Ringing on 5th September

On 5 September a minimal team (two of us!) ringed around the Discovery Hut. We set four mist nets. We also set up a couple of Potter Traps in the hope of catching a moorhen. Potter Traps are small cages with a trap door that is set off when a bird walks in to the trap. The AERG has recently joined a national moorhen colour-ringing project which aims to better characterise the the UK moorhen population, especially in relation to the movement of birds between the UK and mainland Europe. The project is co-ordinated by the Waterbird Colour-marking Group (https://waterbirdcolourmarking.org/moorhen/) who describe the project’s aims as follows. Despite being common, widespread, and familiar, the Moorhen is an understudied species in Britain and Ireland. There is limited information available on its movements at local, national, and international levels. While Moorhen are generally considered to be sedentary, previous ringing recoveries have shown that migratory European birds join resident birds in Britain and Ireland in the winter, and birds ringed in Britain and Ireland have been found on the mainland Europe, indicating movement to the continent. However, these movements have not been effectively recorded, and metal ringing alone does not provide sufficient data on regular or annual movements. Colour-ringing enables ringed birds to be easily reported and we will aim to encourage visitors to Seaton Wetlands to report their sightings of our colour-ringed birds which will help us to understand the dynamics of our local wetlands moorhen population as well as feeding into the national colour ringing project. In addition to the metal BTO ring that we fit to all birds that we capture, moorhens ringed as part of this project also receive an orange colour ring inscribed with three black characters. Our efforts paid off immediately with the capture of a juvenile moorhen which was duly fitted with colour ring number S00.

A total of 33 birds were caught including a lovely male Stonechat

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This stonechat was aged as a 3 - that is this year's bird - and one of the features of a first year bird is the colour of the greater coverts which have been replaced and are clearly darker than the browner juvenile primary coverts.

Last session for the week!

On the second day after our trip to Borrow Pit we were due to visit the Crop Field, but as there were only three of us we decided to stay around the Discovery Hut.

29th August

We managed a further 76 encounters of which 48 were new birds and 28 retraps.  We had half expected a good catch of chiffchaffs, and we were not disappointed with 13 new birds and 11 retraps, but we also had a good number of sedge warblers and a few reed warblers too.  The highlight was probably the four swallows.  We don't normally have a roost of swallows on the Wetlands, or any nesting birds so they are quite an unusual catch for us unless they are feeding low over the reeds as they were today.

Robin and Adrian hard at work.

One of the swallows.

We also caught a couple of retrap Cetti's Warblers

Careful reading of the ring number

One of which had quite dramatic fault bars on its tail.

Species                 New Birds                Subsequent Encounters                 

Blackbird                                                          1

Blue Tit                       7                                    4

Cetti's warbler                                                   2

Chiffchaff                   13                                 11

Dunnock                                                           1

Great Tit                      2

Reed Warbler               4                                    5

Robin                           4                                    1

Sedge Warbler           10                                    3

Swallow                      4

Willow Warbler          4

Total                         48                                   28  =  76

...the posts keep coming.

On the day after we ringed at the Discovery Hut (see the last post) we ventured down to the Borrow Pit.  This is a site we have not ringed much recently.  The pit itself is a rather attractive pond with some nice surroundings.  Little grebe were present on the pit this summer and there are usually some small passerines around, with a few nest boxes and some good cover, but it is a small area surrounded by open field. The forecast was not fabulous but the novelty of the trip to the Borrow Pit attracted a team of five.

Four of the five in earnest discussion.

I arrived a little late, with the nets already up, and walking toward the ringing site I saw a rather attractive female sparrowhawk sitting on the pedestrian gateway.  Five minutes later...

Rest assured the small amount of blood belongs to the ringer not the bird!

A view of the wing.

We also caught a few of one of my favourite birds.

As well as good numbers of chiffchaff and a few other warblers in a total of 33.  Not surprisingly as we visit here rarely, all were new birds.  

As you can see from the top picture the weather was a little overcast so we finished before the rain at around 10 am, but overall it was an enjoyable session and we resolved to visit again soon.

Total for the day were:

Blackcap                       1                             

Blue Tit                        4

Chiffchaff                   15

Dunnock                      1

Great Tit                      1

Long Tailed Tit           3

Robin                          1

Sparrowhawk             1

Willow Warbler          2

Wren                           4

Total                          33

Like London buses...

Continuing with recent ringing news this post covers the first of three sessions in the last week of August during which we made a last gasp try for some sand martins in front of the sand martin bank, visited Borrow Pit for the first time in quite some time in slightly dubious weather, and then finished off with another session at the Discovery Hut.

26th August

We decided to catch in the area around the Discovery Hut to see whether the recent run of good numbers of reed and sedge warblers would continue and to make a last try for some sand martins in front of the wall for the year.  We set similar nets to the previous session to see what effect four days would have on the warbler numbers. Interestingly the numbers of reed and sedge warblers were substantially reduced, with a total of 13 reed and 6 sedge warblers caught.  They were replaced by large numbers of chiffchaff and a good sprinkling of other species. We attracted quite a crowd as we were ringing outside the Discovery Hut and the weather was kind. 

We did manage 6 retrap sand martins.  5 of the 6 had consecutive ring numbers, with the 6 only 3 birds after the last of the 5 consecutive numbers, so it was no surprise that they were ringed on the same day, the 10th August.  The first 4 birds numerically were from the same brood of 4, while the other two birds were from 2 different broods.  We believe that the juveniles only stay around the bank for a few days after fledging and we plan to look at the data to see what it shows us when time allows.

Perhaps the last sand martin of the summer...

...showing the characteristic pale fringes on the feathers indicating a first year bird.

We had one unusual bird for us quite early in the day.  Here is the tail to see if you can identify it!

Probably the highlight of the day...

Or the wing.

It was, of course, a treecreeper. Since the first record in September 2009 we have only ringed 34 of these and this was the second of the year.  The previous one was in 2021.

We had some nice examples of birds to demonstrate moult.

This first year chaffinch shows one unmounted greater covert, more grey than the blacker moulted ones..

Towards the end of the session the onlookers were able to enjoy three kingfishers, which always attracted the crowds.

Adrian working on one of the kingfishers

Ready for the off.

The totals for the session were:

Species            New Birds             Subsequent Encounters

Blackbird                     1

Blackcap                     2                             

Blue Tit                       4                                2

Cetti's warbler            1                                2

Chaffinch                    1

Chiffchaff                 25                                7

Dunnock                                                       1

Goldcrest                    3

Great Tit                     2

Kingfisher                   1                                2

Reed Warbler              8                                5

Sand Martin                                                  6

Sedge Warbler            5                                1

Treecreeper                1

Willow Warbler          2

Better late than never.

The last ringing session reported on here was a month ago, but we have not been idle in that time. We have in fact been busy.  Too busy, it seems, to keep the blog up to date, so many apologies! 

Since the 15th August we have added 329 records to our total for the year.

Below is news of the first two activities after the 15th, on the 17th and 22nd August covering 83 encounters. 

17th August

We started with a brood of four sand martins ringed on the 17th August.  This was the last brood for this year, bringing the total number of pulli ringed to exactly 500.  Doug has been working tirelessly monitoring the nests and we have submitted data for nest records for all these broods to the BTO nest record scheme. This was a gigantic effort in monitoring, ringing and inputting and submitting the data.  There is an excellent summary in the previous article, which includes the birds mentioned below.

 A fascinating start to this project and we are already looking forward to next year!

22nd August

An early start on a beautiful day weather wise, saw us set nets again in the reed areas near the Discovery Hut at the Wetlands. We caught a total of 79 birds, the majority of which were reed and sedge warblers.  We had very few retraps, perhaps suggesting that birds were already on the move to their wintering grounds and that these were recent arrivals at the Wetlands.

The birds were

Species                New Birds        Subsequent Encounters

Blackcap                     1                             

Blue Tit                       3

Cetti's warbler            2                                1

Chaffinch                    1

Chiffchaff                   9

House Sparrow           1

Reed Warber             25                                2

Sedge Warbler          28                                3

Willow Warbler          1

Wren                           2

Three of the team of five

The chaffinch was a bird which hatched this year and was undergoing its post juvenile moult.  The blue head feathers identifying it as a male are starting to come through replacing the brown juvenile feathers.

First year male chaffinch

One of the Cetti's warblers was very young.

Another interesting and extremely successful session.

The Sand Martin Cliff

This article was written by Doug Rudge, the leader of the Sand Martin pulli ringing project, for the 100th newsletter of the Axe Vale & District Conservation Society:

After ten long years, the ‘Cliff’ was eventually used by nesting Sand Martins late in the summer of 2023 when 10 pairs bred in it… their late arrival that year was likely due to the loss of their natural colony earlier in the season, probably through erosion or flooding.  It is known that adult Sand Martins are very faithful to their usual nest sites, returning to them year after year to breed and this may explain why it took so long for them to take up residence at the ‘Cliff’.

In 2024 they returned at the very start of the breeding season and occupied a total of 38 nest chambers.  It is reasonable to assume that the increase in the number of breeding pairs was due to other displaced birds from the same nesting site lost the previous year, along with the offspring from the 2023 season. Juvenile Sand Martins return from their first winter in Africa as sexually mature birds so are able to breed straight away, and because they fully moult their feathers over the winter, they even come back looking like adults!

This year there was a significant increase in activity at the ‘Cliff’ with well over 100 nest holes seen to be visited… (although it turns out that not all were actually used!)

We have no way of knowing whether these were adult and juvenile Sand Martins returning from last year, although it would again seem reasonable to assume so; but the massive increase in numbers is significantly more than expected: Sand Martin survival rates from year to year are quite low, with only around 1 in 3 adults and 1 in 5 juveniles surviving to breed the following year! So we would only have expected around 40 nests this year based on an average productivity of 6.75 offspring per breeding pair.  It seems likely therefore that a second colony has been displaced locally and that they also used the ‘Cliff’ this year.

As a bird ringer and a member of the Axe Estuary Ringing Group (AERG), based at Seaton Wetlands, I have been leading an enthusiastic team of ringers who are keen to answer some of the questions raised above.  The only way to be certain whether individual birds are returning every year is to tag them: to do this we fit small, uniquely numbered metal rings to the birds legs, then attempt to re-trap them in future years to confirm survival rates and longevity…

The absolute best time to ring any bird is as a nestling because you know everything about it – the nest location, number of eggs laid, number that hatch, date of hatching, number that survive to fledge and whether more than one brood was raised in the same nest.

This year there were 87 successful nests, 36 of which had second broods, making a total of 123 broods raised! 

We fitted rings to almost all of the nestlings, exactly 500 in total! 

Doug fitting the 500th ring

We also targeted adult birds in front of the cliff, catching and ringing 118 of the breeding birds…  Three additional ‘adult’ birds were already wearing rings that had been fitted in France last autumn when they were juveniles heading south on their first trip to sub-Saharan Africa (some 2,500 miles away!).  We also caught and ringed 18 additional juveniles, suggesting that there may also be young birds from other colonies roosting in the ‘Cliff’ (because we didn’t fail to ring 18 of the nestlings!).

It will be really interesting to repeat this exercise in years to come to see how many ringed birds return. Next year we would expect around 40 returning adults and 100 returning juveniles...  I’ll let you know how we get on.

In the meantime, if you would like to see what we got up to, we featured on the BBC Countryfile programme from Seaton Wetlands, which was broadcast on 22^nd June 2025 and is available on BBC iPlayer for 1 year. Happy viewing!

There have been a number of posts on this blog relating to the progress of the project during the season, beginning with a post on 28/5/25. 

https://axeestuaryringinggroup.blogspot.com/2025/05/sand-martin-