Moving in a crowded world: ecological and human-related factors affecting brown bear (Ursus arctos) space-use patterns

• Main Author: DE ANGELIS, DANIELE
• Other Authors: Valutatori esterni: Jon Swenson, John Fieberg, Anne Loison, Tutor esterno: Josip Kusak, DE ANGELIS, Daniele, CIUCCI, Paolo, PASQUA, Gabriella
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Università degli Studi di Roma "La Sapienza" 2019
• Subjects: Brown bear; movement ecology; space-use pattern; large carnivore; home range; landscape connectivity; resource selection function; step selection function; partial miigration; Settore BIO/05 - Zoologia; Settore BIO/07 - Ecologia; Ursus arctos
• Online Access: http://hdl.handle.net/11573/1231370

Under the current scenario of human expansion and land-use change, one resource emerges as being particularly disputed between humans and other wildlife species: space. The spatiotemporally detailed and real-time nature of Global Positioning System (GPS) tracking data supports the use of tagged animals as in situ sensors of the environment, to document how ongoing changes are affecting species’ distribution and ecological function. Large carnivores are particularly susceptible to disturbance from infrastructure development, and can represent a promising case study to investigate the effects of human expansion on species spatial ecology at multiple levels, spanning from patch- to landscape scales. I investigated space-use patterns in a south-eastern European population of brown bears (Ursus arctos), whose distribution is shared among more than five countries, from Slovenia to Northern Greece, with its core area located between Slovenia and Croatia. In the first chapter, I investigated ecological and human-related effects on home range size and inner configuration of Dinaric brown bears (Ursus arctos) contrasting two areas, one located in the North (n= 5 bears, 1 females, 4 males) and one in the South (n= 5 bears, 2 females, 3 males), which differed in terms of road and human density, as well as in the availability of supplementary feeding sites. I used Brownian bridge movement models (BBMMs) to estimate circadian and seasonal home ranges and I used linear mixed-effect models (LMM) to investigate the effects of gender, time of the day, season and study area on home range size. Using an individual- based method, I also depicted seasonal core areas and used Environmental Niche Factor Analysis (ENFA) to assess if the internal configuration of seasonal home ranges changed among study areas. Although we failed to find a sex effect on home range size, time of day was an important predictor of home range size, with nocturnal home ranges larger (103.3 km2 72.8) than diurnal ones (62.3 km2 16.6). Then, I detected a ...