Swifts 2024
Blog
Mon 6 May, box #1: Our first swift of the 2024 season arrived this evening at 8.11pm.
Wed 8 May: Swift arrived in #4 at 10am; another in #2 at 8.19pm. Total of three birds roosting tonight.
Fri 10 May: Swift arrived in #3, and partners for #2 and #4, so 6 birds in all roosting tonight.
Swifts pair for life but only spend time together for breeding, so when the later swift of a pair returns from Africa there is often a short period of squabbling as they try to work out if the other is their partner or an intruder into their nest site. Here is how the first swift of pair #4 greeted their partner when they came into the box for the first time this year:
Eight minutes later they had calmed down a bit; first swift was still a bit suspicious, but there was quite a lot of mutual preening:
However, by 10pm they seemed to be comfortable settling down to roost together:
Sat 11 May: one bird roosting in #1 last night, but two flew in together at 7.30am and roosted tonight. Although there was a pair in #2 last night, tonight only one roosted.
Sun 12 May: #3 partner arrived at 1.14pm but did not roost. It looks as if there is now a pair for every box, but only those in #4 are consistently roosting together.
Wed 15 May: Although all our birds have been seen in pairs since Sunday, last night was the first night with a roosting pair in every box.
Thu 16 May: Despite their squabbles on arrival (see 10 May), pair #4 have turned out to be the most devoted of all, spending more time together in the box than the other pairs over the last few days. Today they laid our first egg. I think that one of this pair is the first swift to nest here, in 2017, and acquired a new partner last year.
Sat 18 May: A second egg in #4
Mon 20 May: Third egg in #4.
Wed 22 May: I’m not sure what is going on with the pair in #1. There has only been one roosting on 5 of the 11 nights since the second returned, and yesterday there was never more than one in the box.
Drama in #4 this evening: while one swift was quietly incubating the three eggs, a second bird entered carrying nesting material in its beak, but was immediately followed by a third, initiating a huge fight that went on for nearly half an hour, involving all three birds:
Eventually things settled down and one of the birds left, but the couple remaining seemed to be unhappy with each other, occasionally clashing beaks and squawking:
They carried on like this for over an hour until at 20:38 something quite unexpected occurred:
The nesting swift picked up one egg in its beak and dropped it out of the nest; 40 seconds later it flicked a second egg out. It may not have noticed that it had left the third egg.
The pair carried on bickering off and on for the rest of the evening, but eventually settled down to roost together:
It’s almost as if a new partner had taken over, but I’m pretty sure that the day ended with the same pair as it began, as the intruder had some distinguishing marks on its head that are not visible on this pair before or after today. So why did the parents apparently discard their own eggs? This pair were very wary of each other when they first met this season on 10 May, which may be relevant in some way.
Thu 23 May: One of the pair in #4 left the box at 10am and did not return to roost at night. Remarkably, at 11:55 we saw two eggs in the nest, one of which must have been fresh.
Fri 24 May: Both birds were seen in #4 on and off from 13:25, and both roosted tonight.
Sat 25 May: Proof that there are now 4 eggs in #4, two in the nest and two discarded:
Adding to the remarkable story of the last few days, one of the discarded eggs was removed from the box this afternoon:
…but the next day an attempt to remove the other one failed:
Sun 26 May: There has only been a single bird seen in #1 for the last week, but we now have one egg in #2 and three in #3.
Tue 28 May: A second egg in #2, so egg counts in the four boxes are now 0, 2, 3, 2.
Thu 30 May: Here’s a video of swift parents doing their thing, building the nest and incubating eggs. You’ll see wind-blown feathers being brought in and stuck to the edge of the nest with saliva. Towards the end the adult tucks an egg into place under its belly. If you watch carefully you’ll also see a couple of parasite lousefly moving over nest and bird.
Fri 31 May: third egg in #2
Fri 7 June: Very little has changed over the last week. We have 8 eggs (0, 3, 3, 2) whch are all being so dutifuly incubated that the camera rarely gets sight of them; they should start hatching towards the end of next week. The single swift in #1 roosts every night with no sign of any other bird in the box, which is most unusual.
There are no cameras inside our new 7-box “hotel”, but we have an outside camera keeping watch on the entrances. This has shown one pair coming and going.
Sat 8 June: A hatchling in #4! Look for its relatively huge eyes (which will remain closed for a few days yet), just to the left of the remaining egg.
Here is a video of it being fed. Bear in mind that it is very dark in the box (the camera uses infra-red light), so the adult has to feel its way to the chick’s mouth. It takes a over a minute of probing before the chick consumes a small black bolus of insects.
I think it hatched yesterday afternoon, as the camera caught an adult removing a piece of eggshell from the nest just after 2pm:
Tue 11 June: Second hatchling in #4. The video below shows it draping itself across the neck of its sibling. Although less than half the size of its sibling, towards the end of the clip I think I see it getting a share of the food.
Fri 14 June: All three eggs in #3 hatched over yesterday and today.
It’s been several days since we saw or heard swifts flying around outside – a sign I think that the continuing cold spell is forcing them to spend much more time than usual looking for scarce food, leaving little time and energy for socialising.
Sat 15 June: We’ve been monitoring movements in and out of the new “swift hotel” with an outdoor camera. There is just one pair in residence and over the last week there has been a daily pattern of about five trips out of the box, with a swift leaving the box only a few minutes after a swift enters. This indicates that they are taking turns incubating eggs; going by what we have seen in our internal boxes, we can expect that there will be more trips out per day once the eggs hatch.
Mon 17 June: One egg hatched yesterday and one today in #2. A prospecting swift took an interest in the swift hotel but did not enter.
Tue 18 June: A disaster for the resident pair in the swift hotel when a kestrel took one of them. A rather upsetting video:
There is a small chance that the swift escaped uninjured in flight; we should be able to tell if it returned home by the pattern of movements in and out of the box over the next few days. We have no way of knowing how many eggs were being incubated, but a single parent will have trouble feeding more than one chick on its own.
Not so serious, but there was also a drama in #2 when a swift returned to the box at 21:38 and about a minute later was set upon by the nesting bird, starting a fight that lasted 5 minutes; but by 22:00 they had settled down to roost together on the nest. What was that all about, I wonder?
Wed 19 June: On Monday the swift in #1, after 4 weeks of roosting alone, brought back a partner for the night, but last night it was alone again.
Our last egg, in #3, hatched today, so we now have 8 chicks being fed.
The pattern of movements in and out of the swift hotel box have changed: until today the average interval between a swift entering and a swift leaving has been less than 10 minutes, but today it was 90 minutes. This must be because there is only one adult swift resident now, after the kestrel took one yesterday.
Mon 24 June: The kestrel struck again this morning, taking a swift soon after it left #4. It was spotted feeding on the body in our drive by a neighbour; all it left behind was a few feathers. This leaves one parent with two chicks to feed. As noted above this is not ideal for the chicks; in a normal brood two parents feed no more than three chicks, ie a maximum of 1½ chicks each. We considered taken one of the chicks to Oxfordshire Wildlife Rescue in Blewbury; if there had been three chicks this would be the right course to take, but the two chicks are doing well, so we will just keep an eye on them for the time being. They hatched about 4 days apart, so one is much smaller than its sibling, but we can see it getting a share of the food.
Tue 25 June: There have been a few more swifts flying around in the last week or so, as temperatures rose. Yesterday and today the outside camera has shown all but one of the seven boxes in the swift hotel being approached by prospecting swifts; they fly up to an entrance and immediately away.
Thu 4 July: One parent disappeared from #2 today, possibly taken by the kestrel although we have no evidence of that.
Fri 5 July: The widowed parent in #2 has no chance of successfully raising three chicks, so today we took the two biggest ones to Oxfordshire Wildlife Rescue in Blewbury. The kestrel has obviously got the measure of our boxes, and we haven’t managed to catch it in the act to see where it attacks from. It seems there is little we can do about it except hope and pray.
Fri 12 July: Another tragedy in #4, where one parent has been feeding two chicks since its partner was taken by the kestrel 18 days ago. One chick was much smaller than the other, as this image from yesterday shows:
We thought that the smaller chick had been doing OK, managing to get its share of the food, but this morning at about 5.10am, apparently without any prompting, it left its sibling and parent in the nest and went down the exit tunnel. The parent followed it for a moment and then returned. The small chick has not been seen since but we found a few downy feathers and flesh on the ground below the box, so I assume that it fell out of the box and was predated on the ground by a crow (or kestrel?) soon afterwards. It was certainly insufficiently developed for flight. This timelapse video shows the sequence of events in the box; it runs at about 30 times faster than real time:
With the benefit of hindsight, bearing in mind the unusally large difference in sibling sizes, perhaps we should have taken one of the chicks to OWR when we had the opportunity on 5 July. A lesson for the future.
Sat 13 July: To sum up after all the tragedy, today we have
- in #1 a single swift, roosting mostly alone for two months, a few times with a partner, sometimes absent all night
- in #2 a single parent successfuly raising a chick, now about 3 weeks old
- in #3 a full house – two parents doing a great job with their three indistinguishable chicks, about 4 weeks old
- in #4 a single parent with a healthy chick, about 5 weeks old, now often seen exercising its wings and likely to fledge in the next couple of weeks.
Round the corner in the apex “hotel” we still see a single swift coming and going a few times a day from one box, but not frequently enough to be incubating or feeding chicks. The hotel also gets visits from prospectors most days.
Sun 14 July: The kestrel claimed yet another victim shortly after 7pm, taking the chick from #2 while it was peering out of the entrance.
Wed 17 July: Our oldest chick (6 weeks) fledged from #4 this morning at 6.30am – successfully as far as we can tell. Its parent also quit the nest today and hasn’t been seen since.
Fri 19 July: The single swift in #1 roosted with a partner for three consecutive nights from Monday this week. The pair spent quite a lot of time cuddled up together early each morning, but did not turn up last night. We must hope that they have established a firm relationship for next year.
All eyes are now on #3, from which our last three chicks should fledge any day now. The other three boxes are now empty.
Mon 22 July: The kestrel took a chick that was peering out of #3 at 13:45 today:
Sat 27 July: One of the chicks in #3 chick fledged unusually late in the day at about 9.45pm when it was getting quite dark.
Sun 28 July: After tempting the kestrel by looking out of the entrance for a good 15 minutes, our last chick fledged from #3 shortly before 10am. Watch the exit tunnel at bottom left to catch the tail movement as it prepares for its first flight, and the flash of bright sunlight that follows the sound of it launching itself into the unknown:
Here is the view from outside, in slow motion:
Mon 29 July: the 2024 swift season is over! As far as we know, 5 chicks fledged successfully. Last year it was 11, so that’s rather disappointing. A big problem this year was with the kestrel, which we know took 2, possibly 3, adults and 2 chicks as they were entering or leaving the nest boxes. We’re considering ways that we can protect the entrances next year; a small roof over each may help.
A pair of swifts roosted in the hotel last night, so we may hope that they will return to breed next year.
Temperature chart
This chart shows the maximum and minimum temperatures in box #2 this summer. Box #2 is usually the one that gets warmest, being inside the top west corner of the gable end.
