Black bears alter movements in response to anthropogenic features with time of day and season

Abstract

Background With the growth and expansion of human development, large mammals will increasingly encounter humans, elevating the likelihood of human-wildlife conflicts. Understanding the behavior and movement of large mammals, particularly around human development, is important for crafting effective conservation and management plans for these species. Methods We used GPS collar data from American black bears ( Ursus americanus ) to determine how seasonal food resources and human development affected bear movement patterns and resource use across the Commonwealth of Massachusetts. Results We found that though bears moved more and avoided human development during crepuscular and daylight hours than at night, bears preferentially moved through human dominated areas at night. This indicates bears were mitigating the risk of human development by altering their behavior to exploit these areas when human activity is low. This behavioral shift was most prominent in the spring, when natural foods are scarce, and fall, when energetic demands are high. We also observed a high degree of inter-individual variability among our sample of bears. Bears with a higher density of houses in their home ranges (~ 75 houses/km2) displayed less avoidance of human development than more rural bears. Furthermore, bear movement models had different explanatory variables, with preference or avoidance of a variable being dependent on the individual bear. To account for this individuality in our predictive surfaces, we projected the probability of movement for each season and time of day using a spatially weighted surface centered on each bear’s home range. Conclusions We found that black bears in Massachusetts are operating in a landscape of fear and are altering their movement patterns to use developed areas when human activity is low. We also found seasonal and diel differences among individual bears in resource selection during movement. Accounting for these individual, seasonal, and diel differences when assessing movement for large mammals is especially important if predictive surfaces are to be used in identifying areas for conservation and management. Electronic supplementary material The online version of this article (10.1186/s40462-019-0166-4) contains supplementary material, which is available to authorized users.

Movement behaviour of two social urticating caterpillars in opposite hemispheres

“…Precautions are needed to reduce cutaneous or systemic symptoms that can be caused by medically important Lepidoptera species (see below). Alongside the studies on black bears [1] and fire ants [2] (see Background), determining movements of organisms is crucial when it comes to human and animal interactions. Much of the information for O. lunifer and T. pityocampa pre-pupation processions presented here is novel.…”

“…As humans modify the environment and expand its use for agriculture, housing and recreation, encountering wildlife is not out of the ordinary. Investigating movements of black bears by Zeller et al [1] highlighted the importance of conservation and management of these species in human development. On the other hand, human-induced environmental change has exacerbated the spread of the highly invasive fire ants in United States [2].…”

Forecasting Seasonal Habitat Connectivity in a Developing Landscape

“…The IBMMs were modeled across resistance surfaces representing the ease or difficulty of bear movement across each grid cell in the study area. Individual black bears have varying movement responses to landscape features during different seasons and different times of day, which may translate into different resistance surfaces for each season/diel period [11]. Bears in our study area hibernate in the winter, and during the nonhibernation period they move the least in the spring and the most in the summer [11].…”

“…This filtering was performed to minimize the locational error to < 100 m and resulted in a mean data loss of 3.93% [37,38]. More capture, handling, and data processing procedures are detailed in Zeller et al [11].…”

“…For example, individuals from the same population may have differing responses to the same landscape features [9,10], driven by differences among males and females, age classes, spatial locations, or temperament (e.g., boldness) [10][11][12]. There may also be differing behaviors and responses to landscape features throughout a diel period and across seasons [11,13]. In addition, interannual variability may exist due to disturbance-succession processes, climatic variation, human development, and other landscape changes [14].…”