Summary1. The practice of deliberately moving animals from one site to another for conservation is increasing as a tool to re-establish extirpated populations. Resource managers are faced with developing strategies for reintroduction attempts, but often lack experimentally derived evidence upon which to base decisions. 2. Using the northern water snake Nerodia sipedon sipedon in the USA, we compared the behaviour and performance of resident snakes with that of individuals translocated directly from the wild to a nearby nature reserve or reared in captivity prior to translocation. 3. Both translocated groups had low survivorship relative to resident snakes, but the proximal causes of their poor performance differed considerably. Captive-reared snakes exhibited restricted surface activity and movements and abnormal habitat use, and ultimately failed to maintain appropriate body temperature and body mass, with high mortality associated with the overwintering period. Wild snakes directly translocated to an unfamiliar site maintained body temperatures and growth comparable with residents, but their more extensive movements resulted in frequent excursions off reserve and high mortality. 4. Synthesis and applications. We contend that an individual's prior experience is an important factor in determining their behaviour and performance during the phase of early establishment at an unfamiliar site. This suggests the existence of common underlying mechanisms influencing the outcome of reintroduction attempts, and provides a potentially useful framework for improving reintroduction efforts. Resource managers would likely improve success of reintroductions by matching habitats (and associated resources and conditions) between source and release sites, by temporarily confining animals in enclosures that force new associations to be made while limiting exploratory wanderings, or by enrichment of environmental conditions in captivity.

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Forest loss and fragmentation is expected to shape the genetic structure of amphibian populations and reduce genetic variation. Another factor widely understood to have impacted these same parameters in North America is the range expansion that occurred following glacial retreat at the end of the Pleistocene. The Eastern RedBacked Salamander (Plethodon cinereus) has been subjected to both processes. In this context, we investigated the historical events that are likely to have shaped genetic variation in this species using a panel of six microsatellite markers screened on individuals sampled across ten localities in northeastern Indiana, USA. We found low genetic diversity across forest patches and minimal differentiation. We expected population structure associated with forest fragmentation to result from genetic drift in isolation but instead found that a balance between gene flow and drift was *50 times more likely. Ratios of allele number and range (M), and coalescent modeling of population demography suggested the occurrence of marked historic decline in effective population size across the region. Taken together, the data point to a loss of genetic variation which preceded deforestation over the past 200 years. This result indicates an important role for ancient demographic processes in shaping current genetic variation that may make it difficult to detect the effect of recent habitat fragmentation.

Both ketone‐ and ester‐stabilised phosphorus ylides undergo Michael addition to vinyl ketones to give the β,δ′‐dioxo ylides 3 and 5, respectively, although in the latter case careful temperature control is required to avoid an undesired side‐reaction. Under conditions of flash vacuum pyrolysis at 650 °C the ylides 3 generally undergo Ph3PO extrusion to afford the γ,δ‐alkynyl ketones 14, although these are found to partly undergo a secondary fragmentation. In contrast, the ylides 5 react under the same conditions to give the synthetically useful 1,3‐dienes 20 by way of cyclobutenes. Rate constants for the reaction of selected ylides 3 and 5 are reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Tools designed to electrically induce fish immobilization are increasingly being implemented by practitioners for safe and effective fish handling. Currently used methods for electro-immobilizing batches of fish incorporate a period of hyperactivity that serves to reduce spinal injuries in fish. However, like the hyperactive period that is seen in other fish immobilization techniques, it provides a visually unappealing effect and introduces questions surrounding humane animal treatment. In this study, three different electro-immobilization treatments were evaluated for rates and severity of injury as well as time to immobilization to determine ways of reducing the hyperactive period while also maintaining low rates of injury. Tests were conducted in a Smith-Root EA-1000B System on adult summer steelhead Oncorhynchus mykiss at the Cowlitz Salmon Hatchery (Salkum, Washington). Treatments included an electrical output setting commonly used at the facility, two experimental electrical outputs, and a chemical anesthetic (MS-222) treatment that served as a control. Efficacy, indicated as time to immobilization, was evaluated among electrical output treatments; humane fish treatment, measured by hemorrhage, spinal injuries, and mortality, was quantified and compared among all treatments. Analysis of variance indicated a significant difference in induction times among electrical treatment groups, which ranged from 14.2 ± 4.9 to 53.4 ± 2.6 s (mean ± 95% CI). Some spinal and hemorrhage injuries were observed in all treatment groups; however, only one electrical treatment had significantly higher (P = 0.003) incidence and severity of injuries compared to the control. Results indicate that hatchery managers can