The Norfolk Island Boobook Owl Ninox novaseelandiae undulata is one of the rarest birds on earth.
The boobook was almost extinct in the mid 1980s, with just one female bird left on the island - and therefore the world. Thankfully it has been saved from extinction through crossbreeding with closely-related morepork owls from New Zealand. After a concerted effort numbers grew to around 40 owls.
You can hear their particular 'boo-booork' call from dusk until midnight, especially on warm moonlit nights.
BYOP