Buildings Second To Free Ranging Cats For Bird Mortality

The experts have spoken.  They say that buildings, particularly glass in buildings, are ranked second to free ranging pet cats as the cause of bird mortality in the USA.

It's all based on estimates, however.  There is no solid scientific study about the mortality rate of birds hitting buildings particularly windows.  But the estimates for the number of birds killed in America by buildings is from 100,000,000 to 1,000,000,000.  Let me repeat there is no solid scientific basis on which to base these figures and therefore they are estimates. Estimates should not be converted to "facts". They are often wildly out.

"there currently exist no U.S. estimates of building-collision mortality that are based on systematic analysis of multiple data sources."

As for cats the experts say that the free ranging pet cat kill about 4 times that number, which is quite a shocking figure but we really have to remind ourselves that, as yet, there is no nationwide, conclusive study on the numbers of birds killed by free ranging domestic cats in the USA.  I think actually you could add stray cats and feral cats to that but the expert uses the phrase “free ranging pet cats".  That implies domestic cat so you can see how confused the experts are because it is very important to distinguish between the various kinds of cat.

All studies about the predation on birds by cats are extrapolated from quite small studies and experts will agree that you can't do this with any degree of certainty.

There is a definite need, and there has been some time, for conclusive studies as to how birds are killed in the USA. There is a lot of concern by American ornithologists about the killing of native bird species and I can understand that but it is no good simply bandying around extravagant figures which less well-informed people latch onto and use to criticise the domestic cat and even on occasions abuse the cat.

The current state of affairs with regard to statistics is poor and I hope people realise that they should not go a website and simply recite what the author has quoted which no doubt comes from another website and so on and so forth  - and all of it is based upon estimated figures from “experts".

Source.