Dead Pigeons

In the past week or so I have been noticing a strange amount of dead pigeons near my place of business. My office is in the west, more industrial side of South Boston. I'm not kidding, I counted five in one day (that day being last Friday).

I have beaten the subject to death on google but cannot come up with any other explanation than that these birds are being poisoned on purpose for pest control. This explanation is of course alot cheerier than my first gut reactions:

End of the world
Avian Flu (sp?)
West Nile Virus
End of the world....

What do you think this means? Not to be a total creep but I did take a few cell phone photos (mostly because this was a source of comedy for me around the office this week and everyone else thought I was losing my mind).