Katie M. Dugger Annie Schmidt Arvind Varsani Amelie Lescroel Grant Ballard Phil O'B. Lyver Kerry Barton David Ainley Virginia Morandini 2024 <p><span>Sex-related differences in vital rates that drive population change reflect the basic life history of a species. However, for visually monomorphic bird species, determining the effect of sex on demographics can be a challenge. In this study, we investigated the effect of sex on apparent survival, recruitment, and breeding propensity in the Adélie penguin (</span><i>Pygoscelis adeliae</i><span>), a monochromatic, slightly size dimorphic species with known age, known sex, and known breeding history data collected during 1996–2019 (</span><i>n</i><span> = 2127 birds) from three breeding colonies on Ross Island, Antarctica. Using a multistate capture–mark–recapture maximum-likelihood model, we estimated apparent survival (</span></p> application/pdf 10.1002/ece3.10859 en Wiley Sex-specific recruitment rates contribute to male-biased sex ratio in Adélie penguins article