Situación del mochuelo boreal (Aegolius funereus) y primera nidificación confirmada en el pirineo navarro

The boreal owl Aegolius funereus , L.1758 is a rare and poorly studied species in Navarre, where its presence in the Pyrenean region of this province is based on a few sound record-ings.. Its particular breeding habitat (high altitude mountain forests and its winter breeding habits, make it difficult to locate and study the species. Coinciding with a massive beech tree fruiting in 2017 and likely subsequent boom in the rodent population, nine active males, as well as the first confirmed nesting, were recorded in the Navarran Pyrenees. We also detected a number of unusual behaviours, such as diurnal hooting and interspe-cific relationships with other owl species.