The Brown Pelican is a large bird with a 6½ foot wingspan. It has an immense bill, and in breeding season its distensible gular (throat) pouch is olive to red. The body is grayish-brown with a blackish belly. Non-breeding adults have white heads and necks; breeding adults have dark chestnut hind-necks and a yellow patch at the base of the fore-neck. Immature Brown Pelicans have dark heads. In flight, the long neck is folded back on the body.