Sometimes the weather in the Midwest is not easy to deal with, especially those sudden temperature changes.
Think of it like no screens to keep bugs out, no heating on cold nights, and no air conditioning when the temperature is over 90 degrees.
That's what the Blue Jays face in their stays in Minnesota and Wisconsin. Nest Boxes We provide bluebirds for nesting, egg laying, hatching and feathering the young are usually wooden boxes, no heat, only air ventilation, usually no screens in any ventilation openings to keep black flies in.
Lev Marks, a member of the Bryce Prairie Conservancy, and several other members and volunteers continued the experiment to identify the best robins in the house.
Marks solved the problem of black flies out in early summer by closing the vents, which, on 100-degree days, can be fatal to young birds. Sometimes even before that, there's a night, below freezing, just the first clutch hit.
Mark, Fred Craigof, Bryce Prairie Conservancy, and Cindy Koperskiwith Wisconsin Nature studied some well-designed experiments through the last year. They measured the air temperature inside various bluebird nest boxes, some modified to provide shade and others to provide ventilation or no ventilation.
Hourly air temperature in 10 houses is recorded using HOBO loggers UA-002-64, UA-002-08, UA-001-64, UA-001-08. No nesting birds are allowed in these houses. They do this by placing screens in oval openings.
Curtain panels were installed on several houses to divert sunlight.
After examining the data from these experiments, I believe he is headed in the right direction.
"I'm building my house now as a convertible house," he said. "In the spring, the vents are closed, except for the oval openings through which the birds get in. Then, in the summer, the house is vented, if necessary."
Using screws, not nails, attach the two side panels to the front of each house. There are four screws on the left side panel. There are only two screws on the right side, allowing the panel to be opened for cleaning and inspection.
"In the spring, the two side panels go all the way to the roof, leaving no room for ventilation," said. "It keeps the house warm and keeps the black flies out."
If it gets too hot for the second or third bit of nesting in the summer, the screws holding the panel can be removed, and a half inch of the panel slides off, creating a vent and replacing it with a bit lower screw.
"I used the drill to set the screws lower, so I could do all the work in the field without removing the box from the post and without any danger of putting the new screw holes in the board," says. "Adjustments can be performed even with eggs or baby bluebirds in the nest."
The markings indicate that, in general, it is considered successful if 50 percent of the birds survive.
"If we could get to 75 percent, just by manipulating the nest boxes a bit, that would be a great improvement," he said.
To reduce extreme temperatures, Mark's Club makes all the houses they sell use 7/8-inch cedar, not ½-inch plywood. This provides better insulation and heat and cold.
"I don't recommend painting houses," said. "Painting destroys the wood's ability to breathe. If you use black paint, the house will absorb more heat in the summer. Cedar will last 15 to 20 years without paint, so why paint them?"
Hundreds of houses that have been marked have been inspected and cleaned before it is recommended that everyone do the same with the birds' nesting materials to start assembling.
