Female demographic advantages drive sustainable growth and reintroduction capacity in captive giant panda populations

Captive breeding is a vital ex situ conservation strategy, particularly for giant pandas, yet the demographic impacts of documented sex ratio bias remain unclear. This study integrates pedigree analysis and population viability analysis (PVA) to reveal that while captive giant panda births show balanced sex ratios (1:1), progressive female bias emerges with age due to females' survival advantages: lower mortality rates (31.68% vs 41.89% in cubs) and extended longevity. The population demonstrates strong self-sustainability under current management, with female prevalence accelerating growth. Results identify catastrophe probability reduction and cub mortality control as primary growth drivers, whereas carrying capacity changes exert minimal influence. Reintroduction simulations validate that annually releases of 5-10 individuals sustain source population viability while achieving rewilding targets. Key implications include: 1) Demographic stability accommodates planned reintroductions; 2) Female survival compensates male mortality without genetic compromise; 3) Disaster mitigation and neonatal care surpass enclosure expansion in efficacy. The framework establishes that managing sex-specific mortality and environmental risks concurrently ensures both population resilience and reintroduction success, providing actionable strategies for optimizing ex situ conservation in this flagship species.