Modeling the wildlife–livestock interface of cattle fever ticks in the southern United States

Authors: PFEIFFER, VERA - Washington State University; GARCIA-CARRASCO, JOSE-MARIA - Washington State University; CROWDER, DAVID - Washington State University; Ueti, Massaro; Poh, Karen; GUTIERREZ ILLAN, JAVIER - Washington State University

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/4/2025
Publication Date: 9/6/2025
Citation: Pfeiffer, V.W., Garcia-Carrasco, J., Crowder, D.W., Ueti, M.W., Poh, K.C., Gutierrez Illan, J. 2025. Modeling the wildlife–livestock interface of cattle fever ticks in the southern United States. Insects. 16(9). Article 940.
DOI: https://doi.org/10.3390/insects16090940

Interpretive Summary: Cattle fever ticks (CFT) transmit Babesia bovis and Babesia bigemina, which can cause bovine babesiosis in cattle. Even though bovine babeiosis has been eradicated from the US, CFTs are still commonly found along the permanent quarantine zone at the Texas-Mexico border. If the pathogen is found in these ticks, livestock populations in the US will be greatly affected, especially industries located in the southeastern US where much of the livestock industry is located. One major challenge to the complete eradication of CFTs, is the presence of wildlife, such as white-tailed deer (WTD) and nilgai, that may act as a host to sustain tick populations. To address the potential range of these two wildlife hosts, this project developed species distribution models for WTD and nilgai. White-tailed deer were likely to be found throughout much of the southeastern US, but much less so in the western US. On the other hand, based on the nilgai's native range in India, much of south Texas along the Texas-Mexico border provide suitable habitats for these animals. The possible range expansion of these two CFT hosts based on habitat suitability models continue to threaten the livestock industry and thusly, their populations should be monitored closely.

Technical Abstract: Cattle fever ticks (CFT) are the most economically important pests of cattle in the world, and the recent increase of tick incursions in Texas challenges the Cattle Fever Tick Eradication Program (CFTEP). Heightened pressure from growing wildlife host populations along the Texas-Mexico border is a pressing complication for CFT control initiatives. Spatially explicit prediction of wildlife host distribution may provide information essential for allocation of resources by the CFTEP. In this study, we use species distribution models to project the distribution of white-tailed deer (WTD) and nilgai in the southeastern US to improve our understanding of cattle exposure to native and introduced wildlife hosts of CFT. Our results reveal that ubiquitous WTD presence in the southeastern US tapers off in the arid west, limiting exposure of US cattle to WTD along the Texas-Mexico border. Additionally, the nilgai distribution model based on the species' native range in India indicates a moderate probability of habitat suitability throughout the southeastern US, and a high probability of habitat suitability in southern and eastern Texas. The expansion of nilgai across their projected suitable habitat increases cattle exposure to CFT wildlife hosts, especially in sensitive, transitional areas along the Texas-Mexico border. We posit that modeling existing wildlife hosts and the potential range expansion of introduced wildlife hosts, and overlaying these models with cattle inventory will ultimately help direct efforts to monitor ticks, prevent incursions, and initiative early interventions.