Behavioral effects of an immunocontraceptive vaccine on eastern fox squirrels

Abstract

Managing pest species in urban and suburban areas is challenging, and contraception may provide a socially acceptable and effective management option for many species. The immunocontraceptive vaccine, GonaCon, effectively inhibits reproduction in many species of wildlife, but the behavioral effects are not yet well understood. Contraceptive-induced changes in behavior could raise animal welfare concerns and alter survival and reproductive rates in populations. These vital rates frequently are incorporated in population models to predict the population-level efficacy of contraception. Thus, understanding the behavioral impacts of contraception is necessary to accurately predict populationlevel effectiveness of contraception and to protect animal welfare. We investigated the behavioral effects of GonaCon on eastern fox squirrels (Sciurus niger), a pest species that has invaded much of the western United States, caused widespread damages to human infrastructure, and threatened native western gray squirrels (S. griseus). We used field observations to measure time-activity budgets and dominance, open field trials to measure exploratory behavior, and mirror image stimulation to measure aggression because GonaCon could alter these behaviors. Contrary to our predictions, we failed to detect any significant effects of GonaCon on any of these behaviors. Our results, combined with a previous study finding that GonaCon is highly effective at inhibiting reproduction in fox squirrels, indicate that GonaCon may be a viable control method for fox squirrels and that behavioral changes affecting the demographic parameters are unlikely to undermine population models used to predict the effectiveness of GonaCon. Ó 2015 The Wildlife Society.

Developing fertility control for rodents: a framework for researchers and practitioners

“…2011) but no effects were observed on time‐activity budgets, dominance, and aggression in eastern fox squirrels ( Sciurus niger ) treated with GonaCon TM (Krause et al. 2015).…”

“…Among side effects of contraceptives in rodent species, injection site abscesses were found in eastern gray squirrels (Sciurus carolinensis) injected with GonaCon TM (Pai et al 2011) but no effects were observed on time-activity budgets, dominance, and aggression in eastern fox squirrels (Sciurus niger) treated with GonaCon TM (Krause et al 2015).…”

Evaluation of a single-shot gonadotropin-releasing hormone (GnRH) immunocontraceptive vaccine in captive badgers

“…These differences were commensurate with the higher metabolic demands of pregnancy and lactation. Conversely, GonaCon did not affect social and spatial behaviour in Eastern fox squirrels (Sciurus niger (Krause et al 2015)) and in wild boar (Massei Fig. 13 Variation in mean (± SE) body weight (kg) for males in the vaccinated and control groups.…”

Effects of a Recombinant Gonadotropin-Releasing Hormone Vaccine on Reproductive Function in Adult Male ICR Mice

“…For example, GonaCon administration in dogs can cause swelling and muscular atrophy at the injection site [ 32 ], as well as chronic granulomatous myositis and diffuse coagulative necrosis 33. GonaCon has been documented in a variety of species, and minor to severe side effects were reported in horses ( Equus caballus ), eastern fox squirrels, and non-human primates [ 58 , 59 ]. In the present study, we emulsified a multimer construct protein with an equal volume of MONTANIDE ISA 206 VG adjuvant.…”