The Bird Box Diary 2004

The Chicks' early development
- May 2004

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3 May - A miserably wet morning, although as I write this at 3pm there has been some sunshine.

Despite the dampness, the morning's first trip out took place at 5.35am, after mum had spent time inspecting her offspring.





It was only a couple of minutes before the first food was brought in. Between this feed and 2pm there were a further 89 food items brought in by the parents. In the 2 hour steps from 6am to 2pm they brought in 22, 27, 24 and then 10 items (during the heaviest rain).



In contrast to yesterday, when the female took time to stand off the chicks because of warm conditions at this time, at times during the middle of the day she chose to tuck herself down in the nest cup and fluff up her downy feathers.

Up until 2pm the female has spent some 71% of her time in the nest, still close to the time she was sitting on the eggs.



The head count continues to be a problem as the chicks are never all equally hungry at any one time. When a parent arrives with a morsel, he or she usually gives a series of rapid, chirping sounds to alert the chicks that food has arrived. Sometimes the call has to be repeated several times to get the gaping response.



Here, both parents are trying to get one of the chicks to accept a grub.

It isn't just a matter of popping the grub into an open mouth. At this stage it seems that they almost have to push the food down the throat of the chick. The same grub will be put into the mouths of several chicks before one finally swallows it. Sometimes one parent will take it from the other to have another try.



This webcam image shows how much a hungry chick is already able to stretch up so that its mouth is the first to be noticed as the parent enters the box.


During the afternoon the weather was dry and much brighter. During the period from 2pm until the female 'came in for the night' at 6.51pm she spent some 191 minutes, 65% of the time, on the nest, and another 63 food items were brought in by the parents.


Even after the female had started settling down for the night in the darkened box, her partner brought in a further five larvae, the last one delivered at 7.31pm.

A total of 153 food items were brought in during the course of the day, and, if there are 8 chicks it means that each one could have been fed some 19 times, although it's possible that the female ate some of the larvae.



A late addition to the day's entry comes in the way of this defensive posture at 10.42pm. Mum had been settled, when all of a sudden she went into this defensive posture, audibly flicking out her tail feathers and her wings. I couldn't detect any sound that suggested there was anything outside the box, and there was no sign of a cat, or anything else when I went outside.

She settled back down very quickly afterwards.


4 May - Today has been another largely wet day, with a few sunny periods between heavy rain, hail and thunder. I have not yet started going through the day's video recordings so I can't give any details as yet. However I can confirm that I have seen eight chicks now, and I hope to grab an image to show them when I go through the tapes.

At just before 5pm this afternoon I decided to change the glass in the box. I took my camera with me for the first time since before the eggs were laid, and I managed to get a couple of images of some of the chicks.




Here is a close-up of just one, giving more detail of its head, eyes and beak. They are blind at this stage.



Perhaps I should explain how I was able to get these pictures without disturbing the chicks. The video camera used for the webcam is on a shelf behind the sheet of glass (that I change when dirty). The mirror that gives the view of the chicks is also on that same shelf. Behind the video camera there is a curtain of black fabric with a slit in it just big enough to push the lens of my still camera through.

A few months back, before nesting began I installed a flashgun that operates through the small translucent window that is at the top of the box. I have adapted it so that the power is provided by a battery pack at the end of a long lead so that it can be switched on remotely. Similarly there is a long connecting lead that hangs down the side of the box ready for me to connect to my camera. The flashgun has a light sensor on its front. This cannot be used in the unit's current position, so I have used a fibre optic cable to allow the sensor to measure the light coming through the glass.

The two pictures above were taken via the mirror (front mirrored glass, not usual domestic mirror which causes reflection problems).

After all that technical stuff, it means that at no time is the box opened, or the nest disturbed when I take photographs. It is a technique that I have found worked well in the past when photographing the Blue Tits. At no time do the adults see me during photographic sessions, and by using a digital camera the birds are not disturbed by the sound of a shutter and film winder.

Just after I had taken the chick photographs the mum returned. As this was the first time that I had been present as she came into the box I didn't take a picture after she had fed the chicks and was (I think) dealing with a faecal sac.

She did not respond at all to the flash going off, and neither did she when I took a second photograph. Over the next few days I hope to spend a few sessions in the box watching and, hopefully getting a few more images of the family at this early stage.


I don't think I'm going to be able to spend time this evening getting details of today's progress but it didn't take long to come up with photographic confirmation of the eight chicks.

Mum got up and left the box at 5.20am and within moments there were eight hungry gapes to be seen in the mirror, with seven of them appearing in the main image (centre picture). The first food arrived a couple of minutes later.



Tonight's last feed came, courtesy of the male at 7.38pm, long after his partner had retired for the night.




5 May - Two more chick photographs. I hope to include daily pictures like these from now on.

The first group picture shows clearly the external details of the ear on two of the chicks. These will be completely hidden by the bird's feathers.

You can also see the band of dark spots over the top of the head that mark the positions of the developing feathers.



This second image of the chicks' gapes shows the bright 'target' offered by the chick when they think food is arriving (in this case when an adult was entering the box).

The inside of the right-hand mouth shows some details, including a serrated ridge on the roof of the mouth. I didn't know about these before, and I suspect they act as a 'non-return mechanism. Perhaps they catch onto, or scrape bits off the larvae as the parents push a caterpillar or other larva into the mouth.

I'm hoping that someone with more knowledge can enlighten me on this one. Are these same structures still present in the adult bird?

Just a few details from today's activities -

Mum left the box earlier than ever this morning, at 5.08am, taking with her a faecal sac! She was back in a few minutes later and settled down again until she left again at 5.28am. For the next 49 minutes the chicks had to wait, often with gaping mouths, until she returned with a large caterpillar at 5.47am, which was passed around the brood much in the way described above.

In the twelve hours from 5.08am to 5.08pm food was brought into the box a total of 127 times. Mum spent some 336 minutes in the box ( about 44% of the day - much less than on previous days) in periods from 1 to 29 minutes, although the average stay was around 10 minutes.


This family shot shows the parents and a trio of hungry chicks. Often, when the female is in the nest and her partner brings in food, she leaves almost straight away after him.



During the evening the female spent spent just 39 minutes in the box between 5.13pm  and when it looked as though she was in for the night at 6.48pm (38%).


During that time there were 27 more food deliveries, including this large caterpillar brought in by dad.

He was in the box for the best part of three minutes as he tried to get it down the throats of the chicks. In the top-centre image you can see him actually pulling it out of one mouth!


Then she settled into the nest cup, fairly restlessly until; the male appeared with another feed at 7.59pm.


They both left the box and mum didn't return until 8.11pm, when she finally settled for the night.

Click on images to see larger versions



6 May - It was still dark outside when, at 4.12am this morning the toilet needs of one of the chicks meant that mum had to take a trip outside (many of the faecal sacs are now too big for the parents to eat).

The sequence (clockwise from top-left) shows how she took a long time to decide to brave the darkness.



She did not return until 4.52am. The light you can see outside in the first image is one of our garden lights which she may have triggered just before her return. The second images shows that it is still dark once that light goes out.

The camera didn't start to detect natural light outside until around 5am.

Tonight I will be setting up the computer to record through the night to find out if she has to go out of the box even earlier than she did this morning.

Just one chick photograph today, showing a wing that has a lot of developing to go before it is ready to fly in just two weeks time.

Notice too the tufts of down at the sides of the head, above the eyes.



I'm afraid that this time I was careless and my foot hit something that disturbed the female. I stopped what I was doing and waited until until the male brought in food and she relaxed again before I left.


These two images, taken this afternoon, show the male bringing in what looks like a caterpillar, judging by the arrangement of legs that are visible. The camera caught him just stepping over the nest cup.

It isn't really dark outside the entrance - that effect is due to the camera settings used.


Once the food is eaten, the parent nearly always pauses to wait and see if one of the chicks will reverse its rear end up the side of the nest cup.

This means that there will be a faecal sac to collect and dispose of, and this is what the male is doing here, a few moments after the caterpillar had been consumed.

Both the main and the smaller image were on the same picture, taken at the same moment with the help of the mirror. The top image was then flipped over to get it into the same orientation as the main picture.


I've been sharing my time between the box and another job so I will not be going through the recordings in detail today. However, I have noticed that the female, when in the box has spent periods standing away from the nest cup, as she did on those warm day, even though it's cloudy today, with only the occasional glimpse of sunshine.

The temperature has only threatened to reach 13C a couple of times this afternoon.


Tonight, activity carried on to even later with the female going out for some time around 8pm.




After she returned and seemed to be settling down her partner appeared with a late snack for a chick. After that the box went quiet for the night.



7 May - Today I have only looked through the recordings for the early morning and up to 9am.

Having recorded the nestbox from 1am I found that before 4.40am there was little activity, but then she became restless. By 4.45am she was up, stretching her wings and looking as though she was about to leave, but after looking out she settled again for a short time until 4.53am when she went to the entrance, paused for a minute and then left. She was back in five minutes later (without any food), just before first light, and settled again for twenty minutes before leaving the box again at 5.19am.


This image, recorded while she was away has given me the first, if a bit indistinct, sighting of all eight mouths in the main image.




There was a pause before the first food delivery took place at 5.44am. Between then and 9am there were a total of 44 items brought to the chicks. Between the time that she departed at 5.19am before feeding commenced, and 9am she spent 94 minutes (43%) in the nest.



I wasn't able to spend any more time watching the box until the afternoon when I spent a short time taking a few photographs. This first image shows a wing with its very early feather development, and showing some progress since the previous image, taken yesterday.



This second image shows more clearly the ear of a chick.



This final image shows the female holding a caterpillar that has just been passed to her by her partner.

I have been trying to establish if the adults 'prepare' food like caterpillars in the way that I have seen Blue Tits doing so in past nesting seasons, and over the last couple of weeks.


The Blue Tits remove the heads, and gut the mealworms that they take before passing them to their chicks. The male has also been seen doing the same before feeding his partner. Having said that, my first impressions of the two photographs that  are in the diary so far, is that I cannot see a head on either caterpillar. I need to get some more images before I can be certain.


I wasn't recording the box this evening so I can't say when she settled in for the night, but at 8.25pm she has not yet settled down, in fact she has just been standing at the side of the box as I write this, before settling again..

2004 Bird Box Diary Index.............................Next - The chicks (week 2)

January to March  ..... April Nest building................

Egg laying (p. 1)........ Egg laying (p.2)........... Incubation. ........ Hatching