Ecological Significance of Daily Periodicity in Display Flight of the Latham's Snipe Gallinago hardwickii: A Study on the Presence of Lek Breeding System

Abstract

Breeding hebavior and daily periodicity of the Latham's Snipe Gallinago hardwickii were investigated, and the presence of lek breeding system was discussed. A female was observed to invade the area where a male showed the display flight at the peak period of display activity. The leading male at the peak was fixed and female tried to invade the leading male's court. Display flight had a daily periodicity and peak periods shortly before sunrise and shortly after sunset. It also had peak periods about 24:00 for the 3 or 4 days of the full-moon period. Female invaded into the male's court only at night and at the peak period. Letham's Snipe is considered to choose the time; i.e. around 24:00 about the full-moon nights, in order to increase the encounter of male and female. Male can easily find the female invading from the higher air, under the clear moon-light because the altitude of the full-moon is highest, and the shadows on the earth are shortest. Lek breeding systems have the following characteristics: 1. Males contribute little or none to incubation and feeding. 2. The birds are sexual dimorphic. 3. Males make display flights in a group, and as a result they have an arena. Items 1 and 2 were already verified. Male display flights are intensively conducted at night and they seem to attract the female to his arena, and the female can select the better male. Each male flying in display over the arena is aggressive to others and exclusive, and among them, as a result, there is a ranking to be chosen by the female. Therefore, existance of the leading male means existance of dominance ranking. This shows that Latham's Snipe has a lek breeding system.