2016 | VOLUME 33
Relating natural climate and phenology to captive husbandry in two midwife toads (Alytes obstetricans and A. cisternasii) from different climatic zones
Captive husbandry and breeding may be pivotal to the successful conservation of many amphibian species, with captive stock providing research subjects, educational tools and animals for release into the wild. Husbandry protocols are missing for many species and sub-optimal for many more, which may limit the success of captive breeding attempts. It has been suggested that observations and environmental data taken from species in nature may be used to infer optimal captive conditions for amphibians. For species where data from the wild are not available, ‘analogue’, that is closely related but more accessible species, may be used as surrogates to inform captive husbandry to some degree. These hypotheses, although logically cogent, are not well tested in amphibians. In particular, the suitability of analogue species based on some knowledge of basic ecology and biology is frequently not assessed. We show that captive husbandry requirements and breeding stimuli correlate with field data and phenology in wild populations of the midwife toads Alytes obstetricans and A. cisternasii. In particular, the provision of hot summer temperatures following a cold brumation period of suitable duration may be important for breeding the western-central European A. obstetricans. Conversely, the Iberian A. cisternasii responds to hot summer temperatures with a rest period and reproduces in the cooler autumn and winter months. Brooding success was highly variable in A. obstetricans and smaller than records from wild toads, possibly due to the young age of breeding stock. Clutch size was similar in A. cisternasii to records from wild counterparts. Although specific breeding triggers and annual temperature requirements are likely to vary between localities for both species, these observations provide some useful data on the indoor breeding of both species. Our results also highlight the relevance of field data in designing captive husbandry protocols, while illustrating the inappropriateness of using one species as an analogue for the other in terms of husbandry requirements unless basic aspects of natural history, ecology and phenology can be shown to be broadly similar.
Published: 15 March 2016