Individual animals strive to maximize fitness by gaining access to food while minimizing predation risk, and spatial knowledge of both forage resources and predation risks has long been presumed to be advantageous. Actual fitness benefits of site familiarity, however, have rarely been demonstrated. We placed GPS collars on 57 female black-tailed deer in coastal California over 4 years to track seasonal movements, determine home ranges, and monitor survival and cause of mortality. We used seasonal home ranges and core areas as measures of site familiarity and modeled how mortality risk varied with use of familiar areas, forage availability, age class, and elevational overlap with simultaneously collared pumas using Cox proportional hazards models. The use of familiar areas was the best predictor of mortality risk, and deer that had a 40 % probability of leaving their home range in a given week were four times more likely to die.Puma predation was the largest cause of mortality, and deer whose average weekly elevation was farther from the average elevation of pumas were less likely to die. While forage availability was not related to mortality risk, deer with lower forage availability were more likely to leave their home range during both summer and winter. Our results provide a rare example of fitness benefits associated with site familiarity and the use of familiar areas as a refuge from predation. The benefits of site familiarity are likely widespread in ungulates, especially when there are stable home ranges, complex habitats, and few cues of predation risk.

Direct effects of predators depend upon factors that can vary across seasons, including variations in the abundance and vulnerability of migrating prey. Past studies show conflicting results of whether puma (Puma concolor (L., 1771)) feeding ecology varies among seasons. We employed GPS collars to study puma feeding ecology in a single-prey system with migratory black-tailed deer (Odocoileus hemionus columbianus (Richardson, 1829)). We hypothesized that puma feeding ecology would vary based on changes in prey abundance and spatial distribution, as well as competition with scavengers and decomposers. Our results supported these hypotheses. Kill rates in number of ungulates/week were significantly higher in summer and autumn than in winter, likely owing to the increased availability and density of black-tailed deer fawns. The handling times of blacktailed deer ≥1 year old were significantly higher in winter than in spring, summer, or autumn. We speculated that reduced handling time in summer may have been influenced by black bear (Ursus americanus Pallas, 1780) kleptoparasitism and the decomposition of kills. Pumas killed black-tailed deer at higher elevations in summer than in winter, spring, or autumn, and the elevations correlated significantly with seasonal elevations used by black-tailed deer, suggesting that pumas exhibited seasonal foraging behaviours and tracked prey availability in a system with migrating prey.Résumé : Les effets directs de prédateurs dépendent de facteurs qui peuvent varier selon les saisons, y compris des variations de l'abondance et de la vulnérabilité de proies migratrices. Des études antérieures ont produit des résultats contradictoires quant à d'éventuelles variations de l'écologie alimentaire du couguar (Puma concolor (L., 1771)) selon la saison. Nous avons utilisé des colliers GPS pour étudier l'écologie alimentaire du couguar dans un système à proie unique, à savoir le cerf mulet migrateur (Odocoileus hemionus columbianus (Richardson, 1829)). Nous avons postulé que l'écologie alimentaire du couguar variait selon les variations de l'abondance et de la répartition spatiale des proies, ainsi que la concurrence de détritivores et de décomposeurs. Nos résultats appuient ces hypothèses. Les taux de capture en ongulés/semaine étaient significativement plus élevés à l'été et l'automne qu'à l'hiver, vraisemblablement en raison de la disponibilité et la densité accrues de paons de cerf mulet. Les temps de consommation de cerfs mulets de ≥1 an étaient significativement plus élevés en hiver qu'au printemps, en été et en automne. Nous pensons que les temps de consommation plus courts durant l'été pourraient avoir être influencés par le cleptoparasitisme d'ours noirs (Ursus americanus Pallas, 1780) et la décomposition des captures. Les couguars tuaient des cerfs mulets à de plus hautes altitudes en été qu'en hiver, au printemps et en automne, et les altitudes étaient significativement corrélées aux altitudes saisonnières fréquentées par les cerfs mulets, ce qui donne à penser que les couguars f...

Effective species management and conservation relies on accurate estimates of vital rates and an understanding of their link to environmental variables. We used multistate capture-mark-recapture models to directly quantify effects of predation on age-specific survival of black-tailed deer Odocoileus hemionus columbianus in California, USA. Survival probabilities were derived from individual encounter histories of 136 fawns and 57 adults monitored over 4 years. Based on results from our survival analysis we parameterized a Lefkovitch matrix and used elasticity analyses to investigate contributions of mortality due to predation to changes in population growth. We found strong evidence for age-specific survival including senescence. Survival of females [1 year old was consistently low (0.56 ± 0.18 for yearlings, 0.77 ± 0.13 for prime-aged females, and 0.55 ± 0.08 for senescent individuals), primarily due to high puma Puma concolor predation during summer. Predation from black bears Ursus americanus and coyotes Canis latrans was the primary cause for low annual survival of fawns (0.24 ± 0.16). Resulting estimates of population growth rates were indicative of a strongly declining population (k = 0.82 ± 0.13). Despite high sensitivity to changes in adult survival, results from a lower-level elasticity analysis suggested that predation on fawns was the most significant individual mortality component affecting population decline. Our results provide a rare, direct link between predation, age-specific survival and the predicted population decline of a common ungulate species. The magnitude of predation was unexpected and suggests that ungulates in multi-predator systems struggle to cope with simultaneous reductions in survival probabilities from predators targeting different age classes.

Habitat selection is a complex hierarchical process and in ungulates typically varies at broad spatial and temporal scales and among individuals. Recent advancements in the ability of global positioning system (GPS)‐collars to collect activity data provide opportunities to understand underlying mechanisms or trade‐offs responsible for fine‐scale variation in habitat selection. Based on data from 64 female black‐tailed deer (Odocoileus hemionus columbianus) fitted with GPS‐collars in northern California, USA, between 2004 and 2013, we first investigated habitat selection at the home range scale. We then used data from a subset of 27 individuals to determine if habitat selection within home ranges was influenced by activity states (active or inactive). Habitat selection by black‐tailed deer varied between summer and winter and was mostly explained by differences in elevation, terrain, and vegetation. Within their home ranges, black‐tailed deer showed fine‐scale selection for habitats that varied with activity states. In summer, selection for edge density and forest types varied across activity states highlighting important fine‐scale selection patterns. Activity state also affected our conclusions about the selection of habitats including slope, canopy cover, and forest types by black‐tailed deer in winter. During both seasons, deer selected for apparently secure habitat when inactive, likely to minimize risk of predation. These results highlight the importance of considering activity states when evaluating habitat selection from animal location data. This is particularly important in multi‐use landscapes such as national forests where habitat needs of ungulates are important considerations in management decisions, including timber harvest. © 2018 The Wildlife Society.

Site fidelity and philopatry are behavioral adaptations found in many species and their fitness benefits are well documented. The combined population level consequences of site fidelity and philopatry, however, have received little attention despite their importance for understanding spatial patterns in connectivity and population dynamics. We used an integrative approach to explore consequences of fidelity and philopatry on the fine-scale genetic structure of black-tailed deer (Odocoileus hemionus columbianus). We assessed fidelity to seasonal home ranges based on location data from 64 female deer fitted with global positioning system (GPS) collars between 2004 and 2013. We assessed philopatry from mitochondrial DNA (mtDNA) haplotypes using DNA extracted from 48 deer. Results based on location data revealed very small movements and seasonal home ranges together with high site fidelity. Fidelity improved survival; every 1 km increase in mean interlocation distances between consecutive summers increased the risk of mortality by 56.5%. Results from mtDNA sequencing revealed high genetic differentiation (F ST > 0.30) and low haplotype sharing among geographic areas separated by as little as 4-10 km. The high genetic differentiation indicated multigenerational periods of philopatric behavior in the matrilineage of black-tailed deer. Combined these results suggest that site fidelity together with strong sex-biased philopatry can create marked short-and long-term demographic isolation and trap matriarchal units as a subset of the larger population with locally determined vital rates. Where such fine-scale population structuring as a consequence of fidelity and philopatry occurs, matrilineal groups might in some cases best serve as the basic units of conservation and management.