Abstract
<title>Abstract</title> <p> Large carnivores in the high-altitude Eastern Himalayas are difficult to monitor with conventional field methods, leaving their status poorly resolved. We used structured participatory interviews to document mammal distribution, community-perceived population change, and local threats across high-altitude terrain above 3,500 m in Arunachal Pradesh, north-east India. Across 2,434 interviews in 312 grid cells (10 × 10 km; median six respondents per cell), we recorded contemporary presence in 2017, recalled historical presence around 1998, perceived population trends, and threat severity for 16 mammal species. Contemporary distribution was analysed with a single-season community occupancy model, using respondents as within-cell replicates and conditioning detection on respondent certainty. Perceived change was assessed with two independent measures: a reporting-frequency generalised linear mixed model with grid-cell and respondent random effects, and the proportion of respondents reporting decline. Contemporary ranges were near-universal for most species: estimated occupancy was near its ceiling, and no environmental covariate was distinguishable from zero. Against this broad range persistence, four large carnivores showed convergent decline on both measures: tiger ( <italic>Panthera tigris</italic> ), Tibetan wolf ( <italic>Canis lupus chanco</italic> ), snow leopard ( <italic>Panthera uncia</italic> ) and common leopard ( <italic>Panthera pardus</italic> ). Reporting frequency declined significantly for tiger (77% to 45%) and Tibetan wolf (27% to 16%), and 82–100% of respondents who expressed a trend perceived declines across the four carnivores. Prey species were largely stable in range, although several were perceived to have declined in abundance. Perceived retaliatory killing co-occurred with grazing pressure across grid cells (Pearson's r = 0.57), strongest for wolves. These results indicate that decline is manifesting as reduced encounter frequency rather than range contraction — an early-warning window in which targeted action on livestock conflict may still be effective. Local ecological knowledge, analysed with frameworks matched to its structure, provides a defensible, low-cost basis for detecting large-carnivore change where instrumented monitoring is difficult. </p>