SREL Reprint #3783

Influence of habitat and baiting strategy on oral rabies vaccine bait uptake by raccoons in the southeastern United States

Jacob E. Hill1, Madison L. Miller1, Richard B. Chipman2, Amy T. Gilbert3, James C. Beasley1,4,
Guha Dharmarajan1, and Olin E. Rhodes1,5

1Savannah River Ecology Laboratory, University of Georgia, PO Drawer E, Aiken, SC 29802, USA
2National Rabies Management Program, USDA, APHIS, Wildlife Services, Concord, NH 03301, USA
3National Wildlife Research Center, USDA, APHIS, Wildlife Services, 4101 Laporte Ave,
Fort Collins, CO 80521, USA
4Warnell School of Forestry and Natural Resources, University of Georgia,
180 E Green St, Athens, GA 30602, USA
5Odum School of Ecology, University of Georgia, 140 E Green St, Athens, GA 30602, USA

Abstract: Oral rabies vaccination (ORV) is the primary tool for landscape level control and elimination of rabies virus in terrestrial wildlife species. However, there is currently a limited understanding of how different baiting strategies influence raccoon (Procyon lotor) uptake of ORV baits in non-agricultural habitats in the Southeastern United States, which may hinder the refinement of ORV management for raccoons in this region. Using a combination of new and existing data, we investigated the role of baited area (0.16 vs 3 km2), bait density (75 vs 150 baits/km2) and season (spring vs fall) on placebo ORV bait uptake by raccoons in four rural, non-agricultural habitats in the southeastern United States (bottomland hardwood forest, upland pine forest, riparian forest, and isolated wetlands). Increasing the baited area to 3 km2 increased the proportion of raccoons that consumed baits by 140% in riparian forests and decreased the proportion consuming baits by 70% in bottomland hardwood forests. A greater proportion of raccoons consumed baits in riparian habitat in spring compared to fall, but bait density did not influence uptake in either season in this habitat. Increasing the bait density during spring in bottomland hardwoods increased the proportion of raccoons that consumed baits by 270%, but there was no effect of increasing bait density in bottomland hardwoods during fall. We suggest that variation in habitat contiguity and seasonal resource availability influence how raccoons utilize these habitats which in turn impacts habitat-specific ORV bait uptake. The estimated proportion of raccoons that consumed baits did not exceed 60% for any treatment, and for most treatments was less than 40%. These low uptake rates indicate a need for research into additional strategies to maximize raccoon uptake of ORV baits across rural, non-agricultural southeastern landscapes.

Keywords: Bait density; Biomarker; Didelphis virginiana; Opossum; Procyon lotor; Rhodamine B

SREL Reprint #3783

Hill, J. E., M. L. Miller, R. B. Chipman, A. T. Gilbert, J. C. Beasley, G. Dharmarajan, and O. E. Rhodes. 2024. Influence of habitat and baiting strategy on oral rabies vaccine bait uptake by raccoons in the southeastern United States. Applied Animal Behaviour Science 277(106320).

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).