all avian manure can potentially be carrying pathogens like salmonella, psittacosis, and aspergillus fungi. since it is a manure that contains both colonic and renal wastes, it is acidic and
should probably be composted before applying to your plants.
that being said, i take the
poop from my parrot cage and put it directly on my ornamentals (don't want any potential pathogens on my edibles). always wash your hands thoroughly with warm (hot)
water after handling bird poop. and try not to inhale it, since the pathogens can be transmitted by inhalation like a common cold is.
if your pigeon problem leaves wastes in an area where they are allowed to dry out, the poops can and will grow disgusting, deadly fungi called aspergillus. please be careful.