In the autumn of 1950, small passerine birds, pigeons, butterflies of several species, one species of dragonfly and one species of syrphid fly were seen migrating south and west through the Pyrenees. The syrphids were particularly abundant.
In the autumn of 1950, small passerine birds, pigeons, butterflies of several species, one species of dragonfly and one species of syrphid fly were seen migrating south and west through the Pyrenees. The syrphids were particularly abundant.