Resumen de The biparental pattern of incubation and its relationship to food availability in the yellow-legged gull "Larus michaellis"

José Manuel Igual, Daniel Oro de Rivas, Giacomo Tavecchia

• español

  Examinamos el patrón de incubación de la gaviota patiamarilla Larus michahellis en una colonia de las islas Baleares a partir de la probabilidad de capturar un macho o una hembra en el nido en diferentes horas del día. Los machos atendieron el nido, en promedio, menos tiempo que las hembras. En los machos la probabilidad de incubar se incrementa en la parte central del día, disminuyendo durante la mañana y la tarde (siguiendo un modelo cuadrático). Este patrón no se ha visto alterado ni antes ni después del cierre del principal vertedero de Mallorca, el cual representaba la mayor fuente de alimentación de esta población. Los resultados sugieren que el reparto de la incubación entre sexos durante el día no parece estar relacionado con la disponibilidad de recursos.

• English

  We examined the incubation pattern of yellow-legged gulls Larus michahellis at a colony in the Balearic Archipelago. Incubating gulls were captured at the nest at different times of day. We found that, on average, males attend the nest less than females. Male or female attendance had a marked diurnal pattern: males seem to show a progressive increase in the probability of incubation until the central part of the day, which then declines during the evening hours (following a quadratic model). This pattern remained unaltered during the years that followed the closure of the local open-air landfill site, which represented the main food resource of this population. Our results suggest that the sex-related diurnal pattern of nest attendance during incubation is skewed towards females and is unrelated to food resources.