Yesterday produced the highest total of Booted Eagles, around the 240 mark. The sight of several significant flocks in the area was quite remarkable and made a great sight for the assembled watchers. Today saw a lesser number appear however, interest was maintained with a few Short-toed Eagles, Black Kite, 3 Egyptian Vultures and a flock of 8 Black Storks. Single Black Storks are quite common during the raptor migration though a flock of eight birds is unusual. Much information regarding the migration can be gained from engaging with the Portuguese recorders, working for the Ecosativa organisation - monitoring the effect of wind farms on migratory birds. Some interesting information was given to us by our friend Tiago and, rather than fill more pages with Booted Eagles, I would like to share this information. It is fairly general knowledge now that this organisation (Ecosativa) have the capability to stop the wind turbines when there is an imminent threat to incoming flocks of vultures. (In the last couple of years their casualty rate has been Zero!) The criteria for stopping turbines is when a bird is within a 500 metre radius. Through accurate sighting, an individual turbine can be stopped and not the whole installation. The shutdown criteria does not only apply to the vultures passing through here, but will also take place for a single Osprey, Bonelli's Eagle, Black Stork, to name a few 'specific' species. Three juvenile Egyptian Vultures flew with the Black Storks from time to time. One of these birds is a lighter variant (upperwing) and has spectacular fresh plumage, with no sign of moulting. The second fascinating piece of information we gained today, evolved partly through me bleating about not having seen Bonelli's Eagle or some of the other larger eagle species, this year.
Apparently, there are now a few pairs of Bonelli's Eagles with territories stretching in a line, separating the Sagres peninsula from the Northern hills. The ferocity of a Bonelli's Eagle is well known, having seen it for myself on two occasions here in recent years. The result is that the Bonelli's will not tolerate any large eagle, anywhere in their territory. Yesterday in the hills, Tiago witnessed a Bonelli's Eagle harrassing a Spanish Imperial Eagle to the point where the Imperial Eagle turned around and headed back from where it had come. This may mean that our chances of seeing Golden Eagle for instance, are now somewhat less than previously. Good news for the Bonelli's Eagles though, severely threatened at one time.
Lars Gonçalves
6/10/2019 04:55:05 pm
If you are talking about Tiago Caldeira he doesn't work with Strix but with Ecosativa. Comments are closed.
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