Determinants of litter size and offspring survival in captive European mink Mustela lutreola: Implications for enhancing conservation strategies for the Eastern population

The European mink Mustela lutreola , classified as critically endangered by the IUCN Red List of Threatened Species, has experienced severe population declines due to habitat loss, invasive species, and overhunting. Conservation efforts, including the European Association of Zoos and Aquaria’s (EAZA) captive breeding program (EEP), aim to mitigate these threats. This study evaluates the EEP’s effectiveness by analysing studbook data (1972–2013) to identify factors influencing litter size and offspring survival to reproductive maturity. Findings highlight significant challenges, including increased inbreeding coefficients associated with successive captive generations and reduced offspring survival in larger litters. Higher parental age positively influenced litter size and offspring survival. Key recommendations include reducing inbreeding, enhancing founder representation, integrating wild genetic diversity, prioritizing breeding pairs with older sires and dams, and supporting maternal resource allocation, especially in large litters. Advanced genetic and demographic analyses are recommended to optimize breeding protocols, improve genetic health, and support reintroduction efforts. These findings refine the EEP framework and contribute to broader conservation strategies for endangered carnivores. • Offspring survival probability is lower in mink from larger litters and with higher inbreeding coefficients. • Multivariate analyses show that older sires and dams tend to produce larger litters and offspring with higher survival rates. • Generational captivity trends reveal increased inbreeding within the ex situ population. • Advanced machine learning identifies key predictors of litter size and offspring survival. • Recommendations include genetic diversity integration and optimizing breeding protocols.