Modified Cave Entrances: Thermal Effect on Body Mass and Resulting Decline of Endangered Indiana Bats (Myotis sodalis)

Entrances to many caves occupied by the endangered Indiana bat ( Myotis sodalis ) have been modified to control human access. We show that modifying cave entrances can degrade the bats' winter habitat, we demonstrate one mechanism by which this damage occurs, and we document a restoration experiment. We compared a large bar population in an unmodified cave with a small, reduced bat population in a cave with warm winter temperatures resulting from an entrance wall that impeded air exchange. In the modified cave, mean winter temperature at the hibernation site was 5.0° C higher than in the unmodified cave, bats entered hibernation at a 5% higher body mass, bats lost 42% more mass and the frequency distribution of late-winter mass was truncated, with no bats weighing less than 5.4 g. The results describe unacceptable extremes for hibernation: subfreezing temperatures and warm temperatures causing mass-loss rates of more than 0.009 g/day. Over a decade following removal of the entrance-constricting wall, the population increased from 2,000 to 13,000 bats. Previous recommendations, based on common-sense observation, to open blocked cave entrances are confirmed by this study. The similar case of Coach Cave, Kentucky, offers the potential for recovery of 100,000 Indiana bats.     

Integrated Environmental Management: Moving from Theory to Practice

Integrated environmental management (IEM) and related concepts promoting holistic approaches to environmental management have been evolving rapidly over the past few decades. Although considerable research has examined the substantive dimensions of these concepts, practitioners have forged ahead applying IEM without a clear operational model. The authors link elements of ecosystem management and related fields with interaction to offer a new operational definition and practice paradigm. Interaction among stakeholders and with the public generally is the key operational component for IEM. Focusing on stakeholder interactions, the authors analyse the principle communication and conflict resolution tools employed in integrated approaches. Two illustrative cases from the state of Wisconsin demonstrate the application of interaction techniques and tools in pursuing integrated environmental management.     

Environmental courses require a common core

Shirley Ali Khan is the Director of the Environmental Responsibility Centre at the University of Hertfordshire, and Dr Stephen Martin is a Senior Executive of COUNTEC, Milton Keynes, UK.     

Use of fertilization and grazing exclusion in mitigating lost meadow production in the Sierra Nevada,California, USA

The effects of a single fertilizer treatment (ammonium phosphate at 841 kg/ha, plus dolomite at 336 kg/ha) and cattle exclusion were studied in two meadows in the Sierra Nevada of California in the USA. Grazing exclusion had no effects on soil bulk density during the three years of the study. Fertilization had no effect on total soil nitrogen, soil pH, or crude protein concentrations in graminoids or forbs. Saturated soils and the development of anaerobic conditions close to the surface may have led to denitrification and the loss of usable nitrogen. Fertilization did result in short-term (one- to two-year) increases in available soild phosphorus in the drier of the two meadows, and in total phosphorus concentrations in graminoids and forbs, which were otherwise generally deficient in phosphorus. Few changes in plant species composition or production were detected, although a combination of fertilization and grazing exclusion increased forb production in the drier meadow. Based on our initial results, fertilization with phosphorus was the recommended treatment for meadow improvement projects in the central Sierra Nevada.     

Resistance of pulmonate snail populations to repeated treatments of copper sulfate

Two species of pulmonate snails,Lymnaea cat-ascopium andPhysa integra, were collected from Douglas and Houghton Lakes. Snail populations from the former lake (pristine) had never been exposed to copper sulfate, whereas those from the latter one (treated) had been subjected to the molluscicide for more than 40 years. Molluscs from the treated lake were more resistant to the copper at concentrations of 0.5 and 1.0 ppm than those from the pristine lake. Furthermore, larger lymnaeids had a higher survival rate than smaller ones.