An update from Rich Harris:
The Southam & District Tawny Owl Project has just completed its 4th breeding season.
In 2015 we had 12 breeding pairs in our nest boxes, and this has increased gradually each year so that we now have 27 breeding pairs this season.
The take-up of available boxes is an amazing 36% in 2019; the significant increase this year has been helped by a mild winter and an abundance of prey, especially the Long-tailed Field Mouse (aka Wood Mouse) which has been ever present at breeding sites.
Tawnies have taken to their new homes with gusto in coniferous plantains and mixed woodland where there is a lack of natural tree holes, and all the woods within the project, bar one, have maintained or increased the number of breeding pairs.
However, in ancient, mature woodland with ample natural nest sites, the uptake has been, since the project’s inception, a total blank even though it is clear while we are surveying that owls are present. Therefore I have decided to remove some boxes for repair and relocation to some new areas, and also to places in near to developing strongholds, building on past years successes.
We used a policy of placing boxes in pairs, 100 yards apart – in theory, one box for the breeding site and a second for the roosting male. The outcome has been interesting; either a second pair has taken up residence in the second box or other wildlife have moved in. Only on 3 occasions in 4 years has a male been flushed from the second box. The Tawny Owl is territorial, but seems to be able to tolerate other pairs nesting close by! So this policy has been abandoned going forward.
The positioning of boxes on the edge of woods rather than the interior has been helpful, enabling a passing owl to better identify a possible nest site. Most are East facing which is warmer and drier for the inhabitants and reduces wear and tear on the exposed box.
Although there are many reports of Tawny Owls moving into urban areas the 5 boxes in semi-urban locations have never been taken up; these will also be relocated.