[One study involved killer whales at Marineland in Niagara Falls in Ontario, Canada. An inventive male devised a brand new way to catch birds, and passed the strategy on to his tank-mates. The 4-year-old orca lures gulls into his tank by spitting regurgitated fish onto the water's surface. He waits below for a gull to grab the fish, then lunges at it with open jaws.] They are in a way setting a trap, ... They catch three or four gulls this way some days.
— Michael Noonan
CanadaStudy