Biology Reference
In-Depth Information
excessivelyhotorcold.Andmanyhouseshaveinappropriateholesizesforthebirdsthey
are intended for. When a wren or chickadee house has a hole larger than 1 1/8 inch (2.9
cm),HouseSparrowscanenterandkillthebabies.Whenabluebirdboxhasaholelarger
than 1 9/16 inch (3.9 cm), starlings can get in and kill them.
If the wood inside the box is too smooth below the entry hole, young bluebirds, duck-
lings, and other baby birds often cannot get the traction they need to get out of the box.
Rough cut plywood is a good choice, or you can score the inside or add rough material
below the hole.
Many people like the looks of a bird house with a little perch below the entrance hole.
But birds accustomed to natural cavities and woodpecker holes don't need that perch,
which is an open invitation to House Sparrows. If you buy a birdhouse that has a dowel
or other perch below the entrance, break or cut it off.
Birds don't care about adorable designs. Keep designer birdhouses indoors, and set
outbirdhousesconformingtoplansproducedbyauthoritativesourcessuchastheCornell
Lab of Ornithology
(
www.nestwatch.org
)
, state departments of natural resources or con-
servation, and organizations such as Audubon and the National Wildlife Federation.
Many birds never enter cavities or birdhouses — only a relatively small number of
species do nest in birdhouses. The ones people are usually most interested in providing
housing for include:
American Kestrel (nest box)
American Robin (nest platform)
Barred Owl (nest box with very large entrance)
Bluebirds (nest box)
Chickadees (nest box or tube)
Common Loon (nest platforms)
Eastern Phoebe (nest platform)
Flycatchers, Ash-throated and Great Crested (nest box)
House Wrens (nest box or tube nest)
Oak and Tufted titmice (nest box)
Osprey (nest platform)
Peregrine Falcon (gravel-covered ledge or open box)
Prothonotary Warbler (nest box)
Purple Martin (gourds or nest box with multiple compartments)
Screech owls (nest box — same size as for Wood Ducks)
