Having been unable to travel up to Yorkshire with Kev @kev07713 and Karen, and consequently missing both buff-breasted and white-rumped sandpipers, it was rather fortuitous that a white-rumped sandpiper appeared at RSPB Snettisham in time for our regular Saturday birding trip.
We set off at 4.30am, hoping to arrive ahead of the high tide and catch the bird as it was pushed closer towards the shore. After arriving, we began the reasonably long walk from the RSPB car park down to the shore. Within minutes, we heard the unmistakable call of a turtle dove.
We quickly located it, only for two birds to fly over before one settled in a tree some distance away. We stopped to enjoy the views, and as I moved on, Kev dropped back to the car to collect his glasses, just in case he needed to phonescope anything, as focusing was so much easier with them.
I reached the shore and started working through the dunlin and ringed plovers along the water’s edge, hoping to pick out the white-rumped sandpiper amongst them. As I made my way along, Kev caught me up and we continued together, pausing to watch the red knot swirling in the distance.
There were an impressive 56,000 red knot recorded here during the Wetland Bird Survey (WeBS) count at the beginning of the month, and the sheer number of birds was evident as they wheeled above the Wash. Their flight patterns and constantly changing formations were remarkably reminiscent of starling murmurations.
As the tide pushed further across the mudflats, flock after flock of red knot lifted from the water’s edge, thousands of birds twisting and turning in unison above the Wash. The flock moved almost like a single living organism, constantly changing shape as the birds responded to one another, alternately flashing dark and silver as they banked and caught the light.
The sheer scale of the spectacle was difficult to take in. Wave after wave of red knot rose from the shore, filling the sky before settling back down onto the pool behind, only to erupt into flight moments later. It was an incredible display, made all the more impressive by the vast numbers involved.
No sign of the white-rumped sandpiper though.
We continued working our way along the shore, picking out two peregrines, six kestrels, and a buzzard quartering the land beyond the mudflats. Along the remaining shoreline was an impressive array of curlews, godwits, shelduck, redshank, dunlin, red knot, Mediterranean gulls, and more, all feeding along the water’s edge.
Out in front of us, streams of little terns and a handful of common terns headed out across the Wash, setting off on fishing trips as the tide continued to push in. The latest verified local eBird log for RSPB Snettisham recorded a specific group of 117 little terns on the reserve - reports suggest this area of the coastline supports an average of 314 breeding pairs.
According to the latest (unverified WEBS) count there were 56,000 red knot, 3,943 dunlin, 4,500 oystercatcher, 2,050 black-tailed godwit, 1,435 bar-tailed godwit, 1,560 shelduck, 1,270 curlew, 1,270 grey plover, 1,124 redshank, 662 sanderling, 424 ringed plover, 226 turnstone, and 40 Mediterranean gulls amongst the other species.
There are so many waders here at the moment because yit is the start of the autumn migration period, when The Wash becomes an extremely important feeding and staging area for birds returning from their Arctic breeding grounds.
A few things are happening simultaneously:
- Red knot are arriving back from the Arctic. They make the enormous journey south from breeding areas in places such as Greenland, Canada and Russia. The Wash's extensive mudflats provide an exceptionally rich food supply for them to refuel.
- Dunlin numbers are building too. Late summer onwards is an important period for Dunlin on UK estuaries and mudflats, with birds arriving from further north to spend the winter here.
- The Wash is an exceptionally productive feeding area. The huge expanses of exposed mud provide worms, molluscs and other invertebrates, allowing enormous numbers of waders to feed together. The RSPB describes the area as having "world class mud" - essentially, the food supply is what drives the congregation of birds.
- The tide concentrates them. At low tide the birds can spread across vast areas of mudflat to feed. As the tide rises, that feeding habitat disappears, forcing them towards the shore and Snettisham's roosts. The birds spread across The Wash to feed, then become concentrated at Snettisham as the tide comes in.
Looking back along the shore, we could see a group of birders gathered at the point where the path from the car park joins the coastal path. In front of them was a sizeable gathering of waders, although at that distance we couldn’t make out exactly what they were.
At this point, we checked BirdGuides and saw that a report had just been posted for the white-rumped sandpiper further back along the track, with the sighting subsequently confirmed by another birder who had seen it. Had we somehow missed it, or had the bird already moved from there, perhaps onto the pools or with the distant waders?
We headed back towards the group, only to find that they were already moving off. What they had been watching was predominantly sanderling, with a few dunlin, redshank, ringed plovers, and a couple of turnstones mixed in. The white-rumped sandpiper was still nowhere to be seen - we'd arrived 15 minutes too late for the close views described by others.
After a short while, we walked back up the path to where a growing group of birders had gathered, all scanning the mudflats as the tide began to drop once more. We worked our way through the flocks, commenting that each time we made a sweep, the birds seemed to have relocated further along to the latest stretch of exposed sand.
Some of the birders began making their way back along the shore, and we followed, step by step. Every so often they would stop and scan again, only to move on once more, with us gradually catching them up.
Then, at one point, a couple of birders came hurrying back towards us. They had seen the white-rumped sandpiper, but it had flown and landed beside a channel, where it had quickly disappeared from view. We had missed it again! We scanned and scanned but could find no sign of it. Apparently, the white-rumped sandpiper had left with a group of dunlins, and a small flock was later seen flying off to the right, which probably included our elusive bird.
We moved further to the right and began scanning the area, working through the dunlin and redshanks as more birds gradually filtered through from that direction. While I continued searching from this spot, Kev carried on along the path following a couple of the remaining birders.
About ten minutes later, my phone rang. One of the birders had located the sandpiper, and I immediately set off at a brisk pace along the path and a few minutes later, I caught up with them and, at last, was within reach of our target bird.
It took barely a minute to pick it out among the birds on the mudflats, but then there it was - first in my scope, then in my bins, and finally in front of my camera lens.
The white-rumped sandpiper is a rare but regular vagrant to Britain. It breeds across Arctic Canada and winters mainly in Patagonia, but its transatlantic migration route brings small numbers to Britain and Ireland, particularly during late summer and autumn. To make things even more challenging, it is roughly dunlin-sized and can be surprisingly difficult to pick out amongst hundreds or even thousands of its smaller counterparts. The combination of long wings, a relatively long bill, prominent white supercilium, and streaking extending onto the flanks can be particularly useful when separating it from dunlin.
With the Wash attracting enormous numbers of passage waders at this time of year, perhaps it is not so surprising that the occasional Nearctic vagrant finds its way into these vast gatherings of otherwise familiar species. For a bird arriving from the other side of the Atlantic, the rich feeding grounds of the Wash must provide an ideal place to stop, refuel, and continue its journey.
Walking to the next group of birders we heard that there were two little stints and it wasn't long before we located one, feeding amongst the seaweed and dunlins. The little stint is Britain's smallest regularly occurring wader, at only about two-thirds the size of a dunlin. It is seen mainly on spring and, especially, autumn passage. British birds breed in northern Scandinavia and north-west Russia and winter around southern Europe and western Africa.
The important distinction is that little stint isn't normally expected in the huge tidal flocks of dunlin at Snettisham in quite the same way. You're more likely to find one feeding around the edges of pools or amongst smaller wader gatherings. This makes finding one a matter of carefully checking the less obvious birds rather than simply scanning the main knot/dunlin spectacle.
On the way to the shore from the car park I'd seen a wall butterfly - a species that Kev had not knowingly encountered previously and so on the way back to the car we stopped regularly and searched. We were eventually rewarded by a couple of views, one relatively close. We struggled to get open wing photographs and the only individual that compiled was a bit worse for wear.
The wall is a beautifully marked butterfly, its orange-and-brown wings patterned with dark lines and prominent eyespots. The most striking feature is the large black eyespot with a white centre near the tip of each forewing, complemented by a series of smaller eyespots along the hindwings. When settled with its wings closed, however, it becomes much more cryptic, the mottled grey-brown underside blending remarkably well with dry grass, bare earth and stones.
The wall is a butterfly of short, open, sunny grassland, particularly where there are patches of bare ground. Typical habitats include coastal cliffs and dunes, quarries, railway embankments, grassy tracks and field margins. The caterpillars feed on various grasses. It is particularly associated with warm, sheltered places, and adults often bask on walls, rocks, bare ground and other sunny surfaces. Males can be quite conspicuous when they patrol low over the ground looking for females.
The wall has experienced a very substantial long-term decline. UKBMS data show an 82.8% decline since monitoring began in 1976. Interestingly, the national index has been more stable over the last 20 years and has increased over the last decade, although this doesn't undo the much larger historical loss.
With a three-hour journey home ahead of us, it was time to make tracks, but not before stopping at the café just outside the reserve for a well-earned spot of lunch.
Year list: 272.
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