In my post earlier today, I commented that I saw bird houses made of composite material (such as Trex) and was curious as to their thermal properties, since climate change is making many traditional house designs dangerous due to higher average temperatures.
After reading the articles below, it sounds as though composite lumber heats up faster, retains heat longer, and also loses heat faster than traditional, unfinished softwood.
Even if the heat differential won't kill the birds, it seems to have greater potential to stunt nestling growth and to increase dehydration risk.
I didn't find any articles from birding groups about them being dangerous, but it seems very recent that they have been taking note of increased nest box death, so it may not have much research into it yet.
While the initial thought was something like this should last longer, stay prettier, and be easy to maintain sounded great, seeing it both holds more heat during the day and loses more at night sounds like a negative in both directions. It may be best to stick with unfinished wood.
I'm curious to hear anyone's thoughts on this. Don't take my hour of research as gospel. It just came up in conversation and I haven't seen this discussed.
