Functional aspects of prolonged parental care in Bewick's swans

The importance of biparental care in a precocial, monogamous bird, the bar-headed goose (Anser indicus)

“…Similar male parental effort was reported from other species and on the wintering grounds (Boyd 1953;Raveling 1970;Owen 1972;Scott 1980;Stroud 1982;Black and Owen 1989). Some aspects of this effort even turned out to be positively related to brood size (Lessells 1987;Schindler and Lamprecht 1987).…”

Dispersal, Migration, and Offspring Retention in Saturated Habitats

“…A recent phylogenetic analysis indeed finds support for a relationship between mild winter climate, sedentariness, and cooperative breeding in birds (Arnold and Owens 1999). Interesting exceptions to this pattern are provided by species such as the Bewick's swan Cygnus columbianus, where families are able to remain united during migration and parents provide protection for their young in their first winter (Scott 1980). It would be interesting to know whether parental facilitation can extend to the acquisition of territories on the breeding grounds in any migratory species.…”

Age, body mass and environmental variation shape the foraging ontogeny of Galapagos sea lions

“…Owing to their inexperience, young animals are often inefficient foragers and need to compensate for their reduced foraging success with an energetically costly increase in foraging effort (Weathers & Sullivan 1989, Daunt et al 2007, Thornton 2008. The lack of foraging skills also makes juveniles poor competitors, especially when competing against adults of other species that are of similar size, and negatively affects juvenile foraging success in competitive situations (Scott 1980, Sol et al 1998. This is especially problematic for juvenile mammals whose mass at weaning is often lower than adult mass and who often have not completed their morphological and physiological development.…”