Time in captivity, individual differences and foragingbehaviour in wild-caught chaffinches

Wild-caught animals are often given a settling in period before experimental trials are initiated.We used wild-caught chaffinches (Fringilla coelebs) to investigate (a) the effect ofsettling in period duration on the likelihood that chaffinches foraged during experimental trialsand (b) whether settling in period duration influenced measures of foraging and vigilancebehaviour recorded from those experiments. The probability of collecting foraging data froman individual’s first trial fell below 50% if it had been in captivity for more than 12 days priorto that trial, whereas the probability was >75% if trials were completed within two days ofcapture. The successful collection of foraging data from subsequent trials was also dependenton the number of days an individual spent in captivity prior to its first trial and on whetherthat individual foraged in its first trial, suggesting that some individuals were more inclinedto forage in captivity. Individuals that foraged in their first trial had a 94% higher success ratein subsequent trials than those that did not. However, settling in period duration did not significantlyinfluence the peck rate, mean search period or mean vigilance period of individualsthat did forage. Our results show that allowing a settling in period actually reduced the likelihoodof collecting foraging data from chaffinches and that commencing experiments shortlyafter capture increased data collection efficiency. We discuss the possibility that the inabilityto collect data from certain birds following a settling in period could lead to potentially importantbiases in results, particularly if propensity to forage is linked to an individual’s copingstrategy or personality.We conclude that it may not always be beneficial to allow wild-caughtanimals to habituate to captivity before commencing experiments. In some cases, testing animalssoon after capture may increase the likelihood of data collection, reducing both thenumber of study animals required and the length of time they spend in captivity.

S.J. Butler, M.J. Whittingham, J.L. Quinn &W. Cresswell, Behaviour 143, 535-548