Cats are the leading cause of death for Canada’s birdsGeorge Dvorsky10/07/13 4:20pmFiled to: Animal behaviorenvironmentconservationbiologycatsscience85EditPromoteShare to KinjaToggle Conversation toolsGo to permalinkCanada's national environmental agency has assessed the various ways in which birds meet their untimely end owing to human activity. The main culprit? Cats, who are responsible for a whopping 196 million bird deaths each year.AdvertisementOwing to human activity, birds can get killed any number of ways.Outside of cats, the leading causes of bird deaths in Canada each year include power transmission lines (25.6 million), flying into houses (22.4 million) and vehicles (13.8 million), hunting (4.7 million), agricultural pesticides (2.7 million), and flying into low/midrise/tall buildings (2.5 million). The researchers considered more than 25 human-caused sources of bird mortality.AdvertisementBut nothing compares to cats, which can be divided into two categories: death by feral cats (116 million) and death by domesticated cats (80 million).These numbers are comparable to those of the United States, with recent estimates of bird deaths by cats between 1.4 billion to 3.7 billion each year. It's a North American problem, one with implications to conservation efforts and the spread of diseases (like T. gondii and rabies).