I had a number of my birding mates send congratulatory notes and support on getting a very special sighting ratified... Gee, talk about wearing Madagascar-coloured glasses!
Well, what has happened since?
I contacted an angel, Tamar Cassidy, manager of the bird collection at the Transvaal Museum and asked her if I could possibly have a look at her collection of Cuckoo skins. She offered to do some of the research for me, but after a week suggested, like deefstes, that considering the skins available to work with, my pic does look like a slightly unusual African cuckoo. When offered, I jumped at the opportunity to go look for myself.
I had a bird with what appears to be a white throat and white belly (or at least very lightly barred) and a reasonable view of upper tail spots. As deefstes suggested variable throat and belly colouration, I thought the tail spots would do the trick for me... match that (or eliminate those that do not match) and you will have a winner!
The Transvaal Museum collection lacks a Madagascar cuckoo specimen, but, if I could conclude that my bird was NOT
C. gularis, C. canorus, C. solitarius nor
C. poliocephalus, only
C. rochii remains.
Tamar accompanied me to the area where the skins are kept and pulled the trays containing lots of
C. gularis and
C. canorus. She had one
C. poliocephalus skin. The lesser cuckoo is markedly darker than my bird, trending very close to black. If that is the benshmark, then
C. poliocephalus was out of the frame. Both of us agreed that
C. solitarius wasn't required to feature in our deliberations. European cuckoo went out based on the dark bill that is a sure ID feature seen in all the museum skins. That left only the African cuckoo to consider.
Tamar showed me how she tied together the visual info seen on the pic and the African cuckoo skins...
Large viewWow! That blew my hair back! And my Madagascar specs right off my face!

Unless I actually get hold of a skin from a Madagascar cuckoo to prove otherwise, Tamar has shown me conclusively that African cuckoo cannot be eliminated from my deliberations and probably is the correct ID call for my bird
Final comment... the Transvaal Museum is
the greatest birding resource available to us. Man, you can learn a lot there. I asked if I could look at some other skin collections... no problem!

So, guess what, I got a tray each of Olive and Karoo thrushes to compare... deefstes will probably remember my reference to white vents for Olive and grey vents for Karoo in a previous discussion...
YES! It is true... you can add that to your list of ID features when considering an ID call between these two species. In a Karoo the vent will be grey or grey with a little white spotting. In an Olive thrush the vent will be white or white with a bit of grey spotting.