SciELO - Scientific Electronic Library Online

 
vol.21 número1Escalas en ecología: su importancia para el estudio de la selección de hábitat en avesEnsambles de aves en calles arboladas de tres ciudades costeras del sudeste de la provincia de Buenos Aires, Argentina índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados

Articulo

Indicadores

  • No hay articulos citadosCitado por SciELO

Links relacionados

  • En proceso de indezaciónCitado por Google
  • No hay articulos similaresSimilares en SciELO
  • En proceso de indezaciónSimilares en Google

Bookmark


El hornero

versión On-line ISSN 1850-4884

Resumen

PUJOL, E. Manuela  y  MERMOZ, Myriam E.. Reconstruction of ancestral states of life-history traits in cowbirds: an analysis of adaptations to brood parasitism. Hornero [online]. 2006, vol.21, n.1, pp. 15-23. ISSN 1850-4884.

Parasitic cowbirds lay their eggs in the nest of other species, the host, depending on the host's parental care for their successful reproduction. It has been suggested that cowbirds modified some life-history traits as adaptations to brood parasitism. Specifically, they would have developed small-sized eggs with thicker eggshells, would have shortened their incubation periods, and would have accelerated nestling growth. A previous analysis with independent phylogenetic contrasts found that observed values of those life-history traits in parasitic cowbirds only differ from the predicted ones by their non-parasitic relatives in their thicker eggshell. In this work, we reanalyzed these traits as potential adaptations to brood parasitism in cowbirds by reconstructing ancestral values under two models of character evolution. By comparing the ancestors reconstructed from the parasitic cowbirds with those reconstructed from their non-parasitic relatives, we only found differences in eggshell thickness. This demonstrates that both techniques (ancestor reconstruction and independent phylogenetic contrasts) are consistent, and that the increase in eggshell thickness as a potential adaptation to brood parasitism is a robust result.

Palabras llave : adaptation; ancestor reconstruction; cowbirds; eggshell thickness; egg weight; incubation period; nestling growth.

        · resumen en Español     · texto en Español     · pdf en Español