NEST BOX DESIGN.
It seemed rather obvious that a square, flat back box doesn’t fit well to a round tree trunk! Where the flat back touches the round tree is the only place you can fix it. Right? So even a small amount of side pressure and the nest box will come loose, or worse it falls. Therefore, we designed all our nest boxes with concave backs so that they fit snug against all size of tree trunks. They also fit square on and snug against any wall.
Next we decided that the roofs of our nest boxes would be round for good rain run-off and would have a canopy extension to cover the entrance hole to ensure that no rain can enter and no predators could see inside the nest box or get near the entrance hole to grab mature nestlings.
From the very outset we realised that no soft wood, pine, spruce etc could even be considered for nest box construction, as this would deliberately be putting the nestlings in danger of being eaten alive by either squirrels or woodpeckers with their pneumatic beaks. A squirrel can eat through pinewood in quick time, rather like us eating through cream cheese! So we decided that our construction material would be GRP (glass reinforced plastic), in order to achieve the shape of the nest boxes we desired, and the impregnability from ALL predators. GRP does not rot it is impervious to all weathers offering a lifetime guarantee. We provide a perfect outer surface finished in tropical green gelcoat. The hardwood ply fronts are set into the GRP nest box so no wooden edges are available to be chewed by squirrels. The wooden fronts are also screwed to GRP covered side struts so a squirrel cannot get beyond.
Another significant contribution for the protection of our resident birds against their predators is a precession outer ring entrance hole, additional to the hole in the wooden front. This prevents squirrels from reaching inside the nest box to grab a chick or eggs.
You will be saying, “yes but GRP isn’t good for the birds to grip on inside the nest box” and you would be correct. So we cover the inside surfaces with a sawdust finish.
Now a word on the proper securing of our nest boxes to both, walls or trees. We do not use nails, only screws, which are supplied with each box. To secure onto the wall we provide the exact size rawl-plugs to go into the pair of holes created by your masonry drill into the brickwork or stone work.
To secure against a tree trunk, again we use the appropriate length galvanised screws. A word here on our discoveries at our field testing station on the Isle of Wight since 2004. We had the original concern that any securing screws would go into the tree as it grew incrementally year on year and thereby exerting pressure around the holes of the nest box. The obvious remedy would be to back off the screws every year or two. What we discovered emphatically was that the screws grew out with the tree. So we have never had a problem with a nest box screwed to a tree. Nor have we had even chew mark evidence on any box in St. Lawrence I.O.W, an area abounding in squirrels.