Familiarity Breeds Contempt: Combining Proximity Loggers and GPS Reveals Female White-Tailed Deer (Odocoileus Virginianus) Avoiding Close Contact With Neighbors

Abstract

ABSTRACT:Social interactions can influence infectious disease dynamics, particularly for directly transmitted pathogens. Therefore, reliable information on contact frequency within and among groups can better inform disease modeling and management. We compared three methods of assessing contact patterns: (1) space-use overlap (volume of interaction [VI]), (2) direct contact rates measured by simultaneous global positioning system (GPS) locations (,10 m apart), and (3) direct contact rates measured by proximity loggers (PLs; 1-m detection) among female white-tailed deer (Odocoileus virginianus). We calculated the PL:GPS contact ratios to see whether both devices reveal similar contact patterns and thus predict similar pathogen transmission patterns. Contact rates measured by GPS and PLs were similarly high for two within-group dyads (pairs of deer in the same social groups). Dyads representing separate but neighboring groups (high VI) had PL:GPS contact ratios near zero, whereas dyads further apart (intermediate VI) had higher PL:GPS contact ratios. Social networks based on PL contacts showed the fewest connected individuals and lowest mean centrality measures; network metrics were intermediate when based on GPS contacts and greatest when based on VI. Thus, the VI network portrayed animals to be more uniformly and strongly connected than did the PL network. We conclude that simultaneous GPS locations, compared with PLs, substantially underestimate the impact of group membership on direct contact rates of female deer and make networks appear more connected. We also present evidence that deer coming within the general vicinity of each other are less likely to come in close contact if they are in neighboring social groups than deer whose home ranges overlap little if at all. Combined, these results provide evidence that direct transmission of disease agents among female and juvenile white-tailed deer is likely to be constrained both spatially and by social structure, more so than GPS data alone would suggest.

Fine‐scale spatial genetic structure of deer in a suburban landscape

“…In suburban landscapes, space use is condensed because of the highly fragmented distribution of cover and food resources (Grund et al , Walter et al , Potopov et al ). Our findings are in agreement with recent studies that report that, although deer from the same social group do overlap and move together, deer from different social groups also frequently share space and may even come into contact with members of other groups (Magle et al , Schauber et al , Tosa et al ).…”

Genetic structure and recovery of white‐tailed deer in Missouri

“…Some genetic studies of white‐tailed deer corroborated the expected difference (Grear et al , Cullingham et al ), but others reported somewhat unexpected results including relatively low relatedness among co‐occurring females (Comer et al ) and lower spatial genetic autocorrelation among female yearlings compared to male yearlings (Kelly et al ). A host of factors have been suggested for reasons why fine‐scale genetic structure among females may be less evident than expected including greater hunting pressure, which is thought to increase dispersal rates and alter social group formation (Comer et al ; Tosa et al , ); a high degree of spatial overlap among social groups (Comer et al ); and lower variability in male breeding success, which dilutes the pattern of female relatedness in social groups (Blanchong et al ). In areas where forested patches are highly fragmented, such as northern Missouri, female dispersal rates may be more equal to males (Nixon et al ) and recent field observations corroborate this trend (B. J. Keller, Missouri Department of Conservation, personal communication).…”

Understanding and geo-referencing animal contacts: proximity sensor networks integrated with GPS-based telemetry

“…Notwithstanding study-specific trade-offs, the spatial information associated with contacts can remarkably increase the robustness of inference on animal encounters [36], enhancing a process-based interpretation of these observations [37]. This may prompt a completely new set of questions in behavioural ecology (e.g.…”