Impacts of Seasonality on Activity Budgets and Spatial Movement of Geladas () in Susgen Natural Forest, South Wollo, Ethiopia.

The gelada (), Ethiopia's only endemic primate and the last surviving graminivorous cercopithecid, was studied in Susgen Natural Forest, South Wollo, to examine seasonal variations in activity budgets and ranging ecology. From February to August 2023, encompassing both dry and wet seasons, 3519 behavioral scans were collected from 1680 group observations using instantaneous scan sampling at 15-min intervals (07:00-17:00 h). Data were analyzed with descriptive statistics and nonparametric tests (Kruskal-Wallis and Mann-Whitney ), while home ranges were mapped via minimum convex polygon (MCP) and kernel density estimation (KDE). Results revealed that geladas allocated 43.2% of their time to feeding, 15% to movement, 15.5% to social activities, 13.1% to resting, and 13.2% to other behaviors. Dry seasons elicited significantly greater feeding effort (46.1% vs. 40.4%; < 0.05) and daily travel distances (3658.4 ± 0.902 m vs. 3132.1 ± 2.367 m in wet season; Mann-Whitney , ≤ 0.05), with home ranges analyzed through the MCP method expanding to 190.1 ha in dry season as compared with 118.18 ha in wet season. KDE analysis identified the intensive use of core areas (54 ha) within broader ranges (164.95 ha). These findings underscore how geladas in human-modified landscapes face chronic nutritional stress, adapting through extended foraging and ranging patterns. We recommend immediate conservation measures, including habitat restoration and buffer zone establishment, to mitigate anthropogenic pressures on this threatened endemic species.