With time quickly running out for Mallorcan Midwife toads - or ferrerets - herpetologists and conservationists were swift to take appropriate measures to ensure the continued survival of the species. Combining re-introduction, in-situ and ex-situ research, a diverse educational programme, and captive breeding, the Mallorcan conservation authorities initiated 'The Mallorcan Midwife Toad Recovery Programme' in 1985 with support from the Durrell Wildlife Conservation Trust (formerly the Jersey Wildlife Preservation Trust), The Durrell Institute of Conservation and Ecology (DICE) at the University of Kent; Stuttgart Museum; The Open University; Barcelona Zoo; and Marineland (Palma de Mallorca). This integrated approach has helped to secure the immediate future of this critically endangered amphibian.
Durrell became involved with the species at the request of the Mallorcan Government. It was arranged for a number of toads to be transported to Jersey to form the nucleus of a captive breeding programme. Fortunately, the husbandry, breeding and rearing of the toads proved to be relatively easy and the associated housing and equipment required similarly uncomplicated. One of the primary aims of the programme was to generate captive bred toads and tadpoles for re-introduction to the wild. The first re-introductions were carried out in 1989 and have occurred on an almost annual basis since then.
- Mallorcan Midwife Toad Mallorcan Midwife Toad
- Breeding tanks at Durrell Breeding tanks at Durrell
- Collecting Tadpoles Collecting Tadpoles
- Eggs Eggs
Ensuring Genetic Integrity
Towards the end of 1996, a decision was made to collect fresh breeding stock from the wild for captive breeding. This was to make certain that as wide a genetic base as possible was represented in the captive colonies. New stock was collected from three different wild populations in isolated gorges – 25 tadpoles were collected from each site. These three populations were maintained and bred separately in order to maintain the integrity of potentially genetically distinct groups. This is because in their homeland, the toads cannot cross from gorge to gorge and, as such, little pockets of toads have been reproductively isolated for up to 2,000 years.
The BHS was much impressed by the recovery programme and in 1999 the Society's Captive Breeding Committee awarded a project grant to Durrell. The grant helped to fund new facilities for Durrell's Herpetology Department and financed important, pioneering health-screening work on wild Mallorcan Midwife toad populations.
Today, Mallorcan Midwife toads are held and bred at a number of other European institutions including; The Durrell Institute of Conservation and Ecology (DICE) at the University of Kent; Stuttgart Museum; The Open University; Barcelona Zoo; and Marineland (Palma de Mallorca). Annual surveys are taking place and a reserve has been proposed to help protect the species. The number of suitable sites for re-introduction is limited, so work is currently focusing on the creation of new pools.
As a direct result of Durrell's Mallorcan Midwife Toad Recovery Programme, 25% of the current wild population in Mallorca now originates from captive bred toads. The distribution of the toad has increased by 100% since the instigation of the recovery programme. Moreover, from its estimated range of 100km2 in the early 1980s, the species is now believed to occupy a range in the region of 200km2. Twelve new breeding sites have been established since 1989 through re-introductions of captive bred toads. This compares with an estimated thirteen original wild sites.
Through concerted efforts, the status of the Mallorcan Midwife toad has certainly been improved. The species is now the only amphibian species to have been downgraded on the Red List from 'Critically Endangered' to 'Vulnerable' as part of the 2004 IUCN/SSC Global Amphibian Assessment.
Chytridiomycosis – or chytrid fungus – is an emerging disease responsible for amphibian declines worldwide. A particularly virulent pathogen, chytrid affects the skin compromising the amphibians' ability to regulate water leading to electrolyte imbalance and cardiac standstill. It is fatal for many species. The repercussions of a chytrid infection among Mallorcan Midwife toad populations both in the wild and in captivity could be devastating.
Both captive and wild populations have been subject to rigorous health screening procedures. Although there is currently no known chytridiomycosis in captive or reintroduced populations, outbreaks have very recently been reported from two natural populations. As such the Mallorcan Government in cooperation with Dr. Jaime Bosch from the Consejo Superior de Investigaciones Cientificas (CSIC) has launched an intensive monitoring programme to keep track of the developments within wild populations. Durrell, DICE the Zoological Society of London (ZSL) and Imperial College are exploring potential treatments should a chytrid outbreak occur among captive colonies.