Nestbox Diary - 2006

April (part 3)

Incubation

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20 April - This morning there is no doubt that incubation is underway. As I write this at 9am our female Great Tit has only been out of the box for a few minutes since dawn.

There is, however, uncertainty as to whether she laid an egg this morning. I recorded from 3am and the only sequence that came close to egg laying was this, recorded at 3.25am.

She had been lying in a 'straight out position for about five minutes with her wings slightly spread. Then her breathing seemed to become heavier, after several 'twitches' her tail was raised and her head came up. However, it didn't arch back as on previous mornings, and immediately afterwards she dived down into the nest cup before settling back to sleep.

At around 8am her partner appeared briefly at the entrance after she had responded to his call from nearby.

Then, at 8.38am he brought her some food for the first time. I look forward to many more of these visits over the next two weeks.

That was a pattern followed throughout the day. I didn't attempt to measure the time spent on the nest, but if was certainly far more than the time away. I saw four visits by the male (although it's likely there were more), and these webcam images recorded three of them.

Each time the pattern was similar, with her calling in response to his call, and then taking the food from him as soon he put just his head in through the entrance.

At several other times she called as though checking whether or not he was in earshot, before settling back down to wait.

21 April - I've looked closely at this morning's early video (from 3am onwards) and there is no sign of another egg being laid, so it looks as though that phase is over now.

Our Great Tit left the box for the first time at 6.18am and was back before 6.30am. She left again at 7.04am, just before the video tape ran out, so I don't know how soon she returned. I slept late this morning so wasn't around to change it!

When I did appear at just after 8am she was in the box, and as I walked into the room her partner was feeding her.

Fortunately, the webcam caught the moment for me. As soon as she had taken the caterpillar the male entered the box completely for just a moment as he turned and left immediately.

As I write this at 9am, the female has just returned from another trip out which lasted six minutes.

At the end of the afternoon she was out of the box for a while. I guess she must have eaten during that time, because minutes after she returned, the male turned up with food which she rejected.

He came to the entrance several times, food clearly visible, but she stayed put in the next cup and responded with an extended, squeaky call. Eventually he gave up and went away, and she settled deep down in the nest.

Both birds come to the sunflower feeder during the course of the day, but they usually prove elusive once I have my camera at the ready. Today I managed to ambush the male before he header to the feeder.

It's not obvious in this image, but the black band running down his front below the bib is broader than that of the female. Also, this individual is missing the set of tail feathers that are so obvious in the above images of his partner. That property might be to his advantage when he starts entering the box on a regular basis, assuming they haven't re-grown by then - something else to watch for!

22 April - Incubation continues, with the female going out a bit more often this morning since it has become sunny.

I have seen her partner bring food a couple of times, including this visit when he entered the box very briefly.

At this stage, entering after the food is handed over seems to be more of a necessity rather than a choice. He reaches in so far that reversing against the natural 'flow' of his feathers is not an easy option.

The female continues to bring in soft bedding to supplement the material already compressed around the nest cup.

As usual, she just dumps it around the sides ready to work into the nest later.

In anticipation of nest photographs over the next few weeks I have installed the Olympus E20 behind the glass and the black curtain, mounted on the Manfrotto arm so that the lens is poking through a hole in the curtain. I installed it yesterday evening while the female was away from the nest. It will help the Great Tit become conditioned to the presence of the lens before I actually start taking pictures. She has shown no interest in the addition so far.

When I do decide to take pictures there is no need for me to climb up to the camera at all. The camera is powered my a mains supply, a remote shutter release hangs down and the flashgun can be switched on remotely from ground level. There is a small TV linked to the cctv camera that allows me to monitor the box and choose the moment to press the shutter.

During the morning, she didn't seem at all bothered by the activity in the garden, including me making several visits to immediately in front of the box. That, along with the bright conditions persuaded me to go ahead with a single photograph to show her incubating her eggs using the flashgun that is already in place. Before taking the picture the picture, I pressed the camera shutter several times with the flashgun turned off to test her reactions. She showed no reaction at all to the slight noise made by the camera, so I switched on the flash and went ahead with the shot.

The picture, taken from a slightly lower angle than the webcam images, shows just how deep down into the nest cup the female gets when incubating.

I was reassured by her reaction to the flash. There was hardly any response at all, and she carried on sitting on the eggs exactly as before, and remained for another half an hour before taking one of her trips out.

23 April - On a wet morning, with the temperature pegged at 13C, incubation continues without any problems.

The female spends most of her time snuggled down on the eggs, but there are, as these cctv images show,  occasional interruptions, not only to pop out, but to preen and stand at the side of the nest, presumable to 'have a stretch'!

This sequence, recorded in the middle of the day shows how the male does his 'u-turn' after he has passed some food to his partner.

The female appears to be spending more time in the box today as the rain continues to fall and the temperature remains appreciably lower than yesterday.

I took advantage of one of her trips out to take another look (via the mirror) at the eggs, and this time I used the Canon 20D to get a higher resolution image.

Again, I could only see six eggs, and their arrangement at the bottom of the nest cup suggests to me that there may be just seven in total, which is a small clutch for Great Tits.

I have reduced the interval between images on the webcam to four seconds.

24 April - This cctv camera image from around 8.15am sums up the first part of the day quite nicely. Outside it is extremely dull and damp, and the best place to be is in bed!

In fact, for the female it is business as usual, a mixture of sitting, occasional turning of eggs, preening, and trips out. However, since I started watching at around 7am I have not yet seen her partner.

At 8.30am she left on one of her 'comfort breaks', returning after about 12 minutes.

This visit by the male happened just before 11am. He fed her and then perched in the entrance to peck at the wood for a while, or at least, until his partner seemed to get fed up and pecked at his tail.

The image suggests that his tail seems to have grown a bit since I last photographed him.

25 April - I have been out for most of the day, and haven't been monitoring the box, but tonight the female is safely asleep in the nest.

26 April - Another day spent away from the garden, but during which incubation has continued with out and disasters.

This webcam shows her at about 5.45pm.

I returned home soon after 5.30pm and saw that the female was away from the nest, and the nest cup looked quite clear of bedding. I took the opportunity to look into the nest cup via the mirror and had a pleasant surprise.

At first glance I could see seven eggs, as this photograph confirms, but, although it wasn't possible to photograph it, adjusting the mirror slightly revealed egg number 8 - perhaps laid on the 20th (entry at the top of this page).

It was hidden just out of shot at the bottom of the image.

27 April - A bright morning and a near disaster. While still in my dressing gown I popped down to the box to look again at the eggs while the nestbox was empty. I was only able to see six of them, and as I descended the steps the shutter remote cable for the Olympus caught on my clothing and broke off at the camera connection - I'll have to do a bit of micro-surgery in an attempt to repair it! - Surgery completed successfully by noon, with patient back at work.

Later in the morning we watched as the male came into the box to feed his partner. This is the first time we've seen him do this, although it's possible he had already been doing the same during the last two days.

He entered and handed over the food, and as soon as the female ate it she settled back into the nest cup. He returned to the entrance where he started pecking at the wood.

The female didn't seem to appreciate this, taking several pecks and tugs at his tail feathers before he finally departed.

No doubt a situation where the expression 'hen-pecked' shows its true meaning!

Further feeds during the day confirmed that entering the box has become a normal routine for the male, and while he stopped several times to peck at the entrance, his partner was more tolerant than this morning, only pecking him after a particularly prolonged woodwork session.

28 April - This morning, breakfast and the first woodwork session came early for the Great Tits.

I had made myself a cup of tea and settled down just in time to see the lights come on in the box at 6.45am. The female was deep in the nest cup and within a minute or two the male was at the entrance. He came in and, with one foot resting on his partner's back, the food was given to her.

He then started to peck the entrance, and continued to do so for over ten minutes. He was so enthusiastic about the task that at one stage Sheila (still in bed until then) went over the window to investigate where the Woodpecker was at work!

Sheila has since reminded me that she also heard the same 'woodpecker' early yesterday morning.

The female left the nest for a short time after seven o'clock and the male appeared again at 7.30am with a much larger larva for his partner, and this time spent just a minute or so pecking at the woodwork.

In the images above, and again it this one from just after 9am, the male has a foot across the rear of his partner's back, and I've seen it happen on a couple of other occasions.

Is it just a convenient place to put his foot, or does it have a more important part in the bonding between the pair?

30 April - As we come to the end of the month we are also getting close to the time when the eggs hatch, only a couple of days away now. This weekend, while things are quiet in the box I have been doing other things and so have only been watching the cctv images some of the time.

This evening we were treated to a longer than usual sequence when the male brought in a large caterpillar at just before 6pm.

As his partner struggled to eat the caterpillar, the male went to the entrance and started pecking at the wood. However, instead of leaving he came back in and stayed for a while, peering into a corner despite getting a peck. Eventually he returned to the entrance and pecked again.

Again, he didn't leave but came to the back of the nest again for another inspection before finally heading out.

I don't know what attracted his interest. I suspect that he may have been looking at his reflection in the glass, but at no time did he peck at it as I would have expected, and he has shown no such interest at other times, even when brighter daylight would have produced clearer reflections.

2006 Nestbox Diary Index. .  .....  .Nest building.......

Egg Laying.  ..............Next chapter (May)