Thanks indeed for all of the comments which I have received by email since Saturday's post on this website - especially for that first incoming email from Bill Clark which certainly provoked some feverish, sky-flashing and raptorial, communication between those of us here in Africa and those far away.
On balance I now believe the Karatu bird in the blog post composite picture (RHS) was indeed an immature Booted Eagle as suggested by Dick Forsman, and not a first year Ayres's, nor an adult Booted, nor indeed a young Wahlberg's as was proposed by some. I continue to suspect that there may be some Ayres's Hawk-Eagles (clearly this is preferentially an open forest and/or a forest-edge bird, at least here in Tanzania and, as I recall, in Ethiopia) in which, in immature plumages, the birds are far paler overall, and less broadly or darkly barred on the flight feathers of both wings and tail than is generally believed to be the case. Separation of these birds from young 'wintering' Booted Eagles evidently would require greater care.
Do we have knowledge of any other photographs of young Ayres's?
Current textbook/field guide treatment of the presence or rather absence, or the extent of, barring on the flight feathers (especially on the tail) of immature Booted Eagles is therefore clearly misleading. Check almost any field guide or (Hand =) reference book!
How long I wonder does a typical Ayres's take to reach maturity?
Is immature on RHS in composite picture a Booted Eagle?
Thanks indeed for all of the comments which I have received by email since Saturday's post on this website - especially for that first incoming email from Bill Clark which certainly provoked some feverish, sky-flashing and raptorial, communication between those of us here in Africa and those far away.
On balance I now believe the Karatu bird in the blog post composite picture (RHS) was indeed an immature Booted Eagle as suggested by Dick Forsman, and not a first year Ayres's, nor an adult Booted, nor indeed a young Wahlberg's as was proposed by some. I continue to suspect that there may be some Ayres's Hawk-Eagles (clearly this is preferentially an open forest and/or a forest-edge bird, at least here in Tanzania and, as I recall, in Ethiopia) in which, in immature plumages, the birds are far paler overall, and less broadly or darkly barred on the flight feathers of both wings and tail than is generally believed to be the case. Separation of these birds from young 'wintering' Booted Eagles evidently would require greater care.
Do we have knowledge of any other photographs of young Ayres's?
Current textbook/field guide treatment of the presence or rather absence, or the extent of, barring on the flight feathers (especially on the tail) of immature Booted Eagles is therefore clearly misleading. Check almost any field guide or (Hand =) reference book!
How long I wonder does a typical Ayres's take to reach maturity?
Thank you all once again.