I live in coastal Orange County, CA where there are plenty (with a capital P) of crows. We had a 60 foot tall pine tree next to our driveway that apparently had a crow's nest at the top. One day a large pork rib bone fell from the sky and nearly hit me as I was standing in the driveway. So indeed, crows are opportunistic feeders. The crow nesting at the top of our tree must have raided someone's picnic or trash can. The bone was picked completely clean so there wasn't even anything left for the ants. It must have made a tasty meal for the babies.