Food Size And Foraging Site Selection In A Breeding Population Of Red- Winged Blackbirds (Agelaius Phoeniceus)

The size of organisms fed to nestling red-winged blackbirds was significantly larger than if selection of food were random. There also appeared to be a selection for "soft-bodied" items. This may be due to selection for soft anatomy per se or selection as a function of the ease of capture. The average size of organisms captured in the marsh was significantly larger than those in the adjacent field. This indicated that in terms of feeding efficiency, the field is a less profitable place to forage than the marsh. Female adult red-winged blackbirds were found to feed significantly less often on the field than males. This reduces intraspecific competition and may increase feeding efficiency. It was postulated that there exist two levels of selection during nestling feeding: a selection for larger food items and for foraging sites. As female red-winged blackbirds feed the nestlings unassisted by males, it is necessary for the females to maximize feeding efficiency by selecting the largest items compatible with the energy expense of capture and by selecting foraging locations where these larger items can be found.

Name thesis:degree_name

Master of Science in Biology

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Biology

Year

1975

Author dc:creator

• Wilson, Stephen Wallace

Contributors dc:contributor

• Tom Stombough

• Biology

Statement dc:rights

• © Stephen Wallace Wilson

Repository record dc:identifier

https://bearworks.missouristate.edu/theses/1003

OAI identifier oai:identifier

oai:bearworks.missouristate.edu:theses-2004