The September 2013 issue of the Canadian online journal Avian Conservation & Biology features a number of short research articles associated with Quantifying Human-related Mortality of Birds in Canada.
Individual articles deal with the contributions from specific industries and activities including:
- Vehicle Collisions
- House Cats
- Marine Commercial Fisheries
- Offshore Oil and Gas Production
- Industrial Forestry
- Collisions with Buildings
- Mowing and Other Operations in Agriculture
- Oil and Gas Exploration in the Western Basin
- Collisions and Habitat Loss from Wind Turbines.
All of the articles can be freely viewed online or by downloading a PDF version.
So, which one of the above categories do you think is the biggest contributor towards bird mortality?
The final article, A Synthesis of Human-related Avian Mortality in Canada, puts all the different sources of bird mortality into context. Table 3 in this article shows bird mortality estimates separated by source and split into the categories of landbird, seabird, shorebird, waterbird and waterfowl.
And the biggest bird killer? It is, by a long shot, the house cat with an estimated 135 million birds (almost exclusively landbirds) of which 80 million are attributed to feral cats and the remaining 55 million to the domestic variety. Compare these numbers to the total of 186 million dead birds per year and we have house cats killing over 70% of all birds killed from human-related causes.
There’s a whole lot of interesting information in this issue. Well worth a read.