Despite rapid growth in the field of reintroduction biology, results from scientific research are often not applied to translocations initiated when human land‐use change conflicts with the continued persistence of a species' population at a particular site. Such mitigation‐driven translocations outnumber and receive more funding than science‐based conservation translocations, yet the conservation benefit of the former is unclear. Because mitigation releases are economically motivated, outcomes may be less successful than those of releases designed to serve the biological needs of species. Translocation as a regulatory tool may be ill‐suited for biologically mitigating environmental damage caused by development. Evidence suggests that many mitigation‐driven translocations fail, although the application of scientific principles and best practices would probably improve the success rate. Lack of transparency and failure to document outcomes also hinder efforts to understand the scope of the problem. If mitigation‐driven translocations are to continue as part of the growing billion‐dollar ecological consulting industry, it is imperative that the scale and effects of these releases be reported and evaluated.

inducing carelessness in water conservation. In addition to generally investigating the efficacy of translocation, we compared the effects of continuing with the effects of ceasing the holding facility's water supplementation regimen. After exposure to one of the two water regimens, all tortoises were given the opportunity to hydrate immediately prior to release.We examined behavior, body mass, carapace length, movement, and mortality of tortoises for two activity seasons following release to the wild. Water supplementation was correlated with high rates of carapace growth and distant movements by males after release.Lengthy movements following translocation may be problematic for conservation planning, but this should be evaluated in light of the goals and circumstances of each translocation project. Although the mortality rate was 21.4% in 1997, data suggest that drought conditions at the site rather than the translocation itself negatively affected the tortoises.None of the tortoises died during their second season at the site. Our results indicate that translocation should be considered a useful tool in conservation of the Desert Tortoise.

Anthropogenic environmental modification is placing as many as 1 million species at risk of extinction. One management action for reducing extinction risk is translocation of individuals to locations from which they have disappeared or to new locations where biologists hypothesize they have a good chance of surviving. To maximize this survival probability, the standard practice is to move animals from the closest possible populations that contain presumably related individuals. In an empirical test of this conventional wisdom, we analyzed a genomic dataset for 166 translocated desert tortoises (Gopherus agassizii) that either survived or died over a period of two decades. We used genomic data to infer the geographic origin of translocated tortoises and found that individual heterozygosity predicted tortoise survival, whereas translocation distance or geographic unit of origin did not. Our results suggest a relatively simple indicator of the likelihood of a translocated individual’s survival: heterozygosity.

Batrachochytrium dendrobatidis (Bd) infection on post-metamorphic frogs and salamanders is commonly diagnosed using polymerase chain reaction (PCR) of skin scrapings taken with mildly abrasive swabs. The technique is sensitive, non-lethal, and repeatable for live animals. Tadpoles are generally not sampled by swabbing but are usually killed and their mouthparts excised to test for the pathogen. We evaluated a technique for non-lethal Bd diagnosis using quantitative PCR (qPCR) on swabs scraped over the mouthparts of live tadpoles. The sensitivity of non-lethal (swabbing) and lethal (removal of mouthparts) sampling was assessed using 150 Bd-infected Rana subaquavocalis tadpoles. Swabbing was consistently less sensitive than lethal sampling, but still detected Bd. Experimental Bd prevalence was 41.1% when estimated by destructively sampling mouthparts and 4.7 to 36.6% (mean = 21.4%) when estimated with swabs. Detection rates from swabbing varied with investigator and time since infection. The likelihood of detecting Bd-infected tadpoles was similar regardless of size and developmental stage. Swabbing mouthparts of live tadpoles is a feasible and effective survey technique for Bd, but, because it is less sensitive, more tadpoles must be sampled to estimate prevalence at a confidence level comparable to destructive sampling. KEY WORDS: Batrachochytrium dendrobatidis · Tadpole · Detection · PCR · Technique · Chytridiomycosis Resale or republication not permitted without written consent of the publisherDis Aquat Org 72: [77][78][79][80][81][82][83][84][85] 2006 et al. 2004, Knapp & Morgan 2006, and are killed for histological diagnosis. This limits studies of amphibian disease, particularly those that span life-history stages.The polymerase chain reaction (PCR) is the basis for a highly sensitive, non-destructive diagnostic technique for sampling post-metamorphic amphibians. An animal's skin is scraped or swabbed lightly with a finely pointed, slightly abrasive object, such as a wooden toothpick or cotton surgical swab, to remove the outermost skin cells, which are then screened for Bd DNA using real-time Taqman PCR assays (Boyle et al. 2004). Researchers studying chytridiomycosis in amphibians have used the swabbing technique for about 4 yr, and it is a generally accepted protocol used by several laboratories (Briggs & Vredenberg 2004, Livo 2004, Kriger et al. 2006. We evaluate the sensitivity and feasibility of swabbing tadpole mouthparts for Bd diagnosis as a non-lethal alternative to histology. The project arose from a desire to learn more about the rare Ramsey Canyon leopard frog Rana subaquavocalis in southeastern Arizona, where Bd has been detected at several sites and tadpoles often remain at sites after frogs have become scarce or absent (K. J. Field pers. obs.). Wildlife managers are rightly reluctant to test for Bd by killing large numbers of tadpoles in small, vulnerable populations. Our question was: Could we detect Bd reliably and non-lethally in tadpoles using quantitative PCR? MATERIALS AND...

Ensuring the persistence of at-risk species depends on implementing conservation actions that ameliorate threats. We developed and implemented a method to quantify the relative importance of threats and to prioritize recovery actions based on their potential to affect risk to Mojave desert tortoises (Gopherus agassizii). We used assessments of threat importance and elasticities of demographic rates from population matrix models to estimate the relative contributions of threats to overall increase in risk to the population. We found that urbanization, human access, military operations, disease, and illegal use of off highway vehicles are the most serious threats to the desert tortoise range-wide. These results suggest that, overall, recovery actions that decrease habitat loss, predation, and crushing will be most effective for recovery; specifically, we found that habitat restoration, topic-specific environmental education, and land acquisition are most likely to result in the greatest decrease in risk to the desert tortoise across its range. In addition, we have developed an application that manages the conceptual model and all supporting information and calculates threat severity and potential effectiveness of recovery actions. Our analytical approach provides an objective process for quantifying threats, prioritizing recovery actions, and developing monitoring metrics for those actions for adaptive management of any at-risk species.