This is a new 'Hawk Hive' III with the left side hinged for annual cleanout, waiting for a new home buyer. Any Hawk, Owl, Squirrel, Flikker or Bees are welcome. Sparrows are aggressively discouraged. :>)
This (click on) hyperlink is the story of 'Hawk Hive I It has been a real 'producer'.....if you like Honey.
My Son's family, the owners of Hawk Hive II (Hawks one year, Bees and honey now), have another visiting Hawk hanging around their back yard. The preditory 'Red Eyed Night Herons' lurking in their trees here in New Mexico, have seasonal company. They also hear Owls at night. I offered to build another house for his family's 'Avian' visitors. He brought me a board, now to construct 'Hawk Hive' IV.
He had a 12 foot, One by twelve. 12' X 1" X 12" (3.6m X 25mm X 30cm), 'rough sawn' board, that was aged Barn Wood. They make the best big Birdhouses and Bees like 'em as well, unless you coat the inside roof with either parafin or bar soap. Use gloves with that 'rough sawn wood', it has a few sharp splinters. If wood of that description is not available, use a finished pine board with it's slightly smaller milled dimensions. A shorter board works, if you scale down the dimensions to suit the length.
The Pine board can be cut easily with any saw. Use a 'square' to ensure straight pencil lined cuts. The first cut is marked 24" (61cm) at a two inch angle drop to 22" (59cm) across the width of the board, to allow for a sloping roof. That cut is duplicated by flipping the board you just cut, laying it on top of the long piece and marking the next (a 90 degree) cut (lower edge) for the other side panel.
When completed, you have two side walls, with a two inch slope for the roof. The next cut is made to allow for the long back wall, then cut the shorter front wall. For a ventilation top gap, cut both panels a half inch shorter 21 1/2" 54cm) and 23 1/2" (60cm). The shorter front wall (21 1/2") is going to be the 'swing up' door.
After cutting the front door panel, either use a 'hole saw' or a 'scroll or jig saw' to cut the entrance opening (pilot hole required). Position the hole's lower edge, about 12inches (30cm) up from where the floor will be. While you have the front panel laying flat, saw a substantial number of shallow horizontal grooves into the inner surface from just above the floor, up to the hole. A few on the outside helps the parent grab onto the hole as they fly in.
This 'ladder' allows the baby birds to climb up to the opening after they 'fledge'. This large floored box has enough room to allow them full maturity before taking flight. Set the floor up slightly inside the walls and door so it doesn't allow draining water from the sides to wick into the nest.
A wet nest material encourages larval infestation that suck the blood from the chicks at night. I read that Hawks often bring a live 'Blind Snake' (Worm like) into the nest. It continually scavenges the nest material for Larva. Cut a three inch round hole for Owls and Hawks, to 2 inch for flikkers. This box could also be used for Wood Ducks. They like a somewhat flatter, large oval hole. They have a wider body. Check for actual dimensions 'on-line'. Don't be surprised if a family of Squirrels also finds this large spacious home attractive. If you don't desire squirrels, use aluminum sheathing on the outside to discourage them. If predators (cats and racoons) are a problem, it helps to lay at least one more (aluminum covered) board over the opening to make a deeper hole.
Instead of nails, use stainless steel wood screws 2" (5cm) in length for a long lasting box. Be sure to drill pilot holes to prevent cracking of the panels. Fasten the back between the sides, using four screws total. Remember the front panel must be set 1/2 inch (12.7mm) lower to allow air ventilation as well as swing up for cleaning, so the hinges are the top two screws for that panel. If you did it right, the bottom edges will be all the same level (no problem if they are not), the top front of the door and also the back panel, will be 1/2 " (12.7mm) lower at the top (ventilation). If you forgot, and box is assembled, drill some 3/8 inch (10mm) holes for vents.
Measure for the floor panel allowing for the thickness of the closed door. Cut to dimensions and before inserting, cut off the four corners about an inch to allow for ventilation (saves drilling vent holes). Screw the floor into place using 2 screws on each side and one or two in back. Do Not screw the front swinging door to the floor. Fasten the front panel door with two screws, One on each side, near the top to act as 'swing' pivot points. That way you do not need to buy hinges.
You can either cut a longer board and position it between the two sides if you allowed an extra 3/4ths to 1 inch (1.9cm to 2.5cm) for it, or cut the roof top in two pieces, oversized for overhang. Or find a suitable piece of plywood for the roof. In the later case, allow at least an inch for side overhang and at least three inches for the front (flush in back for mounting to tree).
We have lots of sunshine here in NM, so it is more for shade than rain.
I like a sheet of metal flashing to cover the entire roof for longetivity in weather. Bend the sheet metal in a wrap, and use small brad nails to fasten it around the edges. (Aluminum cuts with heavy scizzors) Tin from coffee or gallon cans, require metal shears. Plastic sheet will work if thick enough. Use your imagination.
I use Linseed Oil for an outer preservative. After it cures, the Bees and Birds don't seem to mind. Paint it with water based paint if you desire a color, but prepare to wait longer for an occupant, maybe a season. They definetly don't like the fresh paint smell. Place a couple of inches of wood shavings, Deco-Bark or dry grass in botton. These birds do not 'gather' for nest building.
This style box is very heavy. Install an eyebolt dead center in the top, being careful to not let a sharp point stick down through the roof above the nest. You will use this to fasten a long rope for pulling the box high into position on your tree (maybe a helper on the ground) to pull the box up... like a pulley.
Anywhere from 10 (3m) to 100 feet (30m) high (scary apartment ledge) works for most of these birds. Hawks like it high, small owls like it medium. Flikkers like a medium high nest. Bees seem to prefer the lower to medium positions but not always predictable. My ladder only allows a 20 foot (6cm) maximum. A 'Bee Person' can help you get the Honey out from time to time, if that's what your Hawk Hive attracts.
While holding the box steady, maintain your grip on the tree or ladder, open the front door and screw the box firmly to the tree using 2 1/2 to 3 inch (6.3 to 7.6cm)screws. It helps to pre-drill the mounting holes through the back before taking it up. Use whatever is handy for your latch.
As seen in the previous 'Bee's Swarming' post I bend a stiff wire into a 2" (5cm) 'L', drill a tight hole into the side panel near the bottom, pound the 'L' into the hole and pivot it to form a latch. One Screw can also be used to hold it shut, but remember to take a screwdriver when you climb annually to clean out the box.
A tall dead snag is favored, but any tree or high mounting position seems to work if the birds and their Prey are in the area. Fasten it to the side of the tree where shade is present. The sun can overheat the box in the Southwest where I live. That is why ventilation is important.
This is the finished 'Hawk Hive' Owl, Northern Flikker Bee, Squirrel (destructive to any box) House number IV. :>)
Saturday morning at son's house. His Daughter's Delta scroll saw, enlarged the entrance hole to 3 inches (7.6cm) He did the climbing of the tall ladder. I pulled the rope he tossed over a higher branch. The chickens were happily pecking at bugs in the grass around us, while We pulled the heavy new box into position so he could screw and wire it firmly to the tree trunk.
This is the new oversized house mounted over 24 feet (7.3m) high in the big Elm tree. Hopefully a new Hawk 'American Kestrel' or Western Screech Owl family will find it satisfactory. Maybe the Bees will stay in their other 'Hawk Hive' several trees away? The apparent solution, as previously mentioned, is to coat the inside of the roof with melted parafin or bar soap to inhibit the attachment of their 'comb'. Looks like the Chickens are happy with their newly installed roost. Their cage is not far from the tree with the 'Hawk Hive'. Don't worry, the Hawk house is not for 'Chicken' Hawks (Cooper's Hawk). They build big nests:>)
You can always just order one smaller and lighter but it is not as satisfying as a 'build it yourself'. I MAY even cut all of the panels and ship them for assembly, with screws...for a fee. :>)