Summary (AGH): Different species of sandpiper vary tremendously in their social behaviour, from ruffs that have display grounds where males jump and flash fancy feathers to try to mate with several females, to phalaropes, in which it is females who are more colourful, and males who care for the young. Shorebirds thus offer great opportunities to understand how display behaviours are shaped for particular social functions. Many species give lengthy display flights that are thought to be roughly equivalent to song in songbirds. Bird songs are familiar to most of us and are well studied, but shorebird display flights are poorly known, mainly because most species nest in the relatively inaccessible north. Sable Island’s population of Least Sandpipers offers a more accessible opportunity to study the pattern of these flights, especially to see whether it serves in territory defense or mate attraction, as song does in songbirds. Flight displays of male Least Sandpipers are a characteristic sound of the island, but only in the spring, when males are attracting a mate. They are given only over the small area where the nest will eventually be; males do not defend areas where they will forage and raise the brood. Thus, display flights appear to serve mainly to attract a mate, and may have evolved to be so conspicuous and elaborate because of competition among males for females (sexual selection).
