Meeting Abstract
The rapid stress-induced elevation of plasma glucocorticoids (GC) is well documented in a variety of animals, and these elevated GC levels are known to strongly influence behavior, learning and memory. In many species, the magnitude and time course of increased GCs varies greatly among individuals. In Florida scrub-jays, these individual differences are repeatable throughout the adult lifespan, which indicates they are a persistent aspect of the individual’s phenotype. These differences are also correlated with behaviors in jays, such as parental care, and are predictive of annual reproductive success and life span. Previous work found that temporarily captive yearling jays varied in their performance on an associative learning test, but these differences were not associated with differences in GC stress-responsiveness. However, the captive conditions could have impacted performance on the test and the performance of the yearlings may not be representative of older jays. To test if the stress-response phenotype of free-living, adult jays covaries with their performance on an associative learning test, we used a SmartFeeder design, controlled by radio-frequency identification (RFID) tags, to target specified jays. Four uniquely colored feeders were aligned 3 meters apart within a jay territory; each was programed to feed only one jay at that site. Thus, each jay was “rewarded” by a specific colored feeder which no other jays could use. Feeder positions were reorder once a day for 4 days and each feeder recorded visitations from assigned and unassigned jays. Lower GC stress-responsive jays performed better on the associative learning test, but the patterns of feeder visits suggested that other factors, such as differences in social learning, may contribute to these findings.
