The horn is a growth on the bill of American White Pelicans that occurs during the breeding season and I am fortunate to live in a location where these big, white pelicans breed. I am able to see them in both breeding and nonbreeding plumage close to home so for period of time during the spring I am able to photograph American White Pelicans with their horns. The horns are also called caruncles and they are a bony plate that might simply be a sexual ornamentation. This American White Pelican image was taken several years ago at a pond near where I live and I think it shows the horn very well. This is full frame and I wish I had zoomed back a little bit because it feels a little “tight” to me.
There are still a few American White Pelicans in the Salt Lake Valley and although most of them have migrated south it is possible to see them as late as December here or until the freshwater lakes and ponds freeze. Most of the big, white birds I will be seeing; and hopefully photographing, this winter will be Tundra Swans.