Activity and resource selection of a threatened carnivore: the case of black bears in northwestern Mexico

Abstract

Abstract. Management and conservation strategies for endangered species require information on their temporal and spatial behavioral and habitat use relationships. We evaluated activity patterns and resource selection of black bears in northwestern Mexico. We surveyed 29 localities with 1450 camera traps stations from 2009 to 2013 in the states of Sonora and Chihuahua, Mexico. In each locality, we calculated the proportion of diurnal, nocturnal, and crepuscular activity through a kernel density estimator based on the time of independent photographic events, and we built a beta regression between diurnal density and annual temperature, seasonal rainfall (SR), human density, road density, daylight hours, season, and management type. To evaluate resource selection, we built a binomial logistic regression model incorporating Normalized Difference Vegetation Index (NDVI), mean and coefficient of variation of annual temperature, human population density (PD), terrain roughness, and season. Black bear activity was primarily diurnal with a bimodal tendency around sunrise and sunset. Diurnal activity (between sunrise and sunset) was positively influenced by daylight hours, SR, and private reserves and negatively influenced by anthropogenic factors. Resource selection was positively influenced by the coefficient of variation in temperature and NDVI and negatively associated with average annual temperature, PD, and terrain roughness. Activity patterns and resource use were similar to other regions in North America. However, temperature was one of the main factors influencing black bear activity and resource selection in our study areas and should be considered when developing management plans given projected increases in temperature expected under climate change scenarios. We present the first work of its kind for northwestern Mexico and considered it as an important component in future survey and management protocols for the species in the southern portion of its distribution.

The effectiveness of opportunistic public reports versus professional data to estimate large carnivore distribution

“…Elevation and mean vegetation productivity were the most important covariates regardless of data type, the latter being influential for ursid space use at broad scales in other areas (e.g., Duquette et al, 2017; Lara‐Díaz et al, 2018). Tye et al (2017) and Coxen et al (2017) also compared citizen and professional data for developing SDMs and found similar predictions and estimates of habitat relationships.…”

Influence of interspecific competition on mule deer birthing and rearing site selection

“…Because location data were not available for feral horses and cattle, we used data from our camera array to create RSFs through a used‐unused design (Manly et al 2002, Lara‐Diaz et al 2018). We created RSFs for each species using generalized linear mixed models with the glmmTMB package in R (Brooks et al 2017).…”

Pleistocene–Holocene vicariance, not Anthropocene landscape change, explains the genetic structure of American black bear (Ursus americanus) populations in the American Southwest and northern Mexico

“…Colorado Plateau and Southern Rocky Mountains, Datil-Mogollon Section, Mexican Highlands, and Sacramento Section) and populations separated by desert and isolated by distance had lower gene flow (e.g., Trans-Pecos and Boulder Mountain). Because female black bears are highly philopatric, the effect of distance on gene flow may be governed by their behavior, but also mediated by long-distance dispersal events by male bears with male bears also having been shown to select against ruggedness (Apps et al, 2006;Johnson et al, 2015;Lara-Díaz et al, 2018;Pelletier et al, 2011).…”

“…Black bears are forest obligates and have evolved morphological and behavioral adaptations associated with exploiting forest stands (Herrero, 1972) and they require thermal refugia (Lara-Díaz et al, 2018) because they are susceptible to hyperthermia (Sawaya et al, 2017). We modeled these features using canopy height (canopy), percent canopy (percan), and water bodies (water) as canopy provides thermal cover and water is necessary for thermoregulation, especially if bears crossed more inhospitable land cover such as desert.…”