Pelecanidae
Circle high
Coastal waters
Headfirst plunge
Diving pelicans learn that a steep dive angle, ranging from between 60 and 90 degrees, reduces aiming errors due to water surface refraction. Located on their breasts just beneath the skin, air sacs act as cushions to avoid injury from surface forces on impact.
“The brown pelican usually plunge-dives head-first for its prey, from a height as great as 33–66 ft, especially for anchovies and menhaden.” – Andrew Elliott