Frequency and duration of contacts between free-ranging raccoons: uncovering a hidden social system

Abstract

Raccoons (Procyon lotor), like most carnivores, are nocturnal and secretive and consequently difficult to observe. We used proximity-detecting collars to determine effects of sex, age, and season on contact rate and duration; document patterns of seasonal contact rates by dyad type and determine whether patterns were random; identify dyads that exhibited contact rates significantly greater than expected and document the persistence of these positive associations across seasons; and document frequency of den sharing as an additional measure of positive associations at an urban study site with a high-density raccoon population. Contact rate and duration were affected by dyad type, season, and their interaction. Male-male (MM) dyads exhibited higher contact values than male-female (MF) or female-female (FF) dyads, and contact parameters were greater during winter and spring than summer and autumn. Contact parameters for MM and FF dyads were not affected by age of dyad members, whereas those of MF dyads were affected by age and its interaction with season. MF dyads with older individuals exhibited greater contact parameters, and this effect was greatest during winter. For all dyad types and seasons, except FF dyads during winter, observed distributions of contact rates differed from expected. Males formed groups, with most positively associated dyads persisting across seasons, and females were associated almost exclusively with members of only 1 male group. Some positively associated MF dyads occurred during autumn and continued through spring. Positively associated FF dyads occurred at a lower rate and were ephemeral, seldom lasting more than 1 season. FF and MF dyads exhibited a greater proportion of low-frequency contacts with conspecifics than expected during all seasons, except winter, which may function to maintain amicable relationships between neighbors or reinforce dominance hierarchies and create a framework for more complex social behaviors. Raccoons appear to live in a fission-fusion society, with many short-term acquaintances and a few long-term associations.

The golden age of bio‐logging: how animal‐borne sensors are advancing the frontiers of ecology

“…proximity collars on raccoons (Prange et al 2011) How do social organization and cooperation stabilize each other in multilevel societies?…”

“…For instance, Prange et al (2011) demonstrated that raccoons (Procyon lotor) fitted with proximity loggers exhibited considerably greater sociality than commonly recognized. Their social interactions were characterized by high fission-fusion dynamics with many short-term interactions and few long-term associations.…”

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

“…predator-prey interactions [22]; intra-specific relationships [23]; social systems [24]) and wildlife epidemiology (i.e. by evaluating contact rate [10]).…”

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

“…Past researchers have quantified contact rates by visual observations (Totton et al 2002), simultaneous telemetry locations (very high frequency [VHF] or global positioning system [GPS]) within a specified distance (e.g., ,10 m, Ramsey et al 2002;Schauber et al 2007), or proximity loggers ([PLs]; Ji et al 2005;Prange et al 2011) but, few studies compare these methods (Walrath et al 2011). Visual observations are challenging for nocturnal and cryptic animals, except at feeding or watering areas.…”