Effects of the features and conditions of pools on the distribution of nonbreeding skuas

GRAÑA GRILLI M.; MONTALTI D

Buenos Aires

Congreso; XXXI SCAR (SCIENTIFIC COMMITTEE ON ANTARCTIC RESEARCH), OPEN SCIENCE CONFERENCE; 2010

SCAR

Brown (Stercorariusantarcticus) and South Polar  Skuas (S.maccormicki)  are territorial birdsthat preclude other birds from their feeding territories by means of aggressivebehaviors. While they are in their young and no reproductive stages they livein groups called clubs, usually located at a pool. The aim of this work was to monitor the number of skuas at differentclubs, looking for any pattern explaining any change in their distributionamong clubs. The third pool is surrounded by hills, has a reduced area and isfarther from the sea compared with the other two. Also, the third one is near agroup of breeding pairs, which show aggressive behaviors to the birds thatapproach the nests. All these differences might explain why the skuas do not chose the thirdpool all the time, and only go there when the other two pools are withoutwater. The water availability might also explain the difference in numbersrecorded between the pools usually chosen