Meeting Abstract

125.3  Tuesday, Jan. 7 14:30  Do migrant and resident White-crowned Sparrows respond differently to changes in their environment? NEMETH, Z*; SMEETS, M; RAMENOFSKY, M; Univ. of California, Davis; Rheinische Friedrich-Wilhelms-University; Univ. of California, Davis znemeth@ucdavis.edu

Organisms are increasingly exposed to rapid changes in the environment, yet it remains difficult to predict their responses to such changes. Migratory birds are considered to be ecologically less flexible than resident species thus it may be hypothesized they are more vulnerable to altered conditions. If so, we predict that migrants may be less able to cope with challenges in the environment than resident congeners. To test this prediction, migratory and resident subspecies of the White-crowned Sparrow (Zonotrichia leucophrys gambelii) and (Z. l. nuttalli) were examined in cognitive, behavioral and physiological tests and the following variables were measured: (1) risk tolerance (i.e. flight initiation distance); (2) problem-solving ability; (3) object neophobia; (4) spatial exploratory tendency; and (5) adrenocortical stress response. All tests, except the exploratory test, were conducted in the non-breeding season. In support of the prediction, migrants were found to be more risk-averse and less innovative in accomplishing a feeding task but did not differ in their response to novel objects, novel space or capture and restraint stress. These results suggest that migrants may be more constrained in their ability to cope with human disturbance and exploit emerging novel resources.