Extra‐pair paternity correlates with genetic diversity, but not breeding density, in a Neotropical passerine, the black catbird

Extra-pair paternity (EPP) in socially monogamous birds is influenced more by genetic diversity than breeding density, according to a study of the black catbird (Melanoptila glabrirostris) in Sian Ka'an Biosphere Reserve and Isla Cozumel. While EPP rates were moderate (9.5–35% of offspring), no correlation was found between breeding density—despite higher mainland densities—and EPP frequency. However, extra-pair offspring exhibited greater heterozygosity than within-pair offspring, suggesting genetic diversity plays a role in mating behavior. The study used single-nucleotide polymorphisms (SNPs) to analyze parentage across two breeding seasons, challenging the notion that tropical songbirds universally exhibit low EPP rates.

LaPergola, J. B., Riehl, C., Martínez‐Gómez, J. E., Roldán‐Clarà, B., & Curry, R. L. (2022). Extra‐pair paternity correlates with genetic diversity, but not breeding density, in a Neotropical passerine, the black catbird. Journal of Avian Biology, 2022(11-12). Portico. https://doi.org/10.1111/jav.03034