The Spanish Imperial Eagle (Aquila adalberti) is a raptor that I’m acquainted with. It’s a giant eagle, solely smaller than the Golden Eagle (Aquila chrysaetos). This fowl is a rabbit specialist, having advanced in isolation within the Iberian Peninsula. Rabbits are endemic to the peninsula and the specialised predator-prey relationship is a attribute of the Spanish Imperial Eagle and the Iberian Lynx (Lynx pardinus) – see my article of 11 August.
I’m very taken with biogeographical distribution patterns and I took the chance of spending a number of days in Hungary, on the plains and marshlands of the Tisza River, to attempt to observe and {photograph} the Spanish Imperial Eagle’s sister species – the Jap Imperial Eagle (Aquila heliaca). I’m acquainted with Hungary’s birds within the spring however this was my first autumn go to. My pal and colleague – Istvan Bartol who runs Oriole Lodge within the village of Tiszaalpár – had notified me that some Jap Imperial Eagles had been visiting his hides. They had been coming right down to carrion however the visits had been irregular. His digital camera traps appeared to point out that the visits had been growing in frequency so, after dialogue with him and Geraldine (my spouse and fellow photographer), we determined danger it.
The primary day was a type of lengthy – dawn to sundown – classes which made you marvel what you had been doing there. We noticed some eagles flying by and touchdown on distant timber, however nothing got here down. Disheartened, we left the conceal after darkish, questioning what to do subsequent. Istvan had a second conceal, this one nearer to the marsh, so we determined to attempt the subsequent day. Virtually instantly, at first mild, the darkish form of an eagle flew over us, shut by. It appeared too massive to be an Imperial, in all probability a White-tailed Eagle (Haliaeetus albicilla) which had been additionally about. One other eagle flew low over us and sat on a close-by tree. This one was definitely an Imperial however wouldn’t it come down?
The climate was good. Mild winds and clear skies. Because the solar rose the imperial on the tree, a primary winter fowl, regarded resplendent. A White-tailed joined it on the tree they usually interacted with one another. It set the theme for an exquisite day with Jap Imperial and White-tailed Eagles spending a lot of the day with us, on the timber and in addition on the bottom feeding on the carcasses which had been unnoticed for them. They had been joined by Frequent Buzzards (Buteo buteo) together with a very aggressive white morph.
Jap Imperial Eagles, not like their Spanish counterparts, are largely migratory, abandoning their harsh breeding areas in a lot of Central and Western Asia within the winter. These Hungarian birds, on the western excessive of the vary the place the winters are mildest, appear to stay all 12 months. You’ll be able to see how the sedentary way of life would have turn into an everyday characteristic of the Spanish Imperial Eagles, dwelling within the delicate climates of the Iberian Peninsula and having an everyday provide of rabbits. In the course of the Pleistocene glaciations these eagles would have turn into remoted from one another, resulting in the eventual cut up into two distinct species. Jap Imperial Eagles would by no means have had pure entry to rabbits however, relying on which a part of the vary they inhabited, would have discovered similarly-sized prey, be it brown hares, susliks, hamsters or pikas in addition to medium-sized birds.
Whereas there, we took the chance of exploring adjoining habitats and wintering birds. Fieldfares (Turdus pilaris) had been about in very giant flocks. In wooded areas in some villages, and even busy cities, we had been proven roosts of Lengthy-eared Owls (Asio otus). Hen (Circus cyaneus) and Western Marsh (Circus aeruginosus) Harriers patrolled the fields and we had been usually handled to spectacular flights of Greylag (Anser anser) and Higher White-fronted (Anser albifrons) Geese as they took off at any time when an Imperial or a White-tailed Eagle flew overhead, with intentions to assault. To spherical up the go to, a session in a consuming pool conceal produced a variety of wintering passerines and a most fantastic grownup male Eurasian Sparrowhawk (Accipiter nisus) which got here right down to drink and bathe and stayed with us for an hour, sitting barely two metres away!
