TreeStuff

Thursday, 30 July 2015

Owls in barns and boxes on trees

A fine owl box on an ash tree bole I wonder, is anyone home?

 

This box is part of a big, long-running barn owl project in the Scottish Borders, in conjunction with The Barn Owl Trust. The project has been very successful, providing nest sites in areas with great habitat with lots of long grass and wide field margins but few suitable nesting sites. Owls like a good hole-some ash but many of our old trees have crumbled and fallen. The holes that are left are hot property with jackdaws, owls (tawny and barn), goosanders and stock doves all contesting ownership. Jackdaws have nested in this box the last year or two (always a major problem as they tend to fill the boxes up with hundreds of sticks and piles of cattle hair and sheep's wool). Turns out that this year someone else had moved in!


Check out his amazing big talons - all the better for catching dinner - a wee mouse or vole has no chance. This adult barn owl did not have a ring so we do not know where he came from. Part of this project involves monitoring all the owls which use the boxes and in order to know who is who, each bird is fitted with a unique BTO ring. See here for a very cool blog of all the UK bird ring recoveries in 2015 so far!


A nearby box also had a single adult female in residence but there were no signs of any successful nesting attempts. We had expected young barn owls however many of the boxes we checked held only a single adult or were completely empty. It is a similar story in many parts of the UK: see hereWhen food is short, often the smallest chick becomes food for the others, and if food is really scarce, only one chick survives. It seems a horrible process but it does ensure that at least one chick survives. And then there were the boxes with squirrel kits in (Note to self: do not bother putting boxes up on woodland corners!). Luckily, the last box of the day was a different story - inside were three fine big barn owl chicks, probably only a few days from taking their first flight out of the box.