Swifts diary

The colony of swifts that nests in the Museum tower has been the subject of a research study since May 1948. It is one of the longest continuous studies of a single bird species in the world, and has contributed much to our knowledge of the swift.

 

What is happening this year?

Details of nesting pairs and their chicks will be updated each week throughout the summer months on this page. The live feed below is from one of two webcams placed in nests in the tower and will stream images throughout the nesting and fledging season each year. Below is a week by week diary of how they are faring.

Swifts Diary 2020

  • 1 May 2020

    The good weather at the end of April seems to have brought the swifts back early this year. The first swift was seen flying around the tower on 27 April and two birds were recorded sitting in the nest boxes on 30 April. On average the
    first swifts in the tower arrive around 5 May. Hopefully, if the good weather continues, this early arrival is a portent of a good breeding year.

     
  • 7 May 2020

    Fine weather has seen an increase in activity around the tower, with screaming parties of up to nine swifts surveying the nest boxes. Inside the tower we have now seen two pairs sitting and four single birds sitting, facing the entrance holes
    and vigorously screaming back at all comers to defend their sites. There is also evidence of some new nest material being added in other boxes as feathers caught on the wing glisten with the fresh saliva used to glue them down.

     
  • 13 May 2020

    Strong cold north-easterly winds have significantly lowered temperatures this week but despite far from ideal conditions for flight and foraging we counted seven pairs of birds and one single bird in the boxes. Unfortunately, though in nest
    boxes nearby, none of these birds has chosen to take up residence in our webcam box. As temperatures are expected to warm next week we expect more swifts to arrive and have our fingers crossed that you will soon be able to watch a pair on
    the nest live for yourselves!

     

  • 20 May 2020

    Rising temperatures and the easing of the northerly winds have seen an increased number of birds arriving and nesting, and we have recorded the laying of the first eggs of the year. This week we counted 21 birds on the nest, with others
    clearly out feeding, and also ten eggs.

     

  • 28 May 2020

    The continued warm weather has brought an increase in occupied nests and breeding activity. There are now 27 occupied nests, with signs of activity in others. The nestcam boxes have finally been occupied with one pair displaying a clutch
    of two new eggs.

     

  • 5 June 2020

    We have 39 nests occupied, most with birds sitting in them, so only 23 eggs were visible but we also have our first chicks. Four were observed but eggshell and faint cheeps from other nest boxes suggest there are more.

     

  • 10 June 2020

    The swifts have had another good start to the breeding season. There have been 41 breeding attempts this year so far; of these 33 are currently active with eggs or young. The remaining eight either did not lay or in two cases laid but
    deserted. On this visit, 30 adults were sitting tight but 33 eggs were visible, as were 38 young. The young were all no more than ten days old and indeed some looked to be newly hatched. If all are successful there should be at least 70 young
    fledging this year.

     

  • 16 June 2020

    The fine weather continues to encourage the swifts. Today 36 nests are in use. There are 29 adults in the boxes, with 34 eggs and 45 young, plus at least six boxes where the adults are sitting tight and hiding whatever they are sitting on.
    Humid conditions are perfect for insects and that means more food for the swifts; the young seem to be well-fed with little begging being heard until an adult enters a box. Should the weather continue as it is at present, we could expect there
    to be over 80 young this year.

     

  • 22 June 2020

    Swifts were very active and noisy today, screaming around the tower in the sunshine. Inside the breeding colony we now have 40 active nests plus one more containing a single cold egg. There were 30 eggs visible and 56 energetic young but
    also one dead chick; four adults sat tight so may be on eggs or small young, time will tell. In total, 27 birds were sitting in the nestbox and four of these were accompanied by their partner. Nestboxes N8A, E8A and S6B are now occupied
    and seem to be starting late with at least one egg in each box.

     

  • 29 June 2020

    Today we have a strong gusty breeze but it is dry. There are very few swifts around the tower despite the warm weather. Inside the tower, however, we have 38 active nests with 24 adults and six pairs in the boxes. Most of the small young
    are being brooded, especially on the west side which is where the breeze is coming from. There are 74 young visible today and 16 eggs, another six nests have adults sitting tight so they may be on either eggs or newly-hatched young.

    There is quite a spread of ages, some of the young have wing feathers half full length, others are newly hatched or fresh eggs, and there are youngsters of every stage in between. It seems to be a good breeding year for swifts thanks to a
    warm sunny May.

     

  • 6 July 2020

    Today was cloudy, dry and mild but with a strong gusty northerly wind. Few swifts were to be seen outside of the tower and reports of large movements of swifts heading south in the UK caused some concern given the recent cool days with
    rain during the preceding week. Inside the tower however, it was reassuring to find that 37 nests were still active. A total of 75 young were visible and 3 adults were sitting tight but with no signs of shells in the box, indicating that they
    were probably still on eggs. Ten adults were in boxes, these containing naked young, so adults brooding to keep the young warm. The temperature in the tower was an acceptable 18 degrees Centigrade but windchill in the boxes on the north face
    was a concern. Three adults were checked for rings but all were new unringed birds. This year the young are about seven days earlier than normal which is probably a result of the hot dry weather in May.

     

  • 13 July 2020

    It has been a cool week, generally overcast but with some sunny spells. The swifts are quiet today, just a few flying around the tower. There are 39 nests active in the tower with 68 young remaining in varying stages of development and at
    least one adult sitting on newly laid eggs.

    Fledging has begun and six young have flown the nest to date. Unfortunately there have also been two losses and two young have disappeared from a nest; it is not unusual for birds to fight over nesting-boxes and for the victor to eject
    a rival's young or eggs.

     

  • 20 July 2020

    It's hot and calm, the sky is clear of clouds and the sun is shining. Outside the tower, flocks of screaming swifts abound; in swirling bursts of sound they sweep around the building. Inside the tower there are now only 44 young remaining
    and many of these are sitting near the entrance of the box waiting for the time when they too can spread their wings and leave on the long trek to Africa. We still have one adult sitting on eggs! A very late breeding attempt, it may be okay
    if the weather stays warm. Thirty-three nests remain occupied so another breeding season is drawing to a close but much earlier than normal; we would normally expect the first young to be leaving this week but almost half of this year's young
    have fledged already. Insect food appears to be plentiful and the young birds feel fat and healthy.

     

  • 27 July 2020

    It's wet and windy today with no birds flying around the tower, so it looks as if summer has gone. Inside the tower, all is silent bar an occasional winnow coming softly from chicks in a few of the boxes. Only 18 active boxes contain
    the remaining 25 young. A year that started so full of hope with counts of up to 80 or more eggs and young has turned into a disappointing 62 survivors; of these 25 remain to fledge. The breeding season started early due to the really hot
    weather in May but this has deteriorated into wet and windy cool days. Fledging started about seven to ten days early this year and it looks as if all the swifts will be gone within the next two weeks.

    All the young were ringed this year and 28 adults either identified or ringed; of the adults, 17 were new birds, which may indicate that there is a problem with adult survival. Of our 147 nesting boxes only a maximum of 41 were occupied indicating
    that food may be the problem rather than nest sites.

     

  • 3 August 2020

    It's very quiet; only the occasional swift slides silently past the tower and flicks into a nest box. The quiet winnowing of a chick welcomes another meal. Inside the tower it is quiet too; only eleven nests remain occupied and most
    of these only contain one chick. Sixteen large chicks remain but many of these are sitting at the box entrance watching the outside world. I think all, or almost all, will be gone by next week but my Monday visit on 10 August will
    confirm the situation. Very few adults remain now, only six were seen today and these were bringing food to the remaining young.

     

  • 10 August 2020

    It's almost all over! We have two nests still occupied containing a total of three young swifts and these are getting ready to go. The screaming parties and most of the adults have already gone south and our final three chicks will soon
    join them on their winter safari to Central Africa.

    Tracking studies have shown that the birds follow the west coast of Europe through Iberia then sweep across the Sahara. They then head eastwards to the rain forests of the Congo where most spend the winter months, although some continue
    towards the east coast of Africa. Six months later, in spring the birds head west again into the Sahel where the rains provide insects for them to fatten up before the long trip north again crossing the Sahara back to the breeding grounds
    of Europe.

    Swifts are nest-faithful and we often find ringed birds in the same nest box every year for as many as ten years in succession. The average life of a swift is up to ten years, although the oldest known in the UK was ringed as an adult,
    so must have been at least 2 years old when ringed, and it was re-captured 18 years later.

     

  • 17 August 2020

    It's all over for another year. The final three young swifts left for the rain forests of Central Africa during the week and the tower is once again silent until they return next year. It was a strange breeding season; the early weeks
    were full of hope and hot weather, then June happened - cold and wet weather discouraged many. Two adults were found dead, eggs were being ejected from nests and chicks began to die. A situation probably caused by a combination of cold wet
    weather and lack of insect food.

    We have 147 nest boxes in the tower and this year there were 56 breeding attempts (defined as an occupied nest with at least one egg) but of these only 33 successfully fledged any chicks. Of those that failed, 14 had birds sitting, but no
    eggs were confirmed so these may have been roosts and nine others failed at either the egg or chick stage.

    On a more positive note, 69 young were ringed and fledged; 20 new adults were ringed and 12 adults re-identified from earlier years, plus one adult joined our colony having been ringed on Merseyside.

 

The average numbers of young swifts ringed each year over the last 50 years are:

  • 1963–72: 36.7
  • 1973–82: 70.4
  • 1983–92: 100.0
  • 1993–2002: 99.2
  • 2003–12: 81.1
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