As part of the recently approved Montseny Brook Newt Recovery Plan, 352 individuals of the species (Calotriton arnoldi) bred in captivity were released into their natural habitat in February. Over 4,200 individuals have been released into streams in the Montseny massif since 2010, the goal being to guarantee the survival of this endemic species, considered to be in critical danger of extinction according to the International Union for Conservation of Nature (IUCN). Participating in the initiative are the Catalan Government Ministry for Territory, Housing and Ecological Transition, Zoo de Barcelona, Barcelona Provincial Council, Girona Provincial Council and the Calafell Environmental Research and Education Centre (CREAC), as well as the Montseny Natural Park and Biosphere Reserve.
The Montseny brook newt is in an extremely vulnerable situation and is included in the Catalogue of Threatened Native Wild Fauna (DECREE 172/2022) as a species in danger of extinction.
Given the urgency, the Montseny Brook Newt Recovery Plan approved by the Catalan Government in August includes actions such as the ex-situ conservation programme (for breeding outside of the natural habitat) and the programme for creating new populations. The latter prioritises new streams identified according to ecological and feasibility criteria, such as the maximum size of the population they can hold, the number of individuals available to be reintroduced, the difficulty of managing the territory and the financial costs linked to restoring and monitoring the new populations. The goal is to maximise the number of new populations and population effects in a period of ten years.
Reintroduction to strengthen existing populations
Specifically, 98 juveniles and 254 larvae were introduced into streams in the Montseny massif on 19, 25 and 27 February, all of them of the western lineage, recently described as a new sub-species (Calotriton arnoldi laietanus). Following the established plan, which prioritises releases in the most suitable areas (not just in terms of the characteristics of the habitat, but also the ownership of the land), all releases have been carried out on publicly owned lands and in areas where the species had already been introduced previously. The specimens come from Zoo de Barcelona, the Catalan Government’s Torreferrussa, Bagà and Pont de Suert Fauna Centres and the Calafell Environmental Research and Education Centre (CREAC), all of which have their own breeding and growth programmes for the larvae of this amphibian.
The monitoring exercises for the released newts are carried out at night, with the participation of forestry wardens from the Montseny Natural Park, who also collaborate in the selection of streams.
Goal: to expand the species’ area of distribution
The goals of breeding Montseny brook newts in captivity and later reintroducing them are, firstly, to maintain a gene pool that guarantees the species’ future and, secondly, to expand its area of distribution, which is currently limited to just eight streams in Montseny that total 12 kilometres.
This unprecedented release in the area requires rehearsal, a biological monitoring process for all the populations reintroduced and an ongoing analysis to adapt future management and improve the results by a multi-disciplinary team of specialists and scientists. In addition, before accessing the streams, the biosecurity protocol has to be applied to avoid the transmission of deadly illnesses for the amphibian.
The Montseny brook newt was discovered in 1979 and was initially confused with the Pyrenean newt (Calotriton asper). It was not until 2005 that morphological and genetic studies confirmed that this was a new species, the most threatened one in Western Europe.
Based on this situation, in 2007 a programme to breed the species in captivity was launched at the Torreferrussa Fauna Centre, and in 2015, Zoo de Barcelona, the Catalan Government, Barcelona Provincial Council, Girona Provincial Council and Forestal Catalana promoted an action plan to improve the conservation of the species. This plan applied for and obtained funding from the European Union LIFE programme which, between 2017 and 2022, enabled the LIFE Tritó Montseny project, coordinated by Barcelona Provincial Council, to be implemented with the goal of resolving the main threats to the species and guaranteeing its protection.
Zoo de Barcelona has had a specific facility in operation since 2018 to disseminate this conservation project. The facility has information panels, videos and other interactive materials, and holds educational sessions on this and other species found in Montseny.
