Dusky dolphins off the coast of Argentina have developed a highly
organized predation technique that has rarely been seen by human eyes.
Small search parties are sent out to locate prey, leaping high out of the
water to get a better look at the sea ahead. Once spotted, a huge "herd" of
southern anchovies are "corralled" into a ball. Perimeters of the ball are
guarded by duskies blowing bubbles, which seems to frighten the fish and
keeps them together in their school.
Soon the massive ball is clustered so tightly, the fish's escape response
breaks down. Oxygen levels in the ball drop and the fish become confused.
At that point it is a matter of gobbling down as much fish as possible.
Bill Barowy, Associate Professor
Technology in Education
Lesley College, 31 Everett Street, Cambridge, MA 02138-2790
Phone: 617-349-8168 / Fax: 617-349-8169
http://www.lesley.edu/faculty/wbarowy/Barowy.html
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"One of life's quiet excitements is to stand somewhat apart from yourself
and watch yourself softly become the author of something beautiful."
[Norman Maclean in "A river runs through it."]