At this time of the year, the loon moults from its striking breeding plumage into its inconspicuous wintertime look. The first two pictures were posted earlier and are reproduced here to illustrate the two states; the last picture was taken two days ago and shows a loon in transition.
This picture of a nesting loon was posted in early June of this year. In addition to the strongly patterned back, the breeding Loon has a dark head and bill.
This loon from early May of last year shows the grey back, and crown along with a white throat and bill.
So, the loon’s moult into breeding plumage takes place in May. The reverse transition is now underway. The bill and throat of this week’s loon are already becoming lighter.
Interesting. Thanks again.