The 2010 Nestbox Diary
July (part 1)
1 July - A much delayed resumption of the diary after our holiday in Cornwall. Not that we have been away all this time. The holiday lasted a couple of days over two weeks, but since our return things have been a bit hectic. Amongst other things I have been trying to transfer to DVDs many of the recordings made on the hard drives during our absence. So far that amounts to around 100 hours. The trouble has been finding the time to watch them, watch what is happening in the boxes now, and do everything else!
Anyway, I will be adding some entries for June in due course. One technical hiccup may restrict that task a little bit. Having set everything up before we left, both hard drive recorders worked as planned, recording 1 hour each morning and 2 hours each evening in both boxes. However, after setting the frame rate on the timelapse recorder to ensure that it recorded the same quad image as seen on the webcam (only at 17fps) continuously for the whole holiday, I forgot to press the record button!!!
Before we left I calculated that the eggs (Laid 20/22 May) in SW(UP) would hatch around 9 June, while the eggs (laid 24/26 May) in SW(LE) were due around four days later, around 13 June, although there was some question about this latter date because of the time those eggs were left unattended during the early part of incubation.
Being precise as to when the eggs actually hatched has been somewhat difficult because both pairs of adults succeeded in keeping the eggs/chicks covered, even during change-overs. However, the appearance of broken shells in the nests indicated that in SW(UP) at least one egg hatched on 8 July. In SW(LE) there was the expected delay, with hatching not occurring until 15/16 June. I will be taking another close look at the recordings to confirm these dates before I put together the June entries.
The webcam image is somewhat deceiving, The cameras/lenses in the two boxes are identical, but with the chicks in SW(UP) perched on top of the Sparrow nest they are much closer to the camera and so look much larger.
The pair in SW(LE) are now about 15 days old and still spend much of their time close together in the nest cup and as this image shows they have a great deal of down covering them. You can see the dark tips of the flight feathers poking out, and a stubby tail.
While this picture of the pair in SW(UP) shows them in a similar pose, it is clear to see that the wing feathers are much more advanced - they are now about 22 days old.
and the amount of down visible varies a great deal when they change position.
This image was recorded just a few minutes after the previous one, and the left-hand Swift looks much more like a miniature adult with its wings crossed behind its body.
This pair are already stretching and exercising those wings as they explore beyond the nest cup itself,
and today I saw a couple of vigorous flapping sessions.
Since hatching occurred the weather has been almost perfect, with plenty of insects about so that the chicks are being fed well, and if the dates above are correct then I would expect the chicks in SW(UP) to fledge around 14 July, while those in SW(LE) should fledge around 21 July.
Turning my attention away from these two nests for a moment, there is some exciting news regarding the new Swift boxes. Every day we see and hear screaming groups of Swifts rushing past, and I have watched them investigating every promising opening around the house, from occupied Sparrow boxes to the bathroom window - a Swift nearly joined me in there a few days ago!
As far as I can tell, so far none have shown interest in using the two empty boxes seen in the webcam, but that isn't the case with a couple of the new boxes that I put up on neighbours' houses.
In this case it is definitely more than just looking in. As I watched I noticed that they were having a problem getting in under the batten that I put across the top of the entrance, so I used a curved rasp to produce a bit of an arch.
Within a couple of minutes a Swift entered the left hand box with no problem at all.
While up the ladder I also checked inside the boxes. The left hand box contained confirmation that at least one Swift has taken up residence. There were several feathers on the bottom of the box, all of them clearly stuck to the base by what I assume was saliva. Also, I was surprised to find four pupae of Crataerina paillida, the parasitic flat-fly species specific to the Common Swift (there was also a single pupa in the right-hand box). These were removed and will add a photograph soon.
Last year I saw an adult insect on one of the Swifts in SW(UP), but have yet to see one on them this year. In contrast, while the pair in SW(LE) appeared free of the parasite last year I have seen the adult insect on one of the adults this year. So far I haven't seen one moving about on any of the chicks.
I'm assured that there have been Swifts going into another of the boxes as well, although I have yet to confirm visits to that pair with a picture.
3 July - The warm, dry and bright weather continues and enables the Swifts to keep their chicks well fed.
In SW(UP) the chicks show less and less down as each day passes and their wing tips now clearly extend to at least the tips of their tails.
They are becoming more adventurous too. Today both chicks ventured at least part way down the 'hill' at the side of the nest. One is seen climbing back up in this image.
Over in SW(LE) there is also some progress to report. There has been some wing stretching going on, and you can see how much the flight feathers have expanded from the sheaths of their early development.
This image captured one of the chicks looking straight at the camera (or more likely at the reflections in the camera lens), showing the light coloured face of a young Swift.
Tonight the two families look quite different.
While in SW(LE) it is clear who the parents are, with the chicks at least partially tucked under one of them,
in SW(UP), for much of the time the group of two chicks and two adults can look rather chaotic to say the least.
Over the last few nights it has been just as likely to see one or both chicks on top of the adults as it is the other way round. In fact, as I write this I see that both chicks are now side by side and using one of the adults as a pillow!
In the image from SW(LE), notice the pile if faecal sacs at the far end of the box. Neither chick has been to that end of the box. Before a chick produces a sac it simply reverses a short way out of the nest cup. The parents clean up the area immediately around the nest cup, but I have yet to be sure that they deliberately leave the sacs in that pile. It is possible that they are simply moved to that corner during the movement of the adults to and from the exit.
There is a similar pile at the far end of SW(UP), but I also see sacs on the ground below that nest, probably as a consequence of the exit being in the floor rather than the side wall.
5 July - With all four chicks continuing to do well as their food is plentiful, the pair in SW(UP) now have just a trace of the down 'stripes' on their shoulders.
In addition to their wing stretching,
they were also taking time to do a bit of tail stretching.
On this occasion the pair took turns, and as soon as the first appeared to have completed its exercises then its partner started.
Again, it was the wing stretching that came first, followed by the tail.
Over in SW(LE) the chicks are still happy to remain in the nest cup, and they continue to look very small next to one of their parents (the male in this case).
Once the adult leaves it is possible to see how their wings have yet to extend past the tips of their tails,
and they look even shorter when they are crossed over in usual Swift style.
However, when one of them stretches a wing it does manage to look a bit longer, at least until you compare them with the wings of the chicks in SW(UP) - what a different a week makes.
8 July - On what became another hot day the pair in SW(UP) have taken what is a big step towards their fledging in around six days.
As the day went by they spent more and more time off the nest and next to the box entrance/exit, although the appearance of a parent would have them returning quickly to the nest itself.
This evening, as one of the pair spent time looking out I took the opportunity to take my first photograph of one of the chicks.
I didn't consider using flash, but the very pale face is unmistakeable. Notice the fly, the Swift took a lot of interest in it!
The very small beak that you see is a very misleading indication of the size of the Swift's mouth. In the second image of this pair you can just make out the Swift's mouth when it yawns!
Tonight, one of the family remained off the nest for a while the nest, although I see that all four are back together at 10.45pm
In SW(LE) the family are all together, although now the chicks are just as likely to be on top, unlike just a few days ago.
Notice how the light bands of down are still present on these chicks.
I haven't been watching enough to tell if Swifts are going into any of the other boxes at the moment, but we have certainly had more aerial activity than I can remember for many years, if ever since we have lived here. Over the last week there have been at least twenty Swifts in the area, and sometimes we have up to sixteen screaming over us, although screaming parties usually number six or eight.
10 July - With perhaps four days to go before they fledge, the youngsters in SW(UP) spent a lot of the day near the exit, but while their appearance getting increasingly difficult to distinguish from that of their parents, they are still very much the chicks when an adult returns, and when they all huddle down together for the night.
I couldn't resist capturing this moment tonight as one of them used a parent as a 'wrap-around' pillow.
These restful periods are inevitably interrupted as a wing needs stretching, or an itch requires attention (the family continues to appear free of flatflies).
And just very occasionally, I catch sight of one stretching its jaws. Perhaps when I review the recording I will be able to capture a wider moment!
An hour later, and the infra-red lighting helps to emphasise the light face of a chick.
Moments later, and the same chick is submitting to being preened around the neck by its sibling, while the parents rest.
Having said that, the chick that was doing the preening a couple of minutes ago is now receiving the same treatment from one of the adults.
In SW(LE), and with another ten days or so to go before they fledge, these are still very much chicks. In this image (captured this morning) the downy bands are still clear, if somewhat reduced on either side of the back, and it seems that their tails have grown more relative to the lengths of the wings over the last couple of days.
They are now moving about the box much more and spending time near the entrance, although as with the other pair, they soon return to the nest cup whenever a parent arrives.
- Click on the images to see larger versions -