Blue tit nest box - what's happening?

dc1500 · #1 (**permalink**) 28-04-2011, 09:44 AM

Last year I had a camera next box and watched the progress from nest building through to successfully hatching seven of the ten eggs with at least 5 making it to the outside world.
Things appeared to be following the same pattern this year albeit about a week earlier. Ten eggs were laid but there seemed a reluctance to incubate with not much activity of the parents noted in the daytime. One of the parents is still sitting on the eggs but it appears only at night. The nest looks untidy and the number has either reduced to three or they have become obscured. Location against the house wall makes predation unlikely? What is going on?

Elizabeth B · #2 (**permalink**) 28-04-2011, 10:50 AM

When was the last egg laid, and do you think incubation has started? The female can sit/roost on the eggs without incubating them - her posture is quite different in the two situations.

Roosting

Incubating. At this stage she will have developed a brood patch, where her breast has no feathers and the warmth of her body affects the eggs. She seems to arch her back to expose the bare skin.

Eggs can remain viable for some time as long as incubation hasn't started. In 2002 there was a fight in one of our boxes after 8 eggs had been laid, and the box was abandoned for nearly three weeks, then a female came in with more nesting material and laid 3 more eggs. Six eggs hatched so some must have been from the original clutch.

RKB · #3 (**permalink**) 28-04-2011, 12:11 PM

As said, tits will often delay incubation, and they're doing it a lot this year. They might delay for a week or two. During this time they'll usually cover the eggs with nest lining, so they're less visible.

Blue Tits are also doing a lot of partial incubation this year, so your bird might be incubating at night. Normally this will lead to a lot of dead eggs.

When laying, or delaying incubation, there is very little activity during the day. They just check it occasionally.

dc1500 · #4 (**permalink**) 28-04-2011, 06:58 PM

Thank you for these knowledgeable replies - it looks like I shouldn't give up on them just yet.

dc1500 · #5 (**permalink**) 02-05-2011, 02:56 PM

Latest is that there are 11 eggs visible but only sitting at night and neither around during the day.
Dave

Elizabeth B · #6 (**permalink**) 02-05-2011, 03:34 PM

It seems that incubation hasn't started yet!

If you want to see some action right now, go to Web Viewer (Box 2 in) on our website. However, it's rather slow to load at the moment - I think there are lots of people watching.

dc1500 · #7 (**permalink**) 05-05-2011, 11:50 AM

Well yesterday more eggs were laid bringing the total to 14!!
There was more activity during the day yesterday and everything was neat and tidy and the mother appeared to be incubating overnight. Looked on the camera this morning and every single egg gone!! Now the box has a standard size hole and is flat against the house brick wall 9ft up. I can't see a way even a mouse could have got in there so they must have been removed by the blue tits.

witham · #8 (**permalink**) 05-05-2011, 01:40 PM

enjoy watching them while you can, my son has a camera box and had been watching blue tits going through the process of nest building etc then they abandoned the nest as it was taken over by bees

RKB · #9 (**permalink**) 05-05-2011, 02:44 PM

Quote:

Originally Posted by dc1500

Well yesterday more eggs were laid bringing the total to 14!!
There was more activity during the day yesterday and everything was neat and tidy and the mother appeared to be incubating overnight. Looked on the camera this morning and every single egg gone!! Now the box has a standard size hole and is flat against the house brick wall 9ft up. I can't see a way even a mouse could have got in there so they must have been removed by the blue tits.

They usually cover them in nest lining when they leave the nest. So they might still be there. A mouse or weasel could easily get into that box, but they would eat the eggs in situ, so there would be lots of fragments.

dc1500 · #10 (**permalink**) 06-05-2011, 08:33 AM

Well you are absolutely right! Despite my wife's protestations about them definitely vanishing they have re-appeared and now there are 16 !! This time though the mother is incubating I'm sure as she is there in the day and the male is occasionally feeding her. She has also left the box briefly this morning and returned. I suspect there will be a lot of sterile eggs but things look more promising.