PROJECT DESCRIPTION
BACKGROUND
The Majorcan midwife toad (Alytes muletensis) is a priority species listed in Annex II of Directive 92/43/EEC and in danger of extinction. It is also included in Appendix II of the Berne Convention and is strictly protected under Spanish legislation.
This amphibian, known as ferreret to locals, is a relict species and endemic to Mallorca with a very limited distribution within the island. Its habitat consists of seasonal water courses in the limestone of the Sierra de la Tramuntana in the north of the island, although at present it is only found in five of them. It was described in 1977 from fossil remains. In 1980 the first correctly identified specimens were collected. The main threats to this species conservation are the introduction of competitors and predators, and environmental changes (dams and water pollution, tourism etc.).
OBJECTIVES
Project objectives are to combat the main threats to midwife toad through habitat recovery and conservation and to achieve population and distribution levels that will guarantee the survival of the species as a stable element of Balearic Island fauna.
Measures include the purchase of land, habitat recovery and management (setting up of a reserve, cleaning up of water courses where the toad is already found or which are recoverable, improvement of breeding biotopes, eradication of predators introduced into the colonies). Direct actions include breeding in captivity and semi-captivity and release of individuals to boost colonies or create new ones. Wardening and information and awareness raising activities are also carried out.
RESULTS
This project achieved very good results from a technical point of view. Thanks to the actions carried out, the species A. muletensis can be considered safe from extinction in the short and medium term.
More than 70 potentially suitable sites for toad populations were prospected, seven of which harboured natural populations. Moreover, six suitable places for the midwife toad were selected because of their availability of water and the absence of predators. The whole area hosting natural populations was included in the Natura 2000 list of pSCI for Balearic Region (Costa Brava de Mallorca, ES0000073).
Additionally, Ses Figueroles, a 222 ha estate, was purchased. This area received toad populations – it is located in a strategic site where it is possible to gain access to other important sites for the species. The Regional government declared the estate a natural reserve for A. muletensis.
The main midwife toad predators are Natrix maura and Rana perezi, which are not native to the island. An intensive control of predators was carried out, resulting in the effective stabilisation of the toad population.
Monitoring of the water quality in rivers with toads was carried out in order to avoid over exploitation and pollution by the bottling plants in the area. An agreement was signed with hydrological authorities in order to know in advance any action in the habitat.
On discovering that the midwife toads occupied artificial water tanks used for extensive cattle in the Sierra de la Tramuntana, a strategy was drawn up aimed at recovering tanks in bad conditions, building some new ones and introducing individuals into them. In total, 11 tanks were restored. These created sites hosted at the end of the project 25% of the population of the species, and they will be more important in the future. These artificial habitats were built to be predator proof.
Monitoring of the populations in the wild through censuses was carried out. A census was performed in 18 ravines. A total of 20 toad populations were counted at the end of the project, some of them in natural habitats and others in artificial reservoirs.
Four research studies were undertaken on the species on the following subjects: breeding behaviour, growth factors in larvae, dispersal and colonising capacity in new habitats and genetic variability. These studies provided the theoretical basis to build the conservation strategy for this species.
The captive breeding of the species was carried out in six places: Stuttgart (GE), the Jersey Wildlife Preservation Trust, the University of East Anglia, DICE (UK), Mallorca, and Barcelona. From 1985 to 1997, a total of 1 292 larvae and 1 659 adults were released at 15 sites. At nine of these sites breeding took place. At three sites the reintroduction failed and in three success was doubtful. Medium- and long-term monitoring will permit the efficacy of the reintroduction to be evaluated. By the end of the project, the reintroduction allowed the surface of sites occupied by the species to be extended from 5.8 ha to 6.4 ha (ponds that shelter the species are very small) scattered in an area of 212 km2 (formerly it was 100 km2). The breeding sites increased from 13 to 20. This was a very good result for the conservation of the species because it spread the risk of extinction of the population in a larger area. The adult population, estimated at 1 000 to 1 200 individuals at the beginning of the project, grew up to 2 036 adult individuals by its end, 25% of which came from the reintroductions carried out.
This program assured the survival of the species in case of an ecological disaster. It also promoted the co-operation for conservation between different institutions and European countries, which was a very good collateral benefit. It has to be highlighted that this co-operation was spontaneous.
Awareness raising became more important than expected at the beginning of the project due to the increasing number of visitors to the karstic ravines. During the course of the project, such visitor pressure directly affected tadpole populations hosted in these sites. Several actions were developed to inform tourists and the general public.
Dissemination materials included a video and two leaflets aimed at a general audience, entitled "The Ferreret, treasure of the Tramuntana" and "Ravines: living sanctuaries". Other materials produced were: a nature notebook entitled "Ferreret Conservation", a comic for children and a poster of the Ferreret. This material was distributed in the schools and visitors centre as Marineland and Lluch Monastery. A permanent exhibition was installed near the Lluch Monastery in the Sierra de la Tramuntana, which receives a million visitors a year.
Twelve press articles and four TV documentaries were produced about the ferreret. The biologist in charge of the field programme was awarded the J&B Nature Protection Price, adding to the good publicity of the project at a national level. An international meeting on the midwife toad was held at the Lluch Centre in Mallorca in December 1996 and included the participation of the institutions involved in the project.
Thanks to this campaign the midwife toad became a Mallorcan mascot, widely known and appreciated by Mallorca inhabitants. It even became the mascot of the island football club.
In all the awareness campaign was considered a great success.