Swifts log 2021

Sun 25 April, nestbox #4: Arrived in the last couple of days, almost certainly one of our original pair who have been back every year since we opened the boxes in 2016. Let’s hope that their partner also returns soon so that they may repeat their past breeding success.

Sun 2 May, nestbox #4: Our early resident has been roosting every night, and spending some of the days foraging for nesting material, but there is no sign of any other swifts. There is now a high resolution camera in nestbox #4, giving a clearer view.

Swift on nestSun 9 May: Single swifts returned to boxes #1 and #3 today.

Tue 11 May, 11:45: Just a small squadron of three birds (probably our three), but the first screaming party of the season just swung by.

A bird sitting on top of a half pipeSat 15 May: after nearly three weeks of lonely roosting, the patient bird in #4 returned to the box in the early evening with a partner in tow; however when I shut down the cameras later, there was just one bird in the box. #1 also acquired a partner today, roosting together tonight. #3 is empty tonight.

Mon 17 May: Last night the pair was roosting again in #1, singletons in #3 and #4, but there is a pair again in #4 this morning. Five birds in total? The group wheeling around in the sunshine at 10 am numbered just four. Tonight: pairs in #1 and #4, other boxes empty.

Wed 19 May: Late last night there was a single swift in #3, but this morning there is a pair. Pairs roosted in #1 and #4 last night. At 10pm there are pairs in all three boxes. The camera also caught a brief visit by a single bird this evening to box #2.

Thu 20 May: Wet and windy day, with all three pairs spending most of the day cuddling up together in their boxes.

Fri 21 May: Switched on the cameras this morning to find a singleton swift in #2 again. Otherwise much the same as yesterday, with occasional forays outside when the rain let off – presumably for food.

Sat 22 May: A sad day. All the birds took advantage of the sunny morning to go out and feed up – except for one in #3. I became suspicious when the camera showed that it had not moved all day, and when its partner returned and cuddled up to it in the evening it showed no signs of life. This is the first time in our five seasons that we’ve had to deal with a death.

A close up of a fishSun 23 May: When its partner had gone out, I removed the dead bird from #3 to be buried in the garden. There is a chance that its partner may find a new mate and breed this year.

Wed 26 May: Turned on the cameras this morning to find two birds in #3; apparently our bereaved swift has found a partner, although it didn’t stay for the night.

Fri 28 May: After dark last night there were two birds in #3, none in #2. This morning at 7.30am there were none in #3 and two in #2. I shall have the cameras on timelapse today to seek confirmation of my suspicion that the bereaved #3 swift has shacked up with their neighbour in #2 – and they haven’t yet decided which box to call home.

First egg of the season

Sat 29 May: There’s an egg in #1. We had some great flypasts this warm and sunny afternoon. Had a couple of bangers round at 21:15, knocking on #2 and #4. Tonight at 10pm #3 is empty and there is a pair in each of the other three boxes.

Sun 30 May: I watched #2 and #3 at around 9am. There was a little dance going on with a single bird moving around in one of them before leaving; a few seconds later a bird (the same one?) entering the other box; later a bird in each box, who then departed almost simultaneously; a few seconds later, two birds entering #3 in quick succession and settling down together on the scrape (see video below). Around 9:30 they left the box. During the rest of the morning there was once or twice a single bird briefly in one or other of the boxes. I have never seen more than a total of two birds in the two boxes since the death last weekend, so I think it is pretty clear that the bereaved partner has taken a shine to their neighbour in #2 and the pair have not agreed where to stay. Perhaps an egg will settle the matter before long. Tonight they are together in #2.

The “two homes” pair

Mon 31 May: An egg in #4. The #2 #3 “pair” were roosting in their separate boxes at 10pm.

Tue 1 Jun: There may be a second egg in#1. While my focus on the last few days has been on #2 and #3, the pairs in #1 and #4 are dutifully minding their eggs.

Wed 2 Jun: There was a pair in #2 at 10pm last night. At 8am this morning there was again a pair in #2, but also a singleton in #3. At 10am there is a small (3 or 4) squadron of bangers testing the nest box entrances. A second egg in #4 today.

Thu 3 Jun: Definitely two eggs in #1 – possibly three. This afternoon there were about a dozen swifts flying around the colony, in addition to the four in the boxes. The “second wave” has clearly arrived.

Fri 4 Jun: An egg in #2 this morning, but it had disappeared from camera view in the afternoon; I opened the box while the parents were both out to find that the egg was cracked open and discarded at the other end of the nest box.

Three eggs in #4

Sun 6 Jun: In a rare moment, I caught #4 with no bird on the nest and could see three eggs.

Tue 8 Jun: A fresh egg in #2.

Fri 11 Jun: A second egg in #2. So we now have 7 eggs in total. Incubation takes about 3 weeks, so we may expect our first hatchling, in #1, before Saturday 19th.

Wed 16 Jun: The cracked egg that was discarded in #2 on 4 June rolled into camera view near the entrance tonight; there are still two eggs in the nest.

Fri 18 Jun: I am making timelapse movies of each box, from stills taken 20 seconds apart. Today this showed that, unusually, the birds kept all their eggs covered all day, probably because it was so cold, never getting above 15 degC; for the last couple of weeks it has usually reached 30degC or more in the boxes and the nests were often left open for a minute or two.

Sun 20 Jun: Probably because it has been so cold over the last two or three days, the parents have been especially slick in changing over their nest duties, never leaving the contents uncovered. I last saw two eggs in #1 on Thursday 17th, but this morning there is a hatchling – see video.

First hatchling in #1

Mon 21 Jun: Two hatchlings in #1. I’m fairly sure that there is at least one in #4 as well.

Tue 22 Jun: The pair in #4 at last allowed the camera a brief view into the nest, revealing three hatchlings.

Three hatchlings in #4

Thu 24 Jun: Summarising, today there are three hatchlings in #1, two eggs in #2 (due to hatch next week) and three hatchlings in #4. The roosting pair in #3 are unlikely to breed this year.

Tue 29 Jun: A first hatchling in #2.

Compare wing and leg size (#4)

Wed 30 Jun: Adult swifts are characterised by huge wings and tiny legs, well-adapted to a life that is almost entirely spent in the air. So it is interesting to see how this size difference is reversed in a week-old hatchling. Incidentally, the hatchling on top in this picture, whose wing and leg we can compare, appears less developed than its siblings – slightly smaller and paler in colouring. It is probably not getting its fair share of the food; but not to worry – there was a similar situation last year in #3, with Tiny chick fledging more than a week after its bigger siblings.

Thu 1 Jul: Here is a timelapse video that compresses life in #1 today, 8 am to 10.30 pm, from 14.5 hours to 3 minutes. See how efficiently the parents deal with the chicks’ copious droppings throughout the day – and an unlucky fly that wandered in at about 7 pm.

A day in #1

And here is a similar video from #4. Look out for what seems to be a visit from a swarm of flying ants at around 4.15 pm – mostly gone by 6pm.

A day in #4

Fri 2 Jul: The camera in #2 is not giving a very clear image, but I’m fairly sure that there is only one hatchling, the second egg having been discarded in the last few days. I have a new camera ready to go in but I don’t want to disturb the parents, so I am waiting until the chick is bigger, when I can expect the parents to leave the chick alone in the nest for short periods while they both go out hunting.

Sat 3 Jul: Definitely only one hatchling in #2.

Wed 7 Jul: Video of chick exercising its wings – for the first time?

Chick in #1 exercising its wings

Tue 20 Jul: A new record high temperature of 42degC set yesterday. The young birds have often not been visible on the cameras as they have been taking refuge in the entrance tunnels where it is probably a degree or two cooler.

Mon 26 Jul: The juvenile pair that was in #3 did not roost there last night…

Tue 27 Jul: … but were back the next night!

Sat 31 Jul: The chicks in #1 and #4 are about 6 weeks old so could be fledging any day now. Last thing tonight there were only three birds in #1 instead of the usual four, while in #4 there were just three birds instead of the usual five. I find it hard now to distinguish adults from chicks, so I don’t know if some chicks have fledged or some parents have abandoned the nests, but the former is more likely.

Sun 1 Aug: Today it became clear that one of the chicks in #1 fledged yesterday. The second fledged this evening, taking the parents somewhat by surprise when they returned later with throats stuffed with food; the first to return had some difficulty in dealing with it (see video below). So tonight it is just the parents roosting in #1. Again just three birds in #4 last thing tonight; at times during the day there was just one bird, so I think two of the three chicks fledged yesterday.

Parent in #1 returns with throat loaded with food but finds no chick to feed

Mon 2 Aug: The third chick fledged from #4 this morning at 8 am; it seemed to be under the guidance of its parents, as they formed a procession of parent-child-parent into the tunnel and left immediately, as seen in the video below. The parents returned to roost at night.

Third chick fledging from #4 (30 minutes compressed to 30 seconds)

Wed 4 Aug: All but one of the chicks have now fledged; the single chick in #2, which is about a week younger than the others, should be fledging soon. For the last two nights we have had roosting birds in all four boxes – the now chickless pairs in #1 and #4, the chick and two parents in #2 and the non-breeding pair in #3. However, last thing tonight only #2 is occupied, with the parents and their only chick.

Thu 5 Aug: Just one parent with the chick in #2 tonight; one bird in #3, other two boxes unoccupied.

Fri 6 Aug: A sad end for our last chick this year. The camera in #2 showed it leaving the box at 9.22am. Jo called me just a couple of minutes later to say that there was a kestrel feeding on something in the drive – see the video below which I started at 9.27. Eventually it flew off with the carcass, leaving behind a few feathers whose pale edges are consistent with those of a young swift.

Kestrel making a meal of our last swift fledgling

Feathers on gravel
A few feathers left behind
The feathers are consistent with those of a young swift


Sat 7 Aug: One swift roosting in each of #2 and #3 last night.

Sun 8 Aug: All boxes empty last night.

Temperature chart