What happens to all the dead birds?

Every bird dies. Yet, I rarely see a dead bird. Why?

I can look out into my back yard and see hundreds of birds in a day – maybe thousands when a flock of some kind passes through. Every one of them has to die some time. Yet in all the years I’ve been here, I never hit a dead one with my mower.

I know some get eaten. But so quickly?
Do birds go somewhere else to die? Where do they go?
Do you see many dead birds in your area?

(I put this in Social so humor is welcome, but I’d seriously really like to know.)