# Intraspecific Contact Among White‐Tailed Deer: A Literature Review and Chronic Wasting Disease Case Study

## TL;DR

This study reviews how white-tailed deer interact with each other and how these interactions may spread chronic wasting disease, focusing on social behaviors and spatial patterns.

## Contribution

The paper introduces a comprehensive framework for understanding intraspecific contact in white-tailed deer and applies it to chronic wasting disease transmission.

## Key findings

- Intraspecific physical touch among deer is rare, occurring less than two times per hour.
- Chronic wasting disease-infected deer show similar contact rates to uninfected deer.
- Between-group disease transmission may be driven by socially dominant males acting as 'super-spreaders.'

## Abstract

White‐tailed deer (
Odocoileus virginianus
) are a valuable game mammal in the eastern United States necessitating detailed understanding of disease transmission. We conducted a literature review on intraspecific contact (i.e., interactions wherein disease transmission may occur) among deer. From 69 studies, we identified five themes underlying research on intraspecific deer contact: physical touch, social groups, spatial overlap, association rates, and social networks. Visual observations determined physical touch to be infrequent (< 2 touches/h) and indicated deer social groups were dependent on spatial dynamics of parturition and dispersal; most females remained with matriarchal family groups while males dispersed and formed bachelor groups. Assessed using global positioning system (GPS) monitoring, spatial overlap and association rates (i.e., instances of deer in close spatial–temporal proximity) were higher in correspondence to within‐group social dynamics, and between‐group scores were correspondingly low. Social network analyses indicated between‐group transmission may be driven by socially dominant males, often termed super‐spreaders (i.e., hosts infecting disproportionately high numbers of healthy individuals). We investigated these themes via a case study of deer infected with chronic wasting disease (CWD) in southcentral Pennsylvania, United States. We assessed spatial overlap and association rates using GPS monitoring data from 180 deer. Our results supported findings in the literature, showing strong correlations among spatial overlap, association rates, and correlated movements. Further, CWD‐infected deer exhibited similar association rates to deer in which CWD was not detected. Our literature review and case study indicate direct transmission of CWD and other diseases is likely greatest within social groups following seasonal behavioral dynamics and that between‐group transmission is likely driven by males via dispersal and mating interactions. Our results may be used to inform population management models with future work focused on high resolution spatial assessments of transmission in localized areas.

We identified five themes underlying research on intraspecific contact among white‐tailed deer: physical touch, social groups, spatial overlap, contact rates, and social networks. We found white‐tailed deer infected with chronic wasting disease exhibited similar rates of intraspecific contact as those without infections.