The Nest Box Diary 2011
August (part 3)
& into September
27 August - The first day of the 'fledging window'. It is 35 days since the first of the chicks hatched and so we have reached the time when the first of the pair could leave at any time, although the disappointing weather over the last week is likely to slow departures down somewhat.
Today has been bright, mainly sunny, and dry apart form the occasional raindrop from a procession of threatening clouds carried in on a blustery westerly breeze. I had hoped to start varnishing a replacement panel for a folding dingy that I've had since my sons were small, but the breeze made sure that there was a constant scattering of birch seeds all day!
The temperature continues to be uninspiring for August with a high this afternoon of 18C after it was 13C at 7am.
Despite early sunshine, the cold start to the day meant that the parents didn't leave until 7.44am, after which there were just three individual returns before noon. During the afternoon they returned nine times, including one occasion when they arrived together at 3.39pm and then left together four minutes later.
After 6pm the adults returned a total of 7 times, finally arriving for the night at 8.16pm (not quite together this time).
As mentioned yesterday, the family has remained quiet apart from the sub-song and wing fluttering of the chicks.
There was one exception. When both parents arrived together and there was great excitement in the box as the chicks vied for their attention just one bird screamed twice.
The chicks spent more time looking out today, several times as a pair, and again the ledge above the exit was visited.
As before it was an opportunity to flex the tail downwards.
This time, as the first chick ended its exercises, its sibling started.
At first it stayed in the nest cup,
but as the other chick moved to look out it also moved that way.
And finally it too climbed up onto the ledge to flex its tail downwards.
28 August - A day of sunshine and showers carried in on a largely westerly breeze. The temperature was just 12C at 8am, rose to 17C by noon, but then fell back to 12/13C by 5pm - decidedly autumnal!
In the box, the cold start meant a late start, with the adults heading out at 7.59am, not reappearing for the rest of the morning with just one of them visiting just once before noon (11.22am).
In the afternoon there were five visits, and after 6pm there were a further 7 returns, including their arrivals for the night at 8.17/8.18pm.
The chicks spent much of the day huddled together, although there were also long spells spent looking out and a few vigorous wing and tail stretching sessions.
29 August - The decidedly autumnal weather continues, although today was dry. There was a lot of fairly high level cloud but some sunshine. The breeze was mainly north-westerly. The temperature was 12C at 8am, reached 17C just briefly in the early afternoon, and then fell slowly during the rest of the day to 14C at 8pm.
The parents headed out a bit earlier this morning, at 7.16/7.19am, but during the morning there were just two visits - both parents arriving together at 10.03am.
having just spent the previous fifty minutes huddled together in the nest cup, at 12.12pm the sound of a bird outside triggered a feeding frenzy by the chicks, each trying to get the other to produce a bolus! The real thing was delivered less than a minute later. This visit produced the strongest wing vibrations I've seen so far, with entire wings quivering briefly. On another occasion, when an adult entered the chicks ignored it and once again turned their attention on each other until one finally noticed the adult in the corner and collected its 'reward'!
There was a total of visits during the afternoon. The evening saw six more returns, with the final arrivals taking place at 8.09/8.10pm, making an overall total of 14 returns today.
While they spent prolonged periods in the nest cup, there were periods when the chicks looked quite agitated today, moving between the nest and the exit, and there was more wing stretching taking place, as well as another visit to the ledge.
After it seemed that the Swifts had settled down for the night one of the chicks had another vigorous exercise session at just before 9pm, over the heads of the rest of the family.
30 August - Another grey morning with the temperature just 11C at 7am and 12C at 8am. It was no surprise to read in this morning's newspaper that this has been the coolest summer since 1993 - not the best start for a late brood of Swifts!
Despite not a glimpse of the sun all morning the temperature soared(!) to 17C by 1pm at which time, and not surprisingly, the chicks were tucked up together in the nest cup.
Not only did the sun not appear, neither did the parents after they headed out at 7.19/7.20am.
I can't help thinking back to when 'our' House Martins experienced similar weather in late summer, found it increasingly difficult to catch enough insects and ended up abandoning their chicks within days of fledging.
In the afternoon the parents reappeared, one at 2.55pm, then at 4.25pm and then the pair arrived at 5.42/5.45pm. And in the evening they returned six times, including when they retired for the night at 8.07pm, making a total of 10 returns today.
As for the chicks, the day followed the now familiar routine of moving between resting and looking out, with the occasional exercise session, with nothing out of the ordinary to report on, although I don't either bird climbed onto the ledge today!
31 August - The month came to an end (but not the diary!) with some all too brief spells of sunshine. The day started off cloudy, although brighter than yesterday, and by the end of the morning there were breaks in the cloud. The temperature at 7am was 12C and had reached 17C by 1pm. It didn't rise beyond that despite the brighter conditions, but neither did it fall again as the afternoon progressed, and it was still 17C at 7pm.
In the box, the lighter morning had the parents leaving a bit earlier even though it was still quite cold. They headed out at 7.03am. However, yet again they stayed away all morning apart from a visit just before noon which was the first of five in the next two hours.
After a mid-afternoon gap visits restarted at 3.27pm, with eight more following by the time the adults retired at 8.07pm. In total they returned to the box 13 times today.
The chicks seemed to spent as much time looking out as they did on the nest today, and on a number of occasions they were side by side at the exit for quite long periods.
There were several vigorous wing exercise sessions (standing in our driveway I could hear the flapping during a couple of these), and at least one of them climbed onto the ledge, but at the end of the day they welcomed their parents 'home' and settled down to wait for the start of September!
1 September - The first chick fledges
It was just 8C at 7am, but with the cloud cover that plagued us in August all but gone, apart from 'cotton-wool' clouds) the temperature rose to over 21C by the early afternoon (with the chicks still on the inside and looking out!). It remained warm all afternoon before cooling to around 16C by 8pm.
The chilly start didn't put the adults off departing at 7.01am, but they didn't return all morning, the first feed of the day not taking place until 1.01pm, with a second visit at 2.22pm. There was just one more afternoon visit, at 4.22pm.
This evening the skies have been cloudless, conditions seemingly perfect for ballooning, and for spotting any birds that may be high overhead.
In fact, the only high flying birds that I saw was a group of six House Martins clearly feeding over us, the largest number I've seen this year. I suspect that it may have been a family group with recently fledged youngsters.
There was no sign of Swifts.
Back to the box, and an interesting end to the day. Even more than yesterday, the chicks spent a great deal of time looking out,
and this evening, around 7pm one of them ventured further out of the exit than either had done previously.
I suspected that it could be on the verge of leaving, but it eventually disappeared back inside and very soon I could hear the sounds of vigorous wing flapping.
The cctv camera shows that at least one of the chicks was quite agitated from around 7.40pm onwards.
I remained outside and saw an adult arrive at 7.58pm, approaching from low over my neighbours' garden with no warning and no sound. While it was in the box one of the chicks looked out. The adult left again at 8.01pm.
An adult entered the box again at 8.08pm. despite its presence on the nest cup, one and then both chicks were soon looking out again. At around 8.25pm one stretched its wings, rejoined its sibling at the exit and just after 8.28pm it turned back to peck at its parent and the nest one last time before it slipped quietly out of the box into the nearly dark skies. This is 41 days after the first chick hatched.
The remaining chick was very restless, first joining its parent but repeatedly heading to the exit and looking out. It carried on doing this for the next half hour but soon after 9pm it seems to be settling down in the nest cup and is busy preening the neck of its parent as I write this.
Of course, what I haven't mentioned is that not only has one of the chicks fledged, but tonight only one of the parents is present in the box.
Here the parent (its wings show up a lighter grey in the infra-red light) is preening its remaining offspring.
As it will most probably be my last opportunity to do so this year, I've made another recording of sounds in the box tonight at around 10.30pm. Once again it features the quiet, almost wheezy sound made by the remaining chick. At the beginning it is quite rapid as the parent preens the chick's neck. Then, as it relaxes again the sound gradually becomes more rhythmical in time with its breathing before another short preen ups the tempo again near the end.
Click here to listen to the clip (51 seconds, 797KB). The recording was made with the input level up high, and it has processed through a high pass filter to remove the constant rumble of distant traffic.
2 September - A thin veil of high level cloud dilutes the blue and the sunshine this morning as I wait for the second chick to fledge.
It was 12C outside when its parent left the box at 7.32am and over the following hour the chick showed no interest in doing likewise, preferring the comfort of the nest cup.
The situation remained unchanged throughout the morning and early afternoon, with the chick alternating between time spent on the nest and looking out. During the morning the look-out sessions lasted an average of 17.5 minutes (in 6 sessions). In the early afternoon this had dropped to less than 10 minutes in four sessions. Up until 2.30pm there have been no parental visits. Incidentally, as the early cloud dissipated the temperature outside rose to 20C by 11am and 24C by 2pm, with a westerly breeze picking up since noon.
By 3pm the temperature had reached 26C before dropping back to 24C by 6pm. In the box the chick continues to spend most of its time in the nest. Between 2.30pm and 6pm it spent a total of less than 12 minutes looking out over two sessions.
This picture shows about the furthest the chick emerged during the course of the day.
And by the end of the afternoon we were still to see a parent return.
I noticed a change in behaviour after 6pm with the chick stretching and flapping its wings more than earlier in the day, and with no sign of a parent returning it started to look out more frequently from around 7.45pm onwards.
From 8.05pm the chick was at the exit almost continuously, apart from a couple of moments when it moved back to stretch its wings. At around 8.20pm it reached out further than I'd seen previously.
It repeated this several times over the next couple of minutes and finally, at 8.24pm it launched itself from the box. It flew over me and over the conifers at the bottom of my neighbours' garden and disappeared into the darkness, 41 days after the second chick hatched.
Incidentally, in the minutes before it left we had a 'fly-over' by a sextet of quacking ducks heading south (appropriately!) and a bat flew down the driveway and did a U-turn between me and the box. I forgot to mention yesterday that a large bat flew over the house at 7.30pm.
And tonight, for the first time since 3 May we are not looking at a Swift in one of our boxes. It has been a fascinating summer, more than making up for some of the disappointments from early in the nesting season.
I will be adding more details and images to the section of the diary relating to the nesting in SW-ri, but there may be quite an extended pause before I embark on that task.
Click on images to see larger versions
2011 Nestbox Diary Index .......... ............................................................