Re: Eastern bluebirds in the Fall
I'd empty them and see if they move in for the winter.
I C&P'd the extract below....seems like it is common for them to look for winter digs.
My understanding is that your breeding pairs probably migrate south, and some of the Northern stock would then migrate in to your area for the winter.
Cover ? Winter
In areas where bluebirds winter, habitat
requirements differ little from nesting
or summer cover types. Woodland
edges, fence rows, open fields, mowed
yards, cemeteries, and farmlands
provide adequate winter cover needs
when mixed with snags, open grassy
areas, and wild fruit-bearing trees and
shrubs. Nest boxes can provide roosting
cover for bluebirds in winter
months as well. Due to the variability
in climates between the cooler, northern
reaches and warmer, southern
reaches of the bluebird?s range, available
food sources may differ but
habitat requirements remain constant.
The year-round availability of insects
determines where bluebirds winter.
Nest Box Design. ? Nest boxes should be
constructed of a weather-resistant wood; cedar is often
recommended. The wood can be painted or stained,
but only on the outside surface. The entrance hole
should be 1.5 inches in diameter. Numerous nest box
designs have been used with success; figure 1 provides
one example. A good method of assisting fledglings in
their climb from the nest to the entrance hole is to
roughen up the inside wood surface under the hole with
a chisel. The lid or one side of the box should open to
facilitate monitoring and cleaning. Three or four
1/4 inch drain holes should be drilled into the box
bottom. Ventilation and shade requirements are met by
overhanging roofs and construction designs described
in figure 1. All bluebird boxes should be fitted with a
galvanized sheet metal predator guard (see fig. 2). The
predator guard should be placed on the pole 6 to 12
inches below the bottom of the box. Also, to help deter
predation, an even coating of non-drying crankcase
grease or carnauba wax can be applied to the pole from
the ground to six inches below the box.
