hey, now thats just ignorence right there. pigeons have just as many diseases as any other animal that has colonized in north america. they just get that reputation because they tend to turn up in cities, where there in more contact with humans. which results in a greater risk of getting a disease from them. now, if there were a study on the amount of pigeons with diseases, then i'll lay you dime to dollar that pigeons have the same amount of diseases as the common woodland animals found outside of cities. and they probably also have the same "ratios" as to how many animals are diseased per amout of animals.Comparing passenger pigeons to the invasive pigeons that plague us today is like comparing black and white. Passenger pigeons were huunted to extinction because people ate them. No one wants to eat any of the nasty diseased pigeons that we are talking about in this thread.
saying there all diseased like you are implying is like saying all reptiles carry salmonilla (no clue on spelling). any reptile owner and herpetologist will tell you differently.