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Background Gloger’s rule postulates that animals should be darker colored in warm and humid regions where dense vegetation and dark environments are common. Although rare in Canis populations, melanism in wolves is more common in North America than other regions globally and is believed to follow Gloger’s rule. In the temperate forests of the southeastern United States, historical records of red wolf (Canis rufus) and coyote (Canis latrans) populations document a consistent presence of melanism. Today, the melanistic phenotype is extinct in red wolves while occurring in coyotes and red wolf-coyote hybrids who occupy the red wolf's historical range. To assess if Gloger’s rule could explain the occurrence and maintenance of melanistic phenotypes in Canis taxa, we investigated differences in morphology, habitat selection, and survival associated with pelage color using body measurements, GPS tracking data, and long-term capture-mark-recapture and radio-telemetry data collected on coyotes and hybrids across the southeastern United States. Results We found no correlation between morphometrics and pelage color for Canis taxa. However, we observed that melanistic coyotes and hybrids experienced greater annual survival than did their gray conspecifics. Furthermore, we observed that melanistic coyotes maintained larger home ranges and exhibited greater selection for areas with dense canopy cover and wetlands than did gray coyotes. Conclusions In the southeastern United States, pelage color influenced habitat selection by coyotes and annual survival of coyotes and hybrids providing evidence that Gloger’s rule is applicable to canids inhabiting regions with dense canopy cover and wetlands. Greater annual survival rates observed in melanistic Canis may be attributed to better concealment in areas with dense canopy cover such as coastal bottomland forests. We suggest that the larger home range sizes of melanistic coyotes may reflect the trade-off of reduced foraging efficiency in lower quality wetland habitat for improved survival. Larger home ranges and differential use of land cover by melanistic coyotes may facilitate weak assortative mating in eastern coyote populations, in which melanistic animals may have lower success of finding compatible mates in comparison to gray conspecifics. We offer that our observations provide a partial explanation for why melanism is relatively low (

Infanticide is an antagonistic behavior that may provide an evolutionary benefit for the perpetrator. Cases of infanticide have rarely been reported in Neotropical carnivores. The objective of this study was to provide empirical evidence of infanticide in a local jaguar (Panthera onca) population in the Brazilian Pantanal. We present infanticide data from opportunistic sampling. Each month, from 2013 to 2015, we monitored pastures for evidence of livestock carcasses. A remotely triggered camera trap was placed at encountered fresh cattle carcasses. Through this monitoring, two cases of infanticide were recorded. Both cases occurred in close proximity to a cattle carcass, a large prey item that may attract multiple jaguars—including females with cubs around age of weaning—and increase the risk of infanticide. Our observations provide new empirical evidence of jaguar social behavior and intraspecific competitive interactions, potentially driven by locally high population density and resource provision.

Distinguishing between non-native species that coexist with native species and those that threaten their persistence is critical for conservation and management. We investigated this distinction for a non-native terrestrial snail (Succinea sp.) (Sp. B) that occurs with the closely-related Chittenango ovate amber snail (Novisuccinea chittenangoensis) (COAS), an endangered species that is restricted to a single, known site. In 2008 and 2009, we performed ex situ competition experiments to examine the effects of density and body size of Sp. B on growth and mortality of COAS. We also conducted mark-recapture surveys from 2002 to 2009 to document trends of the in situ population of COAS and to identify spatio-temporal factors that may mitigate any competitive interactions between COAS and Sp. B. We observed lower growth rates and higher mortality rates of COAS at higher densities and larger sizes of Sp. B, indicating that the species compete. Nevertheless, population trends indicated that COAS population size was fluctuating but not in decline, and the spatial distribution, phenology, and size structure of each species indicated that there were enough mitigating factors to allow COAS to persist in the presence of Sp. B. Collectively, these results suggest that temporal niche partitioning resulting from a trade-off between growth and longevity of each species may enable their coexistence. Our results also suggest that control of Sp. B is unnecessary and, more generally, underscore the importance of conducting research aimed at understanding the effects of non-native species before instituting long-term, costly, and potentially unnecessary control measures.

Efforts in isolating the relative effects of resources and disturbances on animal-distribution patterns remain hindered by the difficulty of accounting for multiple scales of resource selection by animals with seasonally dynamic drivers. We developed multi-scale, seasonal models to explore how local resource selection by the threatened forest-dwelling woodland caribou (Rangifer tarandus caribou) was influenced by both broad-scale landscape context and local resource heterogeneity in the intensively managed region of Charlevoix, Quebec, Canada, located on the southern border of the North American caribou range. We estimated resource selection functions using 23 GPS-collared caribou monitored from 2004 to 2006 and landscape data on vegetation classes, terrain conditions, and roads. We found evidence of thresholds in road “proximity” effects (up to 1.25 km), which underscores the importance of including landscape context variables in addition to locally measured variables, and of fitting seasonal-specific models given temporal variation in the magnitude of selection and optimal scale of measurement. Open lichen woodlands were an important cover type for caribou during winter and spring, whereas deciduous forests, wetlands, and even young disturbed stands became important during calving and summer. Caribou consistently avoided roads and rugged terrain conditions at both local and landscape levels. Landscape context fundamentally constrains the choices available to animals, and we showed that failing to consider landscape context, or arbitrarily choosing an inappropriate scale for measuring covariates, may provide biased inferences with respect to habitat selection patterns. Effective habitat management for rare or declining species should carefully consider the hierarchical nature of habitat selection.

Animals may respond to spatial and temporal heterogeneity by altering their movement patterns. The time an animal spends in an area of a given size is termed ȁ8first-passage timeȁ9 and can be used to identify the scales at which different movement processes occur. Using first-passage time and 2-h observations, we identified nested spatial scales representing three movement behaviours for elk (Cervus elaphus) – inactive/resting (moves

It is usually assumed that landscape heterogeneity influences animal movements, but understanding of such processes is limited. Understanding the effects of landscape heterogeneity on the movements of large herbivores such as North American elk is considered very important for their management. Most simulation studies on movements of large herbivores use predetermined behavioral rules based on empirical observations, or simply on what seems reasonable for animals to do. Here we did not impose movement rules but instead we considered that animals had higher fitness (hence better performance) when they managed to avoid predators, and when they acquired important fat reserves before winter. Individual decision-making was modeled with neural networks that received as input those variables suspected to be important in determining movement efficiency. Energetic gains and losses were tracked based on known physiological characteristics of ruminants. A genetic algorithm was used to improve the overall performance of the decision processes in different landscapes and ultimately to select certain movement behaviors. We found more variability in movement patterns in heterogeneous landscapes. Emergent properties of movement paths were concentration of activities in well-defined areas and an alternation between small, localized movement with larger, exploratory movements. Even though our simulated individuals moved shorter distances that actual elk, we found similarities in several aspects of their movement patterns such as in the distributions of distance moved and turning angles, and a tendency to return to previously visited areas.