Sex-specific differences in space use of Forster's terns (Sterna forsteri) breeding in the South San Francisco Bay, California
Graduation Date
2007
Document Type
Thesis
Program
Other
Program
Thesis (M.S.)--Natural Resources: Wildlife, Humboldt State University, 2007
Committee Chair Name
Mark A. Colwell
Committee Chair Affiliation
HSU Faculty or Staff
Keywords
Humboldt State University -- Theses -- Wildlife, Space use, Radio telemetry, Breeding stage, San Francisco Bay, Forster's tern, Sex differences
Abstract
In seabirds, sex-specific parental care during reproduction can lead to sex-specific differences in foraging location, behavior, and use of foraging areas. Sex-specific differences in location and use of foraging areas have been well documented among dimorphic species, however research on sexually monomorphic seabirds has been limited. I studied Forster's terns (Sterna forsteri), a monomorphic and socially monogamous seabird, in the South San Francisco Bay, California to examine sex-specific differences in the distance from the nest, the foraging range, and the home-range and core-area size of terns. Space use by Forster's terns did not differ between the sexes; however, all measures of space use varied significantly by breeding stage, and to some degree, by colony affiliation. Forster's terns were located farthest from the nest during pre-breeding and post-breeding stages, and found closest to the nest during incubation and chick-rearing stages. Home-range and core-area size significantly decreased as the breeding season progressed and was most concentrated in the post-breeding stage. The foraging range of Forster's terns differed significantly between colony sites. This is the first study of a monomorphic seabird that did not document sex-specific differences in space use, however, sex-specific differences may exist on a finer spatial scale than investigated in this study.
Recommended Citation
Bluso, Jill, "Sex-specific differences in space use of Forster's terns (Sterna forsteri) breeding in the South San Francisco Bay, California" (2007). Cal Poly Humboldt theses and projects. 1047.
https://digitalcommons.humboldt.edu/etd/1047
https://scholarworks.calstate.edu/concern/theses/fj236445c