Tawny owls are rarely seen in the daytime but are supremely adapted to night-time hunting. Although they have good night vision they hunt mostly by sound. Like most owls, tawnies have large wings which allow slow flight and slow wingbeats but much of the secret of the silent flight is in the flight feather design.
Last summer I found two moulted tawny owl primary flight feathers in the garden and I recently took a closer look at them. They have three special features which are different from other bird feathers. The leading edge of the feather shows serrations which are tiny comb-like structures that modify the airflow over the wings to reduce noise although the exact mechanism is not known. Interestingly serrations are much more developed in nocturnal owls such as the tawny owl than in diurnal owls.
For comparison here is the leading edge of the owl feather L compared with a primary flight feather from a wood pigeon R. The velvet was a bit patchy on this feather but bear in mind it was a discarded moulted feather that had been in use for a year or so. The subsequent sale of the specimen or item is illegal unless by a registered person. The legislation surrounding taxidermy and the keeping of dead wild Barn Owls, feathers or eggs and their subsequent sale or purchase, is complex and several licences may be required.
It is important to be aware of the increasingly high-tech approach to wildlife crime that has recently been adopted in the UK. X-rays are now being used to investigate cause of death in some specimens, including taxidermied ones. DNA sampling has been employed to prove the genetic heritage of birds in an attempt to cut down on offences involving wild birds being passed off as captive-bred.
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