15 June 2017

Nest Recording Taster Day, Glamorgan

‘Fledgemore’ is a new nest recording group in Glamorgan. Established in 2015, its members (Andy Bevan, Trevor Fletcher, Dan Jenkins-Jones, Wayne Morris and Graham Williams) have only been nest recording for a few years but, as well as finding and monitoring their own nests, one of their ambitions is to increase the number of local recorders contributing to the BTO’s Nest Record Scheme (NRS). They’ve written this blog about one of the ways they’re doing that.

Nest recorders will tell you that finding and then monitoring nests for the NRS is one of the most challenging, exciting and fulfilling experiences in birding. There’s something new to learn every year, there’s the thrill of finding a new nest and there’s the satisfaction in knowing that you’re gathering vital data for the BTO’s Ringing and Nest Recording Team that will inform birds’ long-term conservation.

There has been a welcome increase in the number of nest records submitted from across Britain & Ireland in recent years. An increase that has been reflected in the totals from our home county of Glamorgan. Up until 2006, barely 100 records a year were being sent from here to the BTO. In 2015, that figure had risen to almost 800. But, when we scratched beneath the surface, we found that there were no more than eight or nine birders regularly contributing nest records from Glamorgan. We’re sure other regions have a similar situation.

Blackbird chicks close to fledging at Rudry (Photo: Dan Jenkins-Jones)

If you’re new to nest recording you can learn a lot about how to find and safely monitor the nests of various species from books and online articles, but nothing beats a first-hand experience in the field with other nest recorders. This is how we learnt to find our first nests and it gave us the leg up we needed. With this mind, we trialled a ‘Nest Record Scheme Taster Day’ at Rudry Common, north of Cardiff, in 2016 in an attempt to increase the number of local recorders and put the Scheme on a more sustainable footing in the county. Despite having no more than five seasons’ nest recording experience ourselves, we felt we had sufficient knowledge to be able to share the basic skills with newcomers and to hopefully enthuse and encourage them to take up nest recording. Five birders took part in that event, two of whom are now members of Fledgemore with 130+ nest records gathered between them so far in 2017! Encouraged by our experiences of this ‘Taster Day’, we held another at Rudry on 14 May this year.

Taster Day 2 started with a short indoor session where we presented the participants with their free hazel ‘tapping stick’ and ‘mirror on a stick’, kindly donated by the Rudry Common Trust and both essential tools of the nest recorder’s trade, which they learnt to use during the day. We introduced them to the NRS Code of Conduct, to some basic nest finding techniques and then we were soon out in the field for six hours of ‘nesting’.

Using a mirror on a stick to examine nests (Photo: Graham Williams)

Seeing a bird’s nest which contains eggs or chicks can be that spark which ignites an individual’s fascination with nest recording – especially if it’s a nest you’ve found yourself. To ensure we’d be able to provide that experience, Trevor recced the area in advance of the event and found a nice variety of nests to show everybody.

We spent the morning working through woodland, finding a number of nests: a Blackbird nest with chicks close to fledging; an active Goldcrest nest and, later, a predated one; Great Spotted Woodpecker with chicks; Song Thrush and a Wren on eggs; a Woodpigeon nest which had sadly failed at the chicks stage; a Blue Tit in a nestbox and Coal Tit and Great Tit with chicks nesting in natural cavities, both of whom enabled Trevor to show off his skills with an endoscope. A number of old nests were found too, which are useful in showing participants the likely places to look for nests in future.

Two of the participants trying out the art of ‘tapping’ for the first time (Photo: Andy Bevan)

Late morning, we left the woodland and moved out onto to Rudry Common in search of a suite of different species. A Linnet nest in gorse, which contained chicks a few days before the Taster Day, was sadly empty, probably lost to predation. Nevertheless, it enabled the participants to get a feel for where to find their own Linnet nests in future. A beautiful Long-tailed Tit nest with chicks, also in gorse, was up next, followed by a well concealed Meadow Pipit with four eggs.

The highlight of the day for most was probably a Willow Warbler nest with eggs, described by one participant as a ‘nest on its side’. It’s such a simple, yet beautiful, construction and superbly camouflaged. Finding one is always a thrill, and yet, with the right fieldcraft and knowing how the female’s off-nest call will help you, finding a Willow Warbler nest can be quite easy.

Willow Warbler nest on Rudry Common (Photo Dan Jenkins-Jones)

Best of all, some of these nests were found by the participants, either by ‘watching birds back’ to their nests or, on one occasion, a Blackbird on four eggs was found by gently ‘tapping’ suitable habitat with a hazel stick which gently flushed the sitting bird. Finding these nests and recording their contents generated a lot of excitement amongst us all. For the participants, it proved very quickly that they could find their own nests, and for us as leaders it was great to be able to show that the tips we’d shared with everybody actually work!

The day was rounded off with another short indoor session where we shared information on how to plan nest visits and what information to gather at the nest: egg or chick counts; nest location and habitat; chicks’ feather structure; the nest’s ‘outcome’ etc.  Finally we ‘crowned’ Tara, one of the participants who found three nests as the ‘New Nest Finder of the Day’. Tara went on to justify her crown by returning to Rudry Common immediately after the event to try and find a Garden Warbler for her Year List, and found another Willow Warbler nest on her own!

Tara was crowned ‘Nest Finder of the Day (Photo: Rob Williams)

An enjoyable day all round and we’ve heard from some of the participants that they’ve already been finding their own nests. Fingers crossed that some, if not all of them turn out to be fully-fledged nest recorders in years to come. And of course, we found some new nests on the day to add to our own monitoring for the Scheme. The BTO is keen to encourage ringers to contribute data to the Nest Record Scheme and, where possible, we are revisiting nests to ring pulli to further contribute data to the Ringing and Nest Recording Team. 

We’d highly recommend other nest recorders hosting similar events in their own regions to build up the numbers of local recorders. You definitely don’t need years of experience behind you, you’ll introduce others to a fascinating aspect of birding, help the Nest Record Scheme get even more records and you’ll enjoy every minute of it.

30 May 2017

Drift migration in action

Following a brisk overnight easterly wind, hopes were high on the morning of 12th May for a few drift migrants arriving at Isle of May Bird Observatory in the Firth of Forth. The highlight was a stunning male Red-breasted Flycatcher found on the beach at Pilgrims Haven, soon drawing a fair crowd (by island standards). It was quickly noticed that the bird was ringed, and knowing it hadn't been ringed on the island, attempts were made to read the ring from photographs. The ring inscription looked foreign, but unfortunately the ring number itself couldn't be read.


So the bird was left to feed for a couple of hours, before ringers returned with a single-shelf net and just minutes later the bird was caught, revealing the ring was from the Swedish Ringing Scheme. After processing, the bird was released in the same spot and was still present the next day.

Being such an unusual record (we've only ever seen one previous foreign-ringed Red-breasted Flycatcher in the UK - details here), a quick flurry of emails back and forth across the North Sea soon revealed the details. TV0721 was ringed just a week earlier (5th May) at Torhamn in southern Sweden. It had presumably been caught up in an area of high pressure over northern Europe, creating an easterly airflow across the region. The synoptic chart (below) for 11th May also shows the ringing and finding locations, some 1,175km apart!


When ringed, the bird weighed 10.0g and a week later 9.7g, so rather than being thought of as a lost vagrant, it should perhaps be considered a drift migrant, carried on the wind on its migration north. Red-breasted Flycatcher breeds from eastern Europe across to the Himalayas, wintering in southern Asia, although it was long been suggested that there may also be a wintering population in west Africa.

Previous recoveries in the UK have all been in autumn, although one record did see a bird ringed on Shetland recaught in southwest Norway two weeks later!

##UPDATE##
Many thanks to Anders Loell who got in touch with some background (and a photo) on the ringing of this bird: "I had the pleasure of finding it in a net here at Torhamn. And as you suspected there were some heavy eastern winds. There were only two nets possible to use on the 5th and the only reason why they were active was due to some schoolkids coming out here to visit the observatory."


10 May 2017

Reading the small print

Within the ringing team, it never ceases to amaze us just how many people spend their time reading bird rings. Only a small percentage of ringed birds are colour ringed as well, so most birds can only be identified by reading the metal ring number, which can be difficult with wild birds. Rings on large birds such as swans and geese can be quite easy to read, due to the ring size and the proximity of the birds in parks and lakes.

Mute Swan account for 44% of all the metal ring reads (sample from 1 Jan 2017 to today), followed by Black-headed Gull with 19% and Shelduck with 5%. The remaining reports are between 57 different species ranging from sea birds like Puffin and Cormorant to passerines like Nuthatch, Goldcrest, Lesser Redpoll and Grasshopper Warbler.


Last week we had a report of a Green-winged Teal (below) at Storavan, Stöcke, Västerbotten, Sweden wearing a BTO ring! Luckily for Johan Forssell and Mikael Wikstrom, very few Green-winged Teal are ringed by our ringing scheme (see ringing totals by species), so finding a match with the given numbers was relatively easy. This bird was ringed as an adult male on 6 Oct 2015 at Caelaverock, Dumfries and Galloway (1,651 km). For more information on the recoveries of Green-winged Teal see our Online ringing reports (don't expect to be overwhelmed by numbers).

BTO ringed Green-winged Teal (foreground). Photo by Johan Forssell




Bardsey Bird Observatory was lucky enough to ring a Pallas's Warbler on 18 April 2017, making this the first spring record for Wales. In fact, this is probably only the third spring record of Pallas's Warbler in the history of our ringing scheme. This bird soon moved away, however a ringed Pallas's Warbler was seen on the island on 7 May.

Pallas's Warbler. Photo by Steve Stansfield in May

Being a very popular bird, this bird was photographed in enough clarity that five of the six digits could be read. This size of ring also fits on Goldcrest and Wren, so is very small indeed. There was only one issue... the ring number didn't match the one that was put on the Pallas's Warbler in April. This was a different bird!

Pallas's Warbler. Photo by Steve Stansfield in May


With the help of the BTO's national ringing scheme database, the origin of this bird was traced. It was originally ringed at Spurn Bird Observatory on 11 Oct 2016! Re-catching a ringed Pallas's Warbler at a different site is incredibly rare, so the details of where this species goes after it reaches our shores is now a little clearer, but there is still a long way to go to fully understand their migration.

Learning to become a ringer takes quite a lot of commitment and time. As these and other previous examples highlight, you don't need to be a ringer to make a real difference to our knowledge of bird demography.

28 April 2017

Bus pass boys at the beach

Allan Hale writes:

The “Bus Pass Boys” are a group of birding pensioners, two of whom are ringers. We make regular visits to Great Yarmouth beach in Norfolk to read colour rings on Mediterranean Gulls, some of us since 1999 (when we didn’t possess bus passes!). Our first birds are on site from about mid-July and most are gone by mid-March.

Mediterranean Gull at Great Yarmouth. Photo taken by Allan Hale.

We have identified nearly 100 different Mediterranean Gulls that were ringed in 10 different countries. They have originated from Belgium, Germany, France, Poland, Britain & Ireland (only two), The Netherlands, Denmark, Czech Republic, Hungary and Serbia. There have been multiple sightings of many of these gulls (click here for a complete ringing scheme overview of recoveries for Med Gull). Many valuable life histories have been identified, with some of the birds mentioned above having also visited Spain, Portugal and The Azores.



Some of our Mediterranean Gulls have been shown to reach a ripe old age. Two of the birds we have seen this winter were originally ringed in 2001, one of them already three years old when ringed.

The BTO were impressed with our efforts and they suggested in 2013 that we should have a “joint venture” to try and cannon net some of these birds and fit them with British colour-rings. Very few Mediterranean Gulls are ringed in Britain so we took this as a challenge! Our aim was to add to the pool of ringed birds at Yarmouth and to further understand where these wintering birds originated. Maybe British breeding birds are there – we just didn’t know.

Stunning summer plumage Mediterranean Gulls. Photo taken by Irina Samusenko.

It wasn’t as easy as we had hoped. It is well known that Mediterranean Gulls are more intelligent than the people trying to catch them (most are also better looking!) At time of writing we have caught and ringed 46 Meds and had 'our' birds seen in The Netherlands, Belgium, France and Poland. We have also establish that some British-breeding Mediterranean Gulls winter at Great Yarmouth.

Last week we received notification of a sighting of one of our birds that was truly spectacular. The bird had been ringed at Great Yarmouth on 22 November 2015. It was seen on the beach until the end of February 2016 then disappeared for the summer. It had returned to the beach by the end of November 2016 and remained until at least 18 February 2017. Remarkably it was next seen 15 April 2017 at Trostenetskij Rubbish Dump, near Minsk, in Belarus. ‘Our bird’ was apparently paired with a colour ringed bird ‘red PKU6’ which was ringed in Poland.

'Our bird' (right), enjoying some delights in Belarus. Photo taken by Irina Samusenko

This represents the first British or Irish Mediterranean Gull that has been reported from Belarus and it is the most easterly sighting of any of our Mediterranean Gulls.

To report any ringed or colour ringed birds please go to www.ring.ac.

21 April 2017

Little Owls in Lincolnshire

Anecdotal reports suggest that some species have started breeding early this year. In this post, Bob Sheppard provides an update on the Little Owls he monitors in Lincolnshire:

Little Owls readily take to nest boxes, particularly in old farm buildings. The box design I use is important as it mimics a hole in a tree. My father designed the box back in 1998.

A very big clutch of Little Owl eggs. Taken by Bob Sheppard/Alan Ball.

In the past nineteen years our Little Owls have increased as more boxes have been installed and we now have 80 pairs breeding. We monitor the adults for the Retrapping Adults for Survival scheme as well as submitting records to the Nest Record Scheme. In late April/early May, my colleague Alan Ball (who works with me to monitor all the boxes every year) and I catch all the adult females at the boxes (males are rarely caught in the boxes). The females are very site faithful and so we often retrap the same birds for several consecutive years. We then make a follow up visit to ring the chicks.

Little Owl struggling to sit on all those eggs. Taken by Bob Sheppard/Alan Ball.

This year we have found eggs during the first week of April which is very early indeed for Lincolnshire. Clutches of four are the average but we do find quite a few fives, including three already this season. Six egg clutches are not unknown and we once had a seven! The egg-laying season is unusually staggered this year; in several boxes we have heavy females yet to lay. Recoveries are rare (see online reports) but we meet lots of old friends as we open the boxes.

Ed - For more information on the details of Little Owl biology, see our BirdFacts page. Lincolnshire holds the record for the highest number of nest records of Little Owl (77) in 2016, with Norfolk following quite a way behind (14). For the 2015 results of any species click here.

28 March 2017

Feeling a bit broody

With winter loosening its grip on the British countryside our bird life is starting to look forward to spring! Here at BTO HQ, we are winding up to a busy nesting season and are searching the hedgerows and bushes for nests.

Egyptian Geese - photo by Rachael Barber

So far this year we have found nests of Coot, Egyptian Geese, Mallard, Robin, Blackbird, Song Thrush, Long-tailed Tit, Wren, Collared Dove and Dunnock, with more species being added every day. Each nest will be fully recorded for the BTO Nest Record Scheme (NRS) with nest finders following the NRS code of conduct.


Mallard nest with nine eggs - photo by Lee Barber


Robin nest - photo by Rachael Barber

Several BTO staff and volunteers record nests around Thetford, Norfolk, but how do we avoid recording the same nest? The answer is that we share a Google Map between us, with colours and shapes used to denote the progress of each nest and a note included of who found the nest. After a day of 'nesting' we update the map with our exciting discoveries and this informs everyone of where the nest is, the species, when it was found and at what stage the nest is at (nest only, nest with eggs, chicks, not active). Each recorder will then follow 'their' nests and submit them to the BTO (usually via the ringing group) at the end of the season/nest completion.


Last years nest locations on a shared Google map

Across the country there are some species that have been nesting for some time already including Grey Heron, Raven, Dipper, Stock Dove, Cormorant and Crossbill. The BTO NRS Forum has come alive with reports of nests, includes a Peregrine laying in Woking, Surrey (webcam link), a Woodpigeon squab about two weeks old in North Cornwall and Moorhen, Mistle Thrush and Ring-necked Parakeet with eggs in London. Dippers have full clutches in the Scottish Borders and some chicks have already been ringed in Wales. A Stock Dove in North Norfolk must have fledged by now as well.

 
Blackbird nest - photo by Lee Barber

Nest recording is vital to our understanding of productivity and every nest counts! It is amazing how much difference one nest record can make. By looking at the NRS submission totals, you can see what nests have been recorded previously (2016 records are still being analysed). In 2015, just 24 Goldcrest, 15 Snipe and nine Grasshopper Warbler were recorded in the whole country. Take that down to the county level and you could make a big difference to the totals, especially if you focus on one particular species. Open nesting birds are particularly under recorded because they are generally harder to find, but with a little practice and patience it can be done. Click here to find out how to take part and develop your nesting skills.

16 March 2017

Ringing, recording and recoveries at Sandwich Bay

Steffan Walton, Assistant Warden at Sandwich Bay Bird Observatory writes:

Life at a south-eastern Bird Observatory is full of surprises throughout the year. Late winter cold snaps on the continent can start the year off with a bang as wildfowl and thrushes burst into the recording area, whilst counts of almost 150 Woodcock in a morning have occurred in recent times. The spring sees thousands of northbound finches flying over, thermalling raptors, and Whimbrels passing through en masse, whilst typically scarce overshoots such as Kentish Plover, Temminck’s Stint, and Serin are reasonably regular. In 2016 an epic Lithuanian Blue Tit recovery set new records in the spring (see Demog Blog story), whilst both Long-billed Dowitcher and Common Crane treated the visiting young Next Generation Birders.


This is what a Lithuanian Blue Tit looks like - photo by Becky Johnson

Summers are typified by the (now increasingly rare in the UK) sound of the Turtle Dove, breeding waders, and of course, the Nest Record Scheme. Co-ordinated efforts to monitor, ring, and assess our breeding populations take priority whilst our recently started Retrapping Adults for Survival (RAS) projects on House Sparrow and Collared Dove are already bearing their first fruits. Bee-eater, Quail, and Honey Buzzard are all possible this time of year but highlights are just as likely to be non-avian being a truly fantastic site for Lepidoptera and Odonata records.

As the summer draws to an end things start to heat up. Autumn is traditionally our busiest time of the year avian-wise. Sandwich Bay Bird Observatory has a long history of ringing unusually large numbers of House Martin, Common Sandpiper, and Lesser Whitethroat during this time, as well as being one of the premier sites in the UK for Pallas’s Warbler. Just under 10,000 birds were eventually ringed in 2016, most of which were caught in autumn. In a typical year 7-8,000 birds may be ringed though a recent high of 11,000 occurred in 2015. Looking back at the most recent autumn, numbers such as 1,350 Blackcaps, 1,200 Chiffchaffs, 585 Robins, and 640 Blackbirds make impressive reading.

Tallies can vary from year to year as weather dictates what arrives and what carries on towards France. Meadow Pipits are usually ringed in excellent numbers, species such as Firecrest, Nightingale, Ring Ouzels, and Redstart frequently show well, as well as being one of the best sites to get to grips with continental Coal Tits. In recent year’s rarities such as Red-flanked Bluetail, Great Grey Shrike, Icterine Warbler, Wryneck, and of course, double-figures of Yellow-browed Warblers have found their way into our mist-nets.


Icterine Warbler - photo by SBBOT

The real highlights though come in the form of some very note-worthy foreign controls including a series of Robin recoveries all arriving in a fantastic three week period in October. One bird from Usquert, Netherlands moved 427 km in 16 days, another 545 km from Helgoland, Germany also in 16 days, but one record stood out from the others, the cream of the crop was an individual that was ringed at Kovda, Kandalakshskiy District, Murmansk Oblast, in RUSSIA! A movement of 2,460 km and believed to be the longest distance and furthest east Robin recovery in BTO history. Further interesting records included a good run of Common Redpolls (one being a Danish ringed bird, a movement of 814 km) as well as another Eastern Lesser Whitethroat (S.c.blythi) confirmed by DNA analysis (below).


Lesser Whitethroat - photo by SBBOT

If you would like to visit or ring, then stop by the Field Centre for more details. The home of Sandwich Bay Bird Observatory offers modern, comfortable, self-catering accommodation, allowing you to be on hand for early morning bird ringing, late night moth trapping, club events or just more time to explore the local area. We offer a self-contained flat, twin, family, and single rooms. All guests have use of shared shower facilities, kitchen, dining room and lounge. What’s more, you just might get a snapshot of all the additional behind the scenes crucial work ongoing at Bird Observatories across the UK. Be it the full digitisation of historic data for Birdtrack, Butterfly Monitoring Scheme Transects, the Kent Moth Group, RSPB Wildlife Explorers and Phoenix clubs, and more.

For more information see our website.

09 March 2017

From across the pond

Britain and Ireland are part of the East Atlantic Flyway, so we regularly get a few high Arctic breeding birds from Greenland or Canada in our country like Greenland Wheatear, Barnacle Goose, Pink-footed Goose or Purple Sandpiper.

The majority of recoveries are of Brent Geese (66%), but 19 species have been recorded either coming from, or going to, North America, Canada or Greenland (the latter is covered by the Denmark Ringing Scheme).

Brent Geese have been excluded from the pie chart to better illustrate the other species involved.

These are not all recent recoveries however. The oldest report is from 18 July 1948 (juvenile Arctic Tern ringed in the Bay of Fundy and found by Lairg, Highlands three months later). Due to a colour ringing project on Ellesmere Island, Nunavut, we have received quite a few Turnstone reports (37% of the total). Several species stand out, including Great Shearwater (one caught by a trawler and the other caught on a boat), Peregrine (downed by a falconer's Peregrine) and a Caspian Tern (found dead).

Below are a few examples of more recent recoveries :

Ringed Plover - you may remember that Ringed Plovers from Canada have been featured recently on the Demog Blog, so we have several reports of them.

Ringed Plover. Photo taken by Lee Collins

Green-winged Teal - one turned up on the Hayle estuary, Cornwall on 9 November 2016 and it didn't take long to notice it was ringed! It took the Cornish ringers and birders quite a while to get enough photos of the bird to get the ring number, but finally on 19 January 2017 they had enough to trace it. Amazingly this bird was ringed as an adult in Quebec in August 2015!

Green-winged Teal. Photo taken by Anne Carrington-Cotton

Knot - in February we received a report of a dead Knot at Old Hunstanton, Norfolk. The likely ringer would have been the Wash Wader Ringing Group but the ring was clearly from the American Ringing Scheme. American rings are also used in Canada, which is probably where this bird was ringed. If this is the case, then this would be the 10th Canadian ringed Knot to be found in Britain or Ireland. Several BTO staff travel to Delaware every year for their holiday to ring 'Red Knot' as part of the Delaware Shorebird Project, so there was quite a 'flap of excitement' until it became clear that it was not one of theirs. We, and the finder, are awaiting the ringing details from the scheme.

Recoveries from the States are still very few and far between so each one is unusual in itself. The information from the tagged Ringed Plovers will be very interesting to follow in the coming years.

For more information on the movements of birds look at our Online Ringing and Nest Recording Report on our website.

16 February 2017

You’re in for a tweet, with National Nest Box Week

Hazel Evans (Nest Records secretary) writes:

With flurries of snow and frosty mornings over the weekend just gone it hardly feels as though spring is in the air, however some of our garden birds such as Blackbirds and Collared Doves have already started nesting and now is the time for nest box residents to start looking for a place to raise their young. This week is the BTO and Jacobi Jayne’s National Nest Box Week, which aims to encourage and promote putting up nest boxes in your garden and local area.

Whether you buy a nest box from your local garden centre or build a selection of your own, there is no doubt that putting up a nest box is one of the most valuable things you can do for your garden birds. The BTO’s National Nest Box Week webpage contains lots of information on which nest boxes are suitable, how to build a box and where to place them. You may be surprised by the variety of boxes that are available, from Barn Owl to House Martin and Blue Tit to Starling.


Nuthatch. Photo by Edmund Fellows

If you are looking to do more than putting up a couple of boxes in your own garden, you might consider contacting a local landowner, farmer, the council at a local park, or if your children are enthusiastic, their school might allow a few nest boxes to be put up in the grounds. Once the boxes are securely in place it is time to wait and keep your fingers crossed!

Hopefully you will soon see some activity at the box; birds entering and leaving, pecking the entrance hole and carrying nesting material in. The real conservation value of erecting a box is the opportunity it provides to monitor nesting attempts. As long as the BTO Nest Record Scheme (NRS) Code of Conduct is adhered to, we can safely look inside at intervals to count the number of eggs and chicks and submit this data to the scheme. This provides incredibly valuable data, and is also a rewarding and fascinating thing to do. This information is used by the BTO to study the breeding performance of wild birds to help identify when reduced productivity might be causing population declines. People can be concerned about opening up a nest box and checking the contents, but done in the correct way the value of the data collected is huge.

Each year, data from NRS are analysed and, alongside results from the Constant Effort Sites (CES) ringing scheme, are used to produce a summary of the breeding season. In 2016, the data collected by NRS and CES volunteers showed that whilst there were good numbers of adults at the start of the season, there was a late start to the breeding season for some species and productivity was generally poor. Additional results from NRS are presented in the annual BirdTrends report.

As this is the Demog Blog, I feel that as well as the nest monitoring side of nest boxes, I should also mention the value of ringing these broods. I am currently a trainee ringer and in addition to monitoring the nests in the boxes at BTO HQ and a local farm, I am able to ring all of the chicks (under the supervision of my trainer). This provides a huge amount of data – this year I will be monitoring around 70 nest boxes – and it is also a fantastic learning experience.

A Blue Tit shaking it's Bluti. Photo by Jill Pakenham

The most common inhabitants of our nest boxes are Blue and Great Tits. Combining the data from the thousands of nests monitored every year with the thousands of pulli ringed, provides an invaluable national picture for these species. The amazing coverage provided by BTO volunteers allows BTO scientists to explore how changes in the environment affect breeding birds and how their responses vary between regions and habitats. 

Nest boxes can of course be put up at any time of year but winter is ideal as it provides time for prospecting birds to find the site before the breeding season. Once used, it is a great idea to clean out old nests the following winter to allow for a fresh start in the spring. To comply with legislation, nests can only be cleaned out between 1 September and 31 January.

This year we are celebrating 20 years of National Nest Box week, so please do get involved by putting up a nest box and make your contribution really worthwhile by registering with the Nest Record Scheme

10 February 2017

We're stuck in 2016

Since the end of 2016, the Demography Team has been hard at work loading all the ringing data received from our ringers. Data are still coming in by the 'file load', but here is a sneak peek at a few highlights of 2016.

The big question is always, "how many birds were ringed in 2016?". I don't think we will reach a million birds ringed this year, possibly due to Blue and Great Tit not having a great year. We are currently on 990,808 birds ringed and there is a corresponding 281,880 records of birds already wearing rings (either caught again by ringers or found dead by anyone).

The graph below shows the 20 most ringed species in 2016. Despite them having a poor year, Blue Tit is still by far the most ringed species but perhaps more interestingly, Goldfinch is in second place. BirdTrends records show that Goldfinch numbers have increased substantially in recent years; however it is only the 10th most recaught species.



Top 20 species of birds ringed in 2016. Click to enlarge.

Unlike Willow Warbler, Chiffchaff has been doing very well recently, and as you can see from the graph, was the fourth most ringed bird in 2016. The preliminary results from the CES scheme show that Chiffchaff had the highest adult abundance in the history of the scheme last year. Unfortunately, productivity was significantly down in 2016 and the Nest Record Scheme results show that the mean laying date was eight days later than average. Chiffchaff that had originally been ringed in the Channel Islands, Germany, Spain, France, The Netherlands and Portugal were found in Britain and Ireland in 2016. All, apart from three birds were caught by our BTO ringers, one was found dead and two hit a window (one survived and one didn't).


A young Chiffchaff. Photo taken by Lee Barber
Coming in at number five of the most ringed bird for 2016 was Blackcap. This bird also had a high adult abundance and an even lower productivity than Chiffchaff  in the preliminary CES results. The North Wilts RG ringed an impressive 2,209 Blackcap in 2016, and their ringing session on 11 September, where they caught 257 Blackcap (most of which would have been on autumn passage), will always be remembered by the team on that day.

Male Blackcap. Photo taken by John Dunn.
Some of the more unusual recoveries we received in 2016 include a Blackcap which was found in a 'Horse water bucket', ringed by the West Wilts RG in 2011. We occasionally get birds being hit by vehicles, however I have never heard before of one which was 'trapped inside locked vehicle (entered through partly open window), fresh dead'. We also received a report of the fourth Slovenian ringed Blackcap found by a non-ringer. There are still a few records to be processed of BTO-ringed Blackcap that were found abroad and we look forward to processing those and letting the ringers know if it is one of theirs.

All of the recoveries of fresh dead birds and recaptures of live birds, feed into the longevity records for Britain and Ireland. It will be a little while until the 2016 records are added, but there are a couple of records that look to update the current longevities. The Bisham Barn Owl Group look to have just pipped the current record by a few days, originally set in 2012 (of 15 years 3 months). Click here for more information. The Mediterranean Gull record currently stand at 15 years 3 months as well, and Allan Hale has reported two colour ringed Med Gulls at Great Yarmouth beach, which were ringed just two days apart breaking the current record by over three months.

This post covers just covers the tip of a very big 'data' iceburg, so as we have more time to look into this data, we will undoubtably uncover more exciting information.

02 February 2017

Where do our wintering Blackcaps come from and why?

Over the next three winters, a new study focusing on Blackcaps wintering in Britain and Ireland will help reveal how novel migratory changes arise and spread.  The study will look at genetic and morphological differences between breeding populations and migration strategies, as well as investigate aspects of wintering behaviour, movements and survival of individuals wintering in Britain.

Up until 50 years ago, wintering by Blackcaps in Britain & Ireland was quite unusual, but numbers have since increased considerably, with many thousands now counted each winter by BTO Garden BirdWatch. Gardens are favoured sites where a combination of ‘natural’ berries and fruit along with specially provided fat, seeds, cake and pastry is the main attraction, often fiercely defended by some individuals. 

Male Blackcap. Photo by Greg Conway.

Typically, the majority of Blackcaps breeding in northern Europe migrate to the Mediterranean region for the winter. However, this is changing – some of these birds may now be migrating in a north-westerly direction to the British Isles instead! These changes appear to be facilitated by milder winters and the abundance of food provided by people, according to research carried out using Garden BirdWatch data.

A number of studies have suggested that our wintering birds come from central Europe (southern Germany/Austria), but the small number of ringing recoveries available (see map below) indicates that many may originate much closer to home, or even be resident!  Unfortunately, few recoveries confirm movements between the breeding and winter season.

Origins of ringed Blackcaps wintering in Britain and Ireland and their locations from the breeding season (red), autumn (blue) and spring (grey) (Migration Atlas – Wernham et al 2002).

To improve our knowledge of migration and breeding origin, a number of wintering Blackcaps have been fitted with Geolocators (accurate to around 70km).  These will reveal where they spend the summer, but only once re-caught back at their wintering sites.

Female Blackcap fitted with a geolocator. Photo by Greg Conway.

Colour ringing allows individuals to be identified with unique combinations and this will be used to learn more about winter behaviour, movements and use of wintering sites in Britain, which is surprisingly little understood.  Some appear to remain in the same garden all winter, but others do not!

Male Blackcap with unique colour rings. Photo by Greg Conway.

We would be very grateful for your help with the following:
Blackcap sightings - If you have wintering Blackcap in your garden please let us know and report your counts using BirdTrack or consider joining Garden BirdWatch.

Colour ring sightings - Please report all observations to: blackcap@bto.org

Ringers – Help with catching and colour ringing more Blackcaps over the coming winters would be much appreciated.  If you don’t have sites with Blackcap we can provide details of local sites where ringing is required.

To find out more about getting involved please contact: blackcap@bto.org

Greg Conway (BTO) & Benjamin Van Doren (Oxford University)
This study is collaboration between Oxford University, BTO, Exeter University and the Max Planck Institute for Evolutionary Biology, Germany.