The essence of this site is not in strange birds like the Cassowary of Papua New Guinea that can kill a man with one swipe of its clawed foot. It is not about the Frigate bird that can glide for more than 24 hours at a time. It is not about the ropen (also of Papua New Guinea) that, being featherless, is not even a bird. Something else flies overhead at night, not as strange as the glowing ropen: seemingly common but strange in its own rare glowing. It is the barn owl.
Barn Owls
"The clamorous owl, that nightly hoots and wonders at our quaint spirits" (William Shakespeare)
Min Min Light
Why is the underside of this barn owl's feathers white? According the Australian author Silcock, it may help the light from bioluminescence to get through.
Notice the top of the feathers: darker colored. Apparently, the barn owl has no need to glow on the top, only on the bottom.

Questions or comments to:
Jonathan Whitcomb
In the book "The Min Min Light - The Visitor Who Never Arrives," the author, F. F. Silcock, presents his case for the intrinsic bioluminescence of the common barn owl. But this bird rarely is seen to glow. Many live in captivity without ever displaying any sign of bioluminescence. That is part of the mystery but this mystery is not without an answer: This owl only glows when necessary and perhaps not all barn owls can glow.
All About Birds
Tyto Alba
Ropen and the Min Min