Autofocus lenses are recommended, if they can work together with an infrared-operating flash. The effects of flash photography on nocturnal birds is a matter of debate among nature photographers. Some say no harm is done, but I'm not so sure. Bird retinas can tolerate the sunlight. Even owls and other nocturnal birds can look at the sun without damage, compared with mammals that are less fortunate.
Sunlight is certainly brighter than that produced by an electronic flash.
However, a retina requires about thirty minutes to adapt to the dark after being exposed to a sudden light. This fact could be crucial for the survival of nocturnal birds. The male can be recognized by its red-orange feathering. The Grand Paradise woods and meadows shelter the homes of many birds. You can obtain superior results by hiding under a camouflage sheet.