Friday 28 February
Recces had been carried out in the morning by Cathy and Hilary at Snettisham, Heacham, Heacham S and Heacham NN starting at 06:15. No good targets were found, totals were 1+5 Oystercatcher at Snettisham, 4+7+4+10 Oystercatcher at Heacham, 50 Oystercatcher at Heacham S and 150 Curlew spread along the beach, with nothing at Heacham NN. However, the Heacham S Oystercatcher left as Hilary arrived on the beach and it was too dark to see exactly where they had come from.
A recce by Hilary and Molly on the afternoon rising tide at Heacham S found Oystercatchers present again that could be a possible target, especially as that was close to where they had been caught on the previous trip, together with 50 Curlew. However, the Oystercatchers were spooked by dogs as the mud covered and didn’t gather on the beach as had been hoped. 230 Sanderling and several Ringed Plover were also found on Heacham NN as the sun set.
As the tides were not suitable for mist netting, this meant that Friday evening was fairly relaxed as the team arrived at the Base House with no need to set nets that day. Plans were made for more recces in the morning, to look for alternative options, and an extensive morning resighting session, followed by setting cannon nets for Oystercatchers in the afternoon.
Saturday 1 March
Teams went to recce sites in both Norfolk and Lincolnshire on rising tides, followed by resighting on the falling tide. Teams were as follows:
Recces (start @ 06:00):
- Heacham S: Guy, Phil, Louise
- Horseshoe: Molly
Resighting
- Snettisham: Isla, Bob, Harriet (09:45-10:30)
- Heacham S: Ed, Shannon, Claudia (09:45-10:40)
- Heacham NN: Guy, Phil, Louise (09:45-11:30)
- Hunstanton: Lucy and James (08:00)
- Frieston: Hilary and Pip (07.15)
The original intention was for resighting to continue as long as possible, with teams returning to the base for food at 13:00, so that nets could be set in the afternoon in Heacham S. However, the recces caused plans to be changed rapidly.
The Heacham S team found a good flock of 450–500 Sanderling, around 150 Curlew and up to 120 Oystercatcher on the beach with the rising tide that could have been a potential catch (and an excellent new café called Breakfast and Brownies – highly recommended), but Molly stole the show with a huge number of birds at the Horseshoe, estimated at between 1–1.5k Oystercatcher, 5k Knot and 1k Bar-tailed Godwit. A call was put out to all teams shortly after 10:00 to get back to the base house for a briefing at 12:00, for an attempt at an evening catch.
Over the next hour or so, plans changed multiple times as team leaders worked out the best approach for what was to be a challenging catch attempt. By the time the whole team was back together for the briefing, decisions had been made and were explained to everyone. With so many birds present, it was decided that we would attempt to catch in the evening, with a second attempt possible on Sunday morning if we did not catch on Saturday. Nets needed to be set by 16:20 in order to get clear of the site in time, so after a quick lunch, preparations were made for a team to head out quickly and set nets, while Sam and David did more resighting on the rising tide. The three main species on the Horseshoe lagoon had been seen in three separate flocks, with the Knot furthest out and judged by Nigel to probably not be accessible. We therefore set two different nets, to try to target possible catches of Oystercatcher (a large-mesh net further on to the land) and Knot (a half net of small mesh, a little further out). Nigel explained that the priority species would be Oystercatchers, as they seem to be struggling in The Wash, possibly due to issues with the mussel and cockle populations, and so detailed data collection on Oystercatchers is particularly valuable at present. Knot and godwit would also be very valuable for long-term monitoring, however.
The teams worked efficiently to get the nets set (once all the cars had made it on to the sea wall – some needing a bit of a push!) and both nets were ready, and the lagoon vacated by 16:30. Nigel then recapped the plan for the evening’s catch attempt. A base camp team of eight people went back onto the site to wait under the tarp for birds to arrive. Other teams also got into position on the saltmarsh behind the sea wall, waiting in the cars, as long stops, or in the hide.
What followed was a spectacular but frustrating evening. Those in the teams behind the sea wall and in the hide were lucky enough to watch huge flocks of Knot, godwit and Oystercatcher pouring off the marsh and onto the lagoon as the tide rose, against a vivid sunset. The soundscape for those under the tarp on the lagoon was awesome.
However, trouble quickly arrived in the form of a Merlin and two Peregrines who proceeded to harass the waders, causing mayhem. Even once one of the Peregrines had killed a Knot and the raptors appeared to have left, there was still no chance of a catch as the waders had changed their behaviour and were reluctant to come onto dry land into the catching area. Eventually, the light fell too far for what would have been a difficult catch in any case, and Nigel took the decision to disconnect the nets and try again in the morning. The base camp team then had a major challenge to crawl out from their hiding place without spooking the waders now roosting on the lagoon, and get back to the cars in the dark, with the sea now covering the path at the bottom of the sea wall.
By the time the whole team was back to the cars, everyone was hungry and a large order of 14 portions of chips was made in Boston!
Sunday 2 March
It needed an early start in the morning to get teams in place in the dark before the birds arrived. With some reshuffling of the teams to provide relief for the base-camp team who had had a very uncomfortable evening on Saturday, the first group left at 04:15, with the whole team assembled on site by 06:15.
Plenty of birds were present in flocks above the saltmarsh, although fewer than the previous evening. It was another long, cold wait as the tide came in and a large number of birds again went to roost on the lagoon, shuffling between various uncatchable positions. At one point, Nigel explained that there were a large number of Oystercatchers and Knot within the catching area of one of the nets, but too many to be able to make a catch of those species together. Eventually, just before 08:00, all the waders on the lagoon flushed, for an unknown reason – quite a spectacle (and noisy!) for the team on the saltmarsh. However, this eventually proved to be the opportunity we needed, as some gradually returned to the lagoon, and at 07:58 Nigel fired the small-mesh net and made a catch. All teams sprang into action and the birds, mostly Oystercatchers with some Knot, were all resting in keeping cages by 08:15.
Ringing and processing went smoothly, with Guy (as cannon-netting trainee) in charge of organising the teams. We made the most of the moderate sized catch to get in plenty of training opportunities, with two repeat-processing teams practicing wing and bill measurements. The five Knot were also colour-flagged.
The final totals were:
| Species | New | Retrap | Total |
| Oystercatcher | 103 | 18 | 121 |
| Knot | 5 | – | 5 |
| Totals | 108 | 18 | 126 |
Once all birds had been ringed, processed and released, the whole team cleared up and packed away the equipment and then went back to the base camp for lunch and a final briefing. Nigel explained that, although it had been hard work for the number of birds, catching a good number of Oystercatchers was very valuable data, particularly as this catch was on the Lincolnshire side of The Wash where Oystercatchers are not commonly caught at this time of year. There was also a bonus, as we caught an Oystercatcher that beat the longevity record for the species that we set in a catch at Snettisham at the beginning of February. FV44734 was originally caught on the Bund on 28 March 1982, when it was aged as an 8 (full adult) – we caught it again on the Horseshoe 43 years later! As it was reringed, if we catch it again we won’t realise that it is so old until we input the data.
Droppings were collected from the Knot, providing data for Isla’s PhD project looking at Knot diet and movements. The catch also gave an opportunity to learn about how to deal with Oystercatchers in a small-mesh net, as they tend to run towards the people lifting (tenting) the net to make their escape. Cathy managed to get a video of the entire catch and lift, which will be very useful in understanding how best to catch Oystercatchers in small-mesh nets and also whether any improvements could be made to how the team worked together.
Rob explained in more detail how the Oystercatcher biometric measurements will be used. As The Wash is an SPA, the government has a duty to maintain the conservation status of those species that it is designated for, which includes many wader species, and to take action if populations are struggling. For Oystercatchers, which rely on shellfish, there is a potential conflict with commercial mussel and cockle fisheries. As the current management plan has come to an end, Natural England are in the process of drawing up a new management plan and have developed a model to estimate the quantity of shellfish needed to sustain Oystercatcher populations, and they need data to test this model. Different individual Oystercatchers have different diet preferences and, since their bills grow continuously, these habits can be inferred from their bill shape – long thin bills correspond to a preference for worms, short blunt bills indicate they have been hammering shellfish, etc. – so taking bill measurements can provide data on feeding, as well as sexing. These data will be used directly to inform the new Wash management plan. In this catch, a number of Oystercatchers were found with arrested moult, indicating that they may not be feeding very well. The proportion of birds with arrested moult was also higher than was seen in a recent catch on the Norfolk side of The Wash.
Finally, Rob shared a very exciting preliminary result with the group from one of the retrap Oystercatchers. If confirmed, this may break the current longevity record, as the bird was thought to have been ringed in March 1982! – see above.
All in all, the weekend was hard work but very successful, with beautiful weather, a decent resighting effort, and in the end a highly valuable catch. Particular thanks go to Cathy, for masterminding excellent food for the whole team at all the right times, despite frequently changing plans, and making sure nothing went to waste – even the leftover chips – and to Hilary for the extremely important but unsung job of disinfecting the catch boxes to maintain biosecurity against HPAI.
Resightings table:
| WWRG colour marks | Sightings | Individuals |
| Bar-tailed Godwit | 26 | 24 |
| Curlew | 112 | 55 |
| Redshank | 0 | 0 |
| Turnstone | 15 | 13 |
| Knot | 0 | 0 |
| Marked elsewhere | ||
| Black-tailed Godwit | 3 | 2 |
| Bar-tailed Godwit | 3 | 3 |
| Headstarted Curlew | 3 | 3 |
| Other Curlew | 2 | 1 |
| Other Knot | 0 | 0 |
| Total | 164 | 101 |
Thanks to Louise Hill for writing this report. Cover photo by Louise HIll.