How does heat help?

[chickadee]

Ok I have been up all night and up early worrying about my martins. I am warm and want them to be warm. But what does providing heat for them do? Help save their energy? And what does it mean when they start to communal roost?

[CraigMo.]

You are right. It takes energy to keep warm. Communal roosting is there way of grouping up to stay warm with each other's body heat. They say so many martins have gotten in one gourd and then one will get trapped in entrance and die which then could block the other pms way out and they all die :( . But most landlords catch this and remove the dead bird.

[Barry Wallace]

Chickadee, your martins can survive the cold but they can't survive without food. Last spring we had three straight weeks of no feeding weather, they survived three snow storms and many nights in the single digits. I had around 50 birds back at that time and did not lose any but they were well fed.