Four repellents representing different modes of action (neophobia, irritation, conditioned aversion, and flavor modification) were tested with captive white-tailed deer in a series of two-choice tests. Two diets differing significantly in energy content were employed in choice tests so that incentive to consume repellent-treated diets varied according to which diet was treated. When the high-energy diet was treated with repellents, only blood (flavor modification) and capsaicin (irritation) proved highly effective. Rapid habituation to the odor of meat and bone meal (neophobia) presented in a sachet limited its effectiveness as a repellent under conditions with a high feeding motivation. Thiram, a stimulus used to condition aversions, was not strongly avoided in these trials, that included only limited exposures to the repellent. These data support previous studies indicating that habituation to odor limits the effectiveness of repellents that are not applied directly to food, while topically-applied irritants and animal-based products produce significant avoidance.

Toxicant coated grain-based baits are widely used to control rodent pests throughout the world, but where alternative food sources are available, bait acceptance and efficacy are often less than optimal. In an attempt to develop baiting strategies to increase bait acceptance and efficacy of zinc phosphide-coated baits, a sugar-enhanced rolled oat based zinc phosphide bait was evaluated. With pre-baiting, 100 and 60% mortality was achieved for California and Belding's ground squirrels, respectively. A series of twochoice tests with a variety of potential bait matrices indicated that rolled oats was a desirable base matrix for both species but the lecithin sticker negatively impacted bait acceptance by Belding's ground squirrels.

High deer densities increase vehicle collisions, damage agricultural crops, and amplify the spread of zoonotic and animal diseases, intensifying human-deer conflict. In addition, deer impact on forest vegetation can influence the distribution and abundance of other wildlife species. Greater demand for non-lethal means of animal damage control has led to an interest in contraception as a wildlife management tool. The development of a single-injection Gonadotropin-Releasing Hormone (GnRH) contraceptive vaccine by NWRC reduces logistical limitations and cost of using immunocontraception as compared to a vaccine that requires two injections. This study assessed the efficacy of two different GnRH-KLH (keyhole limpet hemocyanin) vaccine designs in a single-injection study, to determine if Mycobacterium avium bacterium in the adjuvant is necessary for the success of a single-injection contraceptive vaccine. Forty-two captive female black-tailed deer were divided into 3 groups. Control deer were injected with saline solution, one treatment group received GonaCon ™ (a GnRH-KLH vaccine paired with AdjuVac ™ adjuvant that contains a small quantity of killed M. avium bacterium), and the second treatment group received GnRH-KLH vaccine with DEAE-Dextran/oil as the adjuvant. Contraceptive success was evaluated by monitoring progesterone, pregnancy specific protein, antibodies to GnRH-KLH conjugate and to Johne's bacterium (M. avium), and actual pregnancy rates. Pregnancy rates were significantly different based on treatment (X² = 9.389; df = 2; P = 0.009). Pregnancy rates in deer treated with GonaCon ™ were significantly reduced as compared to saline controls (P = 0.006), but there was no significant difference between GnRH-DD compared to saline (P = 0.297). Significant difference was found between GonaCon ™ and GnRH-DD (P = 0.055). Results suggest that M. avium in the AdjuVac ™ adjuvant is essential for the success of the single-injection GnRH vaccine GonaCon ™ . The development of a single-injection vaccine will increase the practicality and lower the cost of using immunocontraception as a tool to control deer populations.