1w Black Brant

Checking through the brents near Beacon Ponds this morning I noticed a large neck collar on a bird that I thought would be worth a check for Black Brant, I was surprised to see that it belonged to a 1cy/1w bird! Having never seen a 1w bird before I was initially a bit cautious but having done some research online this afternoon I'm happy that it is indeed a 1w Black Brant, a very educational bird.

Bird didn't appear to be associating with any other adults or 1w birds.

large white neck collar with a small break at the back

contrasting white flank patch, not as extensive as in adults

Unbroken neck collar at the front with a thick base line 

Showing the darker mantle shade when compared to 1w DB Brent, not as black as an adult

no brown tones noted on the mantle unlike 1w DB Brent