Effects of taste stimuli (quinine and sucrose) in pelleted, granulated, and wax block baits on feeding preferences of northern pocket gophers (Thomomys talpoides)

Abstract

Author(s): Shumake, Stephen A.; McCann, Geraldine R. | Abstract: A two-choice, taste preference study was conducted using 18 northern pocket gophers to evaluate pelleted sorghum, granulated sorghum, and wax block baits containing either 0.01 to 0.05% quinine or 0.10 to 5.0% sucrose. Bait consumption was significantly higher across treatments (P ≤ .001) for granulated sorghum, followed by pelleted sorghum, and wax blocks. Gophers also showed a high frequency of moving the granulated bait in their cheek pouches to be deposited at alternate locations within their cages. Although increasing sucrose concentration did not produce significantly (P ≥ .10) enhanced consumption for any of the baits, a trend toward increasing preference with increased concentration was noted for the wax block bait. During quinine tests, bait consumption was again significantly highest (P ≤ .01) for granulated sorghum followed by pelleted sorghum and wax block. Quinine treatment also failed to significantly (P ≥ .10) alter bait consumption across the tested concentrations. However, there was a minor trend toward decreasing preference with increasing concentrations in the wax block group. Data indicated that pelleted bait had the advantage of producing more consistent consumption levels without the animals carrying bait in their cheek pouches for caching and subsequent spillage. Although the wax block baits were most influenced by the taste treatments, consumption levels were extremely low. In comparison with most wild rodent species, northern pocket gophers were found to be insensitive or indifferent to both taste stimuli over a wide concentration range.