Gender bias in bird ringing: Uncovering the massive female dropout in volunteer ecological monitoring

Despite progress in academic ecology, volunteer-driven citizen science remains characterized by deep gender inequalities. Operating outside the protective frameworks of labour laws, these deregulated environments rely on informal networks, making them prone to specific mechanisms of exclusion. This study investigates the structural and cultural barriers driving the (self-)exclusion of women in the French bird ringing community. Using a mixed-methods approach comprising a nationwide quantitative survey (N = 561) and qualitative data from interviews and participant observation, our study shows that the gender gap in volunteer science cannot be reduced to personal choices and that female trainees face a cumulative set of constraints. First, the time-intensive nature of volunteer fieldwork conflicts with unequal domestic responsibilities (mental load), leading to a significant female dropout mid-career, particularly among mothers. Second, the community’s competitive culture exacerbates women’s feelings of illegitimacy. Third, an informal, peer-based mentorship system fosters exclusionary co-optation and a gendered division of labour. Finally, geographic isolation and lack of privacy in ringing stations create a potentially hostile environment, with women reporting significantly higher levels of discomfort and insecurity. The withdrawal of fully trained female ringers represents a substantial loss of scientific resources and risks introducing gender biases into ornithological data. To address these imbalances, we suggest actionable institutional reforms, including implicit bias training for mentors, independent reporting mechanisms, and mandatory codes of conduct to ensure safe and inclusive fieldwork.