Dear All,
I was in Nairobi National Park yesterday (4th January 2019), with
Nigel Hunter and his grandson Dillon. The weather was periodically
foul with heavy squalls.
We were at the Ox-bow along the Mbagathi, sitting out the latest
downpour, when I spotted some movement on a patch of mud. I put my
binoculars up and saw it was a White Wagtail this was surprisingly
only the second individual the Park has ever seen, the last being a
pair at Athi Dam fifteen years ago. So the record was exciting enough,
but it looked like no White Wagtail I had ever seen, but was
unquestionable M. alba alba and not some unusual eastern form.

It was the 4th January, but the large breast patch was pitch black
right up to the throat, so this was an adult male in summer (breeding)
plumage, but the head was pale grey, the cheeks were pale grey, in
breeding plumage the males show contrasting black crowns with white
face patches, but this was showing the head of an adult male in winter
plumage. The short black superciliary line maybe related to the future
appearance of the black crown but that is only supposition.

It is difficult to conceive what moult pattern is taking place on this
individual to portray two different times of year at the same time,
and one grossly out of kilter.

Has anyone any idea what is happening here, or seen anything similar.
Itai with all the thousands you must see every season, have you ever
come across this combination? Are some White Wagtails with you already
showing considerable amounts of breeding plumage?

Best to all
Brian