Author: Braydon Forest & Beyond

This will be the final chapter on this topic – unless someone else decides to go all zealous over something that is not necessarily supported by the data available, closing off other avenues of investigation. I intend to cover off the situation regarding that horrible disease Trichomonosis.

From personal anecdote, I know that when I moved to north Wiltshire in 1997 I could find flocks of 30 or so Greenfinch coming to my garden. Back in those days I had a bird table as well as hanging feeders. Everything was always cleaned and disinfected on a regular basis but, of course, wood has places for bacteria, viruses and parasites to hide and possibly avoid the disinfectants. I ditched the bird table two decades ago. Regardless of my precautions, I would occasionally see a Greenfinch showing signs of Trichomonosis. No more than one a year, and I would take down the feeders, clean, disinfect and leave down for a week. I have no idea where they caught it from, but you notice them when they come to your garden, which perhaps explains why so many are prepared to conflate the two: correlation = causation, the bane of science!

I have not seen any sign of any bird with Trichomonosis in my garden for nigh on a decade. These days, the local population has shown good signs of recovery. This year I regularly have four or five pairs visiting the feeders in my garden and I have heard at least three singing males within earshot of the garden. My largest recent sighting in my garden was 25 individuals, in the first week of February this year.

Whilst our group ringing results are very much of the yo-yo variety, there is a distinctly upward trend (which would be better if I ringed in my garden more frequently than I have done recently):

There is no doubt: there was a massive outbreak of Trichomonosis in the west country of the UK in 2005, primarily affecting Greenfinch and Chaffinch (as if Chaffinch didn’t have enough to cope with, with Fringilla papillomavirus as well). However, the parasite had been in the UK for centuries in the bird world, endemic in pigeons and doves. Was this the source of transfer to the finches? If so, what was the mechanism?

It is almost certainly spread within species by infected individuals where both courtship feeding and feeding their young involves regurgitating food: an excellent method of passing the Protistan, Trichomonas gallinae, from the host to a previously uninfected other. It also passed into various birds of prey, noticeably Sparrowhawk and, no doubt, if illegal persecution stops, it will be found in UK Goshawks – because it is, and is long established as such, in European populations. Some of the Sparrowhawk and Goshawk’s favourite prey, particularly female Sparrowhawks, are pigeons and doves, so it is not hard to understand how that transference might have happened. That is something that has been seen the world over, as evidenced by the paper referenced below by de Chapa et al. What is not so clear is exactly how it transferred into Greenfinch and Chaffinch, presumably from pigeons and doves, but, seemingly, not into other species common at bird feeding stations, if bird feeding is the source.

Something else that I find distinctly odd: Goldfinch. They are unarguably the commonest finch found at UK garden feeders these days. I have not seen any reports of UK Goldfinch showing signs of Trichomonosis, certainly not seen any sign in my garden, and they have undoubtedly increased their population significantly since 2005! I have ringed just under twice as many in my garden as I have the next commonest species (Blue Tit, unsurprisingly). However, studies in France have found that the parasite is spreading through their population over there. (Chavatte et al., 2019). The latest RSPB Big Garden Birdwatch results showed that they had gone up one place in their top 10 observations. Why aren’t we seeing the French situation impacting Goldfinch in the UK?

One issue that I have with the story of the spread of Trichomonosis is that, if the anti-bird feeding cohort are to be believed, the UK is not only responsible for it spreading throughout our susceptible birdlife, primarily Greenfinch and Chaffinch, but, apparently, responsible for spreading it to all of the birds that have now caught it in Europe! The bird feeding “boom” in the UK happened in the 1980’s. I would be relatively certain that this was, in part, due to the introduction of the RSPB’s Big Garden Birdwatch in 1979, encouraging people to take more notice of and engage more with, the birdlife in their gardens.

I am not blaming the RSPB for this being the cause of the spread of Trichomonosis. To start with, why did it take 25 years to cross the species boundary, given the lack of awareness about cleanliness, and the spread of various diseases, like Salmonellosis, in the public consciousness, until the early 2000’s?

The Trichomonas parasite, according to the British Veterinary Association, can survive outside of the host, in dry conditions, for a minute or two at most. In damp or wet conditions for two to four minutes. Just think on the likelihood of any individual bird picking up that parasite in that time window from a hanging feeder? Ask the question, given that Blue Tit and Great Tit are so common at feeders, why hasn’t Trichomonosis been found in those species? Or is it there but they are resistant to the parasite? Has anyone looked?

Recently, Dr Alex Lees promoted a paper on Twitter from 2015 which investigated the length of time the parasite can live outside of the host in four different water treatments. They found that, under suitable conditions, the parasite can survive for much longer periods in different wet conditions. Fair enough, however, I have read that paper by Purple et al, referenced below. Their treatments are sensible: but their work was all done under laboratory conditions. They took water samples from real life situations. Then they took their four water types and sterilised them before inoculating them with significant quantities of T. gallinae. These cultures were then kept at a steady 23^oC and samples taken at 0, 15, 30 and 60 minutes. Those samples were transferred to a suitable nutrient medium and incubated at 37^oC, and then assessed for the presence of motile Trichomonas parasites in the sample. They considered that discovering a single motile Trichomonad was evidence of persistence. Let me put this into context: the 500ml samples that they initially incubated were inoculated with approximately one million individual Trichomonads! What is the likelihood of a single Trichomonad, surviving in one litre of water in a bird bath, being in a position to infect a Greenfinch that just happened, unfortunately, to stop off for a drink at just the wrong time? What is the likelihood of there being a million Trichomonads in anyone’s bird bath? How “real” are the experimental parameters? How many bird baths sustain a temperature of 37^oC? Surely the timing should have been done on media kept at the same temperature as the original water samples?

Has anybody done random sampling of bird baths and other water sources under natural conditions and tested for T. gallinae? You can find plenty of warnings about cleanliness being next to godliness, and papers on other diseases unequivocally helped to spread through poor hygiene, but it seems that nobody has actually done the work to see how widespread Trichomonas is in UK bird baths or ponds, or any other water source. If you know better, please point me in the right direction. I have searched for suitable references but been unable to find any, and I would love to read the evidence that renders this post redundant!

A key issue for me, though, is the speed with which the disease has reputedly spread. After such a slow start, 20+ years after the bird feeding boom, until exploding from the West Country in 2005, to being found in Fenno-Scandia in 2008, then Germany and Czechia in 2009. If the UK is to blame, that is an incredibly fast spread for a disease which is not a viral or bacterial infection / contagion. Reputedly, these countries do not have the same density of bird feeding as we do in the UK, so what is behind the spread there? Obviously, birds can fly and migration can spread disease – if they are well enough to make the journey. Most birds I have seen suffering from Trichomonas can barely flutter out of the garden, let alone cross the North Sea!

According to Jim Flegg in his book “Time to Fly”, looking at migration based on ringing data, the Greenfinch is “largely sedentary, with some occasional partial migrants”. Only, as he explains, the migration that does occur is from areas of Fenno-Scandia, but to the east and north-east of the UK. So, this disease had to spread right across the UK to those eastern counties, to infect the Fenno-Scandinavian and central European Greenfinches overwintering in the UK, to then take the disease back to their countries of origin, all within that three year timeframe!

As a newly qualified C-permit holder, I went and spent a long weekend at Gibraltar Point Observatory in 2014. In one session we caught some 30+ Greenfinch and the staff were adamant that they still had a very healthy population of them in Lincolnshire and that they had not seen any particular fall off. I would be interested to see a time-stamped geographical representation of the spread of the disease within the Greenfinch population. As part of my presentations, when I was a BTO Garden Birdwatch Ambassador, I was provided with a set of PowerPoint slides showing the spread of Avian Pox in the Great Tit population. It spread out from the south-east of England to affect birds across the north and west of England in just three years: from 2008 until 2010. The data came from work by Lawson et al, referenced below. That is not too surprising: it is a virus spread by mosquito. Mosquitoes, as everybody knows, can be extremely effective vectors of disease. Both Malaria and Sleeping Sickness are infections spread by mosquitoes, caused by parasitic Protozoans: Plasmodium spp. and Trypanosoma spp. respectively. Has this been considered for the spread of Trichomonosis, or, having decided on what to blame, has nobody looked at the possibility?

The BTO’s ringing recovery data is interesting, in all of the decades that recoveries have been recorded, these are the total numbers of Greenfinch recovered and reported, either ringed in the UK and recovered in other countries and vice versa:

These hardly represent mass movements.

Parasites of the genus Trichomonas are widespread: with many species infecting a wide variety of animals in different ways, including the human animal. In humans it is a sexually transmitted infection. I am not disputing the impact on Greenfinch and Chaffinch but, by going for the easy target, it is entirely possible that other routes of infection are being overlooked and not addressed.

I will repeat: if there is unequivocal evidence, I would love to see it and read it. Not being a zealot: I am open to changing my opinion, based upon new and contradictory evidence.

This is an opinion piece, not a scientific dissertation, so I have listed just the key references that I have used in putting this together. I have read quite a few more.

References:

Kathryn E. Purple, Jacob M. Humm, R. Brian Kirby, Christina G. Saidak, Richard Gerhold: Trichomonas gallinae Persistence in Four Water Treatments; Journal of Wildlife Diseases, 51(3), 2015, pp. 739–742; Wildlife Disease Association 2015

Flegg, J. Time to Fly: Exploring Bird Migration, British Trust for Ornithology, 2004

Manuela Merling de Chapa, Susanne Auls, Norbert Kenntner, Oliver Krone: To get sick or not to get sick—Trichomonas infections in two Accipiter species from Germany; Parasitology Research (2021) 120:3555–3567

Jean-Marc Chavatte, Philippe Giraud, Delphine Esperet, Grégory Place, François Cavalier, Irène Landau: An outbreak of Trichomonosis in European greenfinches Chloris chloris and European goldfinches Carduelis carduelis wintering in Northern France; Parasite 26, 21 (2019); https://www.parasite-journal.org/articles/parasite/full_html/2019/01/parasite180155/parasite180155.html

Lawson B, Lachish S, Colvile KM, Durrant C, Peck KM, et al. (2012) Emergence of a Novel Avian Pox Disease in British Tit Species. PLOS ONE 7(11): e40176. https://doi.org/10.1371/journal.pone.0040176

Robinson, R.A., Leech, D.I. & Clark, J.A. (2024) The Online Demography Report: Bird ringing and nest recording in Britain & Ireland in 2023. BTO, Thetford (http://www.bto.org/ringing-report, created on 4-September-2024)

The plan was to go to Blakehill Farm west today. However, when we were on site there on Good Friday we found a very large bull sitting in the middle of our main netting area. Although the Wildlife Trust’s bulls are as docile as can be, I am not keen on setting up around a one tonne potential net destroyer. That said, it was a good Friday: I had Laura and her boys with me to check on the Barn Owl boxes and we found that both boxes on the west side of Blakehill Farm were each occupied by a pair of Barn Owls. No sign of any eggs yet, but a good sign regardless.

Instead of heading to Blakehill, I decided to have a first go at my breeding season net set up at Somerford Common. This is at the other side of the paddock area where we have the winter feeding station, heading down the ride from the main car park, where we set our ringing station. I was joined for the morning by Laura and Adam. We met at 6:00 to set up the nets and the ringing station:

These are all rides of 3 x 18m 5-shelf nets, plus one single 18m 5-shelf net. Arriving on site we, unfortunately, found that the wind was blowing from north-north-east, and funnelling straight through where the yellow net rides are on the diagram. As you can see, there is a lot of open area at this site, and the only sheltered area were we could set the nets were the two rides in white. So we set considerably less netting than intended.

As we only had the six nets up, we were pleased that they started catching straight away. It was never a heavy catch, two or three birds each time and, to be honest, it died a death at 10:00. Not only that but the wind was getting stronger, and the nets were beginning to billow. I decided that we would give it another 30 minutes, but we caught nothing, so we packed away at 10:30 and were away soon after 11:00.

One of the other considerations was that each net set was clearly in the territory of a male Willow Warbler. We caught the same two Willow Warblers several times each during the session, and I decided that we needed to give them a chance to get on with their lives. I don’t like catching the same bird multiple times in a session.

It was a nice little catch though: Coal Tit 1; Robin 2; Blackcap 3; Chiffchaff 4; Willow Warbler 2(3); Goldcrest 1(1). Totals: 13 birds ringed from 6 species and 4 birds retrapped from 2 species, making 17 birds processed from 6 species.

Two of the three Blackcap were female. They must have been fairly recent arrivals as neither was showing any signs of starting to develop a brood patch, unlike the male, who had a well developed cloacal protuberance.

The retrapped Goldcrest was ringed in October 2022 and has been caught in Spring of 2023. 2024 and 2025. The oldest of the retrapped Willow Warblers was ringed as an adult in April 2023, and has been recaptured in the following two springtimes, having over-wintered in sub-Saharan Africa. Quite a feat of endurance for a bird weighing only seven or eight grams, with a wing length of around about 70mm / wingspan of approximately 155mm.

One of the highlights of the morning for me was this:

What is good about it is that it has been an excellent Spring for Primrose and, at Gospel Oak and Blakehill Farms, the fields are alive with Cowslip, so this completes the set for me. That they have appeared in an area that was covered in trees, until it was cleared for pulping in winter 23/24, without additional human intervention, is testament to the enduring resilience of so many plants. There were multiple clumps across the cleared area. Of course, I was lucky enough to be the one who found the Greater Butterfly Orchids after they widened the rides running north to south, along which I set my nets:

The weather is looking a little unsettled for the next week but hoping to get out again on Thursday.

Getting a new site up and running is not always straightforward. I have been monitoring the Barn Owl boxes at Gospel Oak Farm since 2021. The habitat is lovely: beautifully managed hedgerows, a medium sized pond and a traditional, flowered, hay meadow. This is the aerial view of the site:

Whilst checking out the boxes last year I couldn’t help noticing there was a good level of bird activity around the pond area, particularly attractive to Swallows and House Martins. I approached the landowner and asked if he would allow me to run some ringing sessions there. With his approval I ran a test session, with nets set around the pond, last August. We caught 22 birds from nine species. Not a bad start.

So today we decided to try it out again. I was joined by Miranda, Sarah and Ellie at 6:30 and set the following nets:

So far, so good – only it wasn’t! We caught just six birds all morning! All new, two each of Chiffchaff and Wren, one each of Blue Tit and Blackcap.

There was a lot of bird song but virtually no movement. One encouraging sight: at 10:00 there was a small influx of Swallows, hitting the pond in exactly the way I was hoping they would – only I hadn’t set the appropriate nets!

I am pretty sure that it will come good: we will try again next month and see what goes.

Whilst there we checked on the two Barn Owl boxes: the first was clearly being used by a squirrel as a drey. It was absolutely full of twigs and some mammal fur. I emptied the box out and will check it again in a couple of weeks, make sure they aren’t back there.

We had watched a couple of Jackdaw coming in and out of the second box and on checking I found a lined nest and six warm eggs. I closed up the box and left them in peace. In five weeks I will go back and ring the youngsters.

We packed up at 10:30 and left site soon after 11:15. It was a lovely morning, even if the session was a disappointment. Each of the team got to ring two birds each! Wow! Lucky them: I know it is not down to me, but sometimes, as their trainer, I just feel responsible for things beyond my control.

It was just David and me on site this morning. I have been testing the site in the run up to the start of the CES season. The CES catch has been steadily declining, as you can see from the table and charts below:

The fall in the numbers coincides with declines in the number of species caught each year:

The simple fact is that this is entirely the point of carrying out a CES. The question for me is whether the return is worth the effort put in. Is it worth continuing with? What I decided to do, in the run up to this year’s scheduled CES season, was to test the site, see whether there are any early signs of improvement after the Wiltshire Wildlife Trust carried out some remedial work along and around the rides. My last visit, on the 28^th March, produced 23 birds, which included five Redpoll, on outgoing Spring migration, heading north, as is the tendency of this species in north Wiltshire. Today I was looking to see whether the incoming Spring migrants had arrived and what impact that might have had.

The biggest misses for me are: the loss of Lesser Whitethroat: in double figures up to and including 2019, none since; Sedge Warbler, always a few on passage until 2018, none since; Reed Bunting, between five and eight every year until 2019, only two singles in 2022 and 2023 since. Even Chiffchaff, with three figure catches between 2015 and 2019 inclusive, down to 50 and 45 catches in 2021 and 2022, then just in the 20’s for 2023 and 2024.

Today we set the standard CES nets, with a slight modification, for the three rides in the Wildlife Refuge, plus one extra net, to see if it added anything of value to the catch. It is important to me, as their trainer, to ensure that our sessions produce enough birds for the trainees to get sufficient experience. Ideally I want them to have 15 to 20 birds minimum in a session, especially at this time of year when they are working on sexing birds and looking for brood patch development in females. If I can provide that by setting my standard CES nets, plus a couple of extra nets, then there is a reason to continue with CES. If not, then I think I will need to retire it.

We met at 6:30 to set our nets. Net ride 1 looked like this when we arrived:

I have never seen it so lush with flowering Blackthorn: it is clearly benefitting from the work that Jonathan (the farm manager) and his team and the estates teams have put in to improve the habitat. What would it mean for the catch?

The nets were set as follows:

After a bit of faffing around with rides 3 and 4, due to the need to tame a few brambles that were insisting on becoming involved with the nets, we had them open by 7:45. The first bird hit at 8:15 in ride 2: a retrapped Wren. The next bird hit at 8:45: this was a Cetti’s Warbler ringed as of unknown age, in May 2020. So it is at least six years old. Clearly this bird, a male, has its territory in the area where rides 1 and 2 overlap as it has been caught in that area another 11 times since it was ringed.

As you can probably guess from the title: it really was a bad session in terms of numbers. We caught: Long-tailed Tit 1; Wren (1); Dunnock 1; Cetti’s Warbler (1); Blackcap 1(1); Chiffchaff 1(2); Goldcrest (1); Bullfinch 2. Totals: 6 birds ringed from 5 species and 6 birds retrapped from 5 species, making 12 birds processed from 8 species.

The only positives were 1) the Bullfinches: definitely a pair. They were taken out of the same net in ride 2, where they were close together. After processing we released them together and the flew off together into the same tree, where they shook themselves down before heading off together. 2) the Cetti’s Warbler and 3) David got to see some very clear stage two brood patch developments. (I could add “4) no Blue Tits!”)

It was a lovely morning: the weather was fabulous and we had lovely conversations with a lot of people, just a shame that we didn’t have the birds to make it an excellent morning. We closed the nets at 11:45 and took down, getting away from site at about 12:30. I will try another session in two weeks before making a final decision on whether to carry out the CES this year or to lay it to rest.

During our ringing session at Webb’s Wood today we caught this Blue Tit:

As you can see from the blue primary coverts, this is an adult bird. It should have moulted last autumn after breeding. The state of its primary feathers and tail make it look as if it failed to moult. I am pretty certain that the discolouration would not be the result of a mite infection, but happy to be corrected.

It is a female, and had a developing brood patch. Will it make it through the breeding season? It’s weight was decent: 12.1g, so it seems to be feeding okay.

Tough little bird!

We were scheduled to go to Ravensroost Meadows this morning but the weather forecast was for there to be a gusting breeze from the north-east, getting stronger throughout the morning, until reaching 20mph by 10:00. That is far too windy for an open site like Ravensroost Meadows. Although it was next on the rota, it was with some trepidation that I decided to go to Webb’s Wood. My last visit to Webb’s Wood, on 14^th March, was hugely disappointing. Despite having the feeding station still in operation, and all of the usual nets set up, in four hours I caught just nine birds: four new, five retraps and nothing overly exciting in the mix.

As I was being joined by Miranda, Laura and Ellie for the session, I was rather concerned that we didn’t have a similar poor result. I decided to take a chance and completely ignore our usual net rides and try out somewhere that I hadn’t tried for a long while. It was a bit of a gamble: our average April catch at Webb’s Wood in April is just 21 birds from 8 species. In the diagram below, the red circle is where we usually have our ringing station, the white one is where we set up today:

We met at 6:30 and set the following nets:

While Laura, Miranda and Ellie were setting rides 1 and 2, I was strimming down the border along which we then set net rides 3 and 4. It was a gamble we were taking but it started paying off straight away. It was never massively busy, but we caught regularly, with rides 3 and 4 being where we caught the five Blackcaps we had this morning, along with a number of other birds, so that certainly paid off. In fact, all four rides gave a reasonable return on our investment.

There were some good results, alongside the Blackcaps. We ringed our tenth Braydon Forest Marsh Tit of the year this morning: a second calendar year female. Given how poor Webb’s has been for the species in the past, it is encouraging to see how the population has grown since Forestry England thinned the beechwood and started removing the foreign conifers from the site. Across the Braydon Forest we rarely catch and ring more than one bird per month in the first four months of the year. Until this year, the average between 2014 and 2024 was just 3 Marsh Tits ringed in the first third of the year. We still have three weeks and several sessions to go to improve even further.

My favourite bird of the morning, though, was the last bird out of the nets:

Looking at the head, above the beak, is a four-pronged pollen horn. A definite messy eater!

The catch for the session was: Nuthatch 1; Blue Tit 6(2); Great Tit 3; Coal Tit 2; Marsh Tit 1; Long-tailed Tit 2; Wren 4; Robin 1(2); Blackcap 5; Chiffchaff 2; Goldcrest 1. Totals: 28 birds ringed from 11 species and 4 birds retrapped from 2 species. So this catch was well above average for Webb’s Wood at this time of year.

The weather was good: sunny and bright. It warmed up quickly from a bracing 0^oC when we got to the wood, until about 10:00, when it reached a balmy 14^oC. The woodland managed to keep the worst of the wind off the nets until about 11:00, when the nets started to billow, so we closed them and took down at 11:15, taking a couple more birds out of the net as we did so. We had everything packed away and were off-site just before midday, after a much better session than usual for this site at this time of year.

It is the quiet time: the winter visitors have gone and the summer visitors have just started arriving. The feeding stations are down or, if not, largely ignored by the birds, as there is better food becoming available. I had actually left the feeders up in Ravensroost, topped up on Friday, primarily because I had a small amount of seed left over from the winter and I didn’t want to keep it until next autumn, nor waste it. With Saturday being very windy, even though it was dry and sunny, I scheduled the session for Sunday morning: same sunshine, much lower winds.

I was joined for the morning by David and Ellie at 6:30 and we set the following nets:

It took us a bit longer than usual to get the nets set up and open: mainly because I didn’t want us catching birds until we were good and ready to start extracting, so we kept the nets closed until the last one was set. That was primarily because Ellie has only just started her extracting and I didn’t want to have to stop net-setting to go and extract early birds, nor to leave them in the nets whilst we finished the setting. Once we had the nets fully open, just before 8:00, we soon started catching.

Unsurprisingly, adjacent to the feeding stations we caught Blue, Great and Coal Tits. However, what was good about this morning were the other birds caught. In the second round we caught a Dunnock and two Goldfinch. The Goldfinch are our first caught in the wood since September 2017! Seven-and-a-half years! Not only that, they are the first we have ever caught in April!

We had only actually caught 110 inside the wood in the previous 16 years, with 30 of those on one memorable day: 4th December 2011 (seared in my memory for reasons I will save for another day, but it involves a Lesser Spotted Woodpecker and the reason why I had to change trainer soon after), so any catch of them is very pleasing: even if I can do a couple of hundred every year in my back garden!

In that same round we also caught our first Blackcap of the year:

I was somewhat surprised that it was a female. My expectation is that the males arrive first, establish territory and the females come along later and look for a mate! Two rounds later we did catch a male.

In that round we caught a retrapped Willow Warbler. It was ringed in this wood in April 2023, so clearly at least a second calendar year bird, recaptured on the 8th April 2024, and then again today. Clearly it likes Ravensroost Wood! In our penultimate round we caught another male Willow Warbler.

The last bird out of the nets was a female Goldcrest. Unlike every other bird caught today, she wasn’t yet showing signs of coming into breeding condition.

The list for today was: Blue Tit 4(5); Great Tit 3(4); Coal Tit (1); Dunnock 1; Robin (2); Blackbird 1; Blackcap 2; Chiffchaff 1; Willow Warbler 1(1); Goldcrest 1; Goldfinch 2. Totals: 16 birds ringed from 9 species and 13 birds retrapped from 5 species, making 29 birds processed from 11 species. So, although 29 birds is not a huge catch, it is actually better than our average catch at Ravensroost Wood in April: over 20 sessions in the wood, in this month of the year, the average catch is 24.95.

As well as a nice catch of birds there was a lot else to see. Flowers in bloom were Wood Anemone, Lesser Celandine and some early Bluebells! There were a lot of insects about as well: including my first Orange Tip butterfly of the year, and one of my favourite insects: the Bee Fly.

We decided to close the nets and take down just before midday, as the breeze had finally strengthened and the nets were billowing more than is acceptable. With David’s dad, Trevor’s, help, it didn’t take long and we were away from site soon after 12:30.

With the forecast being for the weather to be bright but breezy, I decided to head for one of the thicker woodlands: Somerford Common West. We set up the same nets as we have done all winter, and I had left the feeding station in place, as I have some seed I want to use up, rather than keeping it to go stale over the summer. I was joined for the morning by Miranda and Ellie, meeting up at 6:30. We had the nets open quite quickly but we didn’t start catching until 8:30, but we didn’t mind: look at what was the first bird out of the nets:

This is only the twelfth Firecrest that we have ringed in the West Wilts group since it came into its current structure on 1st January 2013. i.e. One every year on average. So for Ellie, who got to ring a Firecrest on only her seventh ringing session, that was more than a little special! It did help my decision that Miranda got to ring one back in October and I have ringed three of the twelve, and I am ever such a decent chap as a trainer, so I share out the uncommon birds to my trainees.

Also in that first round we had a couple of Chiffchaff and a couple of Marsh Tit: one new, our ninth of the year so far, and one retrap, plus three Great Tit. The Marsh Tit numbers continue to be encouraging: since the start of the year we have ringed nine. The norm for the first four months of the year is between three and five, so this is exceptional.

One of the key parts of the processing of the birds now, and for the next few months, is identifying sex and breeding condition. This is usually easy for species such as Great Tit, which are sexually dimorphic (actually, second calendar year Great Tits can be difficult, with considerable variety in the degree of pigmentation of the black stripe down the breast), but difficult for sexually monomorphic species like the Marsh Tit. In that case, one blows on the belly and chest to see if the bird is developing a brood patch (female, some males) or developing a cloacal protuberance that sticks out from the body wall (male) or points down the tail (female). I have no idea why but we rather got the idea that this Marsh Tit was a male when we popped him in the weighing pot:

We weren’t catching a lot but we were getting a decent variety of species. Unfortunately, soon after 9:30 the wind really got up and, despite the tree cover, the nets started to billow and blow out the pockets. It was a strong wind, not a breeze with some gusting. Not wanting to potentially compromise the safety of any birds, as shear forces can cause damage, we closed the nets and took down.

The list for the session was: Great Tit 3(3); Coal Tit 1; Marsh Tit 1(1); Wren 1; Song Thrush 1; Chiffchaff 2; Goldcrest 1; Firecrest 1; Chaffinch 1. Totals: 12 birds ringed from 9 species and 4 birds retrapped from 2 species, making 16 birds processed from 9 species.

So, a lovely little catch, with one very obvious and real highlight and we were home in time for coffee!!

A pretty typical March: catch sizes have fallen off as the winter visitors have mainly departed, summer visitors have just started arriving and the resident species feeding flocks have largely dispersed as they get territorial and are seeking a mate! We did get in a good number of sessions as the weather improved significantly on February. I even managed to do three sessions in walking, not Wellington, boots!

In keeping with the latest BTO guidance, I will be lumping Redpoll together for all future reports. The only three Redpoll we caught this month were all at Lower Moor Farm: the latest I have ever caught them at that site. Last year’s were all in the same place: but in Coulston, south-west of Devizes.

Added to the list, compared with last year, are Bullfinch, Green Woodpecker, Jay and Redwing. Missing from the list are Blackcap, Firecrest, Grey Wagtail, Mute Swan, Siskin and Stock Dove.

The Bullfinches were all caught at Lower Moor Farm: two in the wildlife refuge and one in the garden of the farmhouse. The Green Woodpeckers were caught at Lower Moor Farm and Andy’s new site just outside Warminster. Ours at Lower Moor Farm was absolutely covered in ant carapaces. It had clearly been rolling in them: I have never seen anything like it before. Unfortunately, it, along with the Lesser Redpoll, were all caught just after the Swindon Adult Wellbeing Group had departed to their next activity!

The Redwing were a bit of a surprise, given how few my team have caught up north this winter. One in a small catch at Blakehill Farm, the other three in the Firs. With the exception of winter 2014 / 15, I catch very few Redwing in the Firs. Apart from one in 2014, I have not caught them there in March. In fact, with that exception, I have never caught them in Q1 of any other year in the Firs.

Of the birds missing this year, Firecrest and Mute Swan are not really a surprise omission, given that we have caught only ringed one and retrapped one Mute Swan and, given we have caught and ringed 11 Firecrest, in over 12 years, it would have been a surprise if we had.

Missing Blackcap is more of a surprise, but we don’t catch a lot of them in March. Presumably the over-wintering birds from Central Europe have headed back to their breeding grounds and our summer visitors are still in north Africa / southern Spain.

Siskin are more of a surprise: March is usually one of our better months for the species. In the north they are migrants, but they are resident in the Warminster area and are usually nailed on from Andy’s activities. April is also another good month for the species so, hopefully, we will catch a few to make up for March’s shortfall. One of Andy’s other Warminster sites is also a fairly regular catch site for Grey Wagtail, and caught the three from March 2024, but none this year.

Stock Dove are usually caught in Barn Owl boxes during the breeding season. Only four of the 28 ringed, including this one, have been caught in mist nets: two of them in March.

I think the most surprising catches this month were Nuthatch and Treecreeper. Of the Nuthatches, eight were ringed in the Braydon Forest and two ringed in one of Andy’s Warminster sites, seven retrapped in the Braydon Forest, one in Green Lane Wood and the other at the Warminster site. It is our largest ever monthly catch, second largest number ringed in a month.

When it comes to Treecreepers, we had our best ever March catch of them: the previous best was 7. The only better catch was in August 2016: i.e. towards the end of the breeding season. 11 of those Treecreepers were new birds. The five retraps were four at Lower Moor Farm and one at Biss Wood.

So more birds caught but from more sessions and fewer species compared to last March.

Bjork time as in “It’s oh so quiet!”: it seems that the feeding flocks of resident birds have dispersed, presumably to focus on setting up breeding territories and attract a mate; the winter visitors have left, heading north to their summer breeding grounds, and our summer visitors are arriving, but not in any great numbers. The bird feeders are still up but clearly not as attractive as they were! I topped up the feeders at Somerford Common on Thursday morning: the peanut feeder was half emptied but the seed feeder had barely been touched. Clearly no longer needed so they will all be down by the end of next week.

Anyway, I was joined by Rosie, Laura, Adam and Ellie at 6:30. It was great that Rosie could stay for the whole session this morning. We set the usual nets, plus I tried one additional net in front of a stand of conifers:

Unlike Wednesday, when we started with nine birds in the first round, raising our expectations before dashing them, this one started as it intended to go on: just three birds. All Great Tits: two new and a retrap.

Thereafter, every round produced only a couple of birds. There were some nice surprises: a male and female Goldcrest caught adjacent to each other in the net. We wondered if they were a pair, so we released them after processing, and they flew off together, so quite possibly a pair.

Having spent the second part of our recent ringing demonstration at the Firs muttering about wanting to catch Treecreepers, and failing to do so, two Treecreepers caught adjacent to each other in the nets this morning was satisfying for me. They turned out to be two males, not a pair, but nice to have.

A five year-old Marsh Tit was a real surprise. However, looking up his number, that is the twelfth time we have actually caught this individual! With the exception of the year it was ringed and 2022, it has been caught at least three times every year.

Having said “it’s oh so quiet” that was actually overturned on our last two rounds: at 9:30 we took a male Great Spotted Woodpecker out of the nets! There is no louder bird in the woodlands than one of these. We then didn’t catch anything for an hour, whereupon we caught a second! Every bit as loud and shrieking as the first.

Laura had to leave at 10:00, as she is playing in a concert in Malmesbury this evening, and the rest of the morning and afternoon were scheduled for final practice / rehearsal. Mark arrived to chauffeur Adam home at the end of the session.

Despite not catching any this morning, there were a few Blackcap singing in the surrounding woodland, and plenty of Chiffchaffs claiming their territories. Hopefully we will get a few of each in our future catches.

The list for the session was: Great Spotted Woodpecker 2; Treecreeper 2; Great Tit 6(2); Marsh Tit (1); Chiffchaff 2; Goldcrest 2. Totals: 14 birds ringed from 5 species and 3 birds retrapped from 2 species, making 17 birds processed from 6 species.

One thing to note: this is the first time that I can remember that we have run three full session without catching a single Blue Tit!

With nothing caught in the next couple of rounds after the Great Spotted Woodpeckers, we took down and were packed away and off-site soon after 11:15.