Effects of immunocontraception on behavior in fallow deer (Dama dama)

Immunocontraceptives can control growth in wild and captive populations; however, in doing so, they should not disrupt species-typical behavior patterns. The presence of treated females could disrupt social interactions in a population; yet, few studies have examined effects of immunocontraception on behavior. The goal of this project was to determine whether behavior in a fallow deer (Dama dama) population vaccinated with porcine anti-zona pellucida (pZP)-immunocontraceptives differed from behavior in a population of unvaccinated deer. We predicted that pZP-treated females would spend a higher percentage of time exhibiting mating and dominance behavior than nontreated females, and that males interacting with pZP-treated females would spend a higher percentage of time demonstrating mating and aggressive behavior than males interacting with nontreated females. We recorded activity budgets of males and females in two fallow deer populations, one pZP-treated and the other untreated, before, during, and after rut. Females did not differ in time spent displaying mating or dominance behavior compared to nontreated females. Males coexisting with nontreated females spent more time exhibiting aggressive behavior during rut than males living with pZP-treated females, but males did not differ in time spent in mating behavior. Thus, immunocontraception did not seem to affect behavior adversely. However, sample sizes, living conditions, and sex ratios may have affected the results. Given these limitations, future research is needed to confirm our findings. Zoo Biol 27:49-61, 2008. (c) 2007 Wiley-Liss, Inc.