Darwin's Fox: A Distinct Endangered Species in a Vanishing Habitat

The temperate rain forest of Chiloé Island, Chile, is inhabited by an endemic fox ( Dusicyon fulvipes ) first described by Charles Darwin and now designated Darwin's fox. Despite morphological differences, Darwin's fox has been considered only an insular subspecies of the mainland chilla fox ( D. griseus ). This follows the assumption that the island population, with an estimated population of less than 500, has been separated from the mainland chilla fox for only about 15,000 years and may have received occasional immigrants from the mainland. Consequently, this island population has not been protected as endangered or bred in captivity. Recently, a population of Darwin's fox was discovered on the Chilean mainland 600 km north of Chiloé Island. This population exists in sympatry with chilla and possibly culpeo ( D. culpaeus ) foxes, which suggests that Darwin's fox may be reproductively isolated. To clarify the phylogenetic position of Darwin's fox, we analyzed 344 bp of mitochondrial DNA control-region sequence of the three species of Chilean foxes. Darwin's foxes from the island and mainland populations compose a monophyletic group distinct from the two other Chilean fox species. This indicates that Darwin's fox was probably an early inhabitant of central Chile, and that its present distribution on the mainland may be a relict of a once much wider distribution. Our results highlight the ability of molecular genetic techniques to uncover historical relationships masked by recent events, such as local extinctions. The "rediscovery" of Darwin's fox as a distinct species implies that greater significance should be given to the protection of this species and its unique habitat and to documenting the extent of its mainland distribution.     

An ethnobotanic garden

With the help of local schools and the Mount Subasio Park Community, the Assisi Nature Council has created a small ethnobotanic garden in the centre of the ancient city of Assisi, Italy. This short paper describes the opening of the garden and the philosophy which promoted its construction.     

Overview and definition of risk: Its assessment and management

Risk assessment includes both risk estimation (identifying hazards and estimating their outcomes and probabilities) and risk evaluation (determining the significance or value of risks to those concerned with or affected by the decision). Risk estimation is about situations, and risk evaluation about the effect on people. Few situations are absolutely safe. Risks need to be estimated, and for many kinds of risk (e.g., exposures to potentially toxic substances or to potentially catastrophic situations) an expert view has to be formed, which must take account of associated uncertainties. Different sections of the public perceive risk in different ways, and regard some risks more seriously than the expert estimates. Thus studies of risk perception form a further input into the decision-making process. Another input is the benefit of the activity. A regulatory framework consistent with the reality of risk estimation has been proposed. Since risks and benefits fall on different parts of the community, the decision process is essentially political, though it must be informed scientifically. How the decision is taken will depend on national governmental practices.     

TECHNOLOGY,INSTITUTIONS, AND SOCIAL GOALS1

ABSTRACT: The cries of pending water crises are usually cast in terms of water availability and/or water quality. Unfortunately, the real factors underlying a perceived crisis are often overlooked and the solutions prescribed are fax from optimal when measured in either economic or social terms. Today's technology outstrips its implementation, yesterday's solutions are imposed on a new breed of problems, and a static game is being played in a dynamic world. There is a need for the application of innovative and revolutionary tactics, for modernizing institutions, and for educating technologists and decision makers alike in the art of communicating their views and skills. This is the challenge. If it is met, some predicted crises will not materialize, and many others will be diminished in scale. An exciting opportunity exists to extend the boundaries of a new era in water management.     

Model of Japanese serow (Capricornis crispus) energetics predicts distribution on Honshu, Japan.

Understanding what determines a species' range is a central objective in ecology and evolutionary biology. It has important applications for predicting species distributions and how they might respond to environmental perturbations. This paper describes a mechanistic approach to predict past and present distribution of the Japanese serow (Capricornis crispus) on Honshu, Japan. We applied state-of-the-art microclimate and animal biophysical/behavioral models coupled with climate and vegetation data to estimate the distribution of potential range expansion under protection. We tested the model results against detailed empirical distribution data from the Ministry of the Environment for a five-prefecture area in central Honshu. We also applied the models to time-series land use/cover maps to investigate the historical transitions in habitat suitability during 1947-1999 in the Arai-Keinan region. This is the first time to our knowledge that mechanistic models have successfully predicted the landscape scale distribution of a mammal species in the absence of other animal species interactions, such as predators. In this case, animal energetics/behavior-plant interactions seem to be critical. Forest cover appears to be important in summer and winter for suitable serow habitats. The energetics model results indicate that the serow can overheat in some open environments in midday hours in summer. In winter, simulation results suggested that forest cover provides effective refuge to avoid increased metabolic demands of cold temperatures and strong winds. The model simulations suggested that land use/cover changes documented during 1947-1999 resulted in increased suitable serow habitat due to expanding forest cover from agricultural marginalization and ecological succession. The models provide a unique tool for estimating species' range expansion under protection or for selecting suitable reintroduction sites.     

A population study of the polychaete Capitella capitata at plymouth

A population of Capitella capitata (Fabricius) was sampled from January, 1973 to February, 1974. Size of the worms was measured and sexual maturity determined. There is an extensive breeding season, spawning occurring asynchronously throughout the year. Females containing ripe oocytes were almost always present, but most females at any one time contained immature oocytes. A high percentage of males contained active sperm. Oocytes are not released into the coelomic fluid until almost fully developed, and all are released at a single spawning. A large number of eggs are produced at each spawning and there is some evidence to suggest that larval development may be completely benthonic. Gametes first develop in 7 to 8 month old worms and take about 4 months to complete development. Analyses of the female population structure suggests that there are 3 breeding classes. The growth rate is estimated at 30 mm per year, and few worms are believed to survive longer than 2 years.     

Mature and old-growth riparian forests: structure, dynamics, and effects on Adirondack stream habitats.

Riparian forests regulate linkages between terrestrial and aquatic ecosystems, yet relationships among riparian forest development, stand structure, and stream habitats are poorly understood in many temperate deciduous forest systems. Our research has (1) described structural attributes associated with old-growth riparian forests and (2) assessed linkages between these characteristics and in-stream habitat structure. The 19 study sites were located along predominantly first- and second-order streams in northern hardwood-conifer forests in the Adirondack Mountains of New York (U.S.A.). Sites were classified as mature forest (6 sites), mature with remnant old-growth trees (3 sites), and old-growth (10 sites). Forest-structure attributes were measured over stream channels and at varying distances from each bank. In-stream habitat features such as large woody debris (LWD), pools, and boulders were measured in each stream reach. Forest structure was examined in relation to stand age using multivariate techniques, ANOVA, and linear regression. We investigated linkages between forest structure and stream characteristics using similar methods, preceded by information-theoretic modeling (AIC). Old-growth riparian forest structure is more complex than that found in mature forests and exhibits significantly greater accumulations of aboveground tree biomass, both living and dead. In-stream LWD volumes were significantly (alpha = 0.05) greater at old-growth sites (200 m3/ha) compared to mature sites (34 m3/ha) and were strongly related to the basal area of adjacent forests. In-stream large-log densities correlated strongly with debris-dam densities. AIC models that included large-log density, debris-dam density, boulder density, and bankfull width had the most support for predicting pool density. There were higher proportions of LWD-formed pools relative to boulder-formed pools at old-growth sites as compared to mature sites. Old-growth riparian forests provide in-stream habitat features that have not been widely recognized in eastern North America, representing a potential benefit from late-successional riparian forest management and conservation. Riparian management practices (including buffer delineation and restorative silvicultural approaches) that emphasize development and maintenance of late-successional characteristics are recommended where the associated in-stream effects are desired.