Wind driven bird house, casters into the wind

by Kent Vandervelde
(Oak Harbor, WA, USA)

A bit of aviation history - a copy of the tetrahedon that sat in the center of old airports indicating the direction of the wind hence the "duty" runway for incoming, itinerant pilots. Engineered to rotate into the wind when it exceeds 10 kts.

Swallows have been returning on or close to tsx day (15 April) every spring for 20 years chasing away sparrows and other competing tenants before moving in.

The beauty of the design puts the entrance in the lee of the storms, tenants remain warm and dry regardless of the strength or direction of the wind.