Nightjars on the Pebblebed Heaths

Members of the group have for some time had an interest in Nightjars on the Pebblebed Heaths, so when we were approached about tagging nightjars we were keen to take up the opportunity.  The BTO has been running a project where individual nightjars are fitted with gps locators.  These devices are battery powered and can run for about a week, plotting the position of the bird during the night.  The birds were caught while at the nest, since the bird needs to be recaptured a week later to recover the tag.  The female is most often caught in the early evening and then the male may also be caught if the nets are left a little later as he comes in to care for the eggs/chicks.  

The work was carried out in coordination with the RSPB at Aylesbeare Common and the Clinton-Devon Estates on the Pebblebed Heaths.  During the period five nests were located.  The first on Aylesbeare Common was unfortunately predated before we could capture the adult birds.  The second nest belonged to birds found displaying on the night we attempted to catch the first bird.  This nest was very close to a path also on Aylesbeare Common.  The nest was found be myself, and the female was duly trapped and tagged.  Unfortunately she was not recaptured despite extensive attempts and a number of possible bouncing of the bird from the net.  As a result the tag could not be recovered.

Myself, Fiona from the RSPB and Robin with the nightjar in the bag.

The tracker is fitted to the two central tail feathers.

The next bird to be tagged was on Bicton Common.  This bird was very much in the open and was easily found by myself, though the general area of the nest had been reported to me by Lesley from the Clinton-Devon survey team so I knew where to look!  This bird was captured and the tag fitted.  This tag was recovered a week later.  Lesley found another nest on the Hawkerland Common.  We set nets to catch the female and successfully tagged her.  While we were processing this bird we left the net up in the hopes of also catching the male and we were in luck!  We succeeded in catching and tagging this pair and both tags were duly recovered a week later.  

Typically nightjars will open their mouths very wide and hiss like a snake

Beautiful plumage giving excellent camouflage.

In addition we attempted to catch birds at two sights identified by Ed from Clinton-Devon.  One was on a plantation area just north of the Warren car park, and the other was on Stowford Common.  Despite several attempts no birds from these nets were trapped, although both appear to have fledged successfully.

All the nests encountered,apart from the very first, seem to have fledged young.  All bar the nest on the plantation fledged two chicks, while the plantation nest fledged one chick with a second egg which did not hatch.

A typical clutch of two juvenile nightjar chicks from the Picton Common nest

Initial results from the trackers have been very interesting. Hopefully we will be able to post some more information about this in due course.  We are also hopeful that the project will continue next year!

The field work on this project was extremely time consuming and I would very much like to send my appreciation to Adrian, Robin and Alan who joined me on almost all the sessions as well as all those who came along for one or two.  

Swallow Roost Catches

On two of our general ringing sessions this year we caught swallows.  The first, on 15th August, we caught two swallows very early in the morning in the nets in the reeds behind the Discovery Hut.  On the 23rd August we caught a further 5, again early in the morning behind the Discovery Hut.  At this point I started to think that maybe there was a roost in the reed bed and these were birds leaving the roost.

We tested the theory on 31st August.  6 nets were set around the reed bed.  We started ringing early afternoon and caught a few of the classic species for this areas, including sedge, reed and Cetti's warblers as well as some other birds, including a linnet.  The first swallows started to appear about 7pm and we caught a couple on the penultimate net round.  Then the roost started, with sightings of pied wagtails, swallows, sand martins and starlings all circling the reed bed.   Many birds joined the roost and even while extracting our first roosting birds many more were circling overhead.  The final total for the day included 105 swallows, 6 sand martins and 2 pied wagtails.  It was an impressive sight to see all the birds going in to roost.

Having had success on 31/08 we tried again the next week on 06/09 when we again started early afternoon and included a kingfisher as our first bird of the day.  The roost was not as big and there was some concern we might not catch many birds, but then a wave of birds came in to roost.  Starlings were again present, though we did not catch any.  The final total included 86 swallows and 5 sand martins.

13/09 was similarly successful, with a good total of 18 birds caught before the roost including the usual warblers and a good number of chiffchaffs.  The final roosting total came from two waves of birds.  One early wave gave about half the catch, but was followed about half an hour later by a second wave.  The total for the day included 99 swallows and 13 sand martins.  None of the roosting birds caught in any of the three sessions were either controls of birds from outside the area or retraps from previous roost catches.

We made another attempt on 22/09, but disappointingly for us there was no roost present.  We did manage a catch of 7 birds before the roost, including a sedge warbler ringed elsewhere.  Hopefully details will follow shortly!  In addition we caught 3 Cetti's warblers, 2 reed buntings and a chiffchaff.

A mist net full of Swallows 

Processing the catch

Adult Swallow tail streamers, the length is used to sex the bird

Adult Swallow head pattern

More processing...

Birds kept overnight in bags & released at first light

Catching Up

Despite the lack of posts since May the group has been very busy.  Rather than post a blow-by-blow account of our sessions since the last post, it probably makes most sense to give you a series of posts about our activities in topics, between then and now.

We have, of course, continued with some general ringing, targeting warblers particularly, but any breeding birds at the Wetlands.  This gives valuable information about what is present and how it is faring in the breeding season to help inform the Wetlands management and also acts as good training for our trainee ringers.

One species we have particularly been focussing on in this period is the sand martins.  With access to the breeding colony to ring nestlings, as well as catching adults in front of the wall we have spent quite a lot of time working with these fascinating birds.

We have also been involved with a project with the BTO fitting gps tags to nightjar.  This work will hopefully provide data about the birds activities during the night, focussing on their foraging behaviour.  This has meant a number of evenings spent trying to catch female nightjars at their nest sites, as well as possibly catching males.  This project has now finished for this year, but hopefully it will be renewed again next year.

As soon as the nightjars and sand martin field work finished we started ringing at a swallow roost at the Wetlands.  Though we are aware that there has been some roosting of swallows we have never taken advantage of this for ringing, and we have started an approximately weekly catch at the roost.

And finally last week a team of four spent four nights on Lundy Island ringing, and enjoying the island life.  A good time was had with a good number of birds handled.

Hopefully blog posts will begin again in a more predictable way after our sessions in the coming weeks, but for now please enjoy our summaries by topic.

Mist netting 17/5 & Sand Martin pulli

On Sunday 17th May, two of us turned up very early for a mist netting session in the Willows, an area which hadn't been ringed for quite a while. We set 5 nets, and caught 34 birds of 12 species.

In the breeding season, we always check to see if there's evidence of breeding by blowing on the underside of the bird to part the feathers & show either a brood patch (BP) or an enlarged cloacal protuberance (CP). An enlarged CP indicates that the bird is a male, but a brood patch can be present in both females & males depending on the species & whether the male is involved in incubation. 

We caught a male Dunnock which had an obviously enlarged CP, indicating recent breeding. 

Dunnock

Enlarged CP of male Dunnock

A male Great Spotted Woodpecker was caught which had a large brood patch as they help the female to incubate the eggs. 

Male Great Spotted Woodpecker

BP of male Great Spotted Woodpecker

The woodpecker had a moult limit in the Greater Coverts (GCs), with the new inner feathers being a darker black than the old brownish outer GCs & Primary Coverts. The Median & Lesser Coverts had all been replaced during the post-juvenile moult, & were the same dark black as the inner GCs.

Male Great Spotted Woodpecker, age code 5

We caught a number of Blackbirds, including a bird hatched this year which was still in its full juvenile plumage, and therefore age code 3J. Very young birds have very little feathering on the belly, so care must be taken not to confuse them with a female/male with a BP in species where the juvenile & adult plumage are very similar.

3J Blackbird showing juvenile feathers with 'thorns'

Speckled front of 3J Blackbird

Bare belly of 3J Blackbird

The mist netting continued whilst a team conducted the second Sand Martin pulli (chick) ringing session of the year. Two broods had been ringed on the previous Sunday & on this occasion a further 15 broods were ringed, totalling 75 birds in all. Full nest records are being completed for each brood, which include the stage of development of the feathers. 

Sand Martin pulli with feather's yet to emerge from sheaths

More developed Sand Martin pulli 

The SM pulli team.

	Ringed	Retrapped
Blackbird	5	1
Blackcap	3
Blue Tit	2	1
Cetti’s Warbler		1
Chaffinch	2
Chiffchaff	2
Dunnock		3
Great Spotted Woodpecker	1
Great Tit		5
Reed Warbler	2	1
Robin	3
Wren	1
	21	13

Fabulous photos....mist netting 10/11th May

A small group of us had two very early mornings mist netting around the Discovery Hut on Sunday 10th & Monday 11th May, and also ringing the first two broods of Sand Martins in the Sand Martin cliff. We were pleased to be joined on both days by Jimmy Irwin, a professional photographer who has just started a long term project centred on bird ringing activities. He will be working with various other ringers, but as the first, we  were able to give him an introduction to the practice. So sit back & enjoy Jimmy's fabulous photos!

And one of mine.... Jimmy photographing the ringing of the First brood of Sand Martins of 2026. 

10th May	Ringed	Retrapped
Blackbird		1
Reed Warbler	4	5
Robin	1	2
Song Thrush		1
Wren		1
	5	10

11th May	Ringed	Retrapped
Blackbird	2	2
Blackcap	1
Cetti’s Warbler		2
Dunnock		1
Reed Warbler	3	9
Sand Martin	1	1
Sedge Warbler	3
Wren		1
	10	16

First juveniles of the year - mist netting the Crop Field area, 8th May

A team of three early risers set nets around the reed bed and crop field areas of the Wetlands and were soon joined by four more.  One of the first birds in the nets was our first juvenile bird to be ringed of the year - a robin.  I am very fond of these birds as they initially look very little like their parents in terms of their plumage, and then gradually moult into something much more similar.  This particularly bird was still very much in juvenile spotty plumage, with just a very few feathers in pin.  

Also quite early on we caught a greater spotted woodpecker.  We don't catch too many of these birds so it was a nice surprise. Though they are an attractive and interesting bird they are also very noisy and inclined to peck (perhaps unsurprisingly).  Just as we do for almost all our captures, we record biometrics, in this case the wing length is being measured.

This bird is a male, as the back of its head has a red stripe.  This is perhaps  more clearly seen on this picture.

 

Other species caught included linnet and house sparrow, which we rarely encounter in other areas of the reserve.

We also caught three Cetti's warblers which are one of our target species.  I am often reminded of how similar the head of a Cetti's warbler is to a wren. 

This is a Cetti's warbler...  

And here is a wren...

Potentially the highlight bird, which I have no picture of, was a greenfinch which was already ringed, but not with one of our rings, so potentially an interesting recovery.  We await the original ringing details with interest!

Overall a most enjoyable morning with a good number of birds and a good variety of species.  The full list is in the table below.

And thank you to Bev for most of the pictures on today's post!

News from behind the sand martin wall - 29th April 2026

I had the pleasure of joining Doug behind the sand martin wall for a full survey of the nesting holes.  While I did some of the ringing last year, and have helped out a little on a few occasions, I did not have a chance to join in with a full survey last year.

The process is very efficient and gives great data for nest record submissions, as well as to know when we need to be on hand to ring the pulli.  The holes are generally surveyed twice in a week, with a full survey once a week and a survey of the known active holes on a second day.  An endoscope is used to check each nest through a small port in the back of each nest hole so we do not need to visit the front of the wall, and so there is minimal disturbance.

We found 101 nest holes with well formed nests, which compares with 89 holes which were used in 2025.  There were 59 nests with eggs and 41 holes containing substantial amounts of nesting material but no eggs as yet.  There are a further 23 nests cavities with some blades of grass which may be the beginnings of a new nest.  The final nest (for those of you adding up as we go along!) has the first chick hatched of the year!  

This bird obviously hatched on the day and we will see on the next survey how many of the other eggs have hatched.