Fewer Spotted Redshanks

It’s usually a good day if you see a Spotted Redshank in Britain or Ireland. How about a flock of 60?

On 27 July 1975, I was fortunate to be part of a Wash Wader Ringing Group cannon-netting team that caught 60 Spotted Redshanks at Terrington, on the Lincolnshire border of Norfolk. When we fired the nets, we knew that there were some Spotted Redshanks in the catching area but, as these birds were part of a mixed catch of 414, most of which were Redshank and Dunlin, the total number of these elegant ‘shanks came as a very welcome surprise. Why so many, what did we learn about Spotted Redshanks and what do we know now?

How to catch Spotted Redshanks

The spring of 1975 was very wet in East Anglia, with twice the annual monthly rain as is normal in April. Pools formed in fields, seed failed to germinate and there were many bare patches in cereal crops. Rather than leave a muddy pool to bake in the summer sun, a tidy-minded Terrington farmer decided to cultivate a strip through the corner of one of his fields, very close to the sea-wall. Conveniently, he created an area that was just the right width in which to set cannon-nets, meaning that any birds that chose to roost on the bare part of the field over high-tide were almost bound to get caught. It is unlikely that we missed many other Spotted Redshanks when we caught our 60.

This was actually the second catching attempt on the site. Two weeks earlier, on the previous set of spring tides, we had caught 460 birds in two catches – mostly Dunlin and Redshank but with one Spotted Redshank. In the previous 15 years, WWRG had caught just two Spotted Redshanks but more than 4000 Redshanks. Across the whole of Britain & Ireland, between 1909 and 1974, a grand total of 169 Spotted Redshanks had been ringed, which again puts the figure of 60 into perspective.

Where did they go?

The Spotted Redshanks we see in Britain & Ireland are assumed to breed in boggy woodlands in northern Scandinavia and Russia but there are no recoveries of ringed birds to prove this. Prior to the Terrington catch, there had been two foreign recoveries of BTO-ringed birds. A bird caught in Essex in August 1963 was caught by a Dutch ringer in May 1967, presumably on spring passage. Another, caught in July 1966 in Kent, was shot in Malta in April 1968, on its way back from an unknown wintering location in Africa.

There have been two foreign recoveries of the Terrington birds, caught on 27 July 1975; amazingly both were in Morocco. The first was shot in March 1976, perhaps on its way north, but the second, shot in January 1983, may well have been wintering in North Africa. There has been one other foreign recovery of a WWRG since 1975; a bird ringed by WWRG in August 1978 was shot in Italy in March 1979, presumably on spring migration. This was the only Spotted Redshank ringed by WWRG in 1978. Six Spotted Redshanks have been recovered in France since 1975.

According to the 2016 BTO Ringing Report, a total of four foreign-ringed birds have been found in the UK. Two Dutch birds have been found dead at Hayling Island, Hampshire (January) and Tetney Lock, Lincolnshire (January) and a third bird was present at Titchwell, Norfolk in the summers of 2013 and 2016, where the ring was read in the field. A bird ringed in Germany on 10 August 1972 was recaught by ringers at Eyebrook Reservoir, Rutland, 23 days later.

The Terrington-ringed bird shot in Morocco in 1983 still represents the BTO longevity record for the species (7 years 5 months 16 days); this is similar to records set by Finnish and Dutch ringed birds. (There is a WaderTales blog about longevity in waders here)

Summering Shanks?

Many of the Spotted Redshanks we caught on the Wash in 1975 were thought, at the time, to be summering, first-year birds but these were in the days before the publication of the Guide to the identification and ageing of Holarctic Waders (Prater, Marchant & Vuorinen, BTO) and I do wonder whether early onset of moult may have led to some ageing errors. We now know that females can moult very early, having left their partners to finish brooding their eggs and bring up the chicks. Some of their moult can take place near their breeding grounds, which could mean half-summer plumage birds arriving in July. Alternatively, birds could have arrived in June and already be in moult. Had the wader guide been available in 1975, we might have been able to separate out full-plumage males and females by looking at the central under-tail coverts and the edges of the head feathers. Next time …

The latest BirdTrack graph gives pretty clear evidence that there is a gap between the end of spring migration and the start of autumn passage. However, as you can see, it’s short; just the end of May and the start of June. It has been suggested that not all first-year Spotted Redshanks travel to the breeding grounds, with some staying in their wintering grounds and others completing only part of the journey north. The few birds that are still in the UK in the May/June gap could be some of these one-year-old individuals or full adults not in condition to breed.

Looking at numbers

As I prepared for this article, I turned to Twitter to see how unusual the Terrington catch had been, simply in terms of the number of birds counted in flocks. There have been some recent largish counts, including one of 52 at Old Hall Marshes (Essex) in September 2017 and 32 at Blacktoft Sands in Yorkshire in 2015 but, interestingly, I learnt that bigger flocks were mostly historical. According to the three books, The Birds of Norfolk, Suffolk & Essex, the three peak counts have been 187 at Snettisham in 1977, 112 at Minsmere in 1991 and 127 on the River Colne in 1972. Kent beat these East Anglian county records with a maximum of 220 at Stoke Saltings on 8 October 1972 (not Grovehurst, as reported in Birds of Kent, 1981 – thanks to Kevin Thornton for correction).

This story from Northumbrian Birds illustrates a typical recent trend. Here, the record counts were of 27 and 21 at Lindisfarne in 1974 and 1976 but there has been a maximum count of just 7 in the last ten years. At the other end of England, Steve Rogers reported that he had 45 at Ruan Laniholme in Cornwall in 1977 but that “you’ll be lucky to see one” now. This is just a small selection of the comments received from a wide spread of  places, including Poole Harbour in Dorset and Cork in Ireland.

Potentially, the development of new nature reserves around the coast and along our river valleys might have created new opportunities for Spotted Redshanks, with birds spreading out across more sites and hence in lower concentrations? To get a national viewpoint, I turned to the online report from the monthly Wetland Bird Survey (WeBS). What did winter counts by volunteers from across the United Kingdom tell us about what has been happening to the species over the period since 1975? As you can see from the graph alongside, the index has dropped by 50% since the start of this century, in line with the local information for late-summer passage discussed above. (There is a WaderTales blog about WeBS here).

Conservation concerns

According to the BirdLife International species fact-sheet, as downloaded from http://www.birdlife.org on 25/07/2018, Spotted Redshanks are of ‘Least Concern’, largely because the large breeding and wintering ranges (map below) reduces the risk of extinction. Breeding numbers are hard to monitor, due to the low densities in the wooded marshes near the tundra edge, and the series of winter wader counts for the UK is much longer and more comprehensive than any other country in the wintering range. Perhaps there would be more concern if there were other international counts that showed the same sort of declines as seen in the UK?

Here, Spotted Redshank is listed as amber, rather than green, simply because the estimated winter count of about 100 is large in a western European context. Perhaps a decline of 50% should create pressure to change amber to red or, more importantly, to revisit the ‘Least Concern’ designation. Whilst it might be hard to target conservation action at a species which uses such a wide range of breeding, passage and winter locations, perhaps we should acknowledge that, according to what is probably the best evidence available, we are seeing a rapid decline?

Our catch of 60 Spotted Redshanks in 1975 is an amazing memory but concentrations in these numbers could be found at a number of sites on the east coast between at least 1964 and the end of the 20^th Century. For the moment, we must acknowledge that UK autumn flocks of 60 are largely a thing of the past. Perhaps flocks of 30 might soon be consigned to history? Keep counting!

 

WaderTales blogs are written by Graham Appleton, to celebrate waders and wader research.  Many of the articles are based on previously published papers, with the aim of making wader science available to a broader audience.

@grahamfappleton