Sex-specific effects of reproductive season on bobcat space use, movement, and resource selection in the Appalachian Mountains of Virginia

Abstract

Across taxa, sex-specific demands vary temporally in accordance with reproductive investments. In solitary carnivores, females must provision and protect young independently while meeting increased energetic demands. Males seek to monopolize access to females by maintaining large territories and defending them from other males. For many species, it is poorly understood how these demands relate to broad-scale animal movements. To investigate predictions surrounding the reproductive strategies of solitary carnivores and effects of local conditions on bobcat (Lynx rufus) spatial ecology, we examined the effects of sex and reproductive season on home range size, movement rate, and resource selection of bobcats in the central Appalachian Mountains. Male seasonal home ranges were approximately 3 times larger than those of females (33.9 ± 2.6 vs. 12.1 ± 2.4 km 2 , x±SE), and male movement rates were 1.4 times greater than females (212.6 ± 3.6 vs. 155 ± 8.2 m/hr), likely reflecting male efforts to maximize access to females. Both sexes appear to maintain relatively stable seasonal home ranges despite temporally varying reproductive investments, instead adjusting movements within home ranges. Males increased movements during the dispersal period, potentially reflecting increased territoriality prior to breeding. Females increased movements during the kitten-rearing period, when foraging more intensively, and frequently returning to den sites. Both sexes selected home ranges at higher elevations. However, females selected deciduous forest and avoided fields, whereas males selected fields and avoided deciduous forest, perhaps explained by male pressure to access multiple females across several mountain ridges and higher risk tolerance. Seasonal changes in home range selection likely reflect changes in home range shape. Increased female avoidance of fields during kitten rearing may indicate female avoidance of presumably resource rich, yet risky, fields at the time when kittens are most vulnerable. Our results indicate that while reproductive chronology influences the spatial ecology of solitary carnivores, effects may be constrained by territoriality.

Transient persistence of bobcat (Lynx rufus) occurrence throughout a human‐dominated landscape

“…We expected to observe temporal differences in sitelevel colonization and extirpation probabilities either seasonally (winter vs. summer) or over the course of our study (survey season 1 to survey season 6); however, neither season nor survey year was included in any of our most supported models for site-level colonization or extirpation. Prior studies have observed differences in resource selection between seasons (McNitt et al, 2020), so we expected to observe similar differences in site-level colonization and extirpation between seasons. The lack of a temporal response indicates that landcover and anthropogenic factors are the main drivers of bobcat occurrence.…”

“…Previous studies in the region have showed that young male bobcats have very large home ranges (Mayer et al, 2021), so while a camera may be placed within their home range, the extent of the animal's movements throughout their home range may preclude it from having the opportunity to pass by that camera within the 6‐week survey period. Additionally, males typically have larger home ranges and higher frequency of movements within their home range than females as a result of breeding and kitten‐rearing (Conner & Plowman, 1999; McNitt et al, 2020). These differences may affect the probability of detecting a female, and thus decrease overall detection probabilities.…”

Bobcat Hair Cortisol Correlates with Land Use and Climate

“…Additionally, the reproductive demands borne solely by females (gestation, parturition, lactation, parental care) can greatly influence the ecology (McNitt et al 2020) and biology (i.e., cortisol levels; Edwards and Boonstra 2018) of carnivores. The hormonal influence may be substantial for months beyond the reproductive period (Bacci et al 2014).…”

Influence of natal habitat preference on habitat selection during extra‐home range movements in a large ungulate

“…Within this extent, we calculated the Euclidean distance from the forest and agriculture cover types for each pixel, resulting in two distance covariates (dForest and dAg). We used this approach because distance‐based habitat selection analyses are more robust to telemetry error than classification‐based approaches, provide information about selection for proximity to features that may not be explicitly used by the animal, and eliminate the need for inference based upon a reference land cover category (Conner et al, 2003 ; McNitt et al, 2020 ). We then retrieved stream polyline features from the 2019 USGS National Hydrography Dataset ( https://www.usgs.gov/national‐hydrography/national‐hydrography‐dataset ) and primary/secondary road polyline features from the U.S. Census Bureau TIGER/Line dataset ( https://www.census.gov/geographies/mapping‐files/time‐series/geo/tiger‐line‐file.2011.html ), clipped both layers to the study area extent, and generated Euclidean distance rasters at 30‐m resolutions.…”