Dead Birds In Arizona?

I was at first a little mystified, but went along with my daily routines. Happened about 3 days ago I was returning from the gym, when I saw a dead bird with a pigeon on top of it just standing there. With most birds in Arizona moving as you approach this one did not. I saw it looking right at my car the entire time like it was accepting death. After a little regret I brushed it off, and continued. The next day as I was traveling on the west side of town to a friends house I noticed on what street about 2 miles had a total of 5 dead birds, this is when I started to think. On my return home I was on the lookout for dead birds only to find 12 on the ride home excluding the original 5 on this road. What's the deal? Is anyone aware of this as well?