This feather belongs to an Australian bird called the Tawny Frogmouth (Podargus strigoide) . They are one of my favourite birds.I have seen them one or twice a year - I saw one last weekend when I was drawing at Elizabeth Farm inthe outer suburbs of Sydney.
They look like owls but are not . Tawny Frogmouths have fairly weak feet as they use their beaks to catch their prey.Males and females look alike, and are 35–50 cm long. To avoid detection during the day, tawny frogmouths sit upright, completely motionless on branches in trees, with their heads tilted up and eyes closed to slits. Their plumage is finely streaked and mottled in grey and brown, and in this posture the birds look just like broken branches.
If a frogmouth is disturbed, it may adopt a threatening pose, fluffing out its feathers, showing its wide orange eyes and opening its beak in a wide froglike gape to reveal its yellow throat, hoping to appear intimidating.
here is a link to a photo from Australian Museum