Male feeding the female

While the female is incubating the eggs, the male brings her some food every now and then.

Feeding, 17 April 2014 16:22

However, it is not enough so the female still has to leave the nest regularly to find some food herself.

12 eggs now, clutch probably complete

As I expected, this morning there was one more egg: a total of twelve now!

The bird is spending a lot of time on the eggs so I think the clutch is complete now and incubating has started. We should expect the eggs to hatch in about 14 days from now.

New nest for 2014!

I've just returned to the UK after 6 weeks of trekking in the Himalaya's (awesome!). This morning I switched on the nest camera and guess what? There is a blue tit nest with 11 eggs!

I think this is quite early in the year and the clutch size of 11 eggs is big (according to BTO Birdfacts 9.06 ± 2.14 is the normal range). And it appears the bird hasn't started incubating yet so I wouldn't be surprised if there is one more egg by tomorrow morning!

It's good for me that the incubation hasn't started yet because from the start of incubation I can estimate when the eggs will hatch and I'm more likely to catch that event live. Incubation time according to BTO: 13.88 ± 1.31 days.

Nest building started...and aborted?

About two weeks ago the blue tits quite suddenly stopped visiting my birdbox and I soon found out why: they were apparently building a nest in the neighbour’s garden! I saw the female collecting nest material and bringing it to the other garden, so I had already given up hope for this year.

However, this morning suddenly nest building started in my box! The female was bringing in materials and I saw the male being excited and jumping around the birdbox too. 

Nest building has started, 3 May 2013 8:56am

Contrary to last year when the nest was being build quickly and without hesitation, this time it feels like the bird is still in the process of evaluating the box. When she brings in material she spends a lot of time looking around (not in the video). 

But then something remarkable happened. While the nest builder (female) was inside the box, another blue tit appeared in the opening of the box but (at first) did not enter. To me it looked like another female because she was together with another bird that behaved like a male. Actually, I think this is the same male that was with the nest building female.

The bird in the box started to display what I think is a threatening posture towards the bird that is hanging in the opening. I have captured this in the video below. Eventually the bird enters and the nest builder flies out. Since then the nest building has stopped and I have not seen this bird back in the box.

Is this a threatening posture against the bird that is hanging in the opening? 3 May 2013 9:28am

I’m quite puzzled by this situation because there appeared to be two females and one male. The male was not defending its territory against the nest builder. On the contrary it seemed! But then this female gets booted out of the box by another female that has no interest in the box herself? It is hard to tell the individual birds apart, but I think that the bird that chased the nestbuilder off was the female that is nesting in my neighbour’s garden.

The nest building female has not been back since, but the male now keeps checking the box very regularly during the day, including pecking around the opening as if he is evaluating it as a nest site. This is a big difference from the past few weeks because the birds seemed to have lost all interest in my birdbox.

Regular visits

The box is visited by the same pair of blue tits a few times every day. The pattern is usually the same: the male enters and calls the female. Sometime later the female enters and the male flies out at the same time. 

Male calling female into the box, 25 March 2013 9:00am

Outside the box, I have seen the blue tit chasing off a (much bigger) great tit when it was in a bush near the birdbox. The great tit didn’t confront the angry blue tit and just flew off. Although the great tit would likely win any fight, apparently it doesn’t think it was worth it…

Note1:  after I have made the box opening narrower, great tits cannot enter anymore. I have seen them pecking at the opening trying to enlarge it but of course without success (metal).

Note2: I’m now again running the camera regularly with a higher framerate and with sound to capture the calls. The downside of this is that I cannot use motion detection so it can only be done when I’m present.

Evaluating the bird box

Today I captured the video below. The male blue tit calls the female into the box (the video has no sound but you can see his his bill moving). The female then enters and inspects the box. You can see her flapping her wings, indicating she is looking for a place to build a nest. Later on she will use these same moves to spread out the nest materials. Although there is no material in the box yet (and I’m not expecting it for another month), this nest building reflex is already there!

Female evaluating the bird box, 15 March 2013, 8:23am

Catching an Insect

Since I always see the same male blue tit around the birdbox (sometimes together with a female), I’m pretty confident that they will attempt to nest here in the spring. To improve the safety for them I have now made the opening of the box more narrow (25mm instead of 28mm). This means that great tits cannot enter anymore. This improves the safety for the blue tits, but obviously I now completely rely on them for a nest.

I recently captured this footage of the male catching an insect inside the box.

This is the only male blue tit that I see in and around the box, so I think he owns it now :). In this short video you can see him catch an insect (5 March 2013, 12:50pm)

On the same day I captured this footage of what I think is the female. There appears to be a first hint of the flapping wings thing that the females do when they evaluate nest sites in the spring.

First hint of wing-flapping while evaluating nest site? (5 March 2013, 9:58am)