Amphibian biology is intricate, and there are many inter-related factors that need to be understood before establishing successful Conservation Breeding Programs (CBPs). Nutritional needs of amphibians are highly integrated with disease and their husbandry needs, and the diversity of developmental stages, natural habitats, and feeding strategies result in many different recommendations for proper care and feeding. This review identifies several areas where there is substantial room for improvement in maintaining healthy ex situ amphibian populations specifically in the areas of obtaining and utilizing natural history data for both amphibians and their dietary items, achieving more appropriate environmental parameters, understanding stress and hormone production, and promoting better physical and population health. Using a scientific or research framework to answer questions about disease, nutrition, husbandry, genetics, and endocrinology of ex situ amphibians will improve specialists’ understanding of the needs of these species. In general, there is a lack of baseline data and comparative information for most basic aspects of amphibian biology as well as standardized laboratory approaches. Instituting a formalized research approach in multiple scientific disciplines will be beneficial not only to the management of current ex situ populations, but also in moving forward with future conservation and reintroduction projects. This overview of gaps in knowledge concerning ex situ amphibian care should serve as a foundation for much needed future research in these areas.

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The reproductive output of iteroparous females is influenced by parity and resource availability. To gain a better understanding of the reproductive decisions made when animals are faced with potential trade-offs between current and future reproduction; we investigated the relationship of parity and resources availability on reproductive intervals and success by comparing the performance of primiparous and multiparous female Cape ground squirrels Xerus inauris from two study sites that differed in resource availability. Our study included the correlation of reproductive behavioral data with fecal hormonal information to establish a normative endocrine profile for pregnancy and lactation. Parity had a major influence on juvenile emergence with multiparous females having more juveniles emerge successfully. Resource availability did not influence reproductive output, either because of an interaction among multiple resource components including quantity, predictability and length of time those resources were available or because other factors (such as predation or parasitism) have a greater impact on reproductive success.

Cotton-top tamarins (Saguinus oedipus) are a critically endangered species that have been bred successfully in captivity for many years. For two decades, the Cotton-top Tamarin SSP(©) has been challenged with a high rate of reproduction combined with a history of contraceptive failures and nonrecommended births using the current Depo Provera(®) (medroxyprogesterone acetate) injection followed by MGA (melengestrol acetate) implant contraception combination. To address these issues we have developed and tested the use of levonorgestrel (LNG) as an effective contraception option for cotton-top tamarins. LNG was delivered in an injectable, gel matrix consisting of polylactic-co-glycolic acid, triethyl citrate and N-methylpyrrolidone. This gel matrix forms a biodegradable depot at the subcutaneous injection site providing slow release of the active ingredient. Gel matrix composition and LNG concentration were adjusted in four gel formulations to maximize the duration of contraceptive efficacy while minimizing immediate post-injection increases in fecal LNG concentration. LNG treatment (68.44 ± 8.61 mg/kg) successfully eliminated ovarian cycles (fecal pregnanediol-3-glucuronide (PdG) and estrone conjugates (E(1) C)) for 198.8 ± 70.3 days (formulation four; range 19-50 weeks). It was demonstrated that subcutaneous LNG depot injection was an effective, reversible contraceptive option for the management of cotton-top tamarins in captivity.

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