Printable View
One of my daughter's friends has ask be to built her some bird, owl and bat houses & nest. I have never done anything for bats before but got plans that recommended using exterior plywood and coloring the side dark but not using paint. I was thinking of using rough cedar plank sold for fencing and using some Ritz dye to color the interior. Any guidance would be appreciated.
She has a female horned owl with chicks(?) and wants to built her a nest. Again suggestion are appreciated.
Criteria For Successful Bat Houses
1. Design
All bat houses should be at least 2 feet tall (61 cm), have chambers at least 14 inches (36 cm) wide, and have a landing area extending below the entrance at least 3 to 6 inches (8 to 15 cm) (some houses feature recessed partitions that offer landing space inside). Taller and wider houses are even better. Rocket boxes should be at least 3 feet (91 cm) tall and have at least 12 inches (30 cm) of linear roost space. Most bat houses have one to four roosting chambers—the more the better. Roost partitions should be carefully spaced 3/4 to 1 inch (19 to 25 mm) apart. All partitions and landing areas should be roughened. Wood surfaces can be scratched or grooved horizontally, at roughly 1/4- to 1/2-inch (6 to 13 mm) intervals, or covered with durable square, plastic mesh [1/8- or 1/4-inch (3 to 6 mm) mesh, available from companies such as Internet, Inc. at 1-800-328-8456]. Include vents approximately 6 inches (15 cm) from the bottom of all houses 24 to 32 inches (61 to 81 cm) tall where average July high temperatures are 85?F (30?C) or above. Front vents are as long as a house is wide; side vents 6 inches (15 cm) tall by 1/2 inch (13 mm) wide. Houses 36 inches (91 cm) or taller should have vents approximately 10 to 12 inches (25 to 30 cm) from the bottom.
2. Construction
For wooden houses, a combination of exterior plywood (ACX, BCX or T1-11 grade) and cedar is best. Plywood for bat house exteriors should be 1/2-inch (13 mm) thick or greater and have at least four plies. Do not use pressure-treated wood. Any screws, hardware or staples used must be exterior grade (galvanized, coated, stainless etc.). To increase longevity, use screws rather than nails. Caulk all seams, especially around the roof. Alternative materials, such as plastic or fiber-cement board, may last longer and require less maintenance.
3. Wood Treatment
For the exterior, apply three coats of exterior grade, water-based paint or stain. Available observations suggest that color should be black where average high temperatures in July are less than 85?F (30?C), dark colors (such as dark brown or dark gray) where they are 85? to 95?F (30? to 35?C), medium colors where they are 95? to 100?F (35? to 38?C) and white or light colors where they exceed 100?F (38?C). Much depends upon amount of sun exposure; adjust to darker colors for less sun. For the interior, use two coats dark, exterior grade, water-based stain. Apply stain after creating scratches or grooves, or prior to stapling plastic mesh. Paint fills grooves, making them unusable.
4. Sun Exposure
Houses where high temperatures in July average 80?F (27?C) or less should receive at least 10 hours of sun; more is better. At least six hours of direct daily sun are recommended for all bat houses where daily high temperatures in July average less than 100?F (38?C). Full, all-day sun is often successful in all but the hottest climates. To create favorable conditions for maternity colonies in summer, internal bat house temperatures should stay between 80? and 100?F (27? and 38?C) as long as possible.
5. Habitat
Most nursery colonies choose roosts within 1/4 mile (400 m) of water, preferably a river or lake. Greatest bat house success has been achieved in areas of diverse habitat, especially where there is a mixture of varied agricultural use and natural vegetation. Bat houses are most likely to succeed in regions where bats are already attempting to live in buildings.
6. Mounting
Bat houses should be mounted on buildings or poles. Houses mounted on trees or metal siding are seldom used. Wooden, brick or stone buildings with proper solar exposure are excellent choices, and locations under the eaves often are successful. Single-chamber houses work best when mounted on buildings. Mounting two bat houses back to back on poles is ideal (face one house north, the other south). Place houses 3/4 inch (19 mm) apart and cover both with a galvanized metal roof to protect the center roosting space from rain. All bat houses should be mounted at least 12 feet (4 m) above ground; 15 to 20 feet (5 to 6 m) is better. Bat houses should not be lit by bright lights.
7. Protection from Predators
Houses mounted on sides of buildings or on metal poles provide the best protection from predators. Metal predator guards may be helpful, especially on wooden poles. Bat houses may be found more quickly if located along forest or water edges where bats tend to fly; however, they should be placed at least 20 to 25 feet (6 to 8 m) from the nearest tree branches, wires or other potential perches for aerial predators.
8. Avoiding Uninvited Guests
Wasps can be a problem before bats fully occupy a house. Use of 3/4-inch (19 mm) chambers reduces wasp problems. Wasp nests should be removed in late winter or early spring before either wasps or bats return. Open-bottom houses greatly reduce problems with birds, rodents or parasites, and guano does not build up inside.
9. Timing
Bat houses can be installed at any time of the year, but are more likely to be used during their first summer if installed before the bats return in spring. When using bat houses in conjunction with excluding a colony from a building, install the bat houses at least two to six weeks before the actual eviction, if possible.
10. Importance of Local Experimentation
It is best to test for local needs before putting up more than three to six houses, especially comparing those of different darkness and sun exposure.
Ex
There are both water and alcohol based dyes made for dying wood. Woodworking supply stores such as Woodcraft or Rockler carry them in a wide array of colors.