David M. Larson and Susan Carlson
On May 19, 2017, we attended an evening presentation on Eastern Whip-poor-wills by Nancy Landry at the Hellcat Parking Lot on the Parker River National Wildlife Refuge on Plum Island. The evening was a great success, with several Whips and a couple of Common Nighthawks. After the program, we slowly drove north toward the exit, hearing and seeing a dozen Whips and several American Woodcocks. As we neared Parking Lot 2, we noticed a disturbance at the north end of the roped-off lot—two Whip-poor-wills were evident in the headlight beams of our vehicle.
It is not uncommon to see Whips on the ground at night, but one of these birds was engaged in a peculiar display. Standing erect with head down, the bird had its wings spread wide, underwing facing us, advancing in tiny hops toward the other bird. The effect was comical, very odd, and somewhat reminiscent of something out of a vampire movie. We assumed that we were watching courtship behavior, though neither of us had ever seen these moves before. We could not identify the gender of either bird. This behavior lasted about five minutes while we were unsuccessfully attempting to extract a camera from the back seat. Finally the birds moved off into the scrub and out of sight.
At home, we dove into the literature. The species account in The Birds of North America (Cink, et al., 2017) suggests that little is known about courtship displays in this species:
Anecdotal accounts by three authors present three different versions of the event, all three of which were observed in same evening in Kansas (DLC). Female may solicit attention of the male perched above her by strutting on ground with wings and tail outspread and head lowered. Female may rock side to side as she walks, circling first in one direction then the other, producing a guttural chuckle (soft popping sound) as she moves (Coale 1920). Male may respond by approaching the female on the ground (or along a tree branch or downed log), raising and lowering his body in a “sort of undulating” manner (Bolles 1912). Male may circle female and she, in turn, moves her body up and down and/or quivers her wings (Fuller 1960). . . . Male may approach female using Tail-Flashing display in which bird hovers in place with tail fanned maximally and showing all of white on retrices (CLC).
Our observations contain some of the disparate elements mentioned above: a displaying bird advancing—“strutting” might not be the right word—on the ground with wings outspread and head lowered, and moving to the right and left—not really “circling”—as if herding the other bird. The displaying bird’s holding of its wings to display the underwings continuously seemed a new feature. Since both birds were on the ground, perhaps a Tail-Flashing display was precluded.
It was a most interesting end to a very pleasant evening program.
References