Apparently there is a wave of restrictions sweeping Costa Rica banning the use of multi flash photography for hummingbirds at a number of locations. There was reportedly a statement by a “professor” from a Costa Rican university purporting to say that it harmed avian eyes and even could result in blindness. As a physician, this seems like nonsense to me. It would be be highly unlikely that a flash duration of 1/10,000 second at 1/16th power (typical settings for multi flash photography) would harm anything. As one who has done this type of photography, I have never noticed any detrimental effects on hummers, who, after a few initial shots, completely ignore the flashes.
I would appreciate everyone’s input here and particularly any references in the literature that might be useful in counteracting this trend. Thanks so much!