Why is it that a tiny songbird can hit a stationary building and smash itself to a pulp flying under it’s own steam, but a fat pigeon hit by a Vauxhall Astra travelling at 70mph doesn’t leave a mark?
i) You presumably did not see the state of the pigeon, post-impact. Its health might have been impaired.
ii) Seriously sloped windscreen on Vauxhall.
iii) Pigeon: circa 300 grams. Vauxhall circa 1 tonne.
iv) Duck: circa 1500 grams. Aeroplane circa 175 tonnes.
In (iv) above, if duck enters engine, aeroplane has problem.
I hope that this will help.