Nest size and hatchling sex ratio in chinstrap penguins

• Published in: Polar Biology
• Main Authors: Fargallo, Juan A., Dávila, José A., Potti, Jaime, León, A. de, Polo, Vicente
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2004
• Subjects: Antarc*; Antarctica; Chinstrap penguin; Polar Biology; Pygoscelis antarctica
• Online Access: http://hdl.handle.net/10261/57479; https://doi.org/10.1007/s00300-004-0596-2

Variation in the sex ratio at hatching in the chinstrap penguin Pygoscelis antarctica was investigated, using molecular sexing to test predictions of sex allocation theory. The sex ratio was slightly male-biased (0.54) but did not differ significantly from parity. The proportion of males increased with nest size, an estimator of parental quality in chinstrap penguins. High-quality parents were able to produce and rear a higher proportion of male offspring, the more costly sex in this slightly sexually dimorphic species. Our results may be in agreement with Trivers and Willard's (1973) argument on biases in the offspring sex ratio being contingent on parental condition or quality. © Springer-Verlag 2004. Peer Reviewed