The Spanish Imperial Eagle (Aquila adalberti) is a raptor that I’m accustomed to. It’s a giant eagle, solely smaller than the Golden Eagle (Aquila chrysaetos). This fowl is a rabbit specialist, having developed 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 excited about biogeographical distribution patterns and I took the chance of spending just a few 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 Japanese Imperial Eagle (Aquila heliaca). I’m accustomed to 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 Japanese 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 indicate that the visits had been rising in frequency so, after dialogue with him and Geraldine (my spouse and fellow photographer), we determined danger it.
The primary day was a kind of lengthy – dawn to sundown – periods which made you surprise 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 disguise after darkish, questioning what to do subsequent. Istvan had a second disguise, this one nearer to the marsh, so we determined to attempt the subsequent day. Nearly instantly, at first mild, the darkish form of an eagle flew over us, shut by. It appeared too huge 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 actually an Imperial however wouldn’t it come down?
The climate was excellent. Gentle winds and clear skies. Because the solar rose the imperial on the tree, a primary winter fowl, appeared resplendent. A White-tailed joined it on the tree and so they interacted with one another. It set the theme for an exquisite day with Japanese 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 disregarded for them. They had been joined by Widespread Buzzards (Buteo buteo) together with a very aggressive white morph.
Japanese 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 may see how the sedentary life-style would have change into a daily characteristic of the Spanish Imperial Eagles, dwelling within the gentle climates of the Iberian Peninsula and having a daily provide of rabbits. In the course of the Pleistocene glaciations these eagles would have change into remoted from one another, resulting in the eventual break up into two distinct species. Japanese 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 frequently handled to spectacular flights of Greylag (Anser anser) and Better White-fronted (Anser albifrons) Geese as they took off each time an Imperial or a White-tailed Eagle flew overhead, with intentions to assault. To spherical up the go to, a session in a ingesting pool disguise 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!
