Issues in Species Recovery: An Example Based on the Wyoming Toad

Dreitz, Victoria J.

doi:10.1641/0006-3568(2006)56[765:iisrae]2.0.co;2

Cited by 20 publications

(10 citation statements)

References 21 publications

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“…For example, SDM could have aided recovery efforts for Houston toads (Bufo houstonensis), which suffered due to complex local politics and failed reintroduction efforts (Brown & Mesrobian, 2005;Dodd & Seigel, 1991). Adaptive management could also have improved recovery efforts for the Wyoming toad (Bufo baxteri), in which captive-bred toads were reintroduced, but subsequent monitoring was insufficient to evaluate the efforts (Dreitz, 2006).…”

Section: Value Of Sdmmentioning

confidence: 99%

“…Miscommunication among management agencies also hampered conservation efforts, but may have been avoided if SDM was in use (Dreitz, 2006). There are several recent examples of SDM applications for amphibian conservation, including decisions about ex situ conservation (Canessa et al, 2015;Grant, Zipkin, Nichols, & Campbell, 2013;Robinson, McGowan, & Apodaca, 2016).…”

Section: Value Of Sdmmentioning

confidence: 99%

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Structured decision making as a conservation tool for recovery planning of two endangered salamanders

O’Donnell

Messerman

Barichivich

et al. 2017

Journal for Nature Conservation

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At least one-third of all amphibian species face the threat of extinction, and current amphibian extinction rates are four orders of magnitude greater than background rates. Preventing extirpation often requires both ex situ (i.e., conservation breeding programs) and in situ strategies (i.e., protecting natural habitats). Flatwoods salamanders (Ambystoma bishopi and A. cingulatum) are protected under the U.S. Endangered Species Act. The two species have decreased from 476 historical locations to 63 recently extant locations (86.8% loss). We suggest that recovery efforts are needed to increase populations and prevent extinction, but uncertainty regarding optimal actions in both ex situ and in situ realms hinders recovery planning. We used structured decision making (SDM) to address key uncertainties regarding both captive breeding and habitat restoration, and we developed short-, medium-, and long-term goals to achieve recovery objectives. By promoting a transparent, logical approach, SDM has proven vital to recovery plan development for flatwoods salamanders. The SDM approach has clear advantages over other previous approaches to recovery efforts, and we suggest that it should be considered for other complex decisions regarding endangered species.

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Section: Value Of Sdmmentioning

confidence: 99%

Section: Value Of Sdmmentioning

confidence: 99%

Structured decision making as a conservation tool for recovery planning of two endangered salamanders

O’Donnell

Messerman

Barichivich

et al. 2017

Journal for Nature Conservation

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“…In its enzootic form, it can degrade amphibian populations [Berger and Speare, ; Berger et al, ; Green et al, ], affecting long‐term viability [Daszak et al, ]. The potential to incur heavy losses when reintroducing endangered amphibians to historical sites makes it imperitive to assess chytriomycosis risk with a minimum of animal mortality and resource expenditures [Dreitz, ; Muths, ]. The potential effect of Bd on caudate populations is of great concern as well.…”

Section: Introductionmentioning

confidence: 99%

Detection of pathogenic Batrachochytrium dendrobatidis using water filtration, animal and bait testing

et al. 2014

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The pathogen Batrachochytrium dendrobatidis (Bd) can be challenging to detect at endangered amphibian reintroduction sites. Pre-release Bd detection can be confounded by imperfect animal sampling and the absence of animals. In Study 1, we used historical Bd-positive sites, to concurrently evaluate water filtrates and mouth bar (tadpoles) or skin swab (caudates) samples for Bd using molecular beacon realtime PCR. In Study 2, during a natural outbreak, we used PCR to detect Bd from zoospore-attracting keratin baits (three avian, three snake species). In Study 1, no captured animals (n=116) exhibited clinical signs, although 10.6% were positive, representing three of seven species sampled. In contrast, 5.4% of water filters (n=56) were Bd-positive. In Study 2, after short incubation times, a single duck down feather tested Bd-positive. In conclusion, Bd was detected in asymptomatic amphibians and water filtrate at two sites, and from water only, at two other sites. With continued refinement, semi-quantitative Bd water filtrate screening could better define zoospore-specific disease risk, allowing better characterization of the free-living phase of the organism's life cycle. Finally, these results suggest wild aquatic birds (e.g., waterfowl) should be systematically explored as a means of Bd spread. Since large numbers of aquatic birds migrate, even low Bd transfer rates could be a significant means for disease dissemination.

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“…Except for one attempt at soft‐release over a decade ago, past reintroduction efforts for the Wyoming toad have been hard‐release methods where primarily tadpoles (but occasionally older life stages) were released into or near aquatic habitats. Past recovery efforts for the species may have been limited by a lack of scientific data to inform management decisions, communication problems, and minimal monitoring of reintroduced individuals (Dreitz ). However, recent improvements in monitoring protocols and communication have occurred and a large captive breeding program exists; thus, research to understand factors limiting species reestablishment is the next step in recovery efforts for the Wyoming toad.…”

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confidence: 99%

Factors limiting early life stage survival and growth during endangered Wyoming toad reintroductions

et al. 2015

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Understanding the limiting factors of recovery is essential for guiding sound management of endangered species. The Wyoming toad (Anaxyrus baxteri) is a critically endangered amphibian whose cause of decline and inability to reestablish breeding populations despite early life stage reintroductions remains unknown; habitat degradation and the pathogen Batrachochytrium dendrobatidis (Bd) are 2 potential contributing factors. In 2013, we experimentally tested the effects of habitat factors under foodsupplemented and predator-protected conditions (i.e., mesh field enclosures) on time to metamorphosis, the proportion of tadpoles that metamorphosed, tadpole and toadlet size, the proportion of toadlets remaining in enclosures at release (approx. 1 month post-metamorphosis), and Bd prevalence in early life stages of Wyoming toads at Mortenson Lake National Wildlife Refuge. In 2014, we tested the effects of small-scale application of vegetation height management on toadlet size, the proportion of toadlets that remained, and Bd prevalence until 1 month post-metamorphosis. In 2013, median time to metamorphosis (25.5 days) was shorter in warmer water temperatures and proportion of tadpoles that metamorphosed was 0.70. In 2013, toadlet size was positively related to forb cover up to 35% and although overall treatment effect was not significant, mid-vegetation height treatments (10-30 cm) had fewer small toadlets at release than short (0-10 cm) and tall (>30 cm) vegetation heights. In 2014, vegetation height treatment (11.49-31.6 cm) had marginal support for estimating larger size at release. Batrachochytrium dendrobatidis was not detected in water samples or on post-metamorphic toadlets. Our results suggest that in mesh field enclosures, time to metamorphosis is shorter in warm water. In addition, vegetation heights of 10-30 cm and up to 35% forb cover within terrestrial mesh enclosures could increase Wyoming toad post-metamorphic size, which could increase overwinter survival rates. Using mesh field enclosures for soft-release may improve the effectiveness of early life stage reintroduction efforts, but predator attraction and density-dependent growth need to be considered. Habitat management can also influence growth and survival of early life stages of amphibians and may benefit reintroduction efforts for other species. Ó 2015 The Wildlife Society.

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Issues in Species Recovery: An Example Based on the Wyoming Toad

Cited by 20 publications

References 21 publications

Structured decision making as a conservation tool for recovery planning of two endangered salamanders

Structured decision making as a conservation tool for recovery planning of two endangered salamanders

Detection of pathogenic Batrachochytrium dendrobatidis using water filtration, animal and bait testing

Factors limiting early life stage survival and growth during endangered Wyoming toad reintroductions

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