No genetic evidence for parent-offspring relatedness in post-breeding social groups of Black-crested Titmouse (Baeolophus atricristatus)/No hay evidencia genetica de parentesco en grupos sociales posreproductivos del carbonero Baeolophus atricristatus

After the breeding season, territorial adult Black-crested Titmouse (Baeolophus atricristatus) and residing juveniles form social groups that may persist until the following spring. Under the prolonged brood care hypothesis, one would expect these juveniles to be retained offspring with delayed dispersal of the breeding pair. To test if Black-crested Titmouse juveniles that reside in post-breeding territories are offspring of the territorial adult male, we performed microsatellite-based paternity analyses of 6 juvenile-adult male social dyads on 6 different territories. None of the juveniles were offspring of the adult male with which it shared a territory. We discuss several possible evolutionary explanations for this result. Received 13 August 2021. Accepted 14 December 2021. Key words: delayed dispersal, genotyping. microsatellites, non-kin, parentage, paternity. (Spanish)--Despues de la estacion reproductiva. los adultos territoriales del carbonero Baeolophus atricristatus y juveniles residentes forman grupos sociales que pucden persistir hasta la siguientc primavera. Segiin la hipotesis del cuidado prolongado de la nidada. podria esperarse que esos juveniles fueran descendencia retenida con dispersion retrasada de la pareja reproductiva. Para somcter a prueba si estos carboneros juveniles que residen en territorios posreproductivos son descendientes del macho adulto territorial, llcvamos a cabo un analisis de paternidad basado en microsatelites de 6 diadas de juveniles y machos adultos en 6 difcrentes territorios. Ninguno de los juveniles rue descendiente del macho adulto con el cual compartian territorio. Discutimos varias posiblcs explicaciones evolutivas para este resultado. Palabras clave: dispersion retrasada. genotipos, microsatelites, no-parcntesco, parental, paternidad.
In multiple bird species, sexually mature individuals stay in their natal territory and form social family groups (e.g., Brown 1987, Emlen 1995, Koenig and Dickinson 2016). This behavior is widespread [...]