Differential reproduction among female Richardson's ground squirrels and its relation to sex ratio

Summary The reproductive success of ten female Richardson's ground squirrels resident on a grassland pasture in southern Alberta in 1975 was determined by noting the number of their descendants present in 1976, 1977, and 1978.The two most successful females were the progenitors of 67% of the females resident in 1977 and of 57% of the females resident in 1978. None of the other eight females had descendants in the population in 1978. The two most successful females produced more daughters than did the other females and they did so, not by rearing larger litters, but by producing female-biased litters. The daughters of the two most successful females lived slightly longer than did the daughters of other females.Although the adult sex ratio was strongly female biased each breeding season, ranging between 0.26 and 0.42 males per female, typically all females became pregnant.Adult female offspring inherited their mother's home range and, if the mother or any female sibs were present, shared this area with them. Sons rarely remained resident in or near the natal area and adult males rarely remained resident in the same area for two consecutive years. Thus, post-weaning investments were greater in daughters than in sons.There were no conclusive correlations between sex ratio of litters and size of litters, age of the mother, previous reproductive success of the mother, population density, or the length of the overwinter period. More studies spanning several generations are required to elucidate the effects of the sex ratio of litters on the likelihood of an animal being represented by descendants in subsequent generations.     

Preliminary evaluation of the Community Multiscale Air Quality model for 2002 over the Southeastern United States

The Visibility Improvement State and Tribal Association of the Southeast (VISTAS) is one of five Regional Planning Organizations that is charged with the management of haze, visibility, and other regional air quality issues in the United States. The VISTAS Phase I work effort modeled three episodes (January 2002, July 1999, and July 2001) to identify the optimal model configuration(s) to be used for the 2002 annual modeling in Phase II. Using model configurations recommended in the Phase I analysis, 2002 annual meteorological (Mesoscale Meterological Model [MM5]), emissions (Sparse Matrix Operator Kernal Emissions [SMOKE]), and air quality (Community Multiscale Air Quality [CMAQ]) simulations were performed on a 36-km grid covering the continental United States and a 12-km grid covering the Eastern United States. Model estimates were then compared against observations. This paper presents the results of the preliminary CMAQ model performance evaluation for the initial 2002 annual base case simulation. Model performance is presented for the Eastern United States using speciated fine particle concentration and wet deposition measurements from several monitoring networks. Initial results indicate fairly good performance for sulfate with fractional bias values generally within +/-20%. Nitrate is overestimated in the winter by approximately +50% and underestimated in the summer by more than -100%. Organic carbon exhibits a large summer underestimation bias of approximately -100% with much improved performance seen in the winter with a bias near zero. Performance for elemental carbon is reasonable with fractional bias values within +/- 40%. Other fine particulate (soil) and coarse particular matter exhibit large (80-150%) overestimation in the winter but improved performance in the summer. The preliminary 2002 CMAQ runs identified several areas of enhancements to improve model performance, including revised temporal allocation factors for ammonia emissions to improve nitrate performance and addressing missing processes in the secondary organic aerosol module to improve OC performance.     

Resilience and vulnerability of northern regions to social and environmental change

The arctic tundra and boreal forest were once considered the last frontiers on earth because of their vast expanses remote from agricultural land-use change and industrial development. These regions are now, however, experiencing environmental and social changes that are as rapid as those occurring anywhere on earth. This paper summarizes the role of northern regions in the global system and provides a blueprint for assessing the factors that govern their sensitivity to social and environmental change.     

Fatty acid composition as a dietary indicator of the invasive caprellid, Caprella mutica (Crustacea: Amphipoda)

The invasive caprellid amphipod Caprella mutica is one of the most widely dispersed marine non-native species globally. Originating in sub-boreal north-east Asia, it has now been found in both the northern and the southern hemispheres. One potential reason why this species is such a successful invader is its ability to utilise a wide variety of food sources. The contribution of different food sources to the diet of C. mutica was estimated using fatty acids as biomarkers. Caprella mutica was collected from three field sites, including sea cages stocked with Atlantic salmon Salmo salar, shellfish longlines stocked with the blue mussel Mytilus edulis and mooring lines marking the Loch Linnhe Artificial Reef (>2 km from caged finfish aquaculture), where established populations of this species are known to occur. In addition, the fatty acid compositions of C. mutica held in aquaria and either fed the microalga, Dunaliella tertiolecta, or the diatom, Phaeodactylum tricornutum, for a period of 21 days were investigated. The fatty acid composition of the diatom and the microalgal diets was also examined. The results showed that C. mutica contained high levels of polyunsaturated fatty acids, particularly 20:5(n-3); other dominant fatty acids included 18:1(n-9), 22:6(n-3) and 16:0 (in decreasing order based on abundance). Significant differences in the fatty acid profiles between caprellids fed on the microalgae and the diatom diets and between C. mutica collected from the field sites were observed. These results provide evidence that lipid biomarkers can be successfully used to provide evidence of feeding strategy for C. mutica and that the flexibility observed in this strategy may play an important role in its invasion success.     

Experimental evidence for the effects of chronic anthropogenic noise on abundance of Greater Sage-Grouse at leks

Increasing evidence suggests that chronic noise from human activities negatively affects wild animals, but most studies have failed to separate the effects of chronic noise from confounding factors, such as habitat fragmentation. We played back recorded continuous and intermittent anthropogenic sounds associated with natural gas drilling and roads at leks of Greater Sage-Grouse (Centrocercus urophasianus). For 3 breeding seasons, we monitored sage grouse abundance at leks with and without noise. Peak male attendance (i.e., abundance) at leks experimentally treated with noise from natural gas drilling and roads decreased 29% and 73%, respectively, relative to paired controls. Decreases in abundance at leks treated with noise occurred in the first year of the study and continued throughout the experiment. Noise playback did not have a cumulative effect over time on peak male attendance. There was limited evidence for an effect of noise playback on peak female attendance at leks or male attendance the year after the experiment ended. Our results suggest that sage-grouse avoid leks with anthropogenic noise and that intermittent noise has a greater effect on attendance than continuous noise. Our results highlight the threat of anthropogenic noise to population viability for this and other sensitive species.     

Conserving biodiversity that matters: practitioners' perspectives on brownfield development and urban nature conservation in London

Policies designed to conserve sites of nature conservation importance are an important aspect of city planning in the UK. London has led the way in putting in place a spatial hierarchy of sites of nature conservation importance designed to protect wildlife habitats from development. Some wasteland habitats associated with derelict and vacant land receive protection in this way but development pressure on these so-called 'brownfield sites' is high and is likely to continue. This paper examines how conservation professionals in the private, public and voluntary sectors are responding to the threats of biodiversity loss and opportunities for habitat creation posed by re-development of brownfield sites. The study draws on in-depth interviews conducted with conservation professionals and the practices employed by ecological advisers employed by developers seeking to re-develop wasteland sites. It finds that practitioners are negotiating their role in the re-development process in different ways. Key issues relate to the role of ecological science in codifying wasteland habitats, uncertainties about how best to evaluate the conservation importance of such sites and the strategies and tactics employed by different practitioners as they seek to mobilise a range of knowledges and practices to secure ecologically sensitive proposals. Scientific knowledge about wasteland habitats has not stabilised in ways that can consistently inform conservation policy and practice. As a result biodiversity issues of wasteland sites are often discounted in the re-development process. Investment in studies of the basic ecology of urban wastelands could provide a firmer scientific foundation on which conservation policies could build. At the same time, many conservation professionals involved in urban re-development are struggling to promote a pro-active approach to secure environmentally sensitive development. The knowledge and co-operation networks being mobilised to support this approach are fluid and unstable, and favourable development outcomes as yet are few. Formalising these networks to achieve more effective engagements with developers and the construction industry could consolidate ecological practices designed to conserve and re-create the biodiversity of wasteland habitats.     

Environmental cost accounting: The bottom line for environmental quality management

Recent years have seen the environment emerge as one of the most pressing issues facing American business. Eventually, environmental costs will affect the bottom line of every American company. A recent study in the National Law Journal estimates that cleanup of the nation's known hazardous wastes sites will cost $752 billion over thirty years under current environmental policies. Environmental legislation and regulations impose annual compliance costs estimated by the Environmental Protection Agency at more than $30 billion. In the near future, environmental expenses for cleanup, regulatory compliance, and management are anticipated to grow to between 2.5 and 3 percent of GNP. Corporations that wish to be competitive must successfully manage these costs while maintaining or improving their role as responsible corporate citizens. Implementing a comprehensive system for identifying and managing environmental costs requires a multidisciplinary team effort. Environmental costs impact product selection, design and pricing, capital budgeting, and future strategic direction. In order to make informed and meaningful managerial decisions on environmental programs, real cost data are vital. An environmental management systems (EMS) requires information to set goals and then monitor progress towards those goals over time. This article will discuss the current cost accounting systems (CASs) available to support the myriad goals of environmental management systems. In addition, the article will outline a framework for plotting the location of your current EMS on a matrix of regulatory and information requirements and evaluating whether your corporation's CAS is adequate to support the goals and objectives set by your environmental management program. By anticipating future regulatory and information requirements, flexible systems can be developed to adapt to new and more stringent regulations and more complex information requirements.