Amphibians and conservation breeding programmes: do all threatened amphibians belong on the ark?

Biodiversity and Conservation

Volumn 24, Issue 11, 2015, Pages 2625-2646

  Tapley, Benjamin ^a   Bradfield, Kay S ^b   Michaels, Christopher ^a   Bungard, Mike ^c  

^a ZOOLOGICAL SOCIETY OF LONDON   (United Kingdom)

^b Perth Zoo   (Australia)

^c Paignton Zoo ^*  (United Kingdom)

Author keywords

Capacity building; Captive breeding; Husbandry; Zoo

Indexed keywords

AMPHIBIAN; ANIMAL HUSBANDRY; BIRD; CAPTIVE BREEDING; CONSERVATION PLANNING; CONSERVATION STATUS; ENDANGERED SPECIES; EXTINCTION; MAMMAL; PRIORITIZATION; PRIVATE SECTOR; REINTRODUCTION; SELECTIVE BREEDING; SPECIES CONSERVATION; ZOO;

AMPHIBIA; AVES; MAMMALIA;

EID: 84942552672     PISSN: 09603115     EISSN: 15729710     Source Type: Journal    
DOI: 10.1007/s10531-015-0966-9     Document Type: Review

References (132)

1. Alford RA, Richards SJ (1999) Global amphibian declines: a problem in applied ecology. Annu Rev Ecol Syst 30:133–165
2. Altherr S, Goyenechea A, Schubert D (2011) Canapés to extinction—the international trade in frogs’ legs and its ecological impact. A report by pro Wildlife, defenders of Wildlife and animal Welfare institute Munich and Washington
3. Anderson US, Kelling AS, Maple TL (2008) Twenty-five years of zoo biology: a publication analysis. Zoo Biol 26:444–457
4. Andrén C, Mårdén M, Nilson G (1989) Tolerance to low pH in a population of moor frogs, Rana arvalis, from an acid and a neutral environment: a possible case of rapid evolutionary response to acidification. Oikos 56:215–223
5. 3 in amphibian health, behavior, diet and conservation. Comp Biochem Physiol Part A 154:184–190
6. Antwis RE, Haworth RL, Engelmoer DJP, Ogilvy V et al (2014) Ex situ diet influences the bacterial community associated with the skin of red-eyed tree frogs (Agalychnis callidryas). PLoS ONE. doi:10.1371/journal.pone.0085563
7. Araki H, Cooper B, Blouin MS (2009) Carry-over effect of captive breeding reduces reproductive fitness of wild-born descendants in the wild. Biol Lett 5:621–624
8. Azevedo Calderon L, Silva Ade A, Ciancaglini P, Stábeli RG (2011) Antimicrobial peptides from Phyllomedusa frogs: from biomolecular diversity to potential nanotechnologic medical applications. Amino Acids 40:29–49
9. Badio B, Daly JW (1994) Epibatidine, a potent analgetic and nicotinic agonist. Mol Pharmacol 1:564–571
10. Balmford A, Mace GM, Leader-Williams N (1996) Designing the ark: setting priorities for captive breeding. Conserv Biol 10:719–727
11. Barber D, Poole V (eds) (2014) Association of zoos and aquariums amphibian taxon advisory group regional collection plan, 3rd edn. Association of zoos and aquariums, Maryland
12. Bielby J, Cooper N, Cunningham AA, Garner TWJ, Purvis A (2008) Predicting susceptibility to future declines in the world’s frogs. Conserv Lett 1:82–90
13. Birkett J, Vincent M, Banks C (1999) Captive management and rearing of the roseate frog, Geocrinia rosea, at Melbourne Zoo. Herpetofauna 29:49–56
14. Bishop PJ, Angulo A, Lewis JP et al (2012) The amphibian extinction crisis—what will it take to put the action into the amphibian conservation action plan? SAPIENS 5:97–111
15. Bloxam QC, Tonge SJ (1995) Amphibians: suitable candidates for breeding-release programmes. Biodivers Conserv 4:636–644
16. Bowkett AE (2009) Recent captive-breeding proposals and the return of the ark concept to global species conservation. Conserv Biol 23:773–776
17. Brattstrom BH (1990) Maze learning in the fire-bellied toad, Bombina orientalis. J Herpetol 24:44–47
18. Bride IG, Griffiths RA, Meléndez-Herrada A, McKay JE (2008) Flying an amphibian flagship: conservation of the Axolotl Ambystoma mexicanum through nature tourism at Lake Xochimilco, Mexico. Int Zoo Yearb 42:116–124
19. Browne RK, Zippel K (2007) Reproduction and larval rearing of amphibians. ILAR J 48:214–234
20. Browne RK, Seratt J, Vance C, Kouba A (2006) Hormonal induction with priming and in vitro fertilisation increases egg numbers and quality in the Wyoming toad (Bufo baxteri). Reprod Biol Endocrinol 4:1–11
21. Browne RK, Odum RA, Herman T, Zippel K (2007) Facility design and the associated services for the study of amphibians. ILAR J 48:188–202
22. Browne RK, Gaikhorst G, Vitali S, Roberts JD, Matson P (2008) Exogenous hormones induce poor rates of oviposition in the anurans, Litoria moorei and L. aurea. Appl Herpetol 15:81–86
23. Browne RK, Wolfram K, Garcia G, Bagaturov M, Pereboom ZJJM (2011) Zoo-based amphibian research and conservation programs. Amphib Reptile Conserv 5:1–14
24. Chan HK, Shoemaker KT, Karraker NE (2014) Demography of Quasipaa frogs in China reveals high vulnerability to widespread harvest pressure. Biol Cons 170:3–9
25. Cikanek SJ, Nockold S, Brown JL et al (2014) Evaluating group housing strategies for the ex situ conservation of harlequin frogs (Atelopus spp) using behavioural and physiological indicators. PLoS ONE. doi:10.1371/journal.pone.0090218
26. Clulow J, Clulow S, French Guo J et al (2012) Optimisation of an oviposition protocol employing human chorionic and pregnant mare serum gonadotropins in the Barred Frog Mixophyes fasciolatus (Myobatrachidae). Repro Biol Endocrin. doi:10.1186/1477-7827-10-60
27. Collen B, Ram M, Zamin T, McRae L (2008) The tropical biodiversity gap: addressing disparity in global monitoring. Trop Conserv Sci 1:75–88
28. Collins JP, Crump ML (2009) Extinction in our times. Oxford University Press, New York
29. Coloma LA, Almeida-Reinoso D (2012) Ex situ management of five extant species of Atelopus in Ecuador—progress report. Amphib Ark Newslett 20:9–12
30. Crane AL, Mathis A (2011) Predator-recognition training: a conservation strategy to increase post release survival of hellbenders in head-starting programs. Zoo Biol 30:611–622
31. Crump M (2005) Why are some species in decline but others not? In: Lannoo M (ed) Amphibian declines: the conservation status of United States species. University of California Press, Berkeley and Los Angeles, pp 28–33
32. Cunningham AA, Daszak P, Rodriguez JP (2003) Pathogen pollution, defining a parasitological threat to biodiversity conservation. J Parasitol 89:S78–S83
33. Daly JW, Myers CW, Warnick JE, Albuquerque EX (1980) Levels of batrachotoxin and lack of sensitivity to its action in poison-dart frogs (Phyllobates). Science 208:1383–1385
34. Dawson B, Ryan MJ (2012) Evoked vocal responses change with experience in male Physalaemus pustulosus. Copeia 2012:678–682
35. Densmore CL, Green DE (2007) Diseases of amphibians. ILAR J 48:235–254
36. Duellman WE, Trueb L (1994) Biology of Amphibians. John Hopkins University Press, Baltimore
37. Dugas MB, Yeager J, Richards-Zawacki CL (2013) Carotenoid supplementation enhances reproductive success in captive strawberry dart frogs (Oophaga pumilio). Zoo Biol 32:655–658
38. Edmonds D, Rakotoarisoa JC, Dolch R et al (2012) Building capacity to implement conservation breeding programmes for frogs in Madagascar: results from year one of Mitinjo’s amphibian husbandry research and captive breeding facility. Amphib Reptile Conserv 5:57–69
39. Epp KJ, Gabor CR (2008) Innate and learned predator recognition mediated by chemical signals in Eurycea nana. Ethol 114:607–615
40. Estrada AR, Hedges B (2006) At the lower size limit in tetrapods: a new diminutive frog from Cuba (Leptodactylidae: Eleutherodactylus). Copeia 4:853–859
41. Ferrari MC, Chivers DP (2008) Cultural learning of predator recognition in mixed-species assemblages of frogs: the effect of tutor-to-observer ratio. Anim Behav 75:1921–1925
42. Fleming RI, Mackenzie CD, Cooper A, Kennedy MW (2009) Foam nest components of the túngara frog: a cocktail of proteins conferring physical and biological resistance. Proc R Soc B 276:1787–1795
43. Ford MJ (2002) Selection in captivity during supportive breeding may reduce fitness in the wild. Conserv Biol 16:815–825
44. Foufopoulos J, Richards S (2007) Amphibians and reptiles of New Britain island, Papua New Guinea: diversity and conservation status. Hamadryad 31:176–201
45. Frankham R (2008) Genetic adaptation to captivity in species conservation programs. Mol Ecol 17:325–333
46. Frankham R, Loebel DA (1992) Modelling problems in conservation genetics using captive Drosophila populations: rapid genetic adaptation to captivity. Zoo Biol 11:333–342
47. Frankham R, Manning H, Margan SH, Briscoe DA (2000) Does equalization of family sizes reduce genetic adaptation to captivity? Anim Conserv 3:357–363
48. Gagliardo R, Crump P, Griffith E et al (2008) The principles of rapid response for amphibian conservation, using the programmes in Panama as an example. Int Zoo Yearb 42:124–135
49. Gagliardo R, Griffith E, Hill R et al (2010) Observation on the captive reproduction of the horned marsupial frog Gastrotheca cornuta (Boulenger 1898). Herpetol Rev 41:52–58
50. Gascon C, Collins JP, Moore RD et al (eds) (2007) Amphibian conservation action plan. IUCN/SSC Amphibian Specialist Group, Gland
51. Gawor A, Rauhaus A, Karbe D et al (2012) Is there a chance for conservation breeding? Ex situ management, reproduction, and early life stages of the harlequin toad Atelopus flavescens Duméril & Bibron, 1841 (Amphibia: Anura: Bufonidae). Amphib Reptile Conserv 5:29–44
52. Godfrey EW, Sanders GE (2004) Effect of water hardness on oocyte quality and embryo development in the african clawed frog (Xenopus laevis). Comp Med 54:140–145
53. Gonwou LN, Rödel MO (2008) The importance of frogs to the livelihood of the Bakossi people around Mount Manengouba, Cameroon, with special consideration of the hairy frog Trichobatrachus robustus. Salamandra 44:23–34
54. Gower DJ, Doherty Bone T, Loader SP et al (2013) Batrachochytrium dendrobatidis infection and lethal chytridiomycosis in caecilian amphibians Gymnophiona. EcoHealth. doi:10.1007/s10393-013-0831-9
55. Gratwicke B, Evans MJ, Jenkins PT et al (2010) Is the international frog legs trade a potential vector for deadly amphibian pathogens? Front Ecol Environ 8:438–442
56. Gray MJ, Miller DL, Hoverman JT (2009) Ecology and pathology of amphibian ranaviruses. Dis Aquat Organ 87:243–266
57. Griffiths RA, Pavajeau L (2008) Captive breeding, reintroduction and the conservation of amphibians. Conserv Biol 22:852–861
58. Groom M, Meffe GK, Carroll CR (2006) Principles of conservation biology, 3rd edn. Sinauer Associates, Massachusetts
59. Guarino FM, Garcia G, Andreone F (2014) Huge but moderately long lived: age structure in the mountain chicken, Leptodactylus fallax, from Montserrat, West Indies. Herpetol J 24:167–173
60. Hermanns K, Pinxten R, Eens M (2002) Territorial and vocal behaviour in a captive dart-poison frog, Epipedobates tricolor Boulenger, 1899 (Anura: Dendrobatidae). Belg J Zool 132:105–109
61. Hoffmann M, Hilton-Taylor C, Angulo A et al (2010) The impact of conservation on the status of the world’s vertebrates. Science 330:1503–1509
62. Holland B, Rice WR (1999) Experimental removal of sexual selection reverses intersexual antagonistic coevolution and removes a reproductive load. Proc Nat Acad Sci 96:5083–5088
63. Igawa T, Sugawara H, Tado M et al (2013) An attempt at captive breeding the endangered newt Echninotriton andersoni from the central Ryukyus Japan. Anim 3:680–692
64. Iskandar DT, Erdelen WR (2006) Conservation of amphibians and reptiles in Indonesia: issues and problems. Amphib Reptile Conserv 4:60–87
65. James RS, Wilson RS (2008) Explosive jumping: extreme morphological and physiological specializations of Australian rocket frogs (Litoria nasuta). Physiol Biochem Zool 8:176–185
66. Jenkin SE, Laberge F (2010) Visual discrimination learning in the fire-bellied toad Bombina orientalis. Learn Behav 38:418–425
67. Kawata K (2008) Hanzaki pilgrimage: a visit to the home of the giant amphibian. Herpetol Rev 39:407–412
68. Kern S, Ackermann M, Stearns SC, Kawecki TJ (2001) Decline in offspring viability as a manifestation of aging in Drosophila melanogaster. Evolution 55:1822–1831
69. Kouba AJ, Vance CK, Willis EL (2009) Artificial fertilization for amphibian conservation: current knowledge and future considerations. Theriogenology 71:214–227
70. Kouba AJ, Vance C, Calatayud N et al (2012) Assisted reproductive technologies (ART) for amphibians. Chapter 2 in Amphibian Husbandry Resource Guide, Edition 2.0. AZA Amphibian Taxon Advisory Group
71. Kraaijeveld-Smit FJL, Griffiths RA, Moore RD, Beebee TJC (2006) Captive breeding and the fitness of reintroduced species: a test of the response to predators in a threatened amphibian. J Appl Ecol 43:360–365
72. Liang G, Geng B, Zhao E (2004) Andrias davidianus. The IUCN Red List of Threatened Species. Version 2015.2. http://www.iucnredlist.org. Retrieved 21 July 2015
73. Lötters S, Kielgast J, Bielby J et al (2009) The link between rapid enigmatic amphibian decline and the globally emerging chytrid fungus. EcoHealth 6:358–372
74. Loudon AH, Woodhams DC, Parfrey L et al (2013) Microbial community dynamics and effect of environmental microbial reservoirs on red-backed salamanders (Plethodon cinereus). ISME J 8:830–840
75. Maan ME, Cummings ME (2012) Poison frog colors are honest signals of toxicity, particularly for bird predators. Am Nat 179:E1–E14
76. Malhotra A, Thorpe RS, Hypolite E, James R (2007) A report on the status of the herpetofauna of the Commonwealth of Dominica, West Indies. Appl Herpetol 4:177–194
77. Mann RM, Hyne RV, Choung CB (2010) Hormonal induction of spermiation, courting behavior and spawning in the southern bell frog, Litoria raniformis. Zoo biol 29:774–782
78. Margan SH, Nurthen RK, Montgomery ME et al (1998) Single large or several small? Population fragmentation in the captive management of endangered species. Zoo Biol 17:467–480
79. Martins F, Oom MDM, Rebelo R, Rosa GM (2013) Differential effects of dietary protein on early life history and morphological traits in natterjack toad (Epidalea calamita) tadpoles reared in captivity. Zoo Biol 32:457–462
80. Maruska EJ (1986) Amphibians: a review of zoo breeding programmes. Int Zoo Yearb 24:56–65
81. Merilä J, Söderman F, O’Hara R, Räsänen K, Laurila A (2004) Local adaptation and genetics of acid-stress tolerance in the moor frog, Rana arvalis. Conserv Genet 5:513–527
82. Michael SF, Buckley C, Esteban T, Estrada AR, Vincent S (2004) Induced ovulation and egg deposition in the direct developing anuran Eleutherodactylus coqui. Repro Biol Endocrin. doi:10.1186/1477-7827-2-6
83. Michaels CJ, Preziosi R (2013) Basking behaviour and ultraviolet B radiation exposure in a wild population of Pelophylax lessonae in Northern Italy. Herpetol Bull 124:1–8
84. Michaels CJ, Preziosi R (2015) Fitness effects of shelter provision for captive amphibian tadpoles. Herpetol J 25:7–12
85. Michaels CJ, Gini B, Preziosi R (2014a) The importance of natural history and species specific approaches in amphibian ex situ conservation. Herpetol J 24:135–145
86. Michaels CJ, Downie JR, Campbell-Palmer R (2014b) The importance of enrichment for advancing amphibian welfare and conservation goals: a review of a neglected topic. Amphib Reptile Conser 8:7–23
87. 3 growth rates, skeletal structure and coloration in captive oriental fire-bellied toads (Bombia orientalis). J Anim Physiol Anim Nutr. doi:10.1111/jpn.12203
88. Michaels CJ, Antwis R, Preziosi R (2014d) Impact of plant cover on fitness and behavioural traits of captive red-eyed tree frogs (Agalychnis callidryas). PLoS ONE 9:e95207
89. Miller DL, Rajeev S, Brookins M et al (2008) Concurrent infection with ranavirus, Batrachochytrium dendrobatidis, and Aeromonas in a captive anuran colony. J Zoo Wildlife Med 39:445–449
90. Minteer BA, Collins JP (2013) Ecological ethics in captivity: Balancing values and responsibilities in zoo and aquarium research under rapid global change. ILAR J 54:41–51
91. Norris S (2007) Ghosts in our midst: coming to terms with amphibian extinctions. Biosceince 57:311–316
92. Ogilvy V, Preziosi R (2011) Can carotenoids mediate the potentially harmful effects of ultraviolet light in Silurana (Xenopus) tropicalis larvae? J Anim Physiol Nutr 96:693–699
93. Ogilvy V, Preziosi RF, Fidgett AL (2012) A brighter future for frogs? The influence of carotenoids on the health, development and reproductive success of the red-eye tree frog. Anim Conserv 15:480–488
94. Pessier AP, Mendelson JR (2010) A manual for the control of infectious disease in amphibian survival assurance colonies and reintroduction programmes. IUCNSSC Conservation breeding specialist group, Minnesota
95. Preece DJ (1998) The captive management and breeding of poison-dart frogs, family Dendrobatidae, at Jersey Wildlife preservation trust. Dodo 34:103–114
96. Preininger D, Weissenbacher A, Wampula T, Hödl W (2012) The conservation breeding of two foot-flagging frog species from Borneo, Staurois parvus and Staurois guttatus. Amphib Reptile Conserv 5:45–56
97. Pritchard DJ, Fa JE, Oldfield S, Harrop SR (2013) Bring the captive closer to the wild: redefining the role of ex situ conservation. Oryx 46:18–23
98. Pryor GS (2014) Tadpole nutritional ecology and digestive physiology: implications for captive rearing of larval anurans. Zoo Biol 3:502–507
99. Räsänen KR, Laurila A, Merilä J (2003a) Geographic variation in acid stress tolerance of the moor frog, Rana arvalis. I. Local adaptation. Evolution 57:352–362
100. Räsänen K, Laurila A, Merilä J (2003b) Geographic variation in acid stress tolerance of the moor frog, Rana arvalis. II. Adaptive maternal effects. Evolution 57:363–371
101. Redford KH, Jensen D, Breheny JJ (2012) Integrating the captive and the wild. Science 338:1157–1158
102. Rija AA, Khatibu FH, Kohi EM, Muheto R (2011) Status and reintroduction of the Kihansi spray toad Nectophrynoides asperginis in Kihansi gorge: challenges and opportunities. In: Proceedings of the 7th TAWIRI Scientific Conference. Tanzania Wildlife institute, Arusha
103. Robertson RJ, Rendell WB (2001) A long-term study of reproductive performance in tree swallows: the influence of age and senescence on output. J Anim Ecol 70:1014–1031
104. Robertson JM, Robertson AD (2008) Spatial and temporal patterns of phenotypic variation in a neotropical frog. J Biogeogr 35:830–843
105. Rodríguez A, Poth D, Schulz S, Vences M (2010) Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba. Biol Lett. doi:10.1098/rsbl.2010.0844
106. Rowley J, Brown R, Kusrini M et al (2010) Impending conservation crisis for Southeast Asian amphibians. Biol Lett 6:336–338
107. Scheele BC, Hunter DA, Grogan LF, Berger L et al (2014) Interventions for reducing extinction risk in chytridiomycosis-threatened amphibians. Conserv Biol 28:1195–1205
108. Silla AJ, Roberts JD (2012) Investigating patterns in the spermiation response of eight Australian frogs administered human chorionic gonadotropin (hCG) and luteinizing hormone-releasing hormone (LHRHa). Gen Comp Endocr 179:128–136
109. Smith RK, Sutherland WJ (2014) Amphibian conservation: global evidence for the effects of interventions. Pelagic Publishing, Exeter
110. Snyder NFR, Derrickson SR, Beissinger SR et al (1996) Limitations of captive breeding in endangered species recovery. Conserv Biol 10:338–348
111. Sontag C, Wilson DS, Wilcox RS (2006) Social foraging in Bufo americanus tadpoles. Anim Behav 72:1451–1456
112. St-Amour V, Lesbarrères D (2007) Genetic evidence of Ranavirus in toe clips: an alternative to lethal sampling methods. Conserv Genet 8:1247–1250
113. Stuart SN, Chanson JS, Cox NA et al (2004) Status and trends of amphibian declines and extinctions worldwide. Science 306:1783–1786
114. Stuart SN, Hoffmann M, Chanson JS et al (2008) Threatened amphibians of the world. Lynx Edicions, Barcelona, Spain. IUCN, Gland and Conservation International, Virginia
115. Tapley B, Griffiths RA, Bride I (2011) Dynamics of the trade in reptiles and amphibians within the United Kingdom within a ten-year period. Herpetol J 21:27–34
116. Tapley B, Bryant Z, Grant S et al (2014a) Towards evidence-based husbandry for caecilian amphibians: substrate preference in Geotrypetes seraphini (Amphibia: Gymnophiona: Dermophiidae). Herpetol Bull 129:15–18
117. Tapley B, Harding L, Sulton M et al (2014b) An overview of current efforts to conserve the critically endangered mountain chicken (Leptodactylus fallax) on Dominica. Herpetol Bull 128:9–11
118. Tapley B, Rendle M, Baines FM et al (2015) Meeting ultraviolet B radiation requirements of amphibians in captivity: a case study with mountain chicken frogs (Leptodactylus fallax) and general recommendations for pre-release health screening. Zoo Biol 34:46–52
119. Valiente E, Tovar A, Gonzalez H et al (2010) Creating refuges for the Axolotl (Ambystoma mexicanum). Ecol Rest 28:257–259
120. Van Der Spuy SD, Krebs J (2008) Collaboration for amphibian conservation; the establishment of the Johannesburg Zoo amphibian conservation center in South Africa with assistance from Omahas’s Henry Doorly Zoo, USA. Int Zoo Yearb 42:165–171
121. Verschooren E, Brown RK, Vercammen F, Pereboom J (2011) Ultraviolet B radiation (UV-B) and the growth and skeletal development of the Amazonian milk frog (Trachycephalus resinifictrix) from metamorphis. J Physiol Pathophysiol 2:34–42
122. Walker SF, Bosch J, James TY et al (2008) Invasive pathogens threaten species recovery programs. Curr Biol 18:853–854
123. Warkentin I, Bickford D, Sodhi N, Bradshaw C (2009) Eating frogs into extinction. Conserv Biol 23:1056–1059
124. Wedekind C (2002) Sexual selection and life-history decisions: implications for supportive breeding and the management of captive populations. Conserv Biol 16:1204–1211
125. Williams SE, Hoffman EA (2009) Minimizing genetic adaptation in captive breeding programmes: a review. Biol Conserv 142:2388–2400
126. Williams DR, Pople RG, Showler DA et al (2012) Bird conservation: global evidence for the effects of interventions. Pelagic Publishing, Exeter
127. Wilson EO (1984) Biophilia. Harvard University Press, Cambridge and Massachusetts
128. Witzenberger KA, Hochkirch A (2011) Ex situ conservation genetics: a review of molecular studies on the genetic consequences of captive breeding programmes for endangered animal species. Biodivers Conserv 20:1843–1861
129. Woodhams DC, Bosch J, Briggs CJ et al (2011) Mitigating amphibian disease: strategies to maintain wild populations and control chytridiomycosis. Front Zool 8:1–23
130. Wright KM, Whitaker BR (2001) Amphibian medicine and captive husbandry. Krieger Publishing Company, Malabar
131. Zippel KC, Mendelson III Jr (2008) The amphibian extinction crisis: a call to action. Herpetol Rev 39:23–29
132. Zippel K, Johnson K, Gagliardo R et al (2011) The amphibian ark: a global community for ex situ conservation of amphibians. Herpetol Conserv Biol 6:340–352