Theory:
I have found the crows to give away my position to nearby enemies. Thus the reason they show up on your radar....so you can be aware of them....as to not give away your position to your nearby enemies you're sneaking up on. If you startle the crow...your enemies will search around.

That and I have also noticed that more than once I have investigated what turned out to be a crow on my radar and find the critter picking at a body of something that something besides me killed. Most of the time they have been humans.

Crows huh? Nice. And they're shoot-able! You could never kill the vultures in FO3.

It's just too bad you can't eat crow

Seriously? Now that's cool. It's little touches like that and grave-robbing that make me glad Obsidian took over.

I recall seeing something about this in a FO:bible question about the bird noises in FO2's Vault City (being a mistake).

**** Actually.../ Having just looked this up, the exact quote is, "No one knows where those bird noises in Vault City came from.".
Birds do not appear in any Fallout game beside FO3 & NV, but they easily could have had they wanted to include them
(or not forgotten them ~if that's the case). Chris Avelone is the man to ask (prior to FO:NV), but its too late now I think.

I suppose Birds exist now in Fallout, but it makes you wonder... They say domestic cats were eaten to death for their ease of capture
~are birds not preferable to cat, and it easier to catch their eggs?

That doesn't mean I'll stop trying!

Yup, I am enjoying the little touches like that that really make the game. One of the bodies I would have never found, up on an outcropping off the road.

I liked them more when I thought they were ravens.

It would have been really cool if you could shoot them like in Red Dead Redemption.

You had to shoot 5 or 10 crows to complete a sharp-shooter challenge.

This.

I thought the crows were pretty cool. Shooting them is fun. As others have said, they add atmosphere, and this time, that's good enough for me.

They're amazing, that's what they are.

If only there was a way to hide them (and the tumbleweeds, which are also counted as Creatures in the GECK!) from appearing on the radar...

Fallout 1 & 2 did have an area map and motion detector.
(so if it was made with that in mind, it would seem to be showing motion and obstruction ~which the crows and tumble weeds are right? :shrug:)

I suspect the ones that survived were the ones smart enough to build their nests in hard to reach places. The others probably were eaten.