We have recently undertaken the winter maintenance on all tawny owl boxes erected by our group in woodlands across the local countryside. The majority were installed in 2007 and were initially very successful. Many tawny owls were found roosting in the boxes and benefitting from the shelter provided. Sometimes they were found consuming frogs and other prey captured. Progressively however, these boxes have been monopolised by grey squirrels whose population number has been steadily increasing each year. Once occupied by squirrels the tawny owls never return as squirrels fill the boxes with nesting material and create puddles of urine in the bottom. Not content with driving out the tawny owls from these boxes, they immediately turn the waterproof box providing them with shelter into one with gaping holes in the roof, walls and floor as they senselessly gnaw through the woodwork.

A typical example of a tawny owl box found with holes in its front and side.

Year after year we have been patching their damage and spraying the interiors with bird friendly squirrel repellent in an attempt to encourage the tawny owls back. Both these measures have proved fruitless and every year we have continued patching the boxes and patching the patches of previous years, in an effort to justify the hours of hard work spent creating this conservation initiative.

This year the grey squirrel population has exploded and where we were previously seeing a couple of squirrels in woodland areas we are now seeing up to ten. The increase in their numbers has increased their assaults on our boxes to a degree that it is not practical to continue to attempt to maintain many of them. Reluctantly this winter we have admitted defeat and have removed a large number of boxes from areas where the most damage takes place. We have retained some where the damage is not so severe but have given up trying to combat the increasing plague of squirrels in other locations. The time and expenditure wasted is a further disappointment to the failure of a well-intentioned project to benefit tawny owls.

 

The pile of destroyed boxes removed is becoming steadily bigger as time goes by.