Chiff-ful start to the nesting season

Over in Cambridgeshire there’s been wonderful sunshine, but accompanied by overnight frosts. Thankfully this hasn’t put off the resident birds at the National Trust’s Wicken Fen National Nature Reserve, where members of the ringing and nest recording group are getting ready to ring the first broods of Blackbirds. Also, our first Coot brood has just hatched, Long-tailed Tit clutches are about to hatch, Blue Tits and Great Tits are laying, and we’ve started monitoring our first finch nests: an almost fully-built Chaffinch nest was found a week ago and a pair of Goldfinches were spotted building last Thursday.

Water birds such as Coot (pictured) and Moorhen commonly hatch their first broods in mid-April

As for summer migrants, arrivals have been stalled by strong north-westerly winds, according to the BTO migration blog, and indeed Blackcaps at Wicken have been singing on territory for only a week and Willow Warblers still seem thin on the ground. One short-distance migrant, though, has been getting off to a flying start this season and keeping our nest finders very busy: Chiffchaff!

During Easter weekend we saw plenty of male Chiffchaffs singing from tree tops but no birds skulking lower down (a tell-tale sign of a female getting ready to build). Last Monday, things had got busier: males were singing back-to-back and chasing each other off territories and ‘hueet’ contact calls could be heard everywhere. Then, on Tuesday 14, we caught our first glimpse of a bird with a beakful of long grass—a building female! Early next morning we spotted another bird building and then on Thursday 16, Anne, our main nest finder, found five more nests, some almost fully formed (a characteristic domed construction). By Monday 20, we had found 11 nests, two lined with feathers, and that morning we found nest number 12 at an early stage, the female pinging back-and-forth with large bits of material.

Chiffchaff nest at Wicken Fen in 2014. Built just above the ground, the nest is dome shaped, made from reeds and some finer grasses, and lined with feathers. c.200 Chiffchaff nests are monitored across the country for NRS each year.

So what to expect this weekend? Those lined nests will probably have eggs, though females may still be building on other territories. Nest recorders elsewhere have begun reporting Blackcaps on eggs, Whitethroats and Willow Warblers building, and Chaffinches on full clutches.

How far along are nesting birds on your patch? Help the BTO collect vital data on nest productivity and timing of breeding by taking part in the Nest Record Scheme.

A Chaffinch from Lithuania

Chaffinch by Jill Pakenham

Here at the BTO we know a lot about the common species. We are excellent at monitoring their numbers during the breeding and wintering seasons through several of our schemes. The information gathered by thousand of dedicated volunteers is used to help answer the key conservation questions of our time.
The Chaffinch is undoubtedly one of our commonest species, and as is often the case with such species, (take the Dunnock for example), it is easy to overlook them.

BTO ringers ring more than 30,000 Chaffinches each year. 1,402,733 were ringed during the period 1909-2013, and more than 10,000 have been recovered and reported to us in that period.
Many Chaffinches travel to and from the Continent, and even to the Faroes and Iceland! In the winter we are more likely to encounter Chaffinches that have originally been ringed abroad, as they visit UK & Ireland avoiding the harsh continental cold. In the BTO's recovery database there are 15 Chaffinches that covered a distance greater than 2000km, the furthest recorded distance in our scheme is 2362km, as shown in the map below.

T848360 was ringed a Female in 22-01-2006, coordinates 51°35'N 1°43'W (Wiltshire), later Caught by ringer in 31-07-2006, coordinates 60°41'N 32°57'E (Leningrad) Russia. Greatest distance recorded in the BTO database for a Chaffinch: 2,362km 

In the map of recoveries below you can see that the movements of Chaffinches to other countries are most likely to be between the UK and the Scandinavian countries, Belgium, The Netherlands and Germany, with a few going further east to Latvia, Russia and Lithuania.

Chaffinch: Ringed in Britain & Ireland, Found Here; Ringed Here, Found in Britain & Ireland

This week, we received a recovery of a Chaffinch ringed in Lithuania. This bird was ringed at Ventes Ragas on 30/09/2012 and killed by a cat in Gurteen, Galway on 25/11/2013. It travelled a respectable distance of 1926km and is the first ever Chaffinch ringed in Lithuania reported to the BTO. Before this bird, we have only one other record of a Chaffinch travelling between UK and Lithuania; that was ringed in Kilnsea, England, and later found in the same ringing station in Ventes Ragas, Lithuania.

Vast information on ringing and recoveries of all species in the UK & Ireland and associated maps can be found in the Online Ringing Reports - if you haven't visited yet, take a look!

We have also talked about Chaffinches here.

Spring encounters of the bird kind

You will be glad to hear that we are now reaching the 'tail end' of the auk wreck that has effected thousands of Puffins, Guillemots and Razorbills up and down the country (posted previously). We are still however receiving reports from the various ringing schemes involved, showing the great distances these birds can travel during the winter.

Collared Doves have been known to make large movements occasionally and one such bird travelled south from Fair Isle, Shetland all the way to Halkirk, Caithness (238km) to end up being killed by a cat on the 06 April. Reports of interesting movements of Chaffinch include two Norwegian ringed birds, one killed by a cat in Powys and one to be found fresh dead in Wiltshire both found in mid March. At a very similar time a BTO ringed Chaffinch from Lincolnshire met his end in Norway after not seeing a window in time.

Chaffinch - John Harding

Windows were also responsible for 2 BTO ringed Dunnock recoveries of note. One was the 11th record to Norway (again ringed in Lincolnshire - 1721km) and the other was the 2nd ever Dunnock to be found in Denmark (ringed in Suffolk - 744km).

The BTO migration blog and BirdTrack is currently showing a good influx of spring migrants at the moment with species like Chiffchaff, Blackcap and Swallow, and with this comes encounters with ringed migrants. A Sussex ringed Chiffchaff for example (ringed in September 2013) met its end on its return migration when it was found dead in someone's kitchen in Spain (928km).

BirdTrack reporting rate of Chiffchaff

We have also received our first report of a returning Osprey, to the Glaslyn Osprey Centre near Porthmadog, Gwynedd. This bird was identified by a video camera placed near the nest during the winter. It was originally ringed as a chick at Rutland Water in 1998 in a brood of three.

A window was the likely cause of a Lincolnshire ringed Oystercatcher death in Norway (733km) but more positively, several Irish ringed Oystercatchers have been seen in their breeding grounds in Iceland (1519km).

Trichomonosis insight

The impact that diseases have on bird populations is a fascinating topic of research, to which ringers and members of the public can contribute. Many will now be aware of the detrimental effect that Trichomonosis has had on Greenfinch populations in the UK, a relationship established by a piece of research led by scientists at the Institute of Zoology in London and the BTO. A subsequent study from the same team also showed, through molecular analyses, that the disease arrived in Fennoscandia from the UK in 2008, most likely carried by Chaffinches. This link was identified thanks to the known migration route of this species provided by previous ringing data.

Greenfinch showing signs of Trichomonosis by Heather Povey

A project by different authors has recently showed that Trichomonosis spread in Finland in 2008 and 2009 and impacted local Greenfinch and Chaffinch breeding populations. In August-September 2008 the first cases of this disease had appeared in the country, followed by a peak in reported mortality in July 2009, although cases diminished in 2010 to pick up again in 2011. The Finnish study showed that population of breeding Greenfinch declined by 47% in south Finland, but not other parts of the country, at the peak of the outbreak between 2009 and 2010, whilst Chaffinch declined by 4%, between 2006 and 2010, the first population decrease since 1984. Bird body condition was also affected by the disease. Ringing data highlighted that Greenfinches, especially juveniles, were lighter than usual over the autumns 2008 and 2009 in the areas most affected by Trichomonosis.

These studies are a very good example of the important contribution to science that members of the public and ringers provide by reporting changes in birds and garden wildlife, as well as the unique high-quality data and essential information that ringing provides.

For more background information, visit the BTO GBW webpage

Daria Dadam, Research Ecologist

Tricky Customer

From late 2005, we began to receive reports of dead or dying Greenfinches, cases that were subsequently linked to an emerging infectious disease called Trichomonosis. This disease was already known from pigeons and doves but cases in wild finches were unknown. During the outbreak that followed (notably during 2006 and 2007) significant numbers of Greenfinches and Chaffinches died. In areas where the outbreaks were most pronounced we saw Greenfinch and Chaffinch populations decline by 35% and 21% respectively, representing mortality in excess of half a million birds.


Other species have been infected including Goldfinch, Bullfinch, House Sparrow and Tawny Owl. Only last week we had a report of a ringed Tawny Owl that had to be put to sleep due to necrotic Trichomonosis in the throat.


Unfortunately in 2008 Trichomonosis was discovered in Fennoscandia and was the likely result of migrating Chaffinches carrying the disease from the UK.

During the year there used to be a particular peak in reported cases during the autumn, due to the warm wet weather helping the parasite survive outside its host. More recently this trend is much less distinct. The reason for this is not fully understood.

Thanks to Jill Pakenham for the photo.

Our second Chaffinch to Poland

"How many Chaffinches have we had in Poland?" - a question posed by Lee Barber this morning... My guess of none was close, but not quite right! We have (or more accurately had) just one record of a BTO-ringed Chaffinch in Poland: ringed in Oxfordshire in November 1970 and found in Poland in April 1971. But we now have two, after an email arrived with these photos.


This colour-ringed male was part of a project looking at the dispersal of birds away from a winter roost, but this is slightly further than the group expected! They were hoping to just receive a few sightings from local gardens! It was originally ringed on 23 December 2006 at Charnwood, Leicestershire, and found in Poland on 31 March.


This is about as far as Chaffinches go, though we do have two records of BTO Chaffinches found in Russia. Going the other way, we've had two from Russia and one previous from Poland to Britain (ringed in Poland in September 1965 and found in Bewdley in March 1967).

Papilloma in Chaffinches: not for the faint-hearted!

Ringers are in the unenviable position of sometimes seeing birds close up that suffer a manner of different ailments. Perhaps one of the commonest is Papillomatosis and affects species as diverse as Chaffinch, Crossbill and Sedge Warbler.

This is caused by the Papillomavirus, a DNA virus that is more normally associated with parrots and macaws. For those with an abnormal fascination with the virus, more details can be found in this paper.


This Chaffinch is one of the most extreme cases we've ever seen, and was caught on 15 March near Ripon. The extent of the growths is incredible, and the bird obviously has difficulty walking and presumably feeding normally, as it has very abnormal claw growth on its feet. The virus has been noted in the Chaffinch population at the site for several years, though the majority of birds coming to the feeders in the winter still have 'clean' legs. One adult male, though, that had regularly been caught at the site had lost one foot due to the virus.


Thanks (I think) to Yvonne Elvin for the photos and to Jill Warwick for passing them on.