For reasons of pure convenience, this article concerns America. It might be instructive to see if it is possible to rank the cat as a bird killer. What I mean is: where does the cat rank amongst all the ways that birds in the USA are killed? We know that domestic cats that are allowed out and feral cats kill birds. How significant is their contribution in killing birds?
Before starting I think it is worth noting that when and if a cat kills a bird it is an entirely natural process. There is a natural purpose behind it and it is part of nature. If on the other hand a human kills a bird (other than livestock) it is completely unnatural and either a result of the person entertaining himself (sport hunting) or a consequence of neglect and a lack forethought (wind turbines and not factoring in bird deaths). I believe the underlying reason for killing something is a factor in deciding if it is acceptable or not.
Many people find cats killing birds unacceptable. These people will probably find humans killing birds, directly or indirectly, as acceptable. Or more probably they don’t think about that. I think it highly hypocritical of the bird associations to criticize the cat for killing birds when they themselves indirectly support habitat loss through their acceptance of the American way of life e.g. population growth and urban sprawl.
The truth is that trying to rank the cat as a bird killer is impossible to do accurately and conclusively. I came to that conclusion midway through the process of preparing this page but continued anyway! The reasons are:
- By far the greatest killer of birds is urban sprawl causing the destruction of habitat. This is a silent killer. It is probably better described as a barrier to the life of birds. If there is no habitat for birds there are no birds. Experts don’t guess the impact of habitat loss due to human activity on birds in general. They will do in respect of specific species and specific areas. But my guess is that habitat loss is by a factor of many hundreds of percent more damaging to bird populations that all the other killers combined.
- The dreaded statistics are by and large guesstimates. As mentioned, you will get fairly accurate figures for specific locations and species of bird but overall figures could be misleading due to inaccuracies. Often figures are compiled from extrapolations, which is an inherently inaccurate process.
Those caveats declared, here is a chart ranking the cat as a bird killer in comparison to killing as a result of human activity:
You can see this spreadsheet on this page too. You will notice two different figures for feral cats. One is five times the other! Are you surprised? No, because the truth is we don’t know the figure. We don’t even know how many feral cats there are. From data provided by another bird association, I produced another set of figures that are different again, on this page.
As to wind turbines, I believe the figures are incorrect. The reason why the percentage of birds killed by wind turbines ranks as 0% is because the figure is insignificant compared to the total. That shows how statistics can paint an incorrect picture.
It seems that wind turbines have on occasion been erected in areas where birds migrate. That was careless and an indication of the lack of consideration given by business and politicians to wildlife. I am told that more care is now employed in some instances and the design of the turbine is a contributing factor. Larger birds are more at risk it seems (e.g. eagles). This is disturbing.
Can we come to a conclusion? Well yes, of sorts. Here are mine:
- Don’t listen to the bird associations and conservationists bleating about cats killing birds. The figures they produce are likely to be inaccurate and they ignore themselves and their impact on bird populations.
- The cat has a relatively very small impact on bird populations compared to the human.
- If people want to protect the birds they should address the more difficult questions of human population growth and consequential urban sprawl and industrialization. We are a long way off doing that unfortunately. The human likes to put difficult decisions on the back burner.
- The human also likes to pass the buck and blame the vulnerable and silent: the cat.
Other considerations are as follows:
- Some birds are ‘pests’. Personally I don’t consider any animal a ‘pest’ but human urban developments create an increased number of pest birds and predators². The point I am making is the human generates greater predation of cats on birds in environments of their own making. Another reason why humans are hypocritical.
- Despite the point I make in 1 above, garden and suburban birds may still be under less predation from cats than they are from ‘a range of native predators that no longer co-exist close to human habitation’¹.
- Mead 1982
- Sorace 2002
The pictures are in the public domain and from “The Domestic Cat, Bird Killer, Mouser and Destroyer of Wildlife….“1916 by Edward Forbush.