pp. 125-130

Authors: Laura A. Brannelly, Michel E. B. Ohmer & Corinne L. Richards-Zawacki

Abstract: Procuring offspring from captive animals can be important for research and conservation efforts. Yet, reliable methods for obtaining fertilised eggs are unavailable for many species. In this study, we examined the efficacy of one drug, leuprolide acetate, to induce reproduction (i.e. egg production, tadpole hatching) in the northern leopard frog, Rana pipiens. We found that leuprolide acetate successfully induced breeding and larval development in animals that were overwintered in the lab, but not in animals caught during the breeding season. These results indicate that leuprolide acetate can be successful in inducing breeding and fertilisation of frog eggs, but that its effectiveness might be contingent upon length of time in captivity and the animals having undergone an artificial overwintering period in the laboratory prior to induction. Artificial breeding success is species and context dependent; therefore, identifying additional methods effective across taxa will help support species in need of management intervention.

Keywords: Amphibian; Amphibian reproduction; Assisted reproductive technologies; Breeding; Hormone induction; Leuprolide Acetate; Spawning

pp. 115-124

Authors: Sharon Pratt Anzaldua & Javier Goldberg

Abstract: A high concentration of Cuban treefrog ([i]Osteopilus septentrionalis[/i]) tadpoles displaying morphological abnormalities was discovered in an untreated swimming pool in Bonita Springs, Florida. This find initiated a 4-year survey (2012-2015) of surrounding roadside drainage ditches that had been treated with insecticide for mosquito control. The study was extended to the populations of Ave Maria, Florida, and Everglades National Park. The core data set of 36,550 tadpoles from the swimming pool and ditches contained 25,136 abnormal tadpoles, an abnormality average of 68.8 %, well above the 5 % minimum definition for a hotspot. The frogs from Ave Maria and the Everglades National park were 0 % abnormal. The type of tadpole abnormality differed between the suburban treated roadside drainage ditches versus the untreated swimming pool, although the same abnormalities were found in both the suburban treated and untreated water. In the untreated swimming pool, 70.1 % of tadpoles displayed abnormalities such as bent tails, abnormal limbs, and disfigured or absent mouthparts. Larvae in the untreated swimming pool metamorphosed en masse despite abnormalities. The high frequency of abnormal metamorph abnormalities found were: kyphosis, scoliosis, microcephaly, and forelimb abnormalities. In the treated roadside drainage ditches, Gosner stage 16-25 tadpoles could not undergo metamorphosis and experienced mass mortality. The abnormalities found at Gosner stage 16 of the embryo were in the head and body. Tadpoles at Gosner stages 19-25 failed to develop gills, were bloated, had growth retardation, and mouthpart abnormalities. The older Gosner stage 25-41 tadpole populations in the ditches showed bloating, lumps, emaciation, and growth retardation. A brief synopsis of [i]O. septentrionalis[/i] treefrog biology is also given, including breeding congregations, average 8 hour time to hatching, and 19 days metamorphosis.

Keywords: anurans, [i]Osteopilus septentrionalis[/i], tadpoles, normal development, abnormality

pp. 95-114

Authors: Walter E. Meshaka, Jr., James N. Layne & Kenneth G. Rice

Abstract: A 35-year (1967–2002) demographic study was conducted on the gopher tortoise ([i]Gopherus polyphemus[/i]) from two different habitats on Archbold Biological Station located on the southern end of the Lake Wales Ridge in south-central Florida. We found geographic, habitat, and human-mediated effects on several aspects of its biology. Our findings underscore the necessity of long-term demographic data to more accurately answer ecological questions concerning long-lived species, such as how the
gopher tortoise detectably might be affected by habitat quality and human activities.

Keywords: Demography, ecology, gopher tortoise

pp. 82-94

Authors: John Box, Ellen Harpham & Rosie Jackson

Abstract: The great crested newt, [i]Triturus cristatus[/i], is a European Protected Species. Its legal protection requires appropriate mitigation and compensation measures to be developed for populations threatened by built development in order to demonstrate no likely detriment to the maintenance of the favourable conservation status of the species in its natural range. A major regeneration project at a site near Neath Port Talbot in South Wales, United Kingdom, resulted in the destruction of the breeding sites and associated terrestrial habitats of a population of great crested newts. Capture and translocation of 9,500 newts of all life stages was undertaken between 2009 and 2016 to an adjacent receptor site with waterbodies and extensive terrestrial habitats. Eggs and larvae have been observed in waterbodies in the receptor site throughout the monitoring period from 2013 to 2017, and great crested newts are colonising new waterbodies. The translocated population was much larger than the population size predicted from the baseline surveys of waterbodies on the development site. The design, planning and licensing of mitigation and compensation schemes for great crested newts threatened by built development projects need to give full weight to the limitations of survey methods when estimating the size of a population.

Keywords: amphibian, European Protected Species, great crested newt, translocation, [i]Triturus cristatus[/i]

pp. 71-81

Authors:  Rafael Hernández-Guzmán, Luis H. Escalera-Vázquez & Ireri Suazo-Ortuño

Abstract: Global climate change represents one of the most important threats to wildlife populations. Amphibians, specifically
salamanders, are particularly susceptible to the effects of a changing climate due to their restrictive physiological requirements
and low vagility; however, little is known about which amphibian species are more vulnerable to climate change. Therefore,
we aimed to forecast changes in the distribution of the mountain stream salamander, [i]Ambystoma ordinarium[/i], using different climate scenarios. Approximately 70 representative presence records were selected to model the current potential distribution and two scenarios based on 2070 climate projections (RCP 2.6 and RCP 8.5) using the MaxEnt algorithm and three global climate models (BCC-CSM1-1, CCSM4 and HadGEM2-ES). A total of three scenarios were simulated using the 10-percentile training presence as the threshold rule. For all scenarios, the average of the area under the receiver operating characteristic curve for the replicated runs was greater than 0.95 ± 0.005, representing good performance for the current and projected geographical distributions of [i]A. ordinarium[/i]. Under the most conservative scenario, of a total area of 45,876 km2, an average potential distribution area of 5,627 km2 was defined for current conditions, decreasing to 4,406 km2 for BCCCSM1-1 in the optimistic scenario (RCP 2.6) and decreasing to 4,020 km2 for CCSM4 in the pessimistic scenario (RCP 8.5). The results are useful for the development of future conservation plans, identifying landscapes with high probability to be further affected by climate change and to target potentially resilient habitats that provide consistent climatic conditions for [i]A. ordinarium[/i] in the face of environmental changes.

Keywords: [i]Ambystoma ordinarium[/i]; Global climate models; MaxEnt; Salamanders; Species distribution model.