title: The Influence of Sex and Season on Conspecific Spatial Overlap in a Large, Actively-Foraging Colubrid Snake.
abstract: Understanding the factors influencing the degree of spatial overlap among conspecifics is important for understanding multiple ecological processes. Compared to terrestrial carnivores, relatively little is known about the factors influencing conspecific spatial overlap in snakes, although across snake taxa there appears to be substantial variation in conspecific spatial overlap. In this study, we described conspecific spatial overlap of eastern indigo snakes (Drymarchon couperi) in peninsular Florida and examined how conspecific spatial overlap varied by sex and season (breeding season vs. non-breeding season). We calculated multiple indices of spatial overlap using 6- and 3-month utilization distributions (UD) of dyads of simultaneously adjacent telemetered snakes. We also measured conspecific UD density values at each telemetry fix and modeled the distribution of those values as a function of overlap type, sex, and season using generalized Pareto distributions. Home range overlap between males and females was significantly greater than overlap between individuals of the same sex and male home ranges often completely contained female home ranges. Male home ranges overlapped little during both seasons, whereas females had higher levels of overlap during the non-breeding season. The spatial patterns observed in our study are consistent with those seen in many mammalian carnivores, in which low male-male overlap and high inter-sexual overlap provides males with greater access to females. We encourage additional research on the influence of prey availability on conspecific spatial overlap in snakes as well as the behavioral mechanisms responsible for maintaining the low levels of overlap we observed.
authors.affiliation: Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, United States of America.
authors.forename: Javan M
authors.initials: JM
authors.lastname: Bauder
authors.affiliation: NASA Ecological Programs, Integrated Mission Support Services, Kennedy Space Center, Florida, United States of America.
authors.forename: David R
authors.initials: DR
authors.lastname: Breininger
authors.affiliation: NASA Ecological Programs, Integrated Mission Support Services, Kennedy Space Center, Florida, United States of America.
authors.forename: M Rebecca
authors.initials: MR
authors.lastname: Bolt
authors.affiliation: Merritt Island National Wildlife Refuge, Titusville, Florida, United States of America.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Legare
authors.affiliation: The Orianne Society, Athens, Georgia, United States of America.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Jenkins
authors.affiliation: Archbold Biological Station, Venus, Florida, United States of America.
authors.forename: Betsie B
authors.initials: BB
authors.lastname: Rothermel
authors.affiliation: Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, United States of America.
authors.forename: Kevin
authors.initials: K
authors.lastname: McGarigal
mesh_terms: D000818:Animals; D017812:Colubridae / Q000502:physiology*; D017753:Ecosystem; D005260:Female; D005431:Florida; D006702:Homing Behavior; D008297:Male; D012621:Seasons; D012725:Sexual Behavior / Q000502:physiology*; D013686:Telemetry