Thermal tolerance and preferred temperature experimental procedures were conducted on the western and eastern subspecies of critically endangered Montseny Brook newt (C. arnoldi). The results obtained showed that the CTmax of the species exceeded 31 °C, with a significant difference between the two subspecies. We found that the species tolerates low temperatures (<1 °C) well. Although the thermopreference of the species was expected to trend to cold temperatures, some individuals chose relatively high temperatures, obtaining a range of 11.7 °C to 21.6 °C.

Existen distintas metodologías para conocer tendencias poblacionales, detectar declives y disponer de los elementos de diagnosis necesarios para la gestión de poblaciones y especies. Hasta hace poco muchos seguimientos sólo valoraban el estado de las poblaciones comparando distribuciones. Sin embargo, es necesario realizar seguimientos a largo plazo teniendo en cuenta que una gran parte de las especies de anfibios tienen una estructura metapoblacional. Estos seguimientos se basan en el censo de ejemplares en los puntos de reproducción por detección de cantos, conteo visual o captura de larvas. Este tipo de metodología es muy útil para especies que habitan fundamentalmente medios lénticos. La dificultad de localizar los ejemplares adultos y sus larvas en medios acuáticos reófilos obliga a realizar seguimientos muy específicos. En este estudio se presentan la metodología empleada en el seguimiento durante 21 años de una población de Calotriton asper (Dugès, 1852) en el Parc Natural del Cadí-Moixeró (Barcelona, Girona y Lleida) y la usada para la caracterización de todas las poblaciones del Parque, con el objetivo de determinar las poblaciones clave para realizar seguimientos a largo plazo con costes asumibles. Se describen las distintas tipologías de seguimiento utilizadas en las poblaciones de Calotriton arnoldi Carranza & Amat, 2005 dentro del Proyecto Life Tritó del Montseny, y finalmente se exponen los criterios y la metodología de seguimiento utilizados en el proceso de creación de nuevas poblaciones de esta especie catalogada como en peligro crítico.

En aquest context va néixer fa uns anys el projecte "Situació del tritó pirinenc (Calotriton asper) al Parc Natural del Cadí-Moixeró". El seu objectiu principal és obtenir una imatge precisa de l'estat actual de conservació del tritó en un dels parcs del Pirineu català més importants. Des de 2018 s'han fet esforços per prospectar la majoria dels torrents del Parc per tal de detectar la presència de l'espècie i la seva abundància (San Sebastián et al, 2018; 2019), un procés que finalitza el 2020 amb les campanyes que han cobert la vessant sud-oriental del Parc Natural del Cadí-Moixeró.

Calotriton arnoldi is an endemic amphibian inhabiting Montseny Natural Park and Biosphere Re-serve (PNRBM). It was recognized as a new taxon in 2005 by means of genetic and morphologi-cal analyses and, due to its small distribution range and population size, it was listed as “Criti-cally endangered (CR)” by IUCN. Its area of distribution is small and fragmented less than line-ar 5 km. The Montseny Brook Newt is adapted to mountain streams and requires a pristine hab-itat, one which is currently being affected by conservation issues linked to climate change and human activities (logging, water catchments, visitor’s frequency, among others). At the end of 2016, the Life Tritó del Montseny (LifeTM) project (LIFE15 NAT/ES/000757) was launched. This project’s aim was to promote around fifty actions to ensure the conservation of C. arnoldi and its natural habitat, in the Montseny SCI of the Natura 2000 Network, with five strategic lines: 1) To increase scientific and technical knowledge with regard to C. arnoldi conservation status and its habitat management. 2) To ensure its genetic conservation and expand its geographic distribu-tion 3) To eliminate or minimize threats that exist in the riparian habitat. 4) To Involve and en-gage stakeholders and local residents in the conservation of Montseny brook newt riparian hab-itats. 5) To establish proper legal coverage and define long-term strategic planning. Since 2017, several actions linked to the strategic lines 1 and 3 have been initiated. Many unforeseen events have been overcome and there have been some failures, but there have also been several satis-factory results that allow us to be optimistic about the future of the species. These achievements and failures obtained throughout the process provide us with essential information to develop an adaptive habitat management. Dozens of monitoring surveys have been carried out which allow us to understand the evolution of natural populations, to improve our knowledge re-garding their biology and to assess the impact of conservation actions. In relation to eliminating or minimizing threats to the newt’s habitat, some of the actions that are being carried out are: a) Land acquisitions and land exchanges with different private properties. b) Land stewardship with two custody agreements being signed. c) Reduction of water withdrawal with nine water catchments and distribution being remodeled. e) Improvement of water treatments and storage by installing ecological wastewater treatment facilities. f) Ensure ecological connectivity and ri-parian forest restoration by removing twenty-two river connectivity barriers removed and exe-cuting twelve forestry and bioengineering interventions within the riverside habitat. With re-gard to analyzing the conservation status, management activities and scientific and technical knowledge, active long-term monitoring of the newt population and hydrological conditions has begun. Here we present an evaluation of the actions carried out to improve the habitat of this species, including the necessary considerations for them to be implemented correctly and to be successful in a natural area, which is under public-private management.

Citation: Peñuelas, J.; Germain, J.; Álvarez, E.; Aparicio, E.; Arús, P.; Basnou, C.; Blanché, C.; Bonada, N.; Canals, P.; Capodiferro, M.; et al.