Publications

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We used the doubly labeled water method to measure the field metabolic rates (FMRs, in kJ kg−1 day−1) and water flux rates (WIRs, in ml H2O kg−1 day−1) of adult desert tortoises (Gopherus agassizii) in three parts of the Mojave Desert in California over a 3.5-year period, in order to develop insights into the physiological responses of this threatened species to climate variation among...

After nearly a century of recovery from overhunting, sea otter populations are in abrupt decline over large areas of western Alaska. Increased killer whale predation is the likely cause of these declines. Elevated sea urchin density and the consequent deforestation of kelp beds in the nearshore community demonstrate that the otter's keystone role has been reduced or eliminated. This...

Insecticidal pathogens such as baculoviruses are currently under intensive development as biorational agents for the control of lepidopteran pests. However, because the efficacy of these orally infective viruses is influenced by host diet, our ability to use baculoviruses effectively in an integrated pest management program requires understanding the influence of dietary components on...

The California chaparral community has a rich flora of species with different mechanisms for cuing germination to postfire conditions. Heat shock triggers germination of certain species but has no stimulatory effect on a great many other postfire species that are chemically stimulated by combustion products. Previous reports have shown that charred wood will induce germination, and here...

Few references to attacks on sea otters, Enhydra lutris, by killer whales, Orcinus orca, exist in the literature. In an extensive review of predatory and non-predatory interactions between killer whales and other marine mammals, Jefferson et al. (1991) cited only one reference (Nikolaev 1965) in which killer whales aggressively pursued sea otters. In another review of attacks on marine...

Cladistic analysis supports the conclusion that the Orcuttieae tribe of C4 grasses reflect evolution from a terrestrial ancestry into seasonal pools. All nine species in the tribe exhibit adaptations to the aquatic environment, evident in the structural characteristics of the juvenile foliage, which persist submerged for 1–3 months prior to metamorphosis to the terrestrial foliage...

A three-trophic-level interaction among American Black Oystercatchers (Haematopus bachmani), limpets (Lottia spp.), and erect fleshy algae in rocky intertidal communities of central and southern California was documented via manipulative and “natural” experiments. Removal of the territorial limpet (Lottia gigantea) initially caused large increases in the percent cover of erect fleshy...

Orcuttieae is a small tribe of C4 grasses endemic to seasonal pools in the southwestern U.S., comprising the basal genus Neostapfia, Tuctoria, and the most derived group, Orcuttia. Growth is initiated underwater, and when pools dry, species undergo a metamorphosis replacing aquatic foliage with terrestrial foliage. O. californica and O. viscida exhibit CAM-like diel fluctuations in...

Ecological theory and wildlife management often depend on reliable comparison and interpretation of population density estimates. A synthesis of 1,772 mammalian carnivore population estimates (713 unique to reference, species, site, and size of study area) from 74 species revealed global patterns among aspects of study and interpretive design that undermine the reliability and usefulness...