Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact firstname.lastname@example.org with any questions.
Widespread evidence shows that the modern rates of extinction in many plants and animals exceed background rates in the fossil record. In the present article, I investigate this issue with regard to North American freshwater fishes. From 1898 to 2006, 57 taxa became extinct, and three distinct populations were extirpated from the continent. Since 1989, the numbers of extinct North American fishes have increased by 25%. From the end of the nineteenth century to the present, modern extinctions varied by decade but significantly increased after 1950 (post-1950s mean = 7.5 extinct taxa per decade). In the twentieth century, freshwater fishes had the highest extinction rate worldwide among vertebrates. The modern extinction rate for North American freshwater fishes is conservatively estimated to be 877 times greater than the background extinction rate for freshwater fishes (one extinction every 3 million years). Reasonable estimates project that future increases in extinctions will range from 53 to 86 species by 2050.
As the pace and extent of urbanization increase, an understanding of the mechanisms that shape wildlife communities in cities will be essential to their effective management. Predation could be an important determinant of the structure of these communities, but the research to date suggests a predation paradox: Vertebrate predator numbers increase with urbanization, whereas predation rates decline. We reviewed studies on predator abundance and the survival of terrestrial vertebrates in urban and nonurban contexts to evaluate whether the predation paradox is a widespread phenomenon. We conclude that there is substantial support for it. We discuss hypotheses to explain the paradox and suggest that urbanization has fundamentally altered trophic dynamics by reducing top-down control through multiple mechanisms and by increasing bottom-up forcing through the greater availability of anthropogenic foods. The hypotheses are summarized in a conceptual model that generates testable predictions designed to advance our understanding of trophic dynamics in metropolitan areas.
White-nose syndrome (WNS) is a devastating disease affecting hibernating bats, first documented in winter 2006 in eastern North America. Over 5.5 million bats of several species may have died as a result of this disease. The fungus Geomyces destructans is now considered the causal agent of WNS, and this species may have been recently introduced into North American bat hibernation habitats. This overview summarizes the ecology and distribution of Geomyces fungi. Species in this genus are common in the soils of temperate and high-latitude ecosystems and are capable of withstanding and thriving in cold, low-nutrient polar environments. These species are dispersed by wind, groundwater, arthropods, birds, and mammals and are carried by humans, their clothing, and their equipment. These characteristics present significant challenges to biologists, managers, and others charged with controlling the spread of WNS and G. destructans in other parts of North America and the biosphere.
Where did all those dead animals come from? What are they used for? These are questions that natural history museums must be prepared to answer. Specimen collections are a valuable research tool, but their utility remains a mystery to many. In this article, we introduce the Web exhibit “Doing Natural History” ( http://mvz.berkeley.edu/DoingNaturalHistory) as an educational resource that draws connections between early twentieth-century evolutionary biology and innovative museum science today. As a companion to the Web exhibit, in this article, we show how natural history research changed during the twentieth century and argue that collections have provided the basis for innovation in natural history, integrative biology, and, more generally, in the life sciences. Drawing on examples from the University of California, Berkeley', Museum of Vertebrate Zoology, we look at the practice of natural history to reveal the centrality of collections to both practice and theory in the life sciences.
The Guide for the Care and Use of Laboratory Animals (NRC 2011) serves as the principal reference for the oversight of most vertebrate use in research and teaching in the United States. The Guide was developed as a reference for biomedical research. Beyond guiding ethical principles, the Guide contains little information useful for the oversight of research involving wild taxa. To fill this breach, and at the behest of the National Science Foundation, taxon-specific societies in the United States developed independent guidelines that held to the principles of ethical use of animals in research and that were specific to wildlife. Recognition of these taxon-specific guidelines by federal grantmaking agencies and the animal welfare community as appropriate standards for wildlife research will facilitate the required oversight of research involving wild taxa and the ethical use of wild animals in research and teaching.
Assisted migration (AM) id often presented as a strategy to save species that are imminently threatened by rapid climate change. This conception of AM, which has generated considerable controversy, typically proposes the movement of narrowly distributed, threatened species to suitable sites beyond their current range limits. However, existing North American forestry operations present an opportunity to practice AM on a larger scale, across millions of hectares, with a focus on moving populations of widely distributed, nonthreatened tree species within their current range limits. Despite these differences (and many others detailed herein), these two conceptions of AM have not been clearly distinguished in the literature, which has added confusion to recent dialogue and debate. Here, we aim to facilitate clearer communication on this topic by detailing this distinction and encouraging a more nuanced view of AM.