Fluctuations of wild goat populations in relation to weather factors in central Alborz Protected Area

Long-term population trajectories of wild goats ( Capra aegagrus ) remain poorly understood, despite growing evidence that climate variability strongly influences large herbivores. Using one of the longest continuous wildlife datasets in the region, we analyzed 27 years of monitoring in the high-elevation Golestanak core zone of the Central Alborz Protected Area to examine how year-to-year fluctuations respond to key weather conditions. Daily observations from standardized patrols were paired with monthly records of temperature, precipitation, humidity, and snowfall. Population fluctuations were quantified using a Species Sighting Rate (SSR) index, and monthly climatic effects were assessed using GLMs. The population showed clear multi-year cycles, with strong growth from 54 individuals in 1997 to 118 in 2003, a sharp decline to 25 by 2010, a moderate recovery to 59–69 by 2017, and a brief spike to 113 in 2018, before stabilizing at lower levels around 50 by 2023, highlighting continued volatility. June and November critical periods for birth and mating consistently emerged as the most influential months: higher June rainfall and temperature were associated with reduced SSR, whereas November snow depth, temperature, and humidity promoted population increases, while November rainfall had a negative effect. Only June temperature showed a significant long-term rise, indicating increasing warming pressure on early-summer habitats. Nevertheless, climate alone could not account for the largest fluctuations. Disease outbreaks, poaching, habitat loss, livestock grazing, and major infrastructure development likely amplified declines, highlighting the species’ vulnerability to combined climatic and anthropogenic stressors. Effective conservation will require integrating climate-sensitive management with habitat protection, ecological corridor restoration, and mitigation of livestock–wildlife disease risks.