Hi, Ann. I leave all my nestboxes up over the winter months--the ones on the trails and those here at home. I know that some of them are used for roosting as there are plenty of droppings to clean out! Check out the link below for ideas about winterizing nestboxes or building a roosting box.
By the way, where are you in Maryland?
Kathy

Here is a link that might be useful: Fall and Winter Bluebirding

THANK YOU! Very helpful info!

I'm in Arnold (Anne Arundel county.) My yard backs up to the B&A trail, which is the key to my bluebird experiences.

Where are you?

Ann

Kathy and Ann, Linda here from Carroll County, MD.

I'm a hoarder and knew I would have a purpose for the sheets of foam that came in a mail order. It's not styro, but like the noodles folks use in their swimming pools. Cut off the corners and stuffed in the bottom. Can also stuff in the airvents to make the boxes warmer. This is what I have done at my sister's house because her blues are shopping for their winter homes. It'll be easy for her to remove the plugs in the spring without disturbing any blues that may chose to permanently nest there.

For me, I built my own roosting boxes with a hinged roof. One very large box and one small one for the non blues. These have the holes at the bottom and I drilled holes on the inside to insert dowel rod perches. I'm hoping the dees and TUTIs take to these.
The box I built for the blues looks like a regular NABS except its very tall and installed on a 10' galvanized pipe. I drilled a 2" entrance hole at the top. Have read that this is what they prefer to prevent wear and tear on the feathers.

Since this is my first year for this, time will tell.

Linda

That noodle stuff sounds perfect! I was thinking I could incorporate some sort of insulation (like Thinsulate!) into the walls, but then I think it would have to be double layer walls. My carpentry skills are limited...I think this could be disastrous! LOL!

You mentioned a hole at the top of your box---I thought it should be at the bottom, since heat rises.

I have some sign posts in my yard, about 10' tall. I can put the box on that, but can't really put a baffle on it. If I use a metal guard on the hole, do you think that'd be adequate for them? No snakes around in winter...

I think of large boxes as drafty, yet I've heard about large boxes elsewhere. What's the theory? Is that what the birds prefer? I can't imagine it actually fills up with birds!!

So many options...

Ann

Ann, my family resided in Frederick for over 20 years but moved in 2006. We now live in Washington County, just west of Brunswick, on 3 acres. We're just across the river from Harper's Ferry and truly love it here. I have 5 nestboxes here at our home but monitor 30 nestboxes in Frederick County where I also happen to work.

Linda, I've also read of putting the entrance hole at the bottom, since heat rises and would escape if the hole was at the top. I've never tried using an actual roosting box. Did you use plans to make yours? Keep us posted on how it works. I'm all for something that makes survival easier for our blues.
Kathy

Most winter roosting boxes do have the hole at the bottom because the huddled birds generate enough heat even in the coldest weather to pull them through. Supposedly, blues do not roost but pile up on the floor to keep warm, so putting the hole at the bottom won't work. Any boxes I build in the future will have a very large roof overhang and face away from prevailing winds. I may paint the roofs black for more solar gain.

I got various plans off of the internet but hesitate to share them until I'm sure they work. Materials were rather expensive and I put in quite a few hours (and nervous sweat) building them-I'm no finish carpenter and these boxes need to built tight.

I'll keep you informed of what works but for the blues alone, you could just tape over or plug the openings in a regular NABS.

Most predators should be in hibernation but since so many adult birds could be lost, I'll watch these boxes very carefully.

Kathy-I have property in Allegany. Even though Green Ridge surrounds it, I'll put up a box there also. Hopefully, the local black bears will be hibernating all winter and leave my birds and feeders alone.

Linda,

I'm curious as to where you heard they huddle on the floor instead or moving to the top, since all roosting boxes I've seen described had the holes at the bottom. If you found better info, I want to read it!! It seems that enough people have nest cams that good information should be out there!

Thanks a lot!!

Ann

I found the info!! http://www.bestofbbml.audubon-omaha.org/roost.htm

This is profoundly helpful, and my roost box hole won't be at the bottom!

Thanks Linda for calling my attention to this!

This is why I love Gardenweb so much!!

Ann

Got a lot of my info from Keith Kridler. He states observing over a dozen blues at the bottom of a regular nest box-a pair's entire seasons offspring.

A regular box with a removeable front is probably the best bet. Could just flip the front around and remove the plugs from the openings after cold weather. That's why I use decking screws rather than nails.

Have also read that may be possible to make the box too weather tight and block out light. Birds may be hesitant to enter a box where they can't see possible predators inside.

My current plan is to make a Fawzi Emad roosting box (http://audubon-omaha.org/bbbox/nestbox/fawzirb.htm) Modifications I'm considering are the tunnel-style predator guards... (http://www.backyardbird.com/birdguardtree.html or http://www.bluebirdsforever.com/baffles.html)

I think the tunnels will cut way down on drafts. But I read somewhere that they don't like DARK boxes, so I'm thinking about a window. I found this box (http://www.knwoodworks.com/images/roosthouse.gif) but it doesn't seem to be available yet...but the window idea is apparently not new.

Unless some other ideas come up soon, I think I'm ready to roll. Ready to do some amateur wood-working; hope I don't lose any fingers!!

Ann

Be brave, Ann. Start out slow, your skills WILL improve. Take your time-don't rush. Wear safety glasses and watch those fingers. You won't stop at birdhouses.

I have projects all over the garage. Next projects are bat houses and some Gilbertson style PVC houses to hand out to my neighbors. It's addictive.

Thanks Mulchmamma! I'm pretty psyched!

But, I have one more question regarding my roosting house window. In the winter in my house, water condenses on my windows and pools on the window sill. (old windows) Will this happen in the bird house? Or, since they're not washing dishes and cooking in there, will the humidity not be high enough to cause this condensation? I'm trying to think it through...but I just don't know. I would imagine their breath and droppings produce some humidity.

Any thoughts would be much appreciated!

Ann

There shouldn't be enough of a temp difference for condensation to form. Just getting the inside temps raised 10-20 degrees can reduce a bird's energy requirements so that it can survive through the coldest nights or when food is scarce.

Hopefully, we will have success stories to share this spring. I will try to keep a record book of what birds are using each particular box.