For the time being we’re witnessing the height southward migration of Booted (Hieraaetus pennatus) and Brief-toed Snake (Circaetus gallicus) Eagles over the Strait of Gibraltar. These are the 2 foremost species, with over 30 thousand of the previous and round 20 thousand of the latter crossing in a matter of some weeks. These birds are headed for south of the Sahara, spending the winter months primarily within the Sahel.
Each are restricted by the character of their hovering flight, being pressured to cross between the continents the place the ocean crossings are shortest. The Brief-toed Snake Eagle is especially susceptible. Current satellite tv for pc monitoring research have revealed some sudden twists to this story. Brief-toed Snake Eagles from southern Italy transfer north within the autumn, heading for the French Mediterranean coast, then south in direction of the Strait of Gibraltar. Juveniles that attempt to be intelligent by shifting south-west into Sicily find yourself trapped by the ocean and stay caught over the winter, and ultimately perish.
As we’d anticipate, this migration is numerically dominated by birds of the 12 months, which provides us a improbable alternative to watch birds in juvenile plumage. We received’t get this throughout the return migration within the spring. These eagles cross steadily in good climate, peaking late morning. With sturdy easterly winds, that are widespread within the Strait of Gibraltar, they transfer up and down the coast, exploring potential crossing factors. They find yourself going again into the hinterland the place they relaxation and even attempt to hunt. I’ve seen migrating Booted Eagles searching Collared Doves (Sterptopelia decaocto) and Blackbirds (Turdus merula) in gardens throughout the Metropolis of Gibraltar!
The next day, the eagles repeat the operation, solely this time they’re joined by new arrivals from the north. A number of days of dangerous winds produces spectacular gatherings of eagles. Many are interested in the Rock of Gibraltar the place the concentrations in late morning are spectacular, with a whole lot at anyone time. Practically all return north, the winds stopping a crossing. Many inadvertently stray into Peregrine Falcon (Falco peregrinus) territory the place they need to endure the extra hazard of aggressive falcons telling you that you just’re not welcome.
These are two the primary eagles that we see, they’re extremely migratory in any case, however typically we get different species exhibiting up; these are often immatures or juveniles that are dispersing and which do cross into Morocco. Bonelli’s Eagle (Aquila fasciata) is probably the most frequent however, with rising numbers because the inhabitants recovers, Spanish Imperial Eagles (Aquila adalberti) additionally present up. If you happen to’re actually fortunate you may even get the biggest and strongest of all of them – Golden Eagle (Aquila chrysaetos). All in all, a good time for eagle-watching within the Strait of Gibraltar.
Autor Clive Finlayson
