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1
Oh, Hye-Ji, Kwang-Hyeon Chang, Mei-Yan Jin, Jong-Mo Suh, Ju-Duk Yoon, Kyung-Hoon Shin, Su-Gon Park, and Min-Ho Chang. "Trophic Ecology of Endangered Gold-Spotted Pond Frog in Ecological Wetland Park and Rice Paddy Habitats." Animals 11, no. 4 (March 31, 2021): 967. http://dx.doi.org/10.3390/ani11040967.
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The gold-spotted pond frog (Pelophylax chosenicus) is an endangered amphibian species in South Korea. In order to obtain ecological information regarding the gold-spotted pond frog’s habitat environment and biological interactions, we applied stable isotope analysis to quantify the ecological niche space (ENS) of frogs including black-spotted pond frogs (P. nigromaculatus) and bullfrogs (Lithobates catesbeianus) within the food web of two different habitats—an ecological wetland park and a rice paddy. The gold-spotted pond frog population exhibited a broader ENS in the ecological wetland park than in the rice paddy. According to the carbon stable isotope ratios, gold-spotted pond frogs mainly fed on insects, regardless of habitat type. However, the results comparing the range of both carbon and nitrogen stable isotopes showed that gold-spotted pond frogs living in the rice paddy showed limited feeding behavior, while those living in the ecological wetland park fed on various food sources located in more varied trophic positions. Although the ENS of the gold-spotted pond frog was generally less likely to be overlapped by that of other frog species, it was predicted to overlap with a high probability of 87.3% in the ecological wetland park. Nevertheless, gold-spotted pond frogs in the ecological wetland park were not significantly affected by the prey competition with competitive species by feeding on other prey for which other species’ preference was low. Since these results show that a habitats’ food diversity has an effect on securing the ENS of gold-spotted pond frogs and prey competition, we recommend that the establishment of a food environment that considers the feeding behavior of gold-spotted pond frogs is important for the sustainable preservation of gold-spotted pond frogs and their settlement in alternative habitats.
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Smith, Lora L., Jennifer M. Howze, Jennifer S. Staiger, Eric R. Sievers, Deborah Burr, and Kevin M. Enge. "Added Value: Gopher Tortoise Surveys Provide Estimates of Gopher Frog Abundance in Tortoise Burrows." Journal of Fish and Wildlife Management 12, no. 1 (October 27, 2020): 3–11. http://dx.doi.org/10.3996/jfwm-20-030.
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Abstract The gopher frog Lithobates capito is one of the most terrestrial frogs in the southeastern United States and often inhabits gopher tortoise burrows Gopherus polyphemus outside of the breeding season. Gopher frog populations have declined, and the species is under review for listing as threatened or endangered under the U.S. Endangered Species Act. Much of our knowledge on the status of gopher frogs is based on detections of larvae at breeding wetlands, which can be challenging because of environmental variability and provides no information on the terrestrial life stages of the species. Therefore, an alternative method is called for. We recorded observations of gopher frogs during gopher tortoise surveys at four conservation lands in Florida and used line-transect distance sampling to estimate frog abundance. We also recorded burrow size, incidence of frog co-occupancy with tortoises, and distance from frog-occupied burrows to breeding wetlands. We observed 274 gopher frogs in 1,097 tortoise burrows at the four sites. The proportion of burrows occupied by gopher frogs among sites ranged from 0.17 to 0.25. Gopher frog abundance in tortoise burrows was 742 (512–1,076 95% CL) at Etoniah Creek State Forest, 465 (352–615) at Ft. White Wildlife Environmental Area, 411 (283–595) at Mike Roess Gold Head Branch State Park, and 134 (97–186) at Watermelon Pond Wildlife Environmental Area. We observed up to four frogs in a single burrow. The proportion of frogs detected in burrows occupied by a gopher tortoise ranged from 0.46 to 0.79 among sites, and overall, gopher frogs preferred burrows occupied by tortoises over unoccupied burrows (χ2 = 15.875; df = 3; P = 0.001). Gopher frogs used burrows from 7 to 43 cm in width; mean width of frog-occupied burrows did not differ from that of unoccupied burrows (F1,3 = 0.049, P = 0.825). Distance from frog-occupied tortoise burrows to the nearest breeding wetland ranged from 141 to 3,402 m. Our data on gopher frogs collected in conjunction with gopher tortoise monitoring efforts using line-transect distance sampling and burrow cameras provided novel information on frog abundance in their terrestrial habitat and required no additional effort. However, the extent to which frogs use tortoise burrows relative to other available refuges (small mammal burrows, stumps, or other structures) is unknown; thus, our estimates should be considered conservative. We suggest that terrestrial abundance estimates for gopher frogs can complement efforts to monitor breeding activity to provide a more comprehensive means of monitoring population trends in this cryptic species.
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Park, Jun-Kyu, Woong-Bae Park, and Yuno Do. "Identifying Popular Frogs and Attractive Frog Calls from YouTube Data." Sustainability 14, no. 16 (August 18, 2022): 10258. http://dx.doi.org/10.3390/su141610258.
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Public interest in and preferences for certain species can sometimes provide an opportunity for conservation and management. Here, we attempted to identify ‘popular’ anurans from YouTube data. In addition, the attractiveness of anuran advertisement-calling sounds were analyzed using acoustic data. By searching YouTube with the search term ‘frog calling’, 250 videos were selected. Of these, 174 videos could be classified according to species; these videos aided in extracting clean calling sounds, free from the overlapping calls of other male frogs, as well as other sounds. To assess the interests and preferences of viewers for different species, the numbers of videos, view counts, ‘likes,’ and ‘dislikes’ were recorded. From the videos, the calls of 78 species belonging to 17 families were identified. Viewer interest was highest for the Hylidae and Ranidae species, which are often discoverable in the field. In addition, invasive frogs had large numbers of videos and large numbers of ‘likes.’ People tended to prefer frogs calling with lower dominant frequencies. However, there were few videos on endangered species, and these garnered relatively less interest than other species. To manage and conserve invasive or endangered frog species, there is a need to increase ecological understanding by adjusting species awareness and charisma.
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Kouba, A., E. Willis, C. Vance, S. Hasenstab, S. Reichling, J. Krebs, L. Linhoff, M. Snoza, C. Langhorne, and J. Germano. "116 DEVELOPMENT OF ASSISTED REPRODUCTION TECHNOLOGIES FOR THE ENDANGERED MISSISSIPPI GOPHER FROG (RANA SEVOSA) AND SPERM TRANSFER FOR IN VITRO FERTILIZATION." Reproduction, Fertility and Development 24, no. 1 (2012): 170. http://dx.doi.org/10.1071/rdv24n1ab116.
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Species-specific differences in breeding strategies and physiology have limited the application of assisted reproductive technologies (ART) for critically endangered amphibians in captive assurance colonies. In 2006, the Memphis Zoo (MZ) initiated a program to develop ART for the critically endangered Mississippi gopher frog after natural breeding failed. Standard gamete collection and IVF developed by MZ for reproducing endangered toads such as the Wyoming or boreal toad were applied to the gopher frog with little success, especially hormonal therapy for sperm production. Using the leopard frog as a model species for Ranids, we tested the time and dose dependence of a luteinizing hormone releasing hormone analogue (LHRHa) and hCG on sperm quantity and quality. Initial findings from the leopard frog study were critical in designing the study on gopher frogs. Our objectives were to (1) compare 2 different hormones administered intraperitoneal (500 IU hCG vs 15 μg LHRHa) or their combination on spermiation in gopher frogs; (2) develop in vivo oocyte maturation and ovulation protocols using LHRHa (15 μg) and hCG (500 IU); and (3) transfer this technology to another institution as proof of principle. In gopher frogs, 100 and 83% of the males produced sperm in response to the LHRHa and the combination treatment, respectively, whereas only 16% responded to hCG alone. Sperm concentration peaked at 1 h post-administration for all treatments, with the LHRH/hCG cocktail treatment producing the highest concentration of sperm (mean = 4.6 × 106 ± 1.2 × 106 sperm mL–1, n = 6). No differences in motility were observed between treatments (P > 0.05). For females, a series of priming hormones of hCG and LHRHa were given several months before an ovulatory hormone regimen resulting in ovulation by 100% of the females (n = 6), whereas animals not primed failed to ovulate (n = 4). These 3 separate priming and IVF trials conducted between 2008 and 2010 resulted in each female laying ∼2000 eggs, with an average fertilization rate of 76% for inseminated eggs and hundreds of tadpoles produced. These IVF tadpoles represent the first captive reproduction of gopher frogs and highlight how ART can be applied to conservation and genetic management of threatened species. Subsequently, we tested our IVF protocols on gopher frogs at Omaha's Henry Doorly Zoo using fresh (collected on site) and chilled, shipped sperm from MZ. We collected 6169 eggs from 9 hormone-primed females with all animals ovulating. A portion of the total eggs ovulated were inseminated, resulting in 2401 fertilized eggs (38.9% of total eggs collected) across 18 different male–female pairings leading to viable tadpoles. In addition, sperm transferred overnight from the MZ produced 202/441 fertilized eggs (46%). The transfer of this technology and production of endangered amphibians using chilled, shipped sperm from live animals is a conservation milestone that can be applied to other captive breeding programs.
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Narayan, Edward, Frank Molinia, Ketan Christi, Craig Morley, and John Cockrem. "Urinary corticosterone metabolite responses to capture, and annual patterns of urinary corticosterone in wild and captive endangered Fijian ground frogs (Platymantis vitiana)." Australian Journal of Zoology 58, no. 3 (2010): 189. http://dx.doi.org/10.1071/zo10010.
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This study was based on the development of a non-invasive glucocorticoid enzyme-immunoassay for the assessment of stress in wild and captive endangered Fijian ground frogs (Platymantis vitiana). Enzyme-immunoassays were developed and validated for the first time to non-invasively measure both cortisol and corticosterone metabolites in frog urine. Frog urine showed parallel displacement with corticosterone but not cortisol standards, therefore corticosterone enzyme immunoassays were used to examine stress in wild and captive frogs. Urinary corticosterone metabolite concentrations increased in frog urine (n = 4) at 6 h, 1 day and 2 days after injection with adrenocorticotropic hormone (0.44 μg g–1 bodyweight), indicating that the corticosterone enzyme-immunoassay could detect changes in circulating corticosterone in frogs. Urinary concentrations of corticosterone were measured in wild frogs (n = 18) after capture in the field. The first measurement beyond the initial sample was at 2–3 h. Mean urinary corticosterone concentrations rose after the initial sample and were significantly elevated in samples collected 3–4 h after capture. This is the first demonstration of a urinary corticosterone response to capture in amphibians. Urinary corticosterone metabolite concentrations for all months combined were lower in captive males than in wild males, and differed between vitellogenic, non-vitellogenic and captive females. Concentrations did not differ between captive and wild females. In conclusion, urinary corticosterone enzyme immunoassays can be used in frogs for assessing stress responses to capture and natural stress profiles of both captive and wild populations.
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Ruland, Florian, and Jonathan M. Jeschke. "Threat-dependent traits of endangered frogs." Biological Conservation 206 (February 2017): 310–13. http://dx.doi.org/10.1016/j.biocon.2016.11.027.
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Segura Silva, Bernardo. "New record of Insuetophrynus acarpicus Barrio, 1970 (Anura: Rhinodermatidae) in Chile: implications for its conservation." Check List 13, no. 1 (February 15, 2017): 2046. http://dx.doi.org/10.15560/13.1.2046.
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A new record of the Critically frog Insuetophrynus acarpicus was discovered in Chile from a site lying 66 km southwest from the southernmost locality reported for the species. This new population is the first occurrence of the species in a protected area, and considerably extends the geographical and altitudinal range of I. acarpicus, one of the most endangered frogs in the world.
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Narayan, Edward, and Jean-Marc Hero. "Urinary corticosterone responses and haematological stress indicators in the endangered Fijian ground frog (Platymantis vitiana) during transportation and captivity." Australian Journal of Zoology 59, no. 2 (2011): 79. http://dx.doi.org/10.1071/zo11030.
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Physiological stress assessment is important for in-situ conservation and captive management of threatened wildlife. Leukocyte (white blood cell) evaluation, especially the neutrophil : lymphocyte (N : L) ratio, provides a logical representation of experimentally elevated corticosterone (stress hormone) in amphibians. Urinary corticosterone enzyme-immunoassay (EIA) is a rapid non-invasive tool for assessing stress responses in amphibians. To our knowledge, no one has explored the relationship between N : L ratio and urinary corticosterone in wild amphibians in a non-experimental way. This study provides a comparative assessment of relative leukocyte numbers, N : L ratios and urinary corticosterone responses of the endangered Fijian ground frog (Platymantis vitiana) during transportation and captivity. Adult frogs (n = 40) were collected from Viwa, Fiji Island for captive breeding. Frogs showed significant changes in leukocyte proportions during transportation and captivity. N : L ratios were higher 6 h after transportation and over 5 and 15 days in captivity. Urinary corticosterone responses of the frogs were also higher 6 h after transportation and after 5 and 15 days in captivity. All leukocyte proportions, N : L ratios and urinary corticosterone concentrations of the frogs returned near baseline levels after the frogs were kept in an environmentally enriched outdoor enclosure for over 25 days. These results highlight the value of leukocyte evaluation and urinary corticosterone EIAs as physiological tools for evaluating stress in amphibians.
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Backlin, Adam R., Cynthia J. Hitchcock, Elizabeth A. Gallegos, Julie L. Yee, and Robert N. Fisher. "The precarious persistence of the Endangered Sierra Madre yellow-legged frog Rana muscosa in southern California, USA." Oryx 49, no. 1 (November 21, 2013): 157–64. http://dx.doi.org/10.1017/s003060531300029x.
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AbstractWe conducted surveys for the Endangered Sierra Madre yellow-legged frog Rana muscosa throughout southern California to evaluate the current distribution and status of the species. Surveys were conducted during 2000–2009 at 150 unique streams and lakes within the San Gabriel, San Bernardino, San Jacinto, and Palomar mountains of southern California. Only nine small, geographically isolated populations were detected across the four mountain ranges, and all tested positive for the amphibian chytrid fungus Batrachochytrium dendrobatidis. Our data show that when R. muscosa is known to be present it is easily detectable (89%) in a single visit during the frog's active season. We estimate that only 166 adult frogs remained in the wild in 2009. Our research indicates that R. muscosa populations in southern California are threatened by natural and stochastic events and may become extirpated in the near future unless there is some intervention to save them.
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Mann, Reinier M., Ross V. Hyne, Paulina Selvakumaraswamy, and Sergio S. Barbosa. "Longevity and larval development among southern bell frogs (Litoria raniformis) in the Coleambally Irrigation Area - implications for conservation of an endangered frog." Wildlife Research 37, no. 6 (2010): 447. http://dx.doi.org/10.1071/wr10061.
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Context. With the flow of many of the world’s rivers regulated such that water can be diverted for agriculture and human consumption, basic ecological information on the current status of key biota in significant floodplain wetlands and their response following inundation is needed. The maintenance of natural habitat to ensure amphibian survival is gaining increasing recognition, given the ongoing decline of anuran populations. Information on longevity, time required to emerge from the water and to reach sexual maturity, all provide important information about the required timing, frequency and duration of environmental water allocations to ensure successful recruitment among populations of southern bell frogs (Litoria raniformis Keferstein, 1867). Aims. The aims of this research were to establish the longevity of southern bell frogs in the Coleambally Irrigation Area (CIA) in the Riverina region of New South Wales, Australia, and to evaluate the capacity for southern bell frog tadpoles to survive and successfully metamorphose following an extended overwintering period. Methods. Skeletochronology studies were carried out using toe-clips taken from adult and juvenile frogs captured in irrigation channels and rice fields over two rice-growing seasons. For the metamorphosis assay, southern bell frog tadpoles were held back in their development by low temperatures and low food allocation for 290 days, before temperatures and food allocation were increased adequately to allow metamorphosis to occur. Key results. The study indicated that skeletochronological examination of toe-bones was a useful technique for establishing the age structure of southern bell frogs in this region. The oldest animals in the population were found to be 4–5 years old, although the majority of frogs were typically 2–3 years old. Also, the metamorphosis assay indicated that successful metamorphosis was the exception rather than the rule if tadpole development was held back by low food ration and low temperatures. Conclusions. If southern bell frogs reach sexual maturity only after 2 years, and the oldest animals observed in the field are 4 or 5 years old, then there is a very narrow window of opportunity – two to three seasons – for each individual to successfully breed. Implications. The implications for environmental flow management are that habitats for key species identified for protection such as the endangered southern bell frog will need water every 1–2 years to enable each cohort to breed and maintain the wild populations. The extent of the environmental flows needs to be adequate to ensure that water persists long enough for critical biological events such as anuran metamorphosis to occur during the spring and summer months.
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Thomas, Nunia, Clare Morrison, Linto Winder, and Craig Morley. "Spatial distribution and habitat preferences of co-occurring vertebrate species: Case study of an endangered frog and an introduced toad in Fiji." Pacific Conservation Biology 17, no. 1 (2011): 68. http://dx.doi.org/10.1071/pc110068.
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Wildlife management, particularly the conservation of threatened species, often involves habitat management and an understanding of species preferences. Much ecological data used to establish rare and endangered species distributions and/or habitat associations exists in the form of point counts which often violates the assumptions of commonly used statistical techniques. In this study, the spatial distribution and habitat preferences of an endangered, endemic frog (Platymantis vitianus — Fiji ground frog) and an introduced toad (Rhinella marina — cane toad) were observed and mapped on a 60 ha island using a grid of 232 sampling points with 50 × 20 m spacing. The Spatial Analysis by Distance Indices (SADIE) analytical tool demonstrated that despite the wide range of habitats present on Viwa Island, both ground frogs and cane toads displayed clear and defined macrohabitat preferences. Whilst both species showed a strong preference for Inocarpus fagifer forests, there was little overlap in other habitat types with the ground frogs preferring more densely vegetated forest habitats and cane toads preferring more open habitat types close to both permanent and temporary water sources. Within the I. fagifer forests, there was no evidence of overlap in the distributions of the two species. The spatial pattern evident indicates that cane toad and ground frog populations co-exist, probably due to similar habitat preferences. However, a more detailed study on the interactions between the two species within their natural environment is needed to determine the nature and magnitude of the impact of the cane toad on the ground frog.
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Morrison, C., A. Naikatini, N. Thomas, I. Rounds, and B. Thaman Niukula. "Rediscovery of an endangered frog Platymantis vitianus, on mainland Fiji: implications for conservation and management." Pacific Conservation Biology 10, no. 4 (2004): 237. http://dx.doi.org/10.1071/pc040237.
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Many herpetofauna species in the Pacific region have undergone dramatic declines due to invasive species, primarily introduced predators. Fiji has two species of endemic frogs (Family Ranidae, Genus Platymantis) one of which, the Fiji Ground Frog, P. vitianus, has been extirpated from much of its original range due to the mongoose Herpestes javanicus. We conducted a short-term follow up survey to confirm an earlier report (September 2003) of the co-existence between mongoose and the ground frog on mainland Fiji (Vanua Levu). We used systematic nocturnal and diurnal surveys to census the frog fauna of Waisali Reserve and described microhabitat and threatening processes. A series of key management actions are outlined to facilitate the long-term conservation of this frog in the reserve.
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Vásquez-Cruz, Víctor, Luis Canseco-Márquez, and Arleth Reynoso-Martínez. "Distributional and natural history notes for Bromeliohyla dendroscarta (Anura: Hylidae) in Veracruz, Mexico." Phyllomedusa: Journal of Herpetology 18, no. 1 (June 18, 2019): 27–36. http://dx.doi.org/10.11606/issn.2316-9079.v18i1p27-36.
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Distributional and natural history notes for Bromeliohyla dendroscarta (Anura: Hylidae) in Veracruz, Mexico. Two new locality records are reported for the critically endangered hylid frog, Bromeliohyla dendroscarta, in Veracruz, Mexico. The frogs were found in semideciduous tropical forest, an ecotone of semideciduous tropical forest and mountain cloud forest, and an agricultural mosaic; none of these habitats has been documented previously for this species. Information is provided on larval feeding habits, duration of larval development under natural conditions and external morphology of tadpoles.
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Knapp, Roland A., Maxwell B. Joseph, Thomas C. Smith, Ericka E. Hegeman, Vance T. Vredenburg, James E. Erdman Jr, Daniel M. Boiano, Andrea J. Jani, and Cheryl J. Briggs. "Effectiveness of antifungal treatments during chytridiomycosis epizootics in populations of an endangered frog." PeerJ 10 (January 5, 2022): e12712. http://dx.doi.org/10.7717/peerj.12712.
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The recently-emerged amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has had an unprecedented impact on global amphibian populations, and highlights the urgent need to develop effective mitigation strategies. We conducted in-situ antifungal treatment experiments in wild populations of the endangered mountain yellow-legged frog during or immediately after Bd-caused mass die-off events. The objective of treatments was to reduce Bd infection intensity (“load”) and in doing so alter frog-Bd dynamics and increase the probability of frog population persistence despite ongoing Bd infection. Experiments included treatment of early life stages (tadpoles and subadults) with the antifungal drug itraconazole, treatment of adults with itraconazole, and augmentation of the skin microbiome of subadults with Janthinobacterium lividum, a commensal bacterium with antifungal properties. All itraconazole treatments caused immediate reductions in Bd load, and produced longer-term effects that differed between life stages. In experiments focused on early life stages, Bd load was reduced in the 2 months immediately following treatment and was associated with increased survival of subadults. However, Bd load and frog survival returned to pre-treatment levels in less than 1 year, and treatment had no effect on population persistence. In adults, treatment reduced Bd load and increased frog survival over the entire 3-year post-treatment period, consistent with frogs having developed an effective adaptive immune response against Bd. Despite this protracted period of reduced impacts of Bd on adults, recruitment into the adult population was limited and the population eventually declined to near-extirpation. In the microbiome augmentation experiment, exposure of subadults to a solution of J. lividum increased concentrations of this potentially protective bacterium on frogs. However, concentrations declined to baseline levels within 1 month and did not have a protective effect against Bd infection. Collectively, these results indicate that our mitigation efforts were ineffective in causing long-term changes in frog-Bd dynamics and increasing population persistence, due largely to the inability of early life stages to mount an effective immune response against Bd. This results in repeated recruitment failure and a low probability of population persistence in the face of ongoing Bd infection.
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Aaltonen, J. T., T. Bohlender, W. Snyder, J. Krebs, L. Linhoff, M. Snoza, S. Plesuk, et al. "120 THE DEVELOPMENTAL COMPETENCE OF TADPOLES PRODUCED IN VITRO FROM THE ENDANGERED DUSKY GOPHER FROG (RANA SEVOSA) USING EXOGENOUS HORMONE TREATMENT." Reproduction, Fertility and Development 24, no. 1 (2012): 172. http://dx.doi.org/10.1071/rdv24n1ab120.
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Dusky gopher frogs once existed throughout the states of Mississippi, Alabama and Louisiana. Presently, the USA Fish and Wildlife Service estimates that there are less than 100 frogs left in the wild, with almost all of these residing in a single pond in Mississippi, making the dusky gopher frog America's most endangered frog species. Their habitat has been threatened by residential and forestry development, as well as from fire suppression and the decline of gopher tortoises, whose burrows the frogs use for shelter. The USA Fish and Wildlife Service brought the first dusky gopher frogs into captivity in 2001 and they have been kept at the Memphis Zoo since 2003 and at Omaha's Henry Doorly Zoo since 2004. Natural breeding attempts in captivity have been unsuccessful despite efforts to artificially mimic what is known to be the appropriate seasonal environmental (e.g. light, humidity, temperature) and social cues (e.g. calls from wild frogs during the breeding season) that stimulate reproduction in situ. Also, there was a concern about the incidences of abnormalities (e.g. spindly legs) from inadequate husbandry conditions (e.g. nutritional deficiencies) or diseases in tadpoles and froglets produced ex situ (e.g. dermomycoides). The objectives of this study were (1) to examine the developmental competence of tadpoles produced by exogenous hormone treatment for IVF to complete normal metamorphosis into viable froglets ex situ and (2) to determine the incidence of developmental abnormalities or dermomycoides in the froglets produced ex situ. Males and females were first separated by the identification of black male nuptial pads used during amplexus. Males and females were stimulated to spermiate and ovulate, respectively, using a variation of a standard amphibian hormonal stimulation protocol (Kouba et al. 2012 Reprod. Fertil. Dev. 24). As a result, more than 1460 viable tadpoles (61% of fertilized eggs) were produced from 18 segregated genetic pairings. To date, 602 (41%) of the tadpoles have completed normal metamorphosis into viable froglets (over 6 times the known existing population in situ), 51% were either culled to examine for dermomycoides or died for a variety of known (accidental) and unknown reasons (abnormal appendage development accounting for less than 7%) and 8% have yet to metamorphose after 9 months. The incidence of dermomycoides in the culled individuals was 100%; however, a study being conducted concurrently in their native habitat has confirmed that the organism does exist in situ with the dusky gopher frogs, which act as natural carriers. Efforts are currently in place to establish reintroduction programs for the dusky gopher froglets produced ex situ to increase the dwindling wild population now that tadpoles produced by IVF have been shown to be developmentally competent. In conclusion, IVF can be used to produce tadpoles of the dusky gopher frog with a low incidence of abnormalities, but the tadpoles were found to be carriers of the organism dermomycoides similar to their counterparts in the wild.
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Quick, Gemma, Ross L. Goldingay, Jonathan Parkyn, and David A. Newell. "Population stability in the endangered Fleay’s barred frog (Mixophyes fleayi) and a program for long-term monitoring." Australian Journal of Zoology 63, no. 3 (2015): 214. http://dx.doi.org/10.1071/zo14106.
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In the wake of the global decline in amphibians there is a need for long-term population monitoring. Previous research suggested that the endangered Fleay’s barred frog (Mixophyes fleayi) had recovered after a severe decline. We aimed to determine whether this recovery has been sustained and to test an example of a monitoring program that could be employed at intervals of five or more years to assess long-term population stability. We conducted capture–mark–recapture five years after the last detailed census at Brindle Creek in Border Ranges National Park, New South Wales. Frogs were captured along a 200 m creek transect between September 2013 and February 2014. We used program Mark to estimate demographic parameters of adult male frogs using two modelling approaches: robust design (RD) and the POPAN formulation of the Jolly–Seber model. Abundance was estimated at 38.2 ± 0.5 (s.e.) (RD) and 46.0 ± 2.7 (POPAN). Abundance in 2008 was estimated at 53.2 ± 10.0 (POPAN) male frogs. Estimates of apparent monthly survival over our five-month-long study were very high (RD: 1.0 ± 0.0; POPAN: 1.0 ± 0.02). Recapture estimates were also high (RD: 0.40 ± 0.07 to 0.72 ± 0.05 per session; POPAN: 0.84 ± 0.05 per month). These data suggest that the Brindle Creek population has remained relatively stable over a period of ~10 years.
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Morrison, Clare, Clay Simpkins, J. Guy Castley, and Ralf C. Buckley. "Tourism and the Conservation of Critically Endangered Frogs." PLoS ONE 7, no. 9 (September 12, 2012): e43757. http://dx.doi.org/10.1371/journal.pone.0043757.
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Auliya, Mark, Sandra Altherr, Charlotte Nithart, Alice Hughes, and David Bickford. "Numerous uncertainties in the multifaceted global trade in frogs’ legs with the EU as the major consumer." Nature Conservation 51 (February 8, 2023): 71–135. http://dx.doi.org/10.3897/natureconservation.51.93868.
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The commercial trade in frogs and their body parts is global, dynamic and occurs in extremely large volumes (in the thousands of tonnes/yr or billions of frogs/yr). The European Union (EU) remains the single largest importer of frogs’ legs, with most frogs still caught from the wild. Amongst the many drivers of species extinction or population decline (e.g. due to habitat loss, climate change, disease etc.), overexploitation is becoming increasingly more prominent. Due to global declines and extinctions, new attention is being focused on these markets, in part to try to ensure sustainability. While the trade is plagued by daunting realities of data deficiency and uncertainty and the conflicts of commercial interests associated with these data, it is clear is that EU countries are most responsible for the largest portion of the international trade in frogs’ legs of wild species. Over decades of exploitation, the EU imports have contributed to a decline in wild frog populations in an increasing number of supplying countries, such as India and Bangladesh, as well as Indonesia, Turkey and Albania more recently. However, there have been no concerted attempts by the EU and present export countries to ensure sustainability of this trade. Further work is needed to validate species identities, secure data on wild frog populations, establish reasonable monitored harvest/export quotas and disease surveillance and ensure data integrity, quality and security standards for frog farms. Herein, we call upon those countries and their representative governments to assume responsibility for the sustainability of the trade. The EU should take immediate action to channel all imports through a single centralised database and list sensitive species in the Annexes of the EU Wildlife Trade Regulation. Further, listing in CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) can enforce international trade restrictions. More joint efforts are needed to improve regional monitoring schemes before the commercial trade causes irreversible extinctions of populations and species of frogs.
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Snyder, W. E., V. L. Trudeau, and N. M. Loskutoff. "168 A NONINVASIVE, TRANSDERMAL ABSORPTION APPROACH FOR EXOGENOUS HORMONE INDUCTION OF SPAWNING IN THE NORTHERN CRICKET FROG, ACRIS CREPITANS: A MODEL FOR SMALL ENDANGERED AMPHIBIANS." Reproduction, Fertility and Development 25, no. 1 (2013): 232. http://dx.doi.org/10.1071/rdv25n1ab168.
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The World Conservation Union (IUCN) currently recognises Eleutherodactylus locustus from Puerto Rico and Plectrohyla acanthodes from Mexico and Guatemala as critically endangered, and they are recommended for ex situ breeding by several amphibian conservation organizations (e.g. AZA, ATAG, RCP, and AARK). Because of their very small and delicate bodies, conventional injectable methods developed for hormonally stimulating spawning in larger frogs and toads are undesirable, because this can result in trauma and injury. Recently, a protocol was developed for inducing spawning in frogs by co-injection of a gonadotropin-releasing hormone agonist (GnRHa) with metoclopramide-HCl (MET), a dopamine antagonist (Amphiplex; Trudeau et al. 2010 Rep. Biol. Endo. 8, 36). The goal of this study, therefore, was to determine the effectiveness of Amphiplex using 3 routes of exogenous treatments: (1) direct IP injection (0.4 µg of GnRHa + 10 µg of MET per gram of body weight), (2) injection into prey (1 µg of GnRHa + 25 µg of MET per insect) before feeding, and (3) a 60-min immersion in 10 mL of pond water containing 0.17 µg of GnRHa + 0.42 µg of MET per microliter. The northern cricket frog (Acris crepitans), a very common local species, was used as a model because it is also small, delicate, and difficult to handle. A total of 110 cricket frogs were caught locally either late or after their normal breeding season, sexed as males or females, and segregated into a control group that was housed similarly ex situ but not exposed to Amphiplex and the 3 Amphiplex experimental groups. The frogs were monitored daily for egg production and behavioural amplexus (potential spermiation). The results are summarised as follows (Table 1): of the frogs exposed to the Amphiplex-supplemented pond water, 84% of 38 females deposited eggs, and 6 pairs were observed in amplexus (indicating spermiation). Approximately 27% of more than 2242 eggs were found to develop cleavage divisions, and tadpoles were first observed in vitro after 4 days. In conclusion, to our knowledge this is the first report indicating that transdermal absorption of a reproductive hormone cocktail (e.g. Amphiplex) may serve in the application of assisted reproductive technology to increase the populations of critically endangered amphibians such as frogs and toads that may be too small or delicate for conventional methods of exogenous hormone treatments that require handling and injections. Table 1.Treated northern cricket frogs
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Dias, Jemma E., Charlotte Ellis, Tessa E. Smith, Charlotte A. Hosie, Benjamin Tapley, and Christopher J. Michaels. "Baseline Behavioral Data and Behavioral Correlates of Disturbance for the Lake Oku Clawed Frog (Xenopus longipes)." Journal of Zoological and Botanical Gardens 3, no. 2 (April 19, 2022): 184–97. http://dx.doi.org/10.3390/jzbg3020016.
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Animal behavior and welfare science can form the basis of zoo animal management. However, even basic behavioral data are lacking for the majority of amphibian species, and species-specific research is required to inform management. Our goal was to develop the first ethogram for the critically endangered frog Xenopus longipes through observation of a captive population of 24 frogs. The ethogram was applied to produce a diurnal activity budget and to measure the behavioral impact of a routine health check where frogs were restrained. In the activity budget, frogs spent the vast majority of time swimming, resting in small amounts of time devoted to feeding, foraging, breathing, and (in males) amplexus. Using linear mixed models, we found no effect of time of day or sex on baseline behavior, other than for breathing, which had a greater duration in females. Linear mixed models indicated significant effects of the health check on duration of swimming, resting, foraging, feeding, and breathing behaviors for all frogs. This indicates a welfare trade-off associated with veterinary monitoring and highlights the importance of non-invasive monitoring where possible, as well as providing candidates for behavioral monitoring of acute stress. This investigation has provided the first behavioral data for this species which can be applied to future research regarding husbandry and management practices.
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Villacorta-Rath, Cecilia, Conrad J. Hoskin, Jan M. Strugnell, and Damien Burrows. "Long distance (>20 km) downstream detection of endangered stream frogs suggests an important role for eDNA in surveying for remnant amphibian populations." PeerJ 9 (September 27, 2021): e12013. http://dx.doi.org/10.7717/peerj.12013.
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Background Globally, amphibian species have suffered drastic population declines over the past 40 years. Hundreds of species are now listed as Critically Endangered, with many of these considered “possibly extinct”. Most of these species are stream-dwelling frogs inhabiting remote, montane areas, where remnant populations are hard to find using traditional surveys. Environmental DNA (eDNA) could revolutionize surveys for ‘missing’ and endangered amphibian populations by screening water samples from downstream sections to assess presence in the upstream catchments. However, the utility of this survey technique is dependent on quantifying downstream detection probability and distances. Methods Here we tested downstream detection distances in two endangered stream frogs (Litoria lorica and L. nannotis) that co-occur in a remote stream catchment in north-east Australia, and for which we know precise downstream distributional limits from traditional surveys. Importantly, the two last populations of L. lorica persist in this catchment: one small (~1,000 frogs) and one very small (~100 frogs). We conducted eDNA screening at a series of sites kilometers downstream from the populations using precipitation from two fixed water volumes (15 and 100 mL) and via water filtering (mean 1,480 L). Results We detected L. nannotis and the small L. lorica population (~1,000 frogs) at most sampling sites, including 22.8 km downstream. The filtration method was highly effective for far-downstream detection, as was precipitation from 100 mL water samples, which also resulted in consistent detections at the far-downstream sites (including to 22.8 km). In contrast, we had limited downstream detection success for the very small L. lorica population (~100 frogs). Discussion The ecological aspects of our study system, coupled with thorough traditional surveys, enabled us to measure downstream eDNA detection distances with accuracy. We demonstrate that eDNA from a small population of approximately 1,000 frogs can be detected as far as 22.8 km downstream from the population. Water filtration is considered best for eDNA detection of rare aquatic species—indeed it was effective in this study—but we also achieved far-downstream detections when precipitating eDNA from 100 mL water samples. Collecting small water volumes for subsequent precipitation in the lab is more practical than filtration when surveying remote areas. Our downstream detection distances (>20 km) suggest eDNA is a valuable tool for detecting rare stream amphibians. We provide recommendations on optimal survey methods.
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Annas, George J. "Jumping Frogs, Endangered Toads, and California's Medical-Marijuana Law." New England Journal of Medicine 353, no. 21 (November 24, 2005): 2291–96. http://dx.doi.org/10.1056/nejmlim053151.
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Drawert, Brian, Marc Griesemer, Linda R. Petzold, and Cheryl J. Briggs. "Using stochastic epidemiological models to evaluate conservation strategies for endangered amphibians." Journal of The Royal Society Interface 14, no. 133 (August 2017): 20170480. http://dx.doi.org/10.1098/rsif.2017.0480.
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Recent outbreaks of chytridiomycosis, the disease of amphibians caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), have contributed to population declines of numerous amphibian species worldwide. The devastating impacts of this disease have led researchers to attempt drastic conservation measures to prevent further extinctions and loss of biodiversity. The conservation measures can be labour-intensive or expensive, and in many cases have been unsuccessful. We developed a mathematical model of Bd outbreaks that includes the effects of demographic stochasticity and within-host fungal load dynamics. We investigated the impacts of one-time treatment conservation strategies during the disease outbreak that occurs following the initial arrival of Bd into a previously uninfected frog population. We found that for all versions of the model, for a large fraction of parameter space, none of the one-time treatment strategies are effective at preventing disease-induced extinction of the amphibian population. Of the strategies considered, treating frogs with antifungal agents to reduce their fungal load had the greatest likelihood of a beneficial outcome and the lowest risk of decreasing the persistence of the frog population, suggesting that this disease mitigation strategy should be prioritized over disinfecting the environment or reducing host density.
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Kurniawan, Nia. "Ecology and colour variation of Oreophryne monticola (Anura: Microhylidae) with reference to vocalisation and predicted habitat suitability." Herpetological Bulletin, no. 151, Spring 2020 (April 1, 2020): 17–23. http://dx.doi.org/10.33256/hb151.1723.
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The Lombok cross frog (Oreophryne monticola) is endemic to the islands of Bali and Lombok. We describe the colour variation and associated microhabitats of this endangered species, and provide some notes on its call characteristics and predictions of its distribution in Bali and Lombok. We surveyed sites on both islands with similar altitude but slightly different microhabitats. The frogs were more likely to be found in forests dominated by dipterocarp trees, many epiphytic ferns, and ground covered with leaf litter. Possible differences in colour variation and call suggest that there may be cryptic species within O. monticola that could be resolved by morphological and molecular study. The predicted distribution suggests nine isolated areas at around 1100 m a.s.l. on both islands that may be home to this frog.
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Mignet, Fabien. "Biology and Captive Breeding of the Amazonian Milk Frog, Trachycephalus resinifictrix (Goeldi 1907)." Reptiles & Amphibians 22, no. 2 (June 1, 2015): 68–75. http://dx.doi.org/10.17161/randa.v22i2.14047.
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Although the Amazonian Milk Frog (Trachycephalus resinifictrix) is commonly bred in captivity in zoological institutions worldwide, very little information regarding these undertakings has been published. Here, I report my experience with the successful breeding of T. resinifictrix at the Touroparc Zoo. I highlight some fundamental biological traits in order to fulfill the requirements for captive breeding and to ensure the general welfare of these frogs. The aim is to provide guidelines that may be used by zoos, aquariums, and other facilities as well as private contributions to conservation breeding programs for endangered anurans with requirements similar to those of T. resinifictrix. In general, this species is easy to keep in captivity. Larvae are easy to produce and raise with very low mortality rates. They usually metamorphose at six to ten weeks. However, newly metamorphosed frogs are fragile and require more attention. Several pathogens are known to affect the health of amphibians, and stress can play an important role in immune function.
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Driscoll, Don A. "Genetic neighbourhood and effective population size for two endangered frogs." Biological Conservation 88, no. 2 (May 1999): 221–29. http://dx.doi.org/10.1016/s0006-3207(98)00099-8.
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Goldingay, R., G. Daly, and F. Lemckert. "Assessing the Impacts of Logging on Reptiles and Frogs in the Montane Forests of Southern New South Wales." Wildlife Research 23, no. 4 (1996): 495. http://dx.doi.org/10.1071/wr9960495.
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This study describes an assessment of the medium-term effects of selection logging on the reptiles and frogs in the montane forests near Queanbeyan, New South Wales. A total of 15 reptile and two frog species was detected across 20 fixed-area plots that were selected according to broad forest type and logging history. Reptile species richness was not significantly different among the different habitat treatments. Total reptile abundance was significantly higher on logged plots, but was not influenced by forest moisture type. Individual analyses for five lizard species (accounting for 84% of all data) showed that several species (Eulamprus tympanum, E. heatwolei and Pseudemoia spenceri) had significantly greater abundances on the logged plots than on the unlogged plots, while two species (Nannoscincus maccoyi and Niveoscincus coventryi) did not differ significantly in their abundances across treatments. Thus, none of these species (which included arboreal, terrestrial and fossorial species) appeared to be adversely affected by past logging practices. Insufficient data on frogs were obtained for analysis. An additional 26 species (13 reptile and 13 frog species) were recorded during a regional survey involving 57 sites. Only two frog species were detected at more than 10 sites, illustrating the difficulty in obtaining data to determine whether logging has any impact on frog populations. Snakes are similarly difficult to assess: 13 snakes from six species were detected in this study. It is concluded that (i) the most abundant reptile species were not adversely affected by past logging, and (ii) many species of herpetofauna were patchy in their distribution across the study area, preventing resolution of the influence of habitat type or disturbance. The difficulty in collecting quantitative data on frogs and snakes confirms the importance of surveys that target endangered frog and snake species so that protective buffer zones can be delineated. Further research is required on these groups to assess the impact of forest management practices.
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Morrison, C., A. Naikatini, N. Thomas, I. Rounds, B. Thaman, and J. Niukula. "Importance of Waisali Reserve, Vanua Levu for herpetofauna conservation in Fiji." South Pacific Journal of Natural and Applied Sciences 22, no. 1 (2004): 71. http://dx.doi.org/10.1071/sp04013.
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A two day herpetofauna survey of Waisali Reserve was conducted between 4-6th March, 2004. The survey consisted of timed active diurnal surveys for lizards and nocturnal surveys for frogs. Seven herpetofauna species were found during the survey including four endemic species. The most significant find was the confirmation of a population of the endangered Fiji ground frog (Platymantis vitianus), a species previously thought to be extirpated from mainland Fiji due to the presence of mongoose. The other significant finding was that of Emoia mokosariniveikau, only the third location known for this species. Our survey results identify Waisali Reserve as an important site for herpetofauna conservation in Fiji and we propose several management actions to facilitate conservation of herpetofauna in this area.
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Bina Perl, R. G., Sarig Gafny, Yoram Malka, Sharon Renan, Douglas C. Woodhams, Louise Rollins-Smith, James D. Pask, Molly C. Bletz, Eli Geffen, and Miguel Vences. "Natural history and conservation of the rediscovered Hula painted frog, Latonia nigriventer." Contributions to Zoology 86, no. 1 (February 13, 2017): 11–37. http://dx.doi.org/10.1163/18759866-08601002.
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Dramatic global amphibian declines have recently led to an increased concern for many species of this animal class. The enigmatic Hula painted frog (Latonia nigriventer), the first amphibian to be declared extinct but unexpectedly rediscovered in 2011, has remained one of the rarest and most poorly understood amphibians worldwide. Gathering basic biological information on this species, along with an understanding of its disease-related threats remains fundamental for developing risk assessments and conservation strategies. Our surveys in recent years confirmed that L. nigriventer is a localised species with elusive habits. The species appears to follow an opportunistic breeding phenology and has a tadpole morphology similar to its well-studied sister group Discoglossus. However, the adults’ extended annual presence in the aquatic habitat is a major difference from species of Discoglossus. We detected the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), in northern Israel and on Hula painted frogs but did not observe any signs of chytridiomycosis in this species. Our preliminary data on aspects of the innate immunity of L. nigriventer suggest that the skin mucosome of this species contains antimicrobial peptides and a bacterial community differing from other syntopic frogs (Pelophylax bedriagae). The combined knowledge of both natural history and innate immunity of L. nigriventer provides valuable insights to direct future research and conservation management of this critically endangered frog species.
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Santana, FE, RR Swaisgood, JM Lemm, RN Fisher, and RW Clark. "Chilled frogs are hot: hibernation and reproduction of the Endangered mountain yellow-legged frog Rana muscosa." Endangered Species Research 27, no. 1 (February 11, 2015): 43–51. http://dx.doi.org/10.3354/esr00648.
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Brannelly, Laura A., Lee Berger, Gerry Marrantelli, and Lee F. Skerratt. "Low humidity is a failed treatment option for chytridiomycosis in the critically endangered southern corroboree frog." Wildlife Research 42, no. 1 (2015): 44. http://dx.doi.org/10.1071/wr14097.
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Context One of the major drivers of the current worldwide amphibian decline and extinction crisis is the spread of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd). Captive assurance colonies may be the only lifeline for some species. Current antifungal chemotherapies can be effective for clearing infection but may have detrimental side effects. The only non-chemotherapeutic treatment that has been clinically tested is heat, which is impractical for cold-adapted species. The fungus does not survive desiccation, and therefore a plausible alternative non-chemotherapeutic treatment would be a low-humidity regimen. Aims We tested the efficacy of a low-humidity treatment regimen for treating Bd-infected animals of the critically endangered species Pseudophryne corroboree. This species has high tolerance of dry environments, and is thus an ideal candidate for this treatment trial. Methods Forty frogs were exposed to 1 × 106 zoospores. At three weeks after exposure access to water was reduced to once daily for 10 days for 20 animals. Ten of these animals were also rinsed daily with the aim of removing zoospores. Key results The drying regimen neither increased survival nor decreased infection load, and treatment may have hastened mortality. All infected frogs died between 21 and 80 days after exposure, except one untreated frog. Conclusions Our results suggest that a drying regimen is not a viable treatment for chytridiomycosis. Infection may decrease the host’s ability to cope with water stress. Implications The failed drying treatment in P. corroboree suggests that drying is not an appropriate treatment for chytridiomycosis and treatment efforts should be focussed on chemotherapies for cold-adapted species. P. corroboree is a critically endangered species for which chytridiomycosis is the primary cause of decline, yet few experiments have been carried out on this species with regards to chytridiomycosis. All experimental information about this species and disease will benefit the management and protection of the species.
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AMÉZQUITA, ADOLFO, ROBERTO MÁRQUEZ, RICARDO MEDINA, DANIEL MEJÍA-VARGAS, TED R. KAHN, GUSTAVO SUÁREZ, and LUIS MAZARIEGOS. "A new species of Andean poison frog, Andinobates (Anura: Dendrobatidae), from the northwestern Andes of Colombia." Zootaxa 3620, no. 1 (March 5, 2013): 163–78. http://dx.doi.org/10.11646/zootaxa.3620.1.8.
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The poison frogs of the Colombian Andes, Pacific lowlands and Panamahave been recently recognized as a new, monophyletic and well-supported genus: Andinobates. The species richness and distribution within Andinobates remain poorly understood due to the paucity of geographic, genetic and phenotypic data. Here we use a combination of molecular, bioacoustic and morphometric evidence to describe a new species of Andean poison frog: Andinobates cassidyhornae sp. nov. from the high elevation cloud forests of the Colombian Cordillera Occidental, in the northwestern Andes. The new species is associated to the bombetes group and characterized by a unique combination of ventral and dorsal color patterns. Data on 1119 bp from two mitochondrial markers allowed us to reject the null hypotheses that A. cassidyhornae sp. nov. is part of the phenotypically similar and geographically less distant species: A. opisthomelas, A. virolinensis or A. bombetes. The best available phylogenetic trees and the genetic distance to other Andinobates species further support this decision. Altogether, the advertisement call parameters unambiguously separated A. cassidyhornae sp. nov. calls from the calls of the three closest species. The new species adds to a poorly known and highly endangered genus of poison frogs that requires further studies and urgent conservation measures.
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Rojahn, Jack, Dianne Gleeson, and Elise M. Furlan. "Monitoring post-release survival of the northern corroboree frog, Pseudophryne pengilleyi, using environmental DNA." Wildlife Research 45, no. 7 (2018): 620. http://dx.doi.org/10.1071/wr17179.
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Context Translocations are becoming an increasingly important conservation tool to combat rising levels of species extinction. Unfortunately, many translocation efforts fail; yet, the timing and cause of failure often remain unknown. Monitoring individuals in the days and weeks following release can provide valuable information on their capacity to survive this initial hurdle. In Australia, breeding programs have been established for the endangered northern corroboree frog, Pseudophryne pengilleyi, to enable reintroduction to the wild via captive-reared individuals, typically, early life stages such as eggs or juvenile frogs that cannot be monitored via traditional survey methods that target adult frogs (e.g. shout–response). Environmental DNA (eDNA) detects trace amounts of DNA that organisms release into their environment and could provide a means to infer population persistence for wildlife releases and translocations. Aims In the present study, we aim to develop an eDNA assay capable of detecting both sexes of P. pengilleyi across multiple life stages, and use it to monitor their survival. Methods An eDNA assay was developed to target the two corroboree frog species (P. pengilleyi and P. corroboree, the southern corroboree frog) and was tested for its sensitivity and specificity in silico and in vitro. Pseudophryne pengilleyi eggs were released into three naturally occurring ponds and water samples were, subsequently, collected from each pond on several occasions over a period of 78 days. Quantitative polymerase chain reaction was used to detect P. pengilleyi eDNA from water samples. Key Results The developed assay was shown to be sensitive and specific to corroboree frogs. eDNA monitoring of reintroduced P. pengilleyi detected the species’ DNA at three of three release ponds and DNA remained detectable until at least 78 days post-release at two of three ponds. Conclusions We show how the development of a corroboree frog-specific assay allowed us to monitor the post-release survival of P. pengilleyi in naturally occurring pools. Implications eDNA surveys may provide a useful tool to monitor post-release survival of translocated populations in a non-invasive manner, with the potential to identify the timing and causes of failure. Such knowledge can be used to inform the management of translocated populations and future release strategies.
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Narayan, Edward, Ketan Christi, and Craig Morley. "Captive propagation of the endangered native Fijian frog Platymantis vitiana: Implications for ex-situ conservation and management." Pacific Conservation Biology 15, no. 1 (2009): 47. http://dx.doi.org/10.1071/pc090047.
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We present research and management implications for captive propagation of the endangered Fijian Ground Frog Platymantis vitiana to develop methods for supplementing populations in the wild. In 2004, a captive propagation program was instituted at Kula Ecopark, Sigatoka, Fiji. However, there was little success with only a single froglet reared after three years. In 2006, a more intensive programme was undertaken between the University of the South Pacific (USP), Kula Ecopark and the community on Viwa Island. The aim of this programme was to create an outdoor enclosure to mimic natural habitat conditions so the frogs could exhibit natural breeding behaviour. A total of 39 froglets was reared after one year of this programme. We provide information on the methods of captive management, reproductive biology, captive diet varieties, and on problems of rearing froglets in captivity. This research is useful baseline information in guiding captive propagation techniques in zoological parks like the Kula Ecopark and for organizations such as the National Trust of Fiji.
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Silla, Aimee J., Michael McFadden, and Phillip G. Byrne. "Hormone-induced spawning of the critically endangered northern corroboree frog Pseudophryne pengilleyi." Reproduction, Fertility and Development 30, no. 10 (2018): 1352. http://dx.doi.org/10.1071/rd18011.
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Fundamental knowledge of the optimal hormone concentrations required to stimulate amplexus and spawning in breeding pairs of amphibians is currently lacking, hindering our understanding of the proximate mechanisms underpinning mating behaviour. The present study investigated the effects of: (1) the dose of a gonadotropin-releasing hormone analogue (GnRH-a) administered; (2) male–female hormone administration interval; and (3) topical application of GnRH-a, on spawning success in the northern corroboree frog. Administration of GnRH-a at doses of 0.5, 1.0 and 2.0 μg g−1 were highly successful, with a significantly greater proportion of hormone-treated pairs ovipositing (89–100%) compared with the 0 μg g−1 treatment (22%). Of the hormone-treated pairs, those receiving 0.5 μg g−1 GnRH-a exhibited the highest fertilisation success (61%). Administration of GnRH-a to males and females simultaneously (0 h) was more effective than injecting males either 48 or 24 h before the injection of females. Overall, administration of GnRH-a was highly successful at inducing spawning in northern corroboree frogs. For the first time, we also effectively induced spawning following the topical application of GnRH-a to the ventral pelvic region. Topical application of GnRH-a eliminates the need for specialised training in amphibian injection, and will allow assisted reproductive technologies to be adopted by a greater number of captive facilities globally.
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Labisko, Jim, Richard A. Griffiths, Lindsay Chong-Seng, Nancy Bunbury, Simon T. Maddock, Kay S. Bradfield, Michelle L. Taylor, and Jim J. Groombridge. "Endemic, endangered and evolutionarily significant: cryptic lineages in Seychelles’ frogs (Anura: Sooglossidae)." Biological Journal of the Linnean Society 126, no. 3 (January 12, 2019): 417–35. http://dx.doi.org/10.1093/biolinnean/bly183.
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Abarca Alvarado, Juan Gabriel, Esteban Hidalgo-Mora, and Jonathan Navarro-Picado. "NOTES ON GEOGRAPHIC DISTRIBUTION, ADVERTISEMENT CALL AND HABITAT OF THE STARRETT’S TREE FROG Isthmohyla tica (Hylidae) IN THE ZONA DE LOS SANTOS, COSTA RICA." Revista Latinoamericana de Herpetología 5, no. 1 (February 17, 2022): 112–20. http://dx.doi.org/10.22201/fc.25942158e.2022.1.366.
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Central American hylids frogs of the genus Isthmohyla have suffered dramatic decline in highlands. Many species of this genus are considered critically endangered, including Isthmohyla tica, an endemic species of Costa Rica and Panama. We found a population of I. tica inside agricultural coffee ecosystems in Tarrazú, San José, Costa Rica and we describe new advertisement calls of this species. The discovery of this population represents the most recent records in the Zona de Los Santos since the last record in 1963; until now, only stable populations were known in the Children's Eternal Rainforest, Monteverde. The presence of this endangered species, among with other threatened amphibians, reflects the importance of better understanding their presence in these agro-ecosystems and ensuring the conservation of forest patches inside coffee plantations.
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Lötters, Stefan, Rainer Schulte, Jesús H. Córdova, and Michael Veith. "Conservation priorities for harlequin frogs (Atelopus spp.) of Peru." Oryx 39, no. 3 (June 3, 2005): 343–46. http://dx.doi.org/10.1017/s0030605305000852.
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Populations of harlequin frogs Atelopus are declining throughout their geographical range. In Peru six of the 11 nominally described species are Critically Endangered, and there are at least 17 undescribed additional forms (all representing apparently distinct species), the conservation status of which is unknown. Most Atelopus taxa in Peru have relatively small geographical ranges, some known only from single populations, and have only a limited chance of survival. Conservation will require: (1) improvement of the faunistic and taxonomic knowledge of the genus, (2) field surveys, including in remote areas, (3) assessment of all species and populations for chytridiomycosis and research on the agent's biology, (4) ex situ conservation measures to facilitate later reintroduction, and (5) involvement of national and international conservationists and local people.
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GILL, SUMBUL, MUHAMMAD RAIS, MUHAMMAD SAEED, WASEEM AHMED, and AYESHA AKRAM. "The tadpoles of Murree Hills Frog Nanorana vicina (Anura: Dicroglossidae)." Zootaxa 4759, no. 3 (April 3, 2020): 440–42. http://dx.doi.org/10.11646/zootaxa.4759.3.11.
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The genus Nanorana, also called Yunnan Slow Frogs (Frank & Ramus 1995), belongs to the family Dicroglossidae. Murree Hills Frog N. vicina, is an endemic species of Southeast Asian uplands in Pakistan and India and was first reported by Stoliczka (1872) from Murree, Punjab Province, Pakistan. Later Rais et al. (2014) recaptured it from its type locality and described morphology of one juvenile female and one adult male. The species is listed as Least Concern in IUCN Red List of Threatened Species while the EDGE (Evolutionarily Distinct and Globally Endangered) score is 2.64. In Pakistan, it is reported from brook water springs and streams of Murree, Galiat (North Punjab), Ayubia (Khyber Pakhtunkhwa), and parts of Azad Jammu and Kashmir (Rais et al. 2014). Although the adult form has been characterized (Khan 2006; Rais et al. 2014), the morphology of the tadpoles have not yet been described. The current study aimed to describe external morphology and morphometry of tadpoles of N. vicina.
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Hilken, G., J. Dimigen, and F. Iglauer. "Growth of Xenopus laevis under different laboratory rearing conditions." Laboratory Animals 29, no. 2 (April 1, 1995): 152–62. http://dx.doi.org/10.1258/002367795780740276.
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Since the European frogs ( Rana spp.) have fallen under the German endangered species regulation, Xenopus laevis (South African Clawed Frog) is being used increasingly in animal research and education. Optimal growth rates and homogeneity of groups have not necessarily been attained as little statistical analysis of growth data has been available. Following metamorphosis, an as yet not understood variability of growth is exhibited by X. laevis. In this study the effect of environmental factors on this variability was determined. Feeding, population density, background colouring, water temperature, the availability of hiding places, water level and water care were each examined separately. Development of body weight and body length were recorded. A definite correlation between the feeding programme, population density, cover and water care on the one hand and growth on the other were seen. Of lesser importance were water temperature, water level and background colouring. The observed variability of growth is assumed to also be of ethological origin.
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Jurzenski, Jessica, and W. Wyatt Hoback. "Opossums and Leopard Frogs Consume the Federally Endangered American Burying Beetle (Coleoptera: Silphidae)." Coleopterists Bulletin 65, no. 1 (March 2011): 88–90. http://dx.doi.org/10.1649/0010-065x-65.1.88.
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García-Rodríguez, Adrián, Gerardo Chaves, Catalina Benavides-Varela, and Robert Puschendorf. "Where are the survivors? Tracking relictual populations of endangered frogs in Costa Rica." Diversity and Distributions 18, no. 2 (November 26, 2011): 204–12. http://dx.doi.org/10.1111/j.1472-4642.2011.00862.x.
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Lunney, D., A. Curtin, D. Ayers, H. G. Cogger, and C. R. Dickman. "An ecological approach to identifying the endangered fauna of New South Wales." Pacific Conservation Biology 2, no. 3 (1995): 212. http://dx.doi.org/10.1071/pc960212.
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This study used ecological criteria to evaluate systematically the conservation status of all mammals, birds, reptiles and frogs in New South Wales. The outcome was an official schedule of endangered fauna as defined under the New South Wales National Parks and Wildlife Act 1974 as amended by the Endangered Fauna (Interim Protection) Act 1991. The work was modelled on the study by Millsap et al. (1990) which scored a range of biological variables and used expert opinion to determine priorities for conservation. The listing was undertaken by a statutory Scientific Committee and the results provided the first baseline status list for all species in New South Wales. Of the 883 faunal species (including 10 Lord Howe Island subspecies) identified in the state, 233 (26%) were recognized as endangered. Of these, 40 are considered to be extinct in New South Wales. Mammals constituted the worst affected group, with 77 (59%) of the 130 species recorded as endangered, of which 27 species are recorded as extinct in the state. The assessment of the New South Wales fauna also found that adequate ecological information exists for only 6% of the state's species. The outcome of this study not only provided the first official list of the endangered fauna of New South Wales and explained the methods and reasons for listing or excluding each species, but also furnished new material, ideas and directions for programmes to conserve the state's fauna.
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Kruger, Donnavan J. D., and Louis H. Du Preez. "The effect of airplane noise on frogs: a case study on the Critically Endangered Pickersgill’s reed frog (Hyperolius pickersgilli)." Ecological Research 31, no. 3 (March 9, 2016): 393–405. http://dx.doi.org/10.1007/s11284-016-1349-8.
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Graves, Arabella E., Jemma E. Dias, and Christopher J. Michaels. "Effects of Background Color on Stress-Linked Behavior in the Critically Endangered Lake Oku Clawed Frog (Xenopus longipes)." Journal of Zoological and Botanical Gardens 4, no. 1 (February 2, 2023): 99–107. http://dx.doi.org/10.3390/jzbg4010011.
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Ex situ amphibian populations are a key component of global amphibian conservation strategy, and optimal husbandry is vital to ex situ conservation success. Animal behavior can be used to inform captive welfare and improve husbandry practices. However, it has been little used for amphibians compared with mammals and birds. The goal of this study was to explore the effect of different colored tank backgrounds on the behavior of the critically endangered Lake Oku clawed frog (Xenopus longipes) in captivity. This was conducted by studying the behavior of a group of 24 captive frogs in 5 groups using established behavioral indicators of presumed stress. Resting and swimming behaviors, established in the literature as linked to acute stress, were recorded under conditions of three background colors and a standard husbandry control of no background. Frog groups were exposed to each background for five days with behavioral frequencies recorded daily from 11:00 until 13:00. Using generalized linear mixed models, we identified a significant effect of background days after the background was changed and the interaction between the two variables on both swimming and resting behavior. The results of this study suggest an initial response of stress to altering the background, modulated by the color of the background, followed by the extinction of the stress response such that by five days after the background change, behaviors were similar to the baseline and indistinguishable between treatments. Overall, this study suggests that frog stress behavior was not differentially directly affected by green, grey, black, or transparent backgrounds but that green and grey backgrounds were associated with the smallest stress response to background change. These colors may therefore be recommended to reduce the impact of stress from disturbance.
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AZMANIS, P. N., I. STRACHINIS, P. LYMBERAKIS, and R. E. MARSCHANG. "First detection of the amphibian chytrid fungus (Batrachochytridium dendrobatidis) in free- living anuran populations in Greece." Journal of the Hellenic Veterinary Medical Society 67, no. 4 (January 29, 2018): 253. http://dx.doi.org/10.12681/jhvms.15647.
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The amphibian chytrid fungus (Batrachochytrium dendrobatidis) is a widespread, cosmopolitan pathogen largely affecting free-living amphibian populations. So far there are no published studies for the presence of B. dendrobatidis in Greece. In this preliminary study we sampled 59 metamorphosed anurans from four Greek wetlands. Five samples were positive for the fungus by real-time PCR. B. dendrobatidis was detected in three species (Bufo viridis, Pelophylax epeiroticus, Pelophylax ridibundus) but not in endangered endemic Karpathos water frogs (Pelophylax cerigensis). This is the first report of the amphibian chytrid fungus (Batrachochytrium dendrobatidis) in free-living anuran populations from Greece.
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Brannelly, Laura A., Alexandra A. Roberts, Lee F. Skerratt, and Lee Berger. "Epidermal cell death in frogs with chytridiomycosis." PeerJ 5 (February 1, 2017): e2925. http://dx.doi.org/10.7717/peerj.2925.
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Background Amphibians are declining at an alarming rate, and one of the major causes of decline is the infectious disease chytridiomycosis. Parasitic fungal sporangia occur within epidermal cells causing epidermal disruption, but these changes have not been well characterised. Apoptosis (planned cell death) can be a damaging response to the host but may alternatively be a mechanism of pathogen removal for some intracellular infections. Methods In this study we experimentally infected two endangered amphibian species Pseudophryne corroboree and Litoria verreauxii alpina with the causal agent of chytridiomycosis. We quantified cell death in the epidermis through two assays: terminal transferase-mediated dUTP nick end-labelling (TUNEL) and caspase 3/7. Results Cell death was positively associated with infection load and morbidity of clinically infected animals. In infected amphibians, TUNEL positive cells were concentrated in epidermal layers, correlating to the localisation of infection within the skin. Caspase activity was stable and low in early infection, where pathogen loads were light but increasing. In animals that recovered from infection, caspase activity gradually returned to normal as the infection cleared. Whereas, in amphibians that did not recover, caspase activity increased dramatically when infection loads peaked. Discussion Increased cell death may be a pathology of the fungal parasite, likely contributing to loss of skin homeostatic functions, but it is also possible that apoptosis suppression may be used initially by the pathogen to help establish infection. Further research should explore the specific mechanisms of cell death and more specifically apoptosis regulation during fungal infection.
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Gvoždík, Václav, Tadeáš Nečas, Matej Dolinay, Breda M. Zimkus, Andreas Schmitz, and Eric B. Fokam. "Evolutionary history of the Cameroon radiation of puddle frogs (Phrynobatrachidae: Phrynobatrachus), with descriptions of two critically endangered new species from the northern Cameroon Volcanic Line." PeerJ 8 (March 3, 2020): e8393. http://dx.doi.org/10.7717/peerj.8393.
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The Cameroon Volcanic Line, a mountain chain located between West and Central Africa, is a region of numerous endemic diversifications, including of puddle frogs (Phrynobatrachus). This study reviews the phylogeny and taxonomy of puddle frogs of the “Cameroon radiation,” which is a clade containing mainly montane but also at least three lowland species. Molecular data revealed a novel evolutionary lineage from high altitudes in the northern part of the mountains. Puddle frogs from the new, minute-sized (SVL < 20 mm) lineage are identified using molecular, morphological and acoustic data and described as two new species, Phrynobatrachus arcanus sp. nov. (Gotel Mountains, Cameroon–Nigeria) and P. mbabo sp. nov. (Tchabal Mbabo, Cameroon). The tadpole of the first species is also described. Phylogenetic analyses placed the new lineage to the proximity of the recently described lowland small-sized taxa (P. horsti, P. ruthbeateae). Based on the inferred phylogeny, we propose five species groups within the Cameroon radiation: P. arcanus, P. chukuchuku, P. ruthbeateae, P. steindachneri, and P. werneri. The taxonomically enigmatic P. hylaios is proposed to be a member of the P. ruthbeateae species group. The basal radiation evolved during the late Miocene with subsequent diversifications occurring during the Pliocene, while closely related terminal taxa originated during the Pleistocene. We recommend that the newly described species are categorized as Critically Endangered due to their limited ranges and because recent surveys did not identify any individuals at the type localities. This further supports the need for conservation interventions in the mountains of Cameroon and Nigeria.
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Wassens, Skye, David A. Roshier, Robyn J. Watts, and Alistar I. Robertson. "Spatial patterns of a Southern Bell Frog Litoria raniformis population in an agricultural landscape." Pacific Conservation Biology 13, no. 2 (2007): 104. http://dx.doi.org/10.1071/pc070104.
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We investigated changes in the spatial organization of individuals within a population of endangered Southern Bell Frogs Litoria raniformis over an eight-month period. Our results identified strong temporal changes in both spatial organization and the apparent location of L. raniformis within the study site. Ripley's K Function analyses showed that the position of individuals relative to one another shifted from random immediately after the study site was flooded (p < 0.005), to strongly clustered at spatial scales between 0-1500 m during the peak breeding period (p < 0.005). The majority of flooded areas were dry by April and May and individuals again became aggregated within the remaining waterbodies.
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Fasola, Mauro, Daniele Pellitteri-Rosa, Fabio Pupin, Stefano Scali, Roberto Sacchi, Franco Bernini, Augusto Gentilli, and Edoardo Razzetti. "Factors affecting repatriation success of the endangered Italian agile frog (Rana latastei)." Amphibia-Reptilia 29, no. 2 (2008): 235–44. http://dx.doi.org/10.1163/156853808784124910.
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Abstract Repatriations and translocations are among the most frequent actions deployed for conservation of amphibians all over the world. However, very few studies have analysed the effectiveness of these actions. The aims of this study were i) to measure the success of repatriations of Rana latastei carried out within a conservation project in Lombardy (Northern Italy) from 1999 to 2001, and ii) to analyse how the environmental factors affected repatriation success. Eighteen ponds were surveyed from February to April 2006, for an overall of 45 field surveys. Each pond was carefully checked for frogs and egg masses. We classified each pond as newly excavated or pre-existing according to habitat management actions and we measured 16 variables concerning micro- and macro-habitat characteristics, human disturbance and presence of predators. Rana latastei was found in 33.3% of monitored sites and the repatriation outcome of tadpole release did not differ between newly excavated and non managed ponds. Habitat variables influenced the success of repatriations, which increased in sites with higher percentage of woodlands. Finally, repatriation outcome was also negatively influenced by human disturbance and predator occurrence.