Welcome to the LDV NNR ringing blog, this blog is designed to share the experiences, findings and tales from a group of dedicated ringers. We specialise in conservation orientated research projects, largely focusing on wildfowl, waders, owls and birds of conservation concern, in and around the Vale of York NNR's.

Wednesday, 16 April 2014

13/04/14 - Climbing high

Last week we paid the first visit of the year to the local heronry to ascertain how the breeding season was going so far. A good number of adults were present, and many empty egg shells were located beneath the trees. Calls of young birds could be heard and so the spikes were donned ready to scale the dizzy heights of the larch and pine trees, however upon reaching the top most of the young were newly hatched with just one bird being of a ring-able size. This isn’t what we were expecting to find compared with previous years, with the milder spring and higher temperatures a number of species started breeding earlier than last year and so we were expecting the chicks to be much further on. Herons are one of the species known to be early nesters with some records as early as February for birds on eggs, however March is the usual time for herons to start laying with the incubation period c27 days. We shall now return in c10-12 days to hopefully ring and darvic a number of the young.

Herons have bred in the heronry here for at least 40 years, along with Little Egrets in 2010, which went on to produce two young. These two species are known to nest alongside each other, however the latter is a much later breeder. Herons are rather sociable birds, breeding in close quarters, a single tree has been known to hold as many as 10 nests! Herons are known for nesting in long established heronries with data going back as far as 1928 when the first survey by the BTO took place, since then heronries have grown in number with the biggest heronry being on an RSPB reserve in Kent with over 150 nests, down from 200 in previous years.

Last year we managed to ring and darvic 22 birds over the course of four days throughout April and May, with the first visit being on the 16th April and the last being on the 17th May. Out of the 22 birds ringed last year we’ve had two sightings, which is much in line with the national reporting rate of 11%. The first bird was seen briefly locally however the second was seen at Nosterfield Nature Reserve, nr Ripon on the 16th August, three months after being ringed in our heronry.

From the ringing recoveries that we’ve collected over the years in the valley we’ve found out that our young herons undergo a rapid post breeding dispersal to the north, with recoveries 50-60km north of the LDV by July/August. Given that heron numbers also peak in the valley at this time would suggest that these birds include at least some that have dispersed from other sites presumably further south, and are not just the local breeding population as previously thought. 

Foreign recoveries from birds ringed in Britain only make up 3% of the total with the most being in France, and prior to 1940 the proportion of recoveries in foreign countries has declined from 12% to 2% in the 1990’s but the reasons remain unknown as to why. Despite herons being relatively common and widespread there are gaps in our knowledge of heron movements, including the movement during the year of adult birds and the apparent population shift towards coastal areas in the winter as suggested by counts. The national data does however suggest that general dispersal movements occur over the first five months of life, later returning to the natal site to breed, which fits with what we suspected was happening in the valley.

Friday, 28 March 2014

27/03/14 - From Wheldrake to West Africa

Long term followers may remember that in its early days this blog was largely focused on the ringing projects and activities in and around the Lower Derwent Valley NNR, as a way of sharing our experiences and results with other ringers and interested individuals elsewhere in the country. Since then the blog has covered a wider range of activities undertaken by the team (staff and volunteers) here at the Lower Derwent Valley and other NNR’s in North Yorkshire, but our ringing activities have continued throughout, albeit at times restricted due to flooding and seemingly endless weeks of unfavourable weather conditions.

The reason we ring birds is for the purpose of gathering data and in waiting to hear about recoveries and controls of the birds we have ringed which can provide us with insights on dispersal, migration routes and longevity. Some of these recoveries have featured on the blog during the last year such as our elderly Tawny Owl and our first dispersing Grey Heron chick.

Here are some recent and some not so recent recoveries we’ve received concerning birds ringed or recaptured in the Lower Derwent Valley NNR.


We’ve recently received a few more sightings of our colour-ringed Whimbrel from the long term study at the nationally important Wheldrake Ings spring staging site in the Lower Derwent Valley. Once again it shows the importance and use of colour-rings in helping to gather data which otherwise wouldn’t have been possible to get. 

A bird that was ringed at the Wheldrake roost back in 2008 was seen in Normandy, France in May last year, full details below:

Whimbrel (EL99843): Red/Lime Red

2008 - Ringed on the 1st May, seen several times afterwards until the 6th May
2010 - Seen back in the LDV on the 22nd April (DT)
2011 - Seen back in the LDV on the 20th April (PR), present until at least the 24th April (PR)
2013 - Seen in a roost at Manche, Normandy, France on the 3rd May 

We’ve also had one seen on return migration following the breeding season, with a single bird seen in two consecutive autumns on the Ythan Estuary in Aberdeenshire.

Whimbrel (EL45771)
2005 - Ringed at Wheldrake Ings on the 2nd May
2006 - Seen back in the LDV on the 3rd May
2010 - Seen at the Ythan Estuary, Aberdeenshire
2011 - Seen at the Ythan Estuary, Aberdeenshire 

More recently Dutch researchers working in Guinea Bissau in West Africa photographed two colour-ringed Whimbrel wintering over there. One of them was one of our birds originally ringed at the Wheldrake roost in 2008, full details below.

Whimbrel (EL49639)

2008 - Ringed at the Wheldrake roost on the 25th April
2009 - Seen back in the LDV on the 24th April
2011 - Seen back in the LDV on the 25th April
2013 - Seen back in the LDV on the 22nd April
2014 - Seen in Ilha da Ponta, Bijagos, Archipelago, Guinea Bissau on the 14th January

Seen by Dutch ornithologist, Pete de Boer, this bird was one of 48 roosting on a beach at high tide. Another bird in the flock also had colour-rings, this individual had been ringed as one of the small British breeding population on Shetland.

c/r Whimbrel on the beach in West Africa 

We’re now looking forward to the birds heading back to the valley this year – only three weeks or so to go before the first birds arrive at Wheldrake Ings on their way back to the Icelandic or Scandinavian breeding grounds. We’ll be out and about looking for them arriving back, counting the evening roost and searching for the day time feeding fields and checking for our ‘old friends’ coming back.


Last month we received news that one of our darvic'd Shelducks had been seen at Martin Mere, a bird initially ringed in the valley in 2012, details below.

Shelduck (GR42655 - HJ)

2012 - Ringed as a 7F on the 15th February at North Duffield Carrs
2012 - Re caught on the 15th March at Thorganby
2013 - Seen at Martin Mere WWT reserve on the 11th January 

Shelduck fitted with a darvic ring 'TX'

This is now the fourth LDV Shelduck to go to Martin Mere whilst a single bird ringed there has also been seen here. Fitting our Shelduck with the black and white darvic rings pictured above has produced numerous sightings since the project first began back in 2002, with a total of 300 birds caught and darvic'd during that time. The sightings have largely been UK based, with the furthest recovery on record being of a bird ringed in 2004 at North Duffield Carrs, which made its way to Germany several months later. The most recent recovery out of the country is a bird that was ringed in 2007, and was then seen in Dublin Bay, Northern Ireland, 381 Km from its original ringing location. 


Each summer we try to put a lot of time and effort into catching ducklings, so that we can try and find out more about how far our British bred ducklings go and how quickly they disperse. Recently we received details of a Shoveler duckling that was ringed in 2006 and later shot dead in France in 2013, full details below.

Shoveler (FP59233)

2006 - Ringed as a pullus on the 25th June at Wheldrake Ings
2013 - Shot on the 10th November in Saint-Pere-en-Retz, Loire-Atlantique, France, 747 Km to the south.

This is the seventh recovery of a Shoveler duckling ringed in the LDV, with four previous birds shot in France during the autumn/winter (August-January). At seven years and five months it also represents the oldest bird recovered so far.

Shoveler ducklings - Wheldrake Ings

Thursday, 20 February 2014

12/02/14 - Down in the (other) valley

With areas of the valley restricted slightly at the moment due to the flooding it has allowed the team here to get across to Forge Valley, to try and make a dent in the woodland management works that need to be carried out on the site. Along with the Lower Derwent Valley NNR and Skipwith Common NNR, both Forge Valley Woods NNR and Duncombe Park NNR come under our 'bracket' – and so we have to try and split time accordingly between all the sites.

Forge Valley Woods NNR covers 63.63 hectares of some of the best valley side mixed deciduous woodland in North Yorkshire. The valley was initially cut as melt water drained from ice sheets over the North York Moors producing the steep sided gorge. As a result of the underlying geology the woodland grades from acidic higher slopes with Pedunculate Oak woodland, to a more basic middle slope dominated by Ash and Elm through to a neutral valley floor with Alder and Willow woodland.

The site was first scheduled as a SSSI (Site of Special Scientific Interest) in 1954 and was declared an NNR on the 8th March 1977 in an ongoing agreement with the site owners, Scarborough Borough Council. Work over that time has been aimed at improving the woodland composition and structure, increasing the population of many of its notable plants and invertebrate communities and improving public access and enjoyment of the site.

Several work days at Forge over the next few weeks will allow us to carry out a variety of tasks aimed at continuing this work. We shall start by thinning some of the dense stands of Sycamore, these trees initially colonised the site during the first half of the last century. Whilst Sycamore does have a value to wildlife and is gaining a status as a natural feature in our woodlands, the species does tend to form a monoculture by casting a deep shade under which its own saplings are the most likely to thrive, reducing other tree regeneration and a decrease in ground flora diversity. Beech was also planted into the area in the 1960’s and unlike Sycamore was not a natural coloniser, being beyond its natural range in the UK. Beech also casts a deep shade reducing other flora and so we will also be thinning out some of the beech in some areas. This will hopefully help in increasing the natural regeneration of the native tree species across the valleys slope and help some of the plant specialities of the site to thrive.

The site is well known for its colonies of Green Hellebore, Herb Paris, Lily-of-the-valley, Bird's-nest Orchid and Baneberry which have either restricted distributions in the county or are found at the northern edge of their range. Other woodland species such as Toothwort, Columbine, Thin-spiked Wood-rush and Broad-leaved Helleborine also occur, whilst small pockets of Limestone Grassland provide habitats for Quaking Grass, Cowslips, Salad Burnet, Meadow Saxifrage and Thyme, as well as the food plant for the Brown Argus butterfly, Rockrose.

We will be strimming some of these grasslands to improve the site for these flowering species, reducing competition by the ranker more competitive grasses and encroachment by brambles and scrub. We’ll also be carrying on with a programme to reinstate Hazel coppicing to help extend the life of the Hazel stools found throughout the site and again increase the light reaching the woodland floor to allow some of the plants mentioned above to flourish. Likewise we will be taking out other non-native and very competitive species such as Rhododendron and Snowberry.

Whilst present at Forge we took the opportunity to ring at the feeding station over lunchtime. The feeding station at the aptly named ‘birdwatchers car park’ is a popular location for the public to enjoy close encounters with many woodland birds, and many birdwatchers and photographers visit daily to encounter the more unusual species up close such as Nuthatch which visit the tables regularly for peanuts. A single 30 foot net kept us busy and produced a total of 71 birds in just over an hour. 


This complements a joint project between Natural England and the East Yorkshire Ringing Group a couple of miles away in Raincliffe Woods where a further 200 birds have been caught and ringed this winter. Highlights this winter have included 6 Nuthatch, 7 Marsh Tit (a species which is still doing well here despite national declines), 3 Great Spotted Woodpeckers and 5 Brambling amongst the usual common tits and finches – largely Chaffinch. This is producing a good sample of woodland birds which are of conservation concern at the moment.


Signs of spring are starting to show in Forge now which include: Snowdrops, Dog’s Mercury, Early Dog Violet, Woodruff and Lords and Ladies - all out but not yet flowering. Also Green Hellebore which was just starting to bud and will be flowering soon as it’s typically an early woodland species.

Green Hellebore

A variety of fungi was on display today, including a new one that we haven’t come across in the Lower Derwent Valley - Scarlet Elf Cup (below) - a very vibrant red cup that stood out like a beacon amongst the variety of green mosses which cover the woodland floor. Scarlet Elf Cup is a disc fungus which can be seen throughout winter and early spring, often growing on dead wood of deciduous trees, usually surrounded by moss.

Also today we came across Jelly Ear, Yellow Brain, Velvet Shank, Dead Moll's Fingers (2) and Stump Puffball (3).

Scarlet Elf Cup

Dead Moll's Fingers

Stump Puffball

Woodpeckers were drumming throughout the day and a single Woodcock was flushed during our work. We’ll be looking forward to carrying on with our work here over the next few weeks before we cease our woodland management work for another winter as the bird breeding season approaches. It will be interesting to follow the woodland plants as they appear as the months progress.