That is peak time for the migration of Western Marsh Harriers (Circus aeruginosus) throughout the Strait of Gibraltar. These birds are heading south-west, lots of them crossing the Sahara Desert to wintering grounds in West Africa. Others will spend the winter months north of the desert, in Morocco and within the Iberian Peninsula, the place they be a part of the native residents. These migrants are primarily western and central European in origin and others are Scandinavian. As with different raptors, the northernmost ones are essentially the most extremely migratory, they usually leap frog the residents to winter south of them.
In contrast to the bigger, broad-winged, raptors, Marsh Harriers have lengthy and slim wings (with excessive side ratio) they usually depend on powered, flapping, flight to get them throughout boundaries, corresponding to the ocean. For that reason, they don’t mixture at slim sea crossings to the extent that eagles and buzzards, for instance, do. All the identical, good numbers are seen on the Strait of Gibraltar, though these are measured within the lots of, not hundreds as could be the case with the species that depend upon the slim sea crossing.
A broad estimate of the European inhabitants places it at someplace between 100 and 200 thousand pairs, with an obvious rising pattern within the east. The most important populations are within the north-east, in Russia, Belarus and Ukraine, with good numbers in Poland and Germany. These are largely migratory and can embody birds that fly south-west in the direction of Gibraltar. An estimate of the, smaller, Spanish inhabitants places it at round 800-900 pairs.
Other than seeing them crossing the Strait of Gibraltar in spring and autumn, I usually see Marsh Harriers in wintering websites near Gibraltar. The outdated lake of La Janda and the Guadalquivir marshes are favorite haunts. If I wish to {photograph} them, and hides are important for these skittish birds, then the location of the Laguna de El Taray in central Spain is my primary selection. Right here, hides are partly dug into the bottom, providing nice views, and there are many Marsh Harriers all yr. Actually, on this non-public property holds no fewer than sixty breeding pairs of Marsh Harriers!
So, even right here in Gibraltar the place I’m spoilt for selection of enormous raptors of various species, and in enormous numbers, the harriers are amongst my favourites. In the present day, I’ve highlighted Marsh Harrier however passage additionally consists of Montagu’s Harrier (Circus pygargus), which I’ll write about on one other event. To those we should always add a small passage of Hen Harrier (Circus cyaneus), some reaching Morocco and others wintering north of the Strait, and Pallid Harrier (Circus macrourus). The latter is the scarcest however people are usually seen at La Janda on passage and in winter, and certainly additionally crossing the Strait of Gibraltar. These birds could symbolize the latest westward extension of this species’ breeding vary.
