Whilst I was looking for something entirely different (such is the serendipity of the web), I found a rather amusingly bleeped page on Yahoo Answers, under the heading "Where do birds go to die?"
Passerines in particular (which include most common garden birds) produce large numbers of offspring, the majority of which do not suvive to adulthood. Great *@&# for example produce clutches of 8-12 eggs. If all these survived to reproduce, Europe would be knee-deep in Great *@&# within a decade or so. But many die either in the nest or soon after fledging. Many more do not make it through their first winter.
which just goes to show that computers (or rather the people who program them) are much more stupid than the average bear. I wonder if it's just "tits", or the more laddish "Great tits" that triggered their bleepometer? What about marsh *@&# and coal *@&# for example?
Oh, and if anyone knows how to get four consecutive asterisks into a post, do tell 
The FAQ is silent on this matter.
EllieGant
How funny that tits should have got the asterisk treatment, yet the cockatoo survived intact. Perhaps this is the secret of the latter's longevity!
What an interesting article though - I'd never thought about how long they live - or that it was so short. Makes me even more determined to keep up the bird cake production.