The American Bird Conservancy estimates that up to 500 million birds are killed each year by cats — about half by pets and half by feral felines.
Household cats were introduced in North America by European colonists; they are regarded as an invasive species and have few natural enemies to check their numbers.
“They are like gypsy moths and kudzu — they cause major ecological disruption,” Dr. Marra said.
A Nation of Killers...
..living right under our noses...
