Seguiment de les poblacions de micromamífers al Principat d'Andorra segona temporada

(ENG) The assessment of the micromammal populations in the Principality of Andorra 2nd season Research on the micromammal populations in Andorra started in the year 2000 with the first trap setting campaign in the areas of Arinsal and Pal (Western Andorra). The research consists of regular assessment of the micromammals, from both a quantitative and qualitative point of view. The main aim of this research is to obtain a series of data that can be used as reference for the evolution of these populations over time. Micromammals are the feeding base for many other species (birds of prey in particular) and a careful assessment of their populations would allow us to detect and forsee the movements of the species that feed mainly on micromammals. A significant change in the natural environment would initially have reprecussions on the micromammals and consequently on the species from the higher feeding rank. If the fluctuations in the micromammal populations are detected in time, action can be taken regarding the other species before these are affected directly by the environmental changes. The research on the micromammal populations in Andorra will also help to complete the inventory of the species detected during previous research. Although the majority of micromammals found in Andorra have already been located, a few species of shrews, for example, remain to be detected. Lastly, as the quantity or distribution of certain species is virtually unknown in Andorra, research on the micromammal populations in Andorra, over the years, will allow us to have more data on these species, to have more precise knowledge of their biology and to improve the management of their populations. The data for this assessment is obtained through traps located in areas of one hectare and representing different environments. The animals are captured, measured, their sex is determind, they are marked and then freed, in such a way as to have minimal influence on the animals studied and on their population. Two types of traps are used (Shermann type and iron bars) following the trap setting protocol (see issue no. 3 of Habitats for more details). For this second year of research, the capture zones have been increased in order to cover the different environments and aspects of the Principality. The results of this second trap setting season are presented below. This research has been carried out with the collaboration of the Eco-ethology Unit in the Evolution Sciences Institute in Montpellier (University of Montpellier II).