CREAF and ICO (Catalan Ornithological Institute) researchers Sergi Herrando and Lluís Brotons have participated in a study that shows populations of birds described as “mountain specialists” to have fallen by 10% in a decade in Europe. The situation is even more alarming in the Pyrenees and elsewhere in the Iberian Peninsula, where mountain bird populations fell by 21%.
A study in which CREAF participates has revealed that marmots reintroduced in the Pyrenees have very low genetic variability because they come from only two alpine areas and have not mixed. Surprisingly, this low genetic diversity has not proved to be an impediment in reintroduction, which has turned out to be a total success.
This finding is described in an article including CREAF researchers and coauthors Aitor Ameztegui and Lluís Brotons. The study addresses how the superior limit of forest cover in the Pyrenees has changed over 50 years. According to the study, the tree line has advanced upward an average of 40 meters, one of the main causes of this being decreasing pressures from livestock. Contrary to common thinking to date, climate change may play a much lesser role than previously thought.