Le pinson du Nord Fringilla montifringilla L.: un visiteur d'exception dans les forêts d'Ajoie durant l'hiver 2001–2002 | The brambling Fringilla montifringilla L.: a rare visitor in the forests of Ajoie in winter 2001/2002
In the winter of 2001/2002, over a period lasting 110 days, ten to twelve million bramblings (northern Eurasian finches)sought a place to sleep in the region of Villars-sur-Fontenais in Canton Jura, Switzerland. Suitable resting places in the proximity of access roads enabled a great number of ornithologists to carry out regular and numerous observations that were collected by the author in Jura's Natural Science Museum in Porrentruy. A lot of new information on the behaviour of the bramblings at their places of rest was collected, both during the day, on their return, and was also closely observed and described with regard to weather conditions and the change of season. Information was also collected on the ethology of predators. The special aspect of the article is the visit to the resting places after the departure of the bramblings. Much new knowledge was gained from this. Pseudombrophila stercofringilla,a newly discovered Ascomyzete, was actually found by its discoverer in situ. The effect was detected of uric acid,which turned the ground plants brown and destroyed fir needles from the previous year. It would be a worthwhile subject of scientific inquiry to study the effect of enrichment with fertiliser – manifest on trees and mushrooms. A regional study would make it possible to examine whether the scratching activity of the bramblings, allowing beechnuts to fall on fruitful ground, have a positive effect of regeneration of beech forests in the long term.