Why Size Does Not Matter: Sex Driven Home Range Differences in Brown Bears.

Area of Science:

• Ecology
• Zoology
• Wildlife Biology

Background:

• Home range size in large mammals is influenced by sex, body size, and environment.
• The relative importance of these factors is unclear for wide-ranging carnivores like brown bears.

Purpose of the Study:

• To investigate the relationship between home range size and sex, body mass, and body dimensions in brown bears in Türkiye.
• To determine the primary intrinsic driver of home range size in this population.

Main Methods:

• Utilized GPS-collar data and morphometric measurements from 69 brown bears (46 males, 23 females).
• Estimated home ranges using minimum convex polygon (MCP95) and kernel utilization distribution methods.
• Analyzed data using linear models incorporating sex, body mass, body dimensions, and sampling effort covariates.

Main Results:

• Male brown bears exhibited nearly twice the home range size (MCP95) compared to females.
• Sex accounted for the majority of the variance in home range size; body mass and dimensions did not show significant within-sex relationships.
• Multivariate analysis of morphometric traits did not explain additional variation in home range size once sex was considered.

Conclusions:

• Sex is the primary intrinsic driver of home range size in the studied brown bear population, superseding body size and shape.
• Conservation and spatial planning strategies for brown bears should prioritize sex-specific considerations rather than size-specific ones.