Mrs. Bluebird has definitely started incubating her four eggs. Thursday, she sat on them most of the morning before spending most of the afternoon out of the box. She stayed in the box Thursday night, sat on the eggs Friday and again spent the night. The book says it takes 11 to 19 days for the eggs to hatch. Let's say she started Thursday, that means they should hatch sometime between May 2 and May 10. Here's a good look at her sitting on her eggs. About 11:00, you can see her turn the eggs. All birds turn their eggs while incubating them. Theories as to why include, rotating the egg helps deliver albumen - the 'white' of the egg that is protein - to the chick - the 'yolk' and that turning the egg helps warm the egg evenly and and prevents the egg's membrane from sticking to the shell.
I'm still working on a work around for our chickadee box cam that doesn't want to let us record long clips. The camera's default is to record a 12-second clip when it detects motion, with a five minute interval before it will record again. We're getting those clips, the videos below show several 12-second clips merged.
The chickadees are still interested in the southern box, the one the aren't building their nest in. They visit that almost as often as the box where they're building. They've even brought in some moss. Not sure if they're preparing a fallback position in case the first box doesn't work out, or maybe trying to discourage other birds from claiming the box.
And, in the box they're building their nest, we see a starling poke its head in with some moss. The size of the entrance hole should keep the starlings out. Then, we see a couple clips of Mrs. Chickadee bringing in more moss and sort things out.
It takes several minutes for the video to process after I upload it. If the video won't play for you, please check back in a few minutes.
We're watching eastern bluebirds in West Newbury, VT and black-capped chickadees in Piermont, NH, inside specially built nesting boxes with cameras installed to allow us to watch the birds without disturbing them.