Integrating Land-Cover Dynamics and Management Records for Recovery Monitoring of Hainan Eld's Deer in Datian National Nature Reserve.

Abstract

Datian National Nature Reserve is a principal conservation site for the endangered Hainan Eld's deer (Rucervus eldii hainanus). We integrated annual 10 m land-cover maps (2017-2025) as well as the statutory reserve redline, management fence, external ring and reserve management records to examine how these complementary sources can support recovery monitoring at the protected-area scale. Inside the redline, the combined area of trees, grass and shrub/scrub declined during 2017-2021 and partially recovered during 2021-2025. An exploratory land-cover screening index changed from 0.675 to 0.666 and then to 0.667, showing modest variation under the specified rule-based scoring scheme. External rings contained higher proportions of crops and built area and were treated as surrounding land-use context rather than a measured edge-effect gradient. Available annual monitoring counts fluctuated between 336 and 425 individuals, and two releases added 93 deer after the respective annual surveys. Probable python predation accounted for 68.3% of recorded deaths during 2020-2025; attributions were based on available carcass evidence and field observations. Systematic occurrence records and spatially complete locations for releases and mortality events were unavailable, so fine-scale habitat selection, release-site suitability and mortality hotspots could not be assessed. This assessment provides a practical baseline for recovery monitoring, whereas assessing habitat use and demographic processes requires dedicated field data.