Large-scale forest ecological restoration is commonly expected to improve habitat quality and promote population growth of forest-dependent herbivores. Yet, whether vegetation recovery facilitates or constrains herbivore growth and habitat use at local scales within nature reserves remains unclear, as vegetation recovery and canopy closure might alter forage availability and lead to ecological mismatch between vegetation features and population dynamic. Here, we used the endangered species South China sika deer as the study species, and its dominant distribution region—Qingliangfeng Biosphere Reserve—as the study area. Using decadal camera-trapping data (2015–2024) and extracted vegetation and other environmental variables, we quantified decadal trends in sika deer activity intensity and interannual variation in vegetation (leaf area index, LAI, and normalized difference vegetation index, NDVI). We incorporated topographic and anthropogenic disturbance variables and applied generalized linear mixed models and generalized linear models to analyze its habitat use. We found that: (1) Numbers of independent photographs and the relative abundance index of sika deer increased significantly and consistently from 2015 to 2024. (2) LAI exhibited substantial interannual variability without a stable trend. In contrast, segmented regression identified a clear temporal breakpoint in NDVI, with a significant increasing trend before 2021 followed by a pronounced decline thereafter. (3) In all years, distance to settlement had a significant and negative effect on activity intensity, whereas distance to road, elevation, and year had significant positive effects. LAI and NDVI showed negative and weak effects on sika deer activity intensity. In specific years, LAI had a significantly negative effect in early periods whereas NDVI became significantly negative in mid and late periods. Other environmental variables exhibited interannual heterogeneity. Our findings demonstrate that vegetation recovery within the reserve does not automatically improve habitats for forest-dependent herbivores and could lead to a potential ecological mismatch.

Developing habitat selection models is crucial for predicting the potential distribution of rare and endangered insects; however, current modeling approaches largely ignore absolute abundance data from sampling records. Integrating absolute abundance as sample weights involves two contrasting ecological hypotheses: one assumes high abundance reflects superior habitat quality (direct weighting), while the other attributes high abundance to spatially biased sampling effort (inverse weighting). Both hypotheses are plausible for Cheirotonus jansoni (Jordan, 1898), a highly phototactic endangered species, complicating the selection of an appropriate weighting strategy. This study evaluated four weighting strategies (unweighted, linear, inverse, and inverse square) derived from these hypotheses. Results indicated that the sampling effort correction strategy (inverse weighting) outperformed habitat-quality-driven strategies (linear weighting) in habitat suitability mapping, achieving a higher AUC (93.41) compared to the linear weighting (91.32). Notably, the linear weighting strategy performed worse than the unweighted baseline, yielding a lower AUC (91.32) than the baseline’s 93.11. These findings provide methodological guidance for modeling the distribution of phototactic insects and offer scientific support for the in situ conservation, ex situ site selection, and supplementary field surveys of C. jansoni.