The American White Pelicans have been migrating thru West-central Iowa for the past three weeks. These large birds have an awkward prehistoric look with their large bills and head. They are quite skilled at fishing by plunging their bill with a large pouch into the water, scooping up fish to eat. Upon catching prey, they tip their bill up, drain out the water, and swallow their meal.
Pelicans are quite gregarious and can often be seen fishing in unison. Forming a semi-circle, they drive fish to shallow water and have a feeding frenzy.
The large webbed feet propel a pelican while swimming and are quite helpful for the water-skiing landing.
Another use for the large webbed feet is to help propel the bird during take-off; running along the surface of the water to become airborne.
Sometimes, unexpected bird behavior can be witnessed while spending hours in a photo blind.
And yes, birds do poop in flight.
Final Note: The big pouch on the bill is not used for carrying food, contrary to misconceptions, some of which are derived from cartoons.