The not so hidden world of ‘human-related threats to birds’ – cats, houses and cars!
What are the leading causes of human-related bird mortality in Canada?
Findings are in an Environment Canada report (Avian Conservation and Ecology 8(2):11) which can be found at http://www.ace-eco.org/vol8/iss2/art11/ The report details the sources and studies used to generate the data and the range and caveats associated with the numbers which are included.
Michael Runtz (distinguished author of Wild Wings: The Hidden World of Birds) usually dwells on the positive. And although he does not like to look at the negatives, at our February lecture, Runtz outlined these leading causes of bird mortality related to humans. He also gave many insights into a range of other threats, including invasive species, climate change (for example studies with Gray Jays) environmental toxins etc.
Per year in Canada, the leading causes of bird mortality related to human activity, are the following. These factors (cats, buildings, cars) are associated most closely with highly populated areas, and this is where most bird kills due to these causes occur, states the report:
# 1 killed by feral and domestic cats (70- over 200 million birds killed per year)
# 2 collisions or electrocution due to power lines (25 million birds per year)
# 3 collisions with houses (20 million birds per year)
# 4 collisions with vehicles (14 million per year)
A full report of Mike’s talk will be posted soon. Note: photo of Gray Jays by Howard Robinson