bay three times every month for five years from 2014 to 2018 (Figure 1).
Granted these data are just from Three Crabs, but Figure 1 shows the annual cycle of this local Killdeer population very well. During nesting months of March, April, and May, we recorded consistent numbers of territorial adults. The highest counts occurred between June and September, when chicks leave their nests and Killdeer form loose flocks. The lowest time of year occurred in December and January, when many local Killdeer leave their territories and move somewhere else for the winter. Where do they go? Do they migrate south? It’s not certain for our local Killdeer, but it does appear that local numbers decrease in winter.
Killdeer’s nesting season may last several months, much longer than other shorebird species that nest in more northerly climes. The earliest Killdeer pairs around here usually lay eggs in April, then little chicks start running around in May. They almost always lay four well-camouflaged eggs, all crammed inside their gravel nest. After an average incubation period of about 25 days, the eggs hatch within a day of each other. Like many shorebirds, this synchrony is because Killdeer parents don’t start incubating their eggs continuously until the last egg is laid.
Adult Killdeer standing over its nest with four beautifully-camouflaged eggs. Photo by Dow Lambert.
The precocial chicks leave their nest within hours of hatching, sometimes as soon as they dry off. They grow quickly, able to find food for themselves while their protective parents watch for predators. The chicks start flying when they are only three to four weeks old, which means the period between the start of laying eggs and chicks taking flight may be as short as only seven to eight weeks.
If Killdeer begin their first clutch in April and their first chicks are independent by late May, it may give them time to lay second clutches, or replacement clutches if they lose their first nesting attempt. Sure enough, around here we sometimes see chicks as late as August, from eggs laid in June or July. In other, more-southerly areas of the U.S, researchers think some Killdeer may even lay three clutches in a nesting season.
Adult Killdeer with its small chick. Photo by Dow Lambert.
Killdeer don’t form huge flocks like some other shorebirds, but they often gather in small groups, particularly around migration time. The record Clallam County eBird count is 92 Killdeer counted in a Dungeness cow pasture on November 18, 2018. That pasture turns out to be a favorite place for Killdeer in the fall, where they hide out of the wind in the lee of well-spaced cow patties. Within a week after that sighting, those Killdeer were gone and the cow patties stood silent vigil.
Mid-December is also when we hold our annual Sequim-Dungeness Christmas Bird Count (SDCBC). The SDCBC averaged about 67 Killdeer per year over the last 30 years (Figure 2). In reality, Killdeer numbers on the CBC vary from year to year, from a low of only five birds in 1994 and 1995, to a high of 160 in 1998. Despite all the ups and downs, the trend line for SDCBC numbers appears fairly steady. Killdeer are very good at hiding out in fields and pastures during winter, so it is possible that we miss many of them during the CBC.
You probably recognize Killdeer by their loud vocalizations, particularly when they are threatened near their nests. Like chickadees, Killdeers’ call notes get louder and more intense depending on the intruder or predator, sounding the alarm for other birds. As a predator or human approaches, they start out with single loud “DEEEE.” They switch to two-note “DEE--EEE” as the predator moves closer, eventually screaming a three-note “DEE-DIT-DIT” when the predator gets really close. Their namesake “Killdeer” calls finally erupt when they take flight, repeating “KILL-DEER, KILL-DEER, KILL-DEER, KILL-DEER” over and over. They have other trills and grunts that don’t sound like your typical Killdeer.
Killdeer are survivors, one of those species that seems to exist fairly well as humans change habitats in North America. Some authors suggest that there may be more Killdeer now than ever before. But their propensity to nest close to humans, such as in farmland, weed fields, and gravel roads, may also put them at risk for exposure to pesticides and disturbance.
To finish, I’d like to relate a story that seems to illustrate the adaptability of Killdeer. On a cold winter night last January, at about 8:30 pm in the Sequim Costco parking lot, I heard Killdeer flying and calling loudly high up in the dark night sky. There were at least two, maybe more. What the heck were Killdeer doing flying around in the dark during the middle of winter? Killdeer are active day and night, so maybe that’s not surprising. But why over a shopping center, all lit up on a cold winter’s night? It made me appreciate even more the incredible challenges these tough birds face as they survive in our rapidly changing world.
Remember that September 6th is World Shorebirds Day, when we should all count shorebirds and share our eBird lists with WorldShorebirdsDay. See https://www.shorebirdconservation.org/global-shorebird-counts for more information. Instead of rushing to Clallam County to see “rare” shorebirds, it’s time to stay home and appreciate the Killdeer in our midst.
Many interesting facts about Killdeer in this story came from Birds of the World, an on-line resource available through Cornell Lab of Ornithology. I highly recommend that all bird aficionados subscribe to Birds of the World, both for the information and to support the Lab of Ornithology.