Following the report of a pair of Common Terns back in the Lower Derwent Valley recently, our team relaunched the tern rafts last week for another season, and we’re now pleased to say that the pair have already taken up residency on one of the rafts on the pool at Wheldrake.
On the 12th February 2000 we caught and ringed the first Shelduck for the Lower Derwent Valley on the top pond at North Duffield Carrs, and now, 25 years later, we've just ringed the 1000th individual at Bank Island. Whilst that represents something of a milestone itself, the numbers are not the important thing, but rather the amount of data that those birds (as part of our long running colour-ringing project) have produced over the years, to help our understanding of Shelduck both on the reserve and in the wider area.
‘Our’ birds include: the longevity record for the species from the BTO ringing scheme (over 20 years old), regularly returning breeding birds to the LDV year after year, and birds visiting moulting sites on the Dutch/German Wadden Sea, the Humber and other estuaries around the UK.
The map below shows a strong association with the northwest, and it is suspected that the Dee Estuary could now be a new moulting site, with young birds beginning to recruit into it over the last decade or so. Indeed, stable isotope work carried out by Ros Green (as part of a PhD study into the species) has provided very different data from the Dee compared to all of the other northwest European moult sites, and it will be interesting to see how that moulting site develops and with it, the links to the Lower Derwent Valley. A total of 100 birds had small feather samples taken by our team over the 2024/25 winter to allow such analysis, and help us understand how Shelduck use the site here. Many thanks to all involved for helping to collect this valuable data.
A species which is now a highlight in the Lower Derwent Valley each spring is the Black-tailed Godwit, which has increased dramatically in recent years and now occurs earlier than previously. During the early 1990s spring passage flocks increased from 20–30 birds to flocks of up to 100, often appearing for just a day in late April and early May. However, since then, as the Icelandic breeding population has grown, numbers here have also increased, with peak counts now usually occurring in March. This year up to 200 have been present from early February with 543 recorded over the weekend at Wheldrake Ings, with further birds expected to arrive and build up over the coming weeks. These birds are usually best looked for at either Wheldrake Ings or North Duffield Carrs, with the spring passage flocks of summer plumaged birds a real spectacle – last year numbers peaked at 1,120 on the 20th March at Wheldrake Ings – certainly one to look out for on your next visit.
With temperatures rising over the weekend, it’s a time of change in the Lower Derwent Valley once again. Curlew numbers have jumped from 50 to 160+ over the last week with several pairs back on territory throughout the site - it's always a highlight of the year when the first singing and displaying birds are heard across the Ings.
Breeding Oystercatchers have also returned to the reserve, their arrival having moved forward over the last 40 years from mid-March to mid-January, although most arrive from early to mid-February. The now annual build up of Black-tailed Godwits has also started, with just over 200 at Wheldrake Ings during the last couple of weeks. Other signs of spring include breeding activity in the local heronry, the sudden return of Little Egrets, nest-building Mute Swans, singing Woodlarks on Skipwith Common NNR and the appearance of the first frogs. Whilst there is likely to be some cold and wintry weather still to come, it’s a great time of year to get out and about on the reserve and enjoy the changing seasons.
Thanks to local wildlife photographer Terry Weston for the use of his image.
At the weekend several of the team carried out the monthly WeBS UK count of the LDV’s waterfowl, as part of the national ‘Wetland Bird Survey’. These surveys have taken place on the NNR since the 1960s, and with the use of standard methodology, allow trends in wildfowl and wader populations to be studied, both at a site level and across the county.
Of the 27,500 birds counted in the Lower Derwent this weekend 20,500 were swans, geese and ducks which included an impressive 1,092 Pintail. This represents the second highest count on record for the LDV following last winter’s record breaking 1,120 in February 2024. From looking at previous years WeBS data, we can see that the ten-year averages for winter peak counts show that numbers were in the range of 54-70 during the 1960s, 70s and 80s, with numbers then increasing to an average of 186 during the 1990s, and more dramatically to 468 during the 2000s. Peak counts during the 2000s passed 600 birds in four winter periods, with the largest count of that decade of 674 in 2007/08, being surpassed by a count of 716 ten years later in the 2017/18 winter period, before two counts of 800+ more recently as well as last year’s peak of 1,120. It’s great to see the value of these long-term monitoring schemes, and to see Pintail, such a stunning and eloquent duck, doing so well here, perhaps as they start to shift their range in response to climate. Many thanks to all of our counters who have helped to contribute to this data set.
