Wednesday, April 27, 2011

American White Pelican 2

Most American White Pelicans breed in the northern Great Plains of North America.  Across most of this range, they consume shallow water fish (not normally prized by humans) and various aquatic amphibians and crayfish.  In parts of the Dakotas, they subsist mostly on larval Tiger Salamanders (which can be incredibly abundant in that region).

Unlike Brown Pelicans, American White Pelicans do not dive. Instead they often practice cooperative hunting.  The pelicans form a large circle.  They then swim towards each other, making the circle smaller, and trapping their prey between them.  The photo above (from Sand Lake National Wildlife Refuge in South Dakota) shows a feeding frenzy as the pelicans tightened their "noose."  (If you look closely in the left side of the flock, you may notice a pelican's foot held high in the air, as its owner dines.)  Not all flocks form circles.  Often they simply drive their prey to some dead-end from which escape is difficult.

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