Statistic on the causes of bird mortality

Causes of bird mortality	Annual bird mortality estimate
Buildings/windows	550 million
High tension lines	130 million
cats	100 million
Vehicles	80 million
Pesticides	67 million
Communication Towers	4,5 million
Wind turbines	28,5 thousand
Aeroplanes	25 thousand

Source: Ericksonn W., Johnson, G. and Young, D. (2005)