A longitudinal study of antipredator behaviour in four successive generations of two populations of captive red junglefowl

Abstract

Conservation breeding and reintroduction into the wild can only be an effective management tool if behaviours essential for a life in the wild are maintained in captivity. The aim of this study was to investigate how a protected captive environment influences antipredator behaviour over generations. The red junglefowl ( Gallus gallus) was used as a case study. Birds from two different captive populations were followed over four generations. In the last three generations, all birds were hatched and reared in the same indoor settings. Antipredator behaviour was measured in each generation in a standardised test where the birds were exposed to a simulated predator attack. The test was divided into three parts: pre-exposure period, exposure and post-exposure periods. There was an interaction effect between population and generation ( F 3,129 = 4.84, P < 0.01) on behaviour during the pre-exposure period, suggesting that the birds’ “baseline” agitation level may have been altered differently in the two populations. Population differences were also found during the post-exposure period but the populations tended to become more similar over successive generations in their behaviour after the exposure. Furthermore, there were significant effects of generation ( H (d.f. = 1, N = 137) = 10. 94, P < 0.05) as well as population ( H (d.f. = 1, N = 137) = 5.17, P < 0.05) on the immediate reaction to the simulated predator attack. In conclusion, over four successive generations, the two populations altered their antipredator behaviour and tended to become more similar. This study shows that antipredator behaviour may change over generations in a captive environment. This is likely to be one of the most crucial factors for successful reintroduction into the wild and hence, it is a very important aspect to consider for conservation breeding.