10 October 2008

Barn Owl - Tyto alba

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Barn Owl - Tyto alba

There are not many owls around Esperance, probably due to the lack of large indigenous tree species (most trees in the coastal region are small with multi-trunks), so there are few suitable nesting hollows. The photos of this Barn Owl were taken from a road-kill near Salmon Gums 100 km (62 miles) inland from Esperance, where as its name suggests is the home of many large eucalypts.

The Barn Owl will nest on the ground and in caves, but with the current cat and fox problem I doubt if this is an option these days. The similar sized owl-like Tawny Frogmouth, Podargus strigoides is quite common around Esperance, but these build a nest and have no need of tree hollows. The Frogmouths and Owls did have a common ancestor, but that was over 60 million years ago, so they are not exactly closely related, although commonly thought so.

For silent flight, owls have a comb-like structure on the front edge of their wings (see enlarged photo above), the feathers are tightly interwoven with fine soft plume filaments, as they are along their trailing edges. Although these birds look quite large when perched in a tree (enhanced by their light coloring), they are only around 35 cm (14") in length.