Aggressive interactions among white-tailed deer (Artiodactyla: Cervidae) at 4-poster devices for host-targeted tick control

Authors: BAI, NINGZHU - Pennsylvania State University; PESAPANE, RISA - Pennsylvania State University; MACHTINGER, ERIKA - Pennsylvania State University; Li, Andrew

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/25/2024
Publication Date: 5/10/2024
Citation: Bai, N., Pesapane, R., Machtinger, E.T., Li, A.Y. 2024. Aggressive interactions among white-tailed deer (Artiodactyla: Cervidae) at 4-poster devices for host-targeted tick control. Journal of Medical Entomology. 61(4):975-983. https://doi.org/10.1093/jme/tjae059.
DOI: https://doi.org/10.1093/jme/tjae059

Interpretive Summary: White-tailed deer are important hosts for the blacklegged tick and other tick species that transmit Lyme disease and other tick-borne diseases to humans. The USDA-developed ‘4-Poster’ feeders / treatment station has been used as host-targeted tick control tool to suppress tick populations in environment. The efficacy of the device in tick control can be affected by many factors, including the availability of alternative food sources, use by non-target wildlife, and the density of deer populations. Deer behaviors, specifically intraspecific social interactions, are rarely considered in deploying host-targeted acaricide devices yet may impact the efficacy of tick control and/or result in unintended consequences for the deer population that conflict with wildlife management objectives. USDA ARS scientists led a team including university researchers to investigate how deer aggressive behaviors may interfere with the use of 4-poster feeding stations at three field locations in Maryland. Specifically, we quantified aggressive behaviors by time, season, number of individuals, site, and the number of contacts with rollers at baited 4-poster stations. Analysis of image data collected by camera traps at deployed ‘4-poster’ feeding stations revealed a high-level of aggressive behavior among deer, suggesting that deer social dynamics can disrupt ‘4-poster’ use. This study serves as a reminder that intra-species interactions are among important factors that may affect tick control efficacy of the ‘4-poster’ deer bait station and other host-targeted tick control devices.

Technical Abstract: White-tailed deer (Odocoileus virginianus) are the primary wildlife host for blacklegged ticks (Ixodes scapularis) and lone star ticks (Amblyomma americanum), which are the vectors of numerous tick-borne pathogens. The 4-poster passive deer treatment device is a topical, host-targeted method to control free-living tick populations and has been proven to successfully reduce tick abundance in several states. Aggressive behavior of white-tailed deer at concentrated feeding stations are hypothesized to decrease deer use of 4-poster devices and contact with the acaricide applicators, negatively affecting the devices' efficacy in controlling ticks. We analyzed images collected by camera traps at 4-poster feeding stations deployed at three sites in Maryland and found a negative relationship between aggressive behavior and contact with applicators. We found that when aggression occurred, 75% of all behavioral interactions observed in photos were aggressive, and feeding behaviors or contact with rollers was observed in just 26% and 16% of photos, respectively. Our results suggest that deer social dynamics can disrupt 4-poster use, and potentially, mean that maintenance costs outweigh the benefits of using 4-posters to control ticks at these sites. This study serves as a reminder that intra- and inter-species interactions are important to any wildlife management approach.