Bird Watching: Time to start bluebirding thread number 4, 1 by 2dCousinDave

2dCousinDave wrote:
My blues have three nestings each season and she lays four eggs each time. Very predictable. Others report that their blues have larger broods.

She will begin sitting (or is it setting?) on the eggs only after the last one is laid. If she sat on them from the beginning, incubation would begin and the first one laid would be hatched four (or more) days before the last one. Since it only takes 17 days from hatching to fledglng, you can imagine what a growth advantage the first hatchling would have over his siblings. This way, they usually all hatch within hours of each other and each has a better chance to fend for himself in the nest.

For about a week before she lays the first egg, my female goes into the nestbox a dozen or more times a day, but it is usually to arrange the nest. Bluebirds make a very neat cup-shaped nest and folks who have video cams in their nestboxes report that she is very detailed in her preparation. When the male goes in it is usually to check on her progress. A NABS approved birdhouse is only about four inches wide and four inches deep, so there isn't a lot of room in there for the both of them. When one goes in the other usually comes right out. When she begins incubation, he will bring her food, especially if it is cold outside and she is reluctant to leave the nest.

I leave the nestbox up year 'round but as far as I know, my birds have never spent the night in the nestbox, but I have heard of many birds that do, especially on those cold nights up north. They report that as many as half a dozen will crowd in together to escape the cold.

When the birds hatch, the female will spend the next several nights on the nest, brooding. She will spread her wings and honker down close to the babies to keep them warm. They are born with little or no fuzz on their bodies. After about a week she will no longer stay overnight in the nestbox.

My female laid her first egg at 9:00 a.m, day before yesterday. I put the sparrow spooker up and it obviously bothers her and she has laid the second and third eggs yesterday and today,at 10:00 a.m. She usually goes into the nest several times before she actually lays an egg. For the first egg of each brood I check each time she goes in and out of the nestbox, but after that, since she is so predictable, I just wait until about 10:00 beore I bother to look.

Bluebirds are very tolerant of humans. I check on mine about three times a day until the babies are about 12 or 13 days old. After that, iif you open the box you might cause them to prematurely fledge. I sing or whistle as I approach the nestbox and if she is in there, she will usually fly out. If you open the box and she is on the nest, just close it quickly as she may be laying an egg.

As I said, the male will usually be perched nearby and from time to time he may take food to the female in the box. He will not spend the night in the nest, even if the female does. As soon as the eggs hatch, both parents are involved in feeding the hatchlings. When they fledge, the parents take them into the woods for training. After a couple of weeks, the female will break away and build another nest (this time much quicker than the first), and the male will take over exclusive care and feeding of the fledglings. In about a week to 10 days, the fledglings will follow him to the deck and ultimately hang around the meal worm feeder. When they are about 30 days old he will stop feeding them entirely.

This is probably more information than you wanted. But it is hard for me to give short answers.

Also, I find it frustrating that with my fancy cameras I can focus in on a gnat's whisker at 20 feet, but I can't get a good in-focus macro shot of the eggs in the nestbox. The shot below was taken this morning. At least you can see that they are blue. I fully expect that she will lay one more egg tomorrow and begin incubation on Sunday.


Dave

This message was edited Mar 24, 2008 3:16 PM