Bird, headless chicken (5)
'bird' is the definition.
(raven is a kind of bird)
'headless chicken' is the wordplay.
'headless' means to remove the first letter.
'chicken' becomes 'craven' (I've seen this before).
'craven' with its initial letter removed is 'RAVEN'.
(Other definitions for raven that I've seen before include "Flier" , "Bird with hoarse, croaking cry" , "Bird in 1's poem" , "Hungrily devour" , "Species of crow" .)
(Other definitions for owl that I've seen before include "Traditionally wise bird" , "Nocturnal bird of prey" , "Someone solemn or wise or staying up at night" , "Smuggle sheep" , "Wise old night-flier" .)