Spatial variation in life-history trade-offs results in an ideal free distribution in black brant geese / Christopher A. Nicolai, James S. Sedinger, David H. Ward, and W. Sean Boyd.

Includes bibliographical references (pages 1330-1331).

Ideal free distribution theory predicts that individuals distribute themselves so
fitness is equal among patches. In this paper we evaluate all components of adult fitness to
assess the hypothesis that individuals distribute themselves among seven brood-rearing areas
so that trade-offs among different life history traits result in equal mean fitness among
individuals using different areas. We used estimates of vital rates (clutch size, nest survival,
pre-fledging survival, post-fledging survival, juvenile survival, and breeding probability) to
estimate brood-rearing-area-specific per capita recruitment rates and survival for adult
females. We summed brood-rearing-area-specific per capita recruitment and adult survival to
calculate brood-rearing-area-specific estimates of k. We found little variation in k among
brood-rearing areas and lifetime fitness implications of changing brood-rearing area were
negligible (,1% brood-rearing area mean fitness). We conclude that adult female Black Brant
distribute themselves in an ideal free manner, resulting in equal fitness among females using
these areas.