Apus apus (Common swift) - Diary 2019

My notes on the activity of swifts at my house in 2019...


See the main page for notes, photos, and diaries for other years.

2019 Swift diary...

The numbered nestboxes can be seen on this photo, and the entrances to the internal boxes on the gable end in this photo.

Activity in inspected boxes 2019 (prediction in red italic; '≤' 'less-than-or-equal' or '≥' 'greater-than-or-equal' date could be earlier/later). See all years here.
YearNestAdult1Adult2Egg1Egg2Egg3HatchFledge1Fledge2Fledge3Comments
2019#1May-7May-11May-18May-20May-22Jun-9Jul-22Jul-23Jul-24
2019#2≤May-16???-≤Jun-21Aug-2Aug-2-
2019#3≤May-13?May-25/27??~Jun-16Jul-25/30Jul-25/30Jul-25/30
2019#4May-15May-16*May-23May-25May-27Jun-13Jul-24--*First egg removed by 'intruder' swift on May-24. Replaced in nest May-27, but didn't hatch. Only 1 egg hatched.
2019#5≤May-14?≤May-24May-25May-27~Jun-13Jul-25/30Jul-25/30Jul-25/30Swifts took over house-sparrow nest.
2019#g1≤May-12?≤May-24??≤Jun-16xNest empty Jun-21, eggs/embryo on ground outside.
2019#g1a??Jul-2/7≤Jul-8-~Jul-24Sep-3Sep-5-Re-lay by same or different birds.
2019#g3≤May-12≤May-27???~Jun-16Jul-27/30Jul-27/30Jul-27/30
2019#g4?≤May-24???~Jun-16Jul-27/30Jul-27/30Jul-27/30
2019#g6≤May-10≤May-27???≤Jun-16≤Jul-24≤Jul-24Jul-27/30
2019#sb2May-15≤May-17≥May-23≤May-27?~Jun-16Jul-28Jul-28-Only 2 of 3 eggs hatched.

2019-September-7 Summary of swift breeding season 2019: 25 chicks fledged from the 10 nests recorded above (3 more than from the same nests in 2018). And 3 nests with no recording (#w1r, #w2r, and #b1 or #b2) had young which presumably fledged.

2019-September-6 Yesterday evening (5th September 2019) an adult swift entered box #g1 (nest #g1a) at 19:51. At 20:16 (after dark), the single remaining swift chick fledged. The adult left at 10:16 this morning. Will the adult(s) still return to the nest at night, or is that the end for 2019? [Later: no - the adults didn't return.]

2019-September-3 One of the 2 swift chicks in box #g1 (nest #g1a) fledged at 10:51 this morning. It was seen leaving by the outside camera.

2019-September-2 As far as I know, the two young swifts are still there in box #g1 (nest #g1a). I've got the outside camera aimed at the entrance, and seem to be reliably motion-detecting birds entering and leaving. This evening, the two adult birds returned for the night at 19:51 and 19:56 - already two hours earlier than was likely at mid-summer. From dates of egg-laying and hatching, I predict just 2 more days before the young swifts fledge.

2019-August-29 I checked the one nest which still has swift chicks - gable end #g1a.

Gable internal swift box #g1 with chicks
Here are the two chicks in box #g1 (nest #g1a) on 29th August 2019, estimated to be 36 days old, and nearly ready to go. There is also an adult swift present (with eyes closed). Both young swifts have something visible in the corner of their eyes - is it an anatomical feature or a parasite? Zooming in on the high-resolution photo, it could be an insect?

2019-August-16 The last 2 swift chicks in the colony for 2019 (in box #g1, nest #g1a) are progressing fine. While checking #g1, I found an adult swift in #g2. #g2 hasn't so far been used for breeding, but there have been some feathers stuck to the nest-concave during the 2019 season, so perhaps it will be used in 2020. As for why there was a bird there this afternoon...? Well, it was raining, but it still seems late in the season to be hanging on to a nest space if just for next year. Perhaps, when it's not raining, I'll move the outside camera to check for swifts going into the gable-end entrances.

2019-August-7 I checked the one nest which still has swift chicks - gable end #g1a.

Gable internal swift box #g1 with chicks
Here are the two swift chicks in box #g1 (nest #g1a) on 7th August 2019, estimated to be 14 days old. I see that their stage of development is very similar to those in the photo on 23rd July 2016 (in the 2016 diary page). In terms of nest recording with the British Trust for Ornithology, I describe these chicks as "DO" (downy), "EY" (eyes just open), and "FS" (feathers small). The photo has proved valuable, as I was going to put "IP" (in pin) for the stage of primary feather development, but the photo shows a small amount of black feather already emerged from the "pin" (sheath).

2019-August-2 The pair of adult swifts in box #1 are still returning each night, despite it being 9 days since their last chick left, but the birds are no longer returning to #4 and #sb2.

2019-July-30 Gable end boxes #g3, #g4, and #g6 are now empty, so all 3 young swifts in the first two, and the final one in the last have fledged at some point in the last 3 days. As expected, boxes #3 and #5 are empty, so 3 young swifts fledged from each of those at some point in the last 6 days. Still 2 young swifts present in box #2, and a young swift is looking out of #w2r. I don't think young swifts are still present in #w1r, and can't be certain whether they bred in brick-sized boxes #b1 or #b2 - they were active in the former earlier in the season, and more recently swifts have been entering the latter.

So far in 2019, that's 21 swifts fledged, another 4 to go, and 3 nests where I don't know how many fledged. About the same as 2018, with #g2 and #g5 still available but unoccupied.

2019-July-29 Some observations from the 3 nest-boxes with cameras, with all the young swifts in them having fledged (5 days ago in #1 and #4; 1 day ago in #sb2): adult swifts left each nestbox around 07:00. At 11:34, 12:23, and 14:08, a swift returned to #1 bringing nesting material each time (including at least feathers), and spending several minutes glueing it down. No swifts returned to #4 or #sb2 during the daylight hours, but at 21:05:49 (dusk) swifts entered all three boxes simultaneously. The swift entering #sb2 clearly had a full crop of food, despite there being no young to feed. A second adult entered #1 and #4 a few minutes later, but as last night, there is just one adult overnight in #sb2.

2019-July-28 Just before 21:14, both the young swifts in 'starling' box #sb2 fledged, one following the other just 9 seconds apart. They were seen on the outside camera making a quick right turn, needed at this rather obstructed nest-space, and gaining height. There was a single adult swift present at the time, and just the one was present overnight.

2019-July-27 I checked the 6 gable-end boxes from inside the loft. The only thing different from 3 days ago is that I was able to see that there are 2 recently-hatched chicks in #g1a - I'll leave the hatching-date in the table as 'about July-24', as one of the chicks was clearly larger than the other.

While I was in the loft, a swift flew by me from one end of the loft to the other. I assume it was from soffit nest-space #w1r, as they can access the roof space from there. It's possible that the bird flew towards the loft light when I turned it on. I was able to pick up the bird, see that it was an adult, and allow it to fly from my hand through an open window. It's quite possible that it would have found its own way back to the nest-entrance, once the light was off again. I could see another swift sitting on the insulation near nest #w1r.

2019-July-24 The third and last young swift fledged from nestbox #1 at 06:30 this morning. The single young swift fledged from nestbox #4 at 11:20.

I checked all the accessible boxes: 2 of the 3 young swifts have left box #g6; all other young swifts developing and nearly ready to go; a pair of adult swifts were sitting on the nest in #g1a and I didn't want to disturb them - assuming they still have at least 2 eggs, it will soon be time for them to hatch.

While in the loft checking the gable boxes, I could see 2 (presumed young) swifts in soffit nest-space #w1r, which isn't accessible, but these 2 had climbed to a position where I could see them. There are also young in soffit nest-space #w2r, and I think in box #b1.

2019-July-23 From what I'm seeing on camera from nestbox #1, it looks like one young swift fledged yesterday (2019-July-22), and one today (2019-July-23). Just one left by mid-afternoon today.

2019-July-16 Today, I saw a swift enter another 'starling' nest box (they're breeding in the one I call #sb2). This new one is in the same position where #sb2 used to be when it was was first prospected by swifts, so perhaps not surprising that another bird is investigating it.

2019-July-8 A clearer view of nest #g1a: 2 eggs present. There might have been 2 yesterday, but I could only see 1.

2019-July-7 A quick check of the 6 gable-end nest boxes. An adult swift was present in #g1 and at least one egg - a re-lay (nest #g1a) in this box after earlier eggs and one chick were removed by swifts. Chicks developing fine in #g3, #g4, and #g6 (adult birds were present, so didn't want to spend long trying to look at the chicks). There are some feathers stuck to the nest-concave in #g2, so maybe swifts are finally making a start in this box. Nothing in #g5 except some bits of grass brought in by sparrows a long time ago.

2019-July-2 I added a camera to the 'starling' box #sb2 in which swifts are raising 2 chicks (1 egg failed). They raised 2 chicks in this box in 2018, after first 'prospecting' it in 2017. See the usual 'live video' page (link above). It shows the way the adults just 'crash' into the box and drop to the floor, and climb the rough wood 'ladder' to the entrance when they are leaving. I provided the 'ladder' when a swift got stuck in here several years ago.

2019-July-1 A quick check of the 6 gable-end nest boxes: an adult swift was present in #g1 but no new eggs; chicks developing fine in #g3, #g4, and #g6 (an adult was also present in #g3, so couldn't confirm that all 3 chicks were there); and still no signs of any activity in #g2 or #g5.

2019-June-26 The 2nd failed egg in nestbox #4 (where just one hatched) was removed from the nest by the swifts a day or two ago, so (as in 2017) about 11 days after it might have been expected to hatch.

I've just changed the lens of the video camera in nestbox #1 from 8mm (a somewhat zoomed-in view, good for eggs and young chicks), to 3.6mm ('standard' lens, better now the chicks are bigger).

2019-June-23 There are no 'replacement' eggs in #g1 yet - maybe there never will be, but I'm just noting it, so that I'll have an idea when they were laid if I find some later.

I thought that swifts were using brick-size box #b2, as previously, but over the last couple of days, I've seen sparrows in #b2 and swifts in the adjacent #b1. With these, and the soffit-spaces, which can't be inspected, the presence of young swifts can be detected by them looking out of the entrance, or by droppings outside.

2019-June-21 An inspection of some of the non-camera nests:
#2 - 2 recently hatched chicks.
#3 - 3 chicks, all different sizes, estimated first hatched ~2019-Jun-16.
#5 - 3 chicks, estimated as similar to in #4, i.e. hatched ~2019-Jun-13.
#g1 - nest empty, dessicated eggs/embryo on ground outside (one chick and 2 eggs seen on 2019-Jun-16).
#g3 - 3 chicks, estimated first hatched ~2019-Jun-16.
#g4 - 3 chicks, estimated first hatched ~2019-Jun-16.
#g6 - 3 chicks (2 seen previously on 2019-Jun-16).
#sb2 - 2 young chicks, and a failed egg. Estimated first hatched ~2019-Jun-16.

The unexpected thing in those is the empty nest in #g1, which 5 days ago had a young chick and 2 eggs. On looking on the ground outside, I found 2 dessicated broken eggs, 1 clearly with an embryo. My guess is that the same or a different pair of swifts have removed these and will re-lay.

So in total, that's 23 developing chicks in the 10 inspected nests. In 2018, 22 chicks fledged from the same 10 nest-places. There are also swift nests (not inspected) in soffit-spaces #w1r and #w2r, and maybe in brick-size box #b2.

2019-June-16 The first egg in nestbox #4, which I replaced after it was removed (slightly damaged) by an 'intruder' swift, has been removed from the nest by the parent birds. I'm not sure whether intentionally (I saw the event on camera). It had time to hatch before this if it was going to. One of the other eggs hasn't hatched either (still in the nest, but getting too late), so just one chick.

A quick check of the gable-end boxes showed: 1 very young chick and 2 eggs in #g1; 2 very young chicks and 1 egg in #g6; and in #g3 and #g4 a sitting bird obscured the view. Will #g2 and #g5 be occupied for the first time this year? Is it significant that these unoccupied boxes are both in the middle of the row of three?

2019-June-13 At 13:08, one of the eggs in nestbox #4 was seen to have hatched (and the other two eggs hadn't yet hatched).

2019-June-12 At 12:22, at last a sighting of all 3 chicks on camera in nestbox #1. Until now, I'd only seen 2 at once, as the adult birds were always in the way.

2019-June-9 At 12:03, the first egg was observed to have hatched in nestbox #1. So far, I've managed to spot the chick and one egg, but as usual, the parent birds are usually in the way. I'll assume it's just one of three eggs hatched for now.

I checked the 6 gable-end boxes, not helped by a wasp-nest being built in the loft nearby, so I wore my bee-keeping outfit. All was 'as expected', with a swift sitting on eggs (or young?) in #g1 #g3 #g4 #g6, and nothing in #g2 and #g5, so those 2 are still free if/when there are any 'prospecting' swifts (I've not seen any of that so far this year).

2019-May-27 At 13:58, the first clear view of the nest in nestbox #4 showed that the 3rd egg was laid sometime this morning. The first egg was replaced in the nest in #4 after being 'fostered' in nestbox #5 for 3 days (by today, #5 had 3 of their own eggs, plus this 'extra' one).

2019-May-25 At 10:42, the camera recorded the 2nd egg in nestbox #4 (as reported below, the first egg was removed by an 'intruder' swift yesterday). In the same recording, the pair of birds at the nest were disturbed by another attempting to enter - the 'intruder' dropped to the ground below the nestbox, where I moved some potted plants to give it a clear way to take off (which it did). Will it be back to remove this egg as well (if indeed it's the same intruder)? [Later: no, it didn't return.]

2019-May-24 Action in nestbox #4 today: Both swifts were present last night and this morning. At 14:34, with no birds present, a swift entered - maybe a 'stranger', as it was looking around as though unfamiliar with the place. At 14:36, it picked up the single egg, and removed it towards the entrance. At 14:44, it departed. I decided to look inside the box, and found the egg still there, but not in the nest - I decided to replace it in the nest, thinking that if it was really determined, then the swift could remove it again. At 16:23, probably the same swift returned, and at 16:28 it removed the egg again, this time outside the box, and departed. I found the egg on the ground below the nestbox. So what's that about? We'll see if a pair of swifts returns tonight - still plenty time for more eggs. The removed egg had some slight damage - maybe from hitting the ground. As a bit of an experiment, I marked it with a pen, and added it to the nest in box #5, which had one existing egg. I'll probably never know what happens to it, as there's no camera in that box, but I might find the shell at the end of the season.

Around 17:00, I checked the 6 gable-end boxes from inside the loft. There was 1 egg in #g1, a pair of swifts in #g4 (couldn't see whether any eggs), and nothing in the other 4 (swifts might be returning at night, but no eggs yet). I should probably check after dark which are occupied.

2019-May-23 The first egg in nestbox #4 was sighted at 11:00 this morning.

2019-May-22 A third egg in nestbox #1 was sighted at 11:44 this morning. I checked 'starling' box #sb2 since it's easily accessible - no eggs yet, but the pair of swifts are still seen going in and out on camera. Also looked in box #2 (easily accessible from an upstairs window)- quite a lot of house-sparrow nesting-material, but I think that swifts are in occupation here.

2019-May-20 A second egg in nestbox #1 was sighted at 11:09 this morning.

2019-May-18 The first egg in nestbox #1 was sighted at 10:47 this morning, when the pair of birds first left for the day.

2019-May-17 I've aimed the 'outside' camera at 'starling' box #sb2. The swifts (which bred here last year) seem to have taken posession, with a pair seen going in this morning. I don't know whether the starlings were planning a second brood, but starling-activity here is limited to one clinging on the outside of the nest-hole occasionally, but not going inside.

2019-May-16 At 11:36, a second swift arrived back in nestbox #4 (one had been there for about 20 minutes - I can't say which was the newcomer).

After all yesterday's starling-activity around their nestboxes, there has hardly been any today. My hand-tame starling arrived with a lame leg (mainly standing on just one) - has he been fighting a swift? I've occasionally seen garden birds with a bad leg - usually it seems OK again by the next day.

I saw a swift enter nestbox #2 for the first time this season.

2019-May-15 At 14:54, the first swift arrived back in nestbox #4, and stayed for an hour before heading out again. I saw a swift enter soffit-space #w2r.

I suspect that the garden starlings are planning second broods. They are displaying near their nestboxes. In the most easily observed starling box (#sb2), the male starling happens to be the hand-tame one I've known for 3 years - he's been removing old nest material, and adding new. This box was used by swifts last year after the starlings had gone, but there wasn't a starling second brood last year.

As half-expected above: at 19:40 a swift arrived at starling-box #sb2, and was brought to ground by one of the resident starlings (after all, the box is quite close to the ground, compared to most swift nest-sites). It was easy to see what a disadvantage the swift is at, once on the ground - just able to crawl around, and as I know from before, how small a swift looks close up - about half the weight of a starling. I gave the swift a bit of help - just keeping the starling away while the swift took off, and gained height circling the garden before flying off. I expect this battle will continue - there's another unoccupied starling-box a couple of metres higher, if the swift fancies trying that instead.

At 20:56, after endless fly-bys (was it checking for starlings, having been attacked by one last time?), a swift entered starling-box #sb2. Evidently the starlings aren't staying in there for the night, as they haven't got eggs or young at the moment.

2019-May-14 Swifts are entering soffit-space #w1r. Today, I saw a mid-air tussle between a swift and a house-sparrow, no doubt after the swift had approached a nest-space which the sparrow is also interested in. The swift was nearly brought to the ground (from past experience, they are perfectly capable of taking off from the ground).

At 18:48, a pair of swifts were making repeated approaches to nestbox #5 (full of house-sparrow nest), and one of the swifts managed to enter (no sparrows were present). Not necessarily the first time a swift has managed to enter - just the first time I've seen it.

2019-May-13 In addition to those mentioned already, today I saw swifts enter #g1, #3, and #b2 - all locations which were used in recent years. As last year, sparrows are currently using brick-sized #b1.

2019-May-12 At 20:05, I just happened to see a swift enter gable-end box #g3, and another trying to get in #5, which is mainly full of a house-sparrow nest. Both of these boxes have been used by swifts for a few years now. I don't think the swift succeeded in entering #5 - not because of sparrow aggression, but just it being blocked by sparrow nesting material. I'll observe what's going on there - I don't intend interfering, unless it becomes obvious that this isn't an active sparrow nest - I could always add yet another swift-box nearby.

2019-May-11 At 07:41 this morning, a second swift arrived in box #1 to join the first one.

2019-May-10 For the two nestboxes with cameras, so far this season, just a single bird in #1, and nothing in #4. I've not really been observing outdoors, as the weather hasn't been good, but I just happened to see a swift enter gable-end box #g6 today (swifts first occupied this box in 2016, and bred in 2017 and 2018).

2019-May-8 The single swift in nestbox #1 stayed overnight last night, and didn't appear bothered by the sudden switching of the new lighting (see here), off at dusk, and on at dawn. Maybe it looked round briefly to see what had happened, but it's difficult to say.

2019-May-7 I had not seen any swifts at all in 2019 until one returned to nestbox #1 at 12:16. It stayed for about 40 minutes before going out again.

2019-April-29 Only a week or so until swifts might be expected to arrive. Some weeks ago, house sparrows were taking a lot of interest in the swift-boxes, and going inside some of them (in addition to their own nesting places elsewhere). I decided to block the entrance of the two camera-boxes, as I didn't want a sparrow 'haystack' blocking the view. Today, I unblocked them again in case swifts arrive early. I haven't had sparrows in the swift-boxes before, but there's what I assume is an active sparrow nest in swift box #5, and some sparrow nesting material in #2. I'm going to let nature take its course with these - I've often seen swift-boxes elsewhere where swifts have nested on top of sparrow-material, possibly after evicting the sparrows!

After swifts used a box intended for starlings in the last two seasons, the 2019 season starts with starling boxes in the same configuration as last year. Starling box #sb4 was taken down over winter, so starlings didn't start nesting in it. I've just put it back up. Below it on the same wall, the starlings are raising 4 chicks in box #sb2 (used by swifts to raise young last year). Last year, the arriving swifts initially went into #sb4, but as soon as the starlings left #sb2, the swifts transferred to that one (which they'd 'prospected' in 2017). We'll see what happens this year.

2019-February-8 I have just been updating the web pages ready for the 2019 season. The only news so far is that I have replaced the daytime white lighting in the two usual camera boxes - the new lights seem a lot brighter.

The two video cameras are not yet online for the 2019 season (link to live video above).

This is nestbox #1 in which swifts raised young for the first time in 2012.

In 2013 (with a camera in the box for the first time) they raised 3 chicks; 2 in 2014; 3 in 2015; 2 in 2016; 1 in 2017; and 2 in 2018.

The dates of arrival of the first swift in this box were: 2013 May 6th evening; 2014 May 5th evening; 2015 May 5th evening; 2016 May 4th afternoon; 2017 May 6th midday; 2018 May 7th afternoon; 2019 May 7th afternoon.

This is nestbox #4 in which swifts raised young for the first time in 2014 (with a camera in the box).

2 chicks were raised in 2014; 3 in 2015; 2 in 2016; 3 in 2017; and 2 in 2018.

The dates of arrival of the first swift in this box were: 2014 May 7th evening; 2015 May 4th evening; 2016 May 5th evening; 2017 May 5th evening; 2018 May 18th morning; 2019 May 15th afternoon.


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Author: Clarke Brunt (clarke.brunt@viridis.net)
Last modified: 7th September 2019