[Following on from difficulties with little tern rings, an update from China shows this is a common problem]
A Team lead by SBS in China and with five international wader experts: Nigel Clark from BTO, James Phillips from Natural England, Guy Anderson and Andy Schofield from RSPB, and Rich Hearn from WWT, has come together to survey the autumn concentration of spoonie on the Jiangsu coastline. The survey has been supported by the MBZ Species Conservation Fund, RSPB and the participants.
We are now half way through our survey, having lost a day to the edge a typhoon. Each day we have split up so that we can cover the maximum length of coastline. It has been hard work, but very rewarding as so far every team member has seen multiple spoonies on every day! The intertidal flats are so vast at low tide that we would not have a hope of surveying adequately, so we have surveyed the upper mudflats in the last couple of hours before they are covered by the incoming tide. This is always a race against time but can be very effective as the birds are constantly being forced to move as the water approaches. SBS are remarkably difficult to spot amongst large flocks of roosting waders and we are trying to check the legs for colour marked birds-not easy when they are roosting on one leg!
Once the tide has covered the flats we try and locate birds in the roosting flocks and make total counts of waders before following them back out to the flats on the falling tide. After about three hours, the birds have dispersed too much and we lose the ability to focus, so it is then time to compare our notes and summarise the day's data to ensure that we have everything recorded properly.
At the end of the breeding season, 19 individually marked adult birds left the breeding grounds to migrate to their winter quarters. Looking for them several thousand miles away is really like looking for a needle in a haystack so we were not too hopeful. Remarkably, one was found on the first day but it was not possible to read the inscription in the windy conditions.
We decided to go back to the same site the next day to try to find it and, to our surprise, we did and were able to read the inscription. It was Lime 04 which was seen in the same place in the spring. Another team member came back from the other end of the site having seen a second bird, but alas they could not read it completely but we could be sure it was not Lime 04. At high tide we undertook a survey of the massive wader flocks and counted over 40,000. This included some 830 Nordmann’s greenshank, which was almost identical to the count at the same place last year confirming that this site holds over half the known world population for the species. Unfortunately, the area where these birds are concentrated is earmarked for reclamation, so their future looks bleak.
The next day's survey was equally amazing as we found Lime 01, nicknamed the monument male, on the rising tide, then again on its roost and finally on the falling tide. Lime 01 was seen in the same place last autumn, showing just how site-faithful the species is.
Buoyed by the success so far, we went to our third core site not expecting to be able to do as well as the previous couple of days. On the rising tide we had about 10,000 small waders on the mud in front of us. Luckily the tide did not completely cover the flats and the birds stayed for three hours. First we found a bird with a lime flag on its right leg. This means that it was marked as a chick. It was roosting on one leg, the wrong one for us so we watched it for the next 45 minutes for it to show its flag. Then disaster - a gull flew low over the flock and it was gone. Next we found a flagged bird with the flag on the left leg. Same problem but this time 4 of us watched it for a glimpse. An hour later the whole flock lifted off and we lost it. It was not going to be our day! Disheartened we searched the flock in its new roosting site and eventually located one with a flag on the left leg. The only problem was that it was too far away and there were several thousand waders between us and it. We slowly edged forward, and after what seemed like an age, we were in range but it was feeding frenetically in pools and shallow creaks. Then it stopped for a second, and we could see that the first digit was a 1 - but what was the second? It stopped again- it’s a 5 came the call from all of us at the same moment as it suddenly gave a clear view.
Adding the totals together for the three sites we have now seen a minimum of 183 SBS, clearly showing that virtually the whole population goes through its annual wing moult on this piece of coastline. Let’s hope that there will still be intertidal flats for future generations to see this unique bird. Without the flats they will not survive.
Tomorrow the weather looks good and we have high hopes – time will tell.