Brown pelicans have also been known to eat some crustaceans, usually prawns. Brown pelicans have extremely keen eyesight. As they fly over the ocean, sometimes at heights of 60 to 70 feet, they can spot a school of small fish, or even a single fish. Diving steeply into the water, they may submerge completely or only partly, depending on the height of the dive, and come up with a mouthful of fish. Air sacs beneath the pelican's skin cushion the impact and help it surface.
Brown pelicans nest in large colonies on the ground, in bushes or in the tops of trees.
On the ground, a nest may be a shallow depression lined with a few feathers and a rim of soil built up 4 to 10 inches above ground, or it may be a large mound of soil and debris with a cavity in the top. A tree-top nest is built of reeds, grass and straw heaped on a mound of sticks interwoven with the supporting tree branches. Two or 3 chalky-white eggs hatch in approximately 1 month. They soon develop a soft, silky down, followed by feathers. Average age at first flight is 75 days.