Population dynamics and spatial use by didelphid marsupials are fundamental for understanding gene flow, community structure, and ecosystem functioning, as these animals play key roles in seed dispersal, food web dynamics, metapopulation processes, and disease ecology. However, available data often show contradictory patterns across study areas. This study was developed in order to describe and analyze the home range of Didelphis albiventris in a broad landscape within the ecotonal region between the Atlantic Forest and Cerrado. Additionally, there were examined abundance, sex ratio, reproductive females, residence time or movement between fragments, and their relationships with body mass. Sampling was conducted over 14 months using Tomahawk, Sherman, and pitfall traps in a capture–mark–recapture design. Distances ranged from 0.20 to 4.16 km. Home ranges, based on three to six recaptures, varied from 2.10 to 8.49 km in perimeter and 0.0007 to 1.17 km² in area. There were captured 146 individuals (95 females and 51 males) with 126 recaptures. The mean litter size was six. The sex ratio favored females across all sampled fragments. The average residence time in fragments was 19.33 days. Regression analyses showed no significant relationship between body mass and displacement or permanence. Home ranges were larger than those previously reported. Females were more numerous and exhibited longer and more frequent movements between small forest fragments. Litter size was smaller than that reported for other regions of southeastern Brazil. Overall, D. albiventris in this region showed high abundance, a female-biased population, and expanded spatial use.
