Abstract: To investigate the habitat characteristics and habitat preferences of Hynobius yiwuensis during the breeding season, we conducted a systematic survey in Jinhua City, Zhejiang Province, in December 2023. Based on data from 38 study plots and 57 control plots, we quantitatively analyzed its habitat preferences and ecological adaptation mechanisms by using principal component analysis (PCA) and resource selection function (RSF) models. The results showed that H. yiwuensis preferred small temporary and still water ponds with lower water temperature [(10.20±0.51) ℃], slightly alkaline pH (7.14±0.04), and water transparency of 0.2-0.4 m, with an average area of (85.97±40.79) m². The riparian vegetation was dominated by bamboo forests (42.1%) and grasslands (28.9%). The coverage of submerged vegetation in breeding pits reached 65.8%. Key influencing factors included physical water characteristics (area, temperature), water quality indicators (pH, transparency), vegetation types (riparian bamboo forests, submerged plants), and egg mass substrates, with habitat selection synergistically regulated by factors of water-vegetation-terrain. Our results revealed the quantitative characteristics of breeding habitat in H. yiwuensis, which would provide a scientific basis for targeted conservation and management of this endangered species and its habitat.

Key words: Hynobius yiwuensis, habitat characteristics, habitat selection