Genetically based demographic reconstructions require careful consideration of generation time.

Bakker et al. use Robinson et al.'s reconstruction of three species of vulture to illustrate how incorrect generation time estimates can yield inaccurate results, underscoring the importance of generation time specification for genetically based reconstructions, especially for comparisons and species of conservation concern.

Foraging behavior, contaminant exposure risk, and the stress response in wild California condors (Gymnogyps californianus).

Wild California condors (Gymnogyps californianus) are frequently exposed to lead via lead-based ammunition ingestion, and recent studies indicate significant exposure to organochlorines (e.g. dichlorodiphenyldichloroethylene (DDE) and polychlorinated biphenyls (PCBs)) for condors feeding on beach-cast marine mammals.

Terrestrial Scavenging of Marine Mammals: Cross-Ecosystem Contaminant Transfer and Potential Risks to Endangered California Condors (Gymnogyps californianus).

The critically endangered California condor (Gymnogyps californianus) has relied intermittently on dead-stranded marine mammals since the Pleistocene, and this food source is considered important for their current recovery. However, contemporary marine mammals contain persistent organic pollutants that could threaten condor health. We used stable carbon and nitrogen isotope, contaminant, and behavioral data in coastal versus noncoastal condors to quantify contaminant transfer from marine mammals and created simulation models to predict the risk of reproductive impairment for condors from exposure to DDE (p,p'-DDE), a major metabolite of the chlorinated pesticide DDT.

Effects of Lead Exposure, Flock Behavior, and Management Actions on the Survival of California Condors (Gymnogyps californianus).

Translocation is an increasingly important tool for managing endangered species, but factors influencing the survival of translocated individuals are not well understood. Here we examine intrinsic and extrinsic drivers of survival for critically endangered California condors (Gymnogyps californianus) whose wild population recovery is reliant upon releases of captively bred stock. We used known fate models and information-theoretic methods to compare the ability of hypothesized covariates, most of which serve as proxies for lead exposure risk, to predict survival rates of condors in California.

The Use of Surrogate Data in Demographic Population Viability Analysis: A Case Study of California Sea Lions.

Reliable data necessary to parameterize population models are seldom available for imperiled species. As an alternative, data from populations of the same species or from ecologically similar species have been used to construct models. In this study, we evaluated the use of demographic data collected at one California sea lion colony (Los Islotes) to predict the population dynamics of the same species from two other colonies (San Jorge and Granito) in the Gulf of California, Mexico, for which demographic data are lacking.

What is the future of conservation?

In recent years, some conservation biologists and conservation organizations have sought to refocus the field of conservation biology by de-emphasizing the goal of protecting nature for its own sake in favor of protecting the environment for its benefits to humans. This 'new conservation science' (NCS) has inspired debate among academics and conservationists and motivated fundamental changes in the world's largest conservation groups. Despite claims that NCS approaches are supported by biological and social science, NCS has limited support from either.

Using population viability criteria to assess strategies to minimize disease threats for an endangered carnivore.

Outbreaks of infectious disease represent serious threats to the viability of many vertebrate populations, but few studies have included quantitative evaluations of alternative approaches to the management of disease. The most prevalent management approach is monitoring for and rapid response to an epizootic. An alternative is vaccination of a subset of the free-living population (i.

Evaluating the potential effectiveness of compensatory mitigation strategies for marine bycatch.

Conservationists are continually seeking new strategies to reverse population declines and safeguard against species extinctions. Here we evaluate the potential efficacy of a recently proposed approach to offset a major anthropogenic threat to many marine vertebrates: incidental bycatch in commercial fisheries operations. This new approach, compensatory mitigation for marine bycatch (CMMB), is conceived as a way to replace or reduce mandated restrictions on fishing activities with compensatory activities (e.