Animal activists are calling for more humane ways of dealing with Canada geese in the area after learning hundreds of the birds have been put to death as a public safety precaution.

The U.S. Department of Agriculture has been removing the geese from 12 locations around JFK and LaGuardia Airports, saying they pose a threat to airplanes.

Nearly 400 were rounded up at Prospect Park earlier this month and were killed with carbon dioxide. But at a vigil for the geese Saturday, State Senator Eric Adams said many residents were upset to learn the birds were dead.

"Government is not supposed to operate in the middle of the night. Government is supposed to be open and transparent. For us to go to sleep with geese, and wake up to find out that geese went to a slaughterhouse, that's unacceptable," Adams said.

"There is absolutely no reason and no rationale for them to kill the animals who are here in Prospect Park. The resident geese who are here pose no danger to aviation, and what we are trying to hope for is that they will concentrate on a more humane, more effective, and more transparent program," said Patrick Kwan of The Humane Society of the United States.

Removing the birds became a high safety priority last year after a disabled US Airways flight ditched into the Hudson River because Canada geese flew into its engines.