On Monday I posted photographs of a common merganser (Mergus merganser) speeding through the water while leaving a wake like a motorboat. (Common Merganser Courtship?? 05-01-2017)
Meanwhile. . . . an American white pelican (Pelecanus erythrorhynchos) was following the merganser.
When I first noticed the merganser it was sunning itself on a partially submerged log. Nearby a pelican was also sunning itself. When the merganser slipped into the water and began its unusual behavior, the pelican also entered the water and began following the merganser. For the entire time I watched the merganser shoot across the water, the pelican followed the merganser.
I was curious why the pelican kept following the merganser. At first I thought the pelican might try to steal any fish the merganser caught. Or perhaps the pelican hoped to scoop up any fish the merganser might “herd”. However, as I said in my previous post, the merganser did not appear to be feeding. Nor at any time did the pelican approach the merganser or seem to eat anything itself. Still, as Leonard said, perhaps the pelican was “hanging around in a casual way in the hope that it might eventually pay off” in the form of a meal.
Four days later I returned to Crystal Lake (Shasta County CA). This time the pelican and merganser were sitting next to each other on the same submerged log. Upon seeing me they both entered the water. This day the merganser sedately swam around the lake with the pelican trailing about ten feet behind. I watched the two continue in this manner for over fifteen minutes before leaving.
I have no idea why the pelican was swimming directly behind the merganser. The behavior seems unusual to me. Any ideas?
A bit of trivia: In England the common merganser is known as a “goosander”.