Analyses of sympatric and allopatric populations of Sceloporus
occidentalis and S. graciosus from central Oregon indicate a high degree
of similarity in diet. Relative abundance, the equivalent number of
equally common taxa (E), and the probability of similarity (SIMI) were
used in the analyses. Shifts in diet between populations of...
Vertebrates communicate with one another and coordinate intraspecific reproduction by using a variety of sexually dimorphic signals, such as plumage, ornaments, sounds, and/or scents. These sexual dimorphisms are maintained by physiological factors, typically sex-specific hormones (though see Chapter 3 for an exception). The purpose of the research in this dissertation...
Emerging infectious diseases are increasing globally and are a threat to human, wildlife, and ecosystem health. The emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd), or amphibian chytrid fungus, is associated with worldwide amphibian population declines and extinctions. Bd has been found on every continent where amphibians exist and has been documented...
Climate change is predicted to affect ecosystems, including systems already stressed by human impacts. One ecosystem that is already highly impacted by human land use is the cold headwater stream system of the Pacific Northwest. One method of assessing the function of an ecosystem is by using an indicator species....
Analysis of the pinniped remains from site 35 LNC 14 reveal
the presence of four species: Eumetopias jubata (Stellar sea lion),
Zalophus californianus (California sea lion), Callorhinus ursinus
(Northern fur seal),'and Phoca vitulina (Harbor seal). Ratios
based on minimum number of individuals calculations disclose a
high incidence of mature Stellar...
Although it is generally assumed that the intensifying abiotic environment is the primary effect of drought on aquatic organisms, drought-induced top predator extinctions may be an important underlying mechanism. I used manipulative experiments to disentangle the impacts of drying and top predator extinctions on arid-land aquatic invertebrate communities. I then...