Eagle Identification Safaris in East Africa

On 17 February Tommy Ek and I saw yet another large, long-winged, barred and spotted Snake-Eagle in the damp savanna area of Minziro forest reserve on the Uganda border.

It was too far for a photo.

Can one but suspect Beaudouin's?

Stop Press:
December 21.
The latest Snake-Eagle has now been conclusively identified by Bill Clark as an adult Short-toed Snake-Eagle.
The other one (in 2006) was almost certainly an adult as well, and therefore was also a Short-toed.
I am still checking references to Beaudouin's however.

Excellent news!
James (the Birdman)

Bill Clark wrote me today:
I have looked at hundreds of museum specimens of this and other
Circaetus taxa in numerous museums world-wide. I have seen juvenile BBSE
in various stages of moult into the next plumage. All show a dark
brown to rufous hood on the breast and dark spots on the belly, but
differ from Short-toed SE's in their secondaries, which are unmarked on
retained juvenile feathers and boldly barred on new ones. All of these were
collected within the breeding range of BBSE. No STSE's showed similar
secondaries. In fact, second plumage STSE's are characterized by whitish
heads and lack the dark breast.

See also:
Clark, W. S. 1999. Plumage differences and taxonomic status of three
similar Circaetus snake-eagles. Bull. BOC:119:56-59.

I reckon the timing issue and place is of marginal concern. Yes migrants like some sort of route and some sort of schedule. But it is all hay-wire when they hit the equator and arrive in monsoon-influenced areas.
We have for example, right now, European Hobbys. They are moving up from the south.........heading for rain to our north; when folks would like them to be moving south. Who cares? They only care for finding food, wherever the conditions in Africa are the most favourable.
The obvious juvenile is disputably a Black-breasted Snake-Eagle or a Short-toed. But I suspect it is a first year BBSE.

The other does look like a Short-toed. I'll will try to download it and see it carefully at home on my own computer.

Have just come from India, and saw a few 'Short-toeds' there.

They fly a little differently to Black- breasted S-Es, appearing heavier and broader winged.

But the two can be sometimes only separable in the hand. Remember that Bill Clark examined a specimen of Short-toed taken from Lake Turkana and found it to be a Black-breasted despite all.

Whilst on this Snake-Eagle identification thread it was with considerable glee (on Saturday December 8) that we realized an eagle sitting motionless for nearly half an hour on a dead snag in a tall tree beside the Kikuletwa river at TPC Sugar Estate near Moshi was not a Southern Banded, but my first Tanzanian Western Banded Snake-Eagle (Circaetus cinerascens). There are some old historical records from north eastern Tanzania but very few recent ones.

I initially thought that bird was a Southern, for this species continues to survive within, or at least quite near to, the upper Pangani drainage system (of which the Kikuletwa is part). Consequently I encouraged my two companions: Caro and Fred North-Coombes to check the tail very carefully when the bird eventually took flight. However to my great surprise we agreed unanimously that there was in fact only one broad white tail mid-band and a very narrow pale terminal fringe.

There are no confirmed breeding records from East Africa. Also it has been suggested that some of the East African records of this species are of birds visiting from breeding areas outside the region. There is reportedly a peak in the August - February period which coincides with an apparent scarcity in areas further south e.g. Zimbabwe. Breeding takes place from January onwards in areas to the south of us. However with maybe an average of ten keen-ish birders in the field on any one day in e.g. the whole of Tanzania - what do we know - really?

Over the past century the three long-winged, 'spotted and barred', Snake-Eagles have been considered either three separate 'entities', or three forms of the same 'entity'. Presumably they became more or less reproductively isolated from one another during some moister period in the distant past; perhaps nearly three million years ago?

In the modern era in the northern Old World one finds the obligate migrant form with which European and West and Central Asian birders are most familiar i.e. the Short-toed Snake-Eagle Circaetus gallicus; in the sub-sahelian belt across the great bulge of western Africa one finds Beaudouin's Snake-Eagle (C.beaudouinii) and in southern and eastern Africa this form is repaced by the Black-chested Snake-Eagle (C.pectoralis).

According to Roberts VII at ten months of age pectoralis will show broad brown tips to the belly feathers; however the same source quoted in Roberts states that at six months the first black feathers should appear on the upper breast. Now as far a I have noted, or can recall, or see from the few rather poor quality photogarphs neither of the two Osugat birds showed any black chest feathers whatsoever.

Osugat Update - so, in the same place, on the same day, a year later; we have two photos, of two birds, of two different ages - yet presumably of one and the same form/species or hybrids between two forms/species?

It seems to me a rather bizarre coincidence that not until exactly one year later, and after maybe forty further visits to the Osugat in between times, and many score of days birding on safaris elsewhere in Tanzania, should another very similar, boldly marked bird appear before me - i.e. 'a barred and spotted' Short-toed / Black-chested Snake-Eagle. Remarkably it was crossing almost exactly the same part of the Osugat plain and was also heading for the "Kilimanjaro- Meru migrant raptor gap" and the huge expanse of the snake-rich Maasai steppe beyond!

Clearly I might be missing them at other times here; yet must ask - does anyone else see such heavily marked (spotted on breast and barred on flight feathers) Black-breasted Snake-Eagles in East or Southern Africa; and more particularly do they see them during the boreal summer - that is between April and September?