I've seen Killdeer doing this and similar behaviors a number of times early in the breeding season. Sometimes in pairs, sometimes several birds together. My impression is that it has both territorial and courtship components. Pairs do something similar during a "nest scrape display"...the male bows, spreading his tail and trills constantly when the pair is at one of the nest scrapes the male makes when the two are deciding on a nest site. Here are a couple of photos of this behavior:
http://marieread.photoshelter.com/gallery-image/Killdeer/G0000u7AkHC8sfg8/I0000ALsXWhF3uvM/C0000zQU3lDkq6SE http://marieread.photoshelter.com/gallery-image/Killdeer/G0000u7AkHC8sfg8/I00006rJaalHoVTk/C0000zQU3lDkq6SE Cool observation! Marie Marie Read Wildlife Photography 452 Ringwood Road Freeville NY 13068 USA Phone 607-539-6608 e-mail m...@cornell.edu http://www.marieread.com Author of Sierra Wings: Birds of the Mono Lake Basin Available here: http://marieread.photoshelter.com/gallery/Sierra-Wings-Birds-of-the-Mono-Lake-Basin/G0000NlCxX37uTzE/C0000BPFGij6nLfE ________________________________________ From: bounce-118984747-5851...@list.cornell.edu [bounce-118984747-5851...@list.cornell.edu] on behalf of Lauren Flesher [superduperw...@aim.com] Sent: Thursday, March 26, 2015 11:38 AM To: CAYUGABIRDS-L Subject: [cayugabirds-l] Killdeer Courtship at Myers This morning at Myers Point, the group I was with observed two Killdeer engaging in what we assumed was a courtship ritual. They stood on the log at the end of the gravel parking lot, back to back, with tails raised high, and backed into each other until tails were close to touching. They then began imitating each other, with flicks and dips. The whole time they were calling constantly, so that it sounds like one continuous trill. No one in our group had ever seen the likes of it before, or heard of it. Unfortunately we had to leave before seeing the end of this display, but my curiosity was piqued. I came home and checked on Birds of North America for more information, and found nothing except a small reference to the 1967 paper "Prenuptial courtship in wintering shorebirds" by J.B. Funderburg. Google searching this paper lead me to a website describing the ground courtship displays of Killdeer. I find it quite interesting, so I thought I'd share it with you all! Found on the website birdsbybent.com. A 1929 bulletin - 146 (part 2: 202-217) - written by Arthur Cleveland Bent for the Smithsonian National Museum. "The most noticeable courtship performances of the killdeer are those that take place in the air--the nuptial flight--but those that occur on the ground, although less often seen, are also spectacular. Aretas Saunders (1926) thus describes the display: Two birds would crouch side by side but facing in opposite directions. Then they would droop the tips of the wings so that they exposed the ochraceous patch of the lower back, spread the tail, and tip the breast forward, slowly lifting the wing tips till the came way above the back, but never covered it from view. All the while they kept up a continual call, the long-trilled note 't-r-r-r-r-rrrrr.' The displaying birds would often begin the performance or end it with a little fighting." Try as I might, I couldn't find the original Saunders source. Have any of you witnessed this behavior before? Happy birding! Lauren -- Cayugabirds-L List Info: Welcome and Basics<http://www.northeastbirding.com/CayugabirdsWELCOME> Rules and Information<http://www.northeastbirding.com/CayugabirdsRULES> Subscribe, Configuration and Leave<http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm> Archives: The Mail Archive<http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html> Surfbirds<http://www.surfbirds.com/birdingmail/Group/Cayugabirds> BirdingOnThe.Net<http://birdingonthe.net/mailinglists/CAYU.html> Please submit your observations to eBird<http://ebird.org/content/ebird/>! -- -- Cayugabirds-L List Info: http://www.NortheastBirding.com/CayugabirdsWELCOME http://www.NortheastBirding.com/CayugabirdsRULES http://www.NortheastBirding.com/CayugabirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/Cayugabirds 3) http://birdingonthe.net/mailinglists/CAYU.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
