Canada geese south of the border have become the targets of several recent mass killings, both state-sanctioned and otherwise.

The U.S. Department of Agriculture says about 400 geese were wiped out in Brooklyn's Prospect Park last week because of concerns they were endangering airplane flights.

The department says the birds were herded into a fenced area, taken to a building and gassed with carbon dioxide.

Authorities in New Jersey say today that 18 geese were found beaten and shot in the head in the western part of the state.

Ted Cheskey, with Nature Canada, says it's not surprising the birds have become problematic as people have created the perfect habitat for the geese, with freshly cut grass and open waters that no longer freeze.

Cheskey says while he's not against culling, he doesn't like the solution, and says cities need better management and planning.