Well some are only a lot of the larger ones are opportunists i.e. will eat anything they can get their beaks into.
Now I’ve got a problem with that. For example the world is full of corvoids.
As an example lets talk crows. Natures dustbin (trash) collectors.
If it’s dead they’ll eat it. If it’s small and defenseless, they’ll also have a go at eating it, usually as a “gang” but hey, if opportunity knocks, singletons will have a go at most things.
So what about sea birds, especially gulls.
Supreme scavengers they are and definitely aren’t fussy about what they will attack or eat. From small and furry to dogs and humans. Well not actually eating grown ups but if they were dead??
So what’s to do about them?
In survival terms if it breathes and bleeds in theory you can eat it. Well sort of.
Except I wouldn’t want to consume something that has just fed on some form of biological matter which may be harboring bacterial infections or parasitic creepy crawlies.
As for where that bird has been? You really haven’t got a clue.
From the horrors of CBRN to what it may have consumed in the form of control poisons, stepped in, flown through, swam in, you really haven’t got any idea what nasty stuff what you’d be eating.
So lets talk water birds. Ducks, swans, and geese.
They’ve got to be OK haven’t they. Veggie or fish eaters in the main.
Only consider the water they swim in. As an example, on the river I live on there are no less than 5 sewage treatment plants, innumerable farms along the banks, and many towns plus a fully grown up city.
Now imagine if something simple happened and the electricity went off.
At some point the sewage treatment plants may over flow.
As for towns and cities?
The thought of all that waste and nowhere for it to go except into the rivers as overspill is frightening.
Add a bit of CBRN and the stew they are swimming in won’t be doing them much good.
Only how would you know?
Most wild life just keeps on going until it drops. OK it may show some signs of sickness and contamination but I’m not a skilled person so unless it’s blatantly obvious, I’m not going to know.
I’d guess most people don’t have testing kits to ensure the meat is safe either.
So is any bird life safe to eat?
If there is an outside chance that whatever has happened is down to some form of CBRN contamination (Chemical, Biological, Radiological, or Nuclear) you simply can’t take the chance.
Does cooking not kill every sort of bug?
Well maybe if you can cook it correctly only cooking doesn’t neutralize chemicals and especially anything radioactive.
There again, can you afford not to eat bird?