Bird box advice

Hi have been given a bird box without a hole. Was wondering what size hole i should put in as its an unusual shape. It is tall (approx 12”) with a steep sloping roof to 5” at the front. Its about 5” wide. Any advice? 

  • Hi Alex,   I would say a good average size for a bird box is 28mm entrance hole which birds like blue tits and great tits could use;  I found 25mm a bit small when watching well grown chicks trying to squeeze out upon fledging.     Personally,  I would also add a metal nest hole plate to cover the 28mm entrance hole to protect it further.    If you get birds like Great Spotted Woodpeckers you may also need to add some quarter inch wire mesh to the sides and underneath the box to prevent them destroying the box;    the mesh works incredibly well.       See HERE      Good luck for next years season and hope your new box gets used.      Site the box between North and East direction.    

  • Thanks Hazel. Will do that. Just wanted to check it wasn’t a box that was designed for a specific species. I originally wondered if it could be a bat box.
  • I think the general size is just short of 6" across for nest boxes but don't see why tit birds wouldn't use this box. Bat boxes appear to be more wedge shaped from what I've seen, a bit like the shape for a Treecreeper box.