Chough reports: July and August 2012

Reports from Liz Corry

JULY 2012

Captive breeding at DurrellChoughs in display aviary. Photo by Liz Corry

All of the choughs have started to moult: juveniles around the 11th whilst the breeding pairs started a few days later.

Captive breeding at Paradise Park

The sexes of the three chicks bred this year have been confirmed as 1 male and 2 female.


Captive breeding at Durrell

Chough at food bowl. Photo by Liz CorryAll the choughs are now being given their non-breeding/winter diet whereby the protein levels are reduced, i.e. the ox heart has been removed and less insects are given. In past years we have given mixed corn in winter as wild choughs are known to forage in cereal fields when insect numbers are low. However, the choughs in captivity at Paradise Park and at Durrell rarely touch the corn so it has been removed from the diet completely.

The breeding pairs have now finished for the season. Normally they would be integrated back into the display flock; however, due to the release planned for this autumn/winter we will keep the breeding birds separated from the potential release birds for now.

Display flock

Liz trains the choughs. Photo by Fiona MarchantThe low productivity of chough chicks this year means that the trial release cohort will consist of the three chicks hatched at Paradise Park this year and another three selected from the older juveniles in the display aviary at Durrell. In preparation for their release these birds will be trained to fly to target boards for food as this will help with the supplementary feeding once in the wild and allow the keepers to call the birds back if they need to be shut away in the release aviary.

Chough target board. Photo by Liz CorryTraining began at the end of July and looked promising at the start of August. The birds are accustomed to flying down for food, but they need to learn to respond to their cue for food. Working with a large group rather than training on an individual basis has proved challenging. We increased the number of target boards so that each bird has a chance of getting to food which in turn strengthens the learned behaviour. However, there are still a couple of individuals who hang back whilst the dominant birds fly down first and take all the food. We will continue with the training and looking at ways to improve the birds’ success.


All the juvenile choughs have somehow managed to lose an ID ring. Five have lost their metal rings and the sixth has lost its plastic ring. One metal ring has been recovered and it looks as if it has been prised open. All six birds can still be identified but new (and improved) rings will be added before any release.


Turtle dove: the UK’s most threatened farmland bird

News from the RSPBTurtle dove in St Ouen's Bay. Photo by Miranda Collett

Since Operation Turtle Dove was launched by the RSPB, Conservation Grade, Pensthorpe Conservation Trust and Natural England in May, the reporting hotline has had 429 calls reporting the elusive bird.

Norfolk came top as the county with the most reported turtle dove sightings (112), second was Suffolk (69), closely followed by Cambridgeshire (61), with Essex (32), Kent (29), and Lincolnshire (20) coming fourth, fifth and sixth. In Jersey we may have had only one breeding pair this year and it is unclear whether these were successful in rearing any young.

Alison Gardner from the RSPB’s Operation Turtle Dove, said: ‘It’s great that we’ve already had so many people supporting Operation Turtle Dove and looking out for these birds.

‘At this time of year, just before turtle doves Streptopelia turtur head off on migration, juveniles and family groups are easier to spot so we’re hoping for some more reports before the season’s out and are appealing to anyone who spots a turtle dove to call and give us as much information as possible.’

Turtle dove numbers have fallen dramatically since the 1970s with just nine birds now for every 100 there were 40 years ago. Once widespread across much of England and Wales, the species has been lost from many areas and are now primarily restricted to areas of East Anglia and southern England. Not so long ago, turtle doves were widespread in Jersey in summer but are now close to disappearing.

Reasons for the turtle dove’s population crash are not fully understood. However, since the 1960s the diet has changed from mainly the small seeds of wild plants to one dominated mainly by crop seeds, which are scarce early in the breeding season and may provide a poorer quality diet for turtle doves.

Simon Tonkin, the RSPB’s senior farmland advisor, said: ‘turtle doves feed almost exclusively on seeds. Many of the traditional wild foods are now scarce on farmland and it is uncertain whether crop seeds are providing an adequate substitute. Additionally, turtle doves prefer to nest in hedgerows or areas of scrub over 4m tall, habitats that are less common than in the past.’

Operation Turtle Dove’s hotline has also received a number of calls from people with large gardens, often backing onto agricultural land, who’ve spotted turtle doves taking food from their bird feeders and using the garden pond to drink from and bathe in.

RSPB researchers have also found nests in gardens and amenity areas bordering farmland, which may reflect a shortage of resources on agricultural land, meaning the birds are forced to find alternatives to survive.

Simon added: ‘This means farmers and householders in rural areas have a huge role to play in the conservation of this beautiful bird. While there are some great advocates out there doing all they can, it still needs more support.’

To report your turtle dove sightings, call the Operation Turtle Dove Hotline 01603 697527 or you can submit your sightings to Please also send in your records to the Jersey Bird Recorder at the Société Jersiaise or through Jerseybirds.

The RSPB has two advice sheets on how to help turtle doves, one for farmers and one for people with large gardens or outside spaces that back onto arable fields and are available free by emailing

The emergence and spread of finch trichomonosis in the British Isles

News from BTO

Finch trichomonosis, caused by the protozoal parasite Trichomonas gallinae, was first recognized as an emerging infectious disease of British passerines in 2005 and is detailed in a new paper published this week. The first year of seasonal epidemic mortality occurred in 2006 with significant declines of greenfinch Carduelis chloris and chaffinch Fringilla coelebs populations. In the newly published paper it is demonstrated that large-scale mortality, principally of greenfinch, continued in subsequent years, 2007–2009, with a shifting geographical distribution across the British Isles over time.

Greenfinch in winter. Photo by Mick DrydenConsequent to the emergence of finch trichomonosis, the breeding greenfinch population in Great Britain has declined from c. 4.3 million to c. 2.8 million birds and the maximum mean number of greenfinches (a proxy for flock size) visiting gardens has declined by 50 per cent. The annual rate of decline of the breeding greenfinch population within England has exceeded 7% since the initial epidemic. Although initially chaffinch populations were regionally diminished by the disease, this has not continued.

Retrospective analyses of disease surveillance data showed a rapid, widespread emergence of finch trichomonosis across Great Britain in 2005 and the paper’s authors  hypothesize that the disease emerged by T. gallinae jumping from columbiforms (Pigeons and Doves) to passeriforms (Songbirds). Further investigation is required to determine the continuing impact of finch trichomonosis and to develop our understanding of how protozoal diseases jump host species.


Woodpigeons hit record high in UK gardens

From BTO press release

Woodpigeon. Photo by Mick DrydenWoodpigeons are fast becoming the UK’s most recorded garden bird. Recent results from the year-round BTO Garden BirdWatch survey show that 87% of gardens have been visited during a typical week this year – more than by robins, great tits or house sparrows.

The march of woodpigeons into UK gardens appears to be unstoppable. Nationally, only blue tit (90%) and blackbird (95%) now stand in their way from taking top spot. In some areas, including Hertfordshire, Nottinghamshire, Warwickshire, The West Midlands and West Sussex, it appears that woodpigeons are already top of the podium. In Jersey, these pigeons are in the Top 10 species recorded in gardens but still face competition from old favourites like robins, house sparrows and blackbirds.

Their growing success in gardens is likely to have been caused by several factors. In the UK countryside, increased production of oil seed rape has provided fresh ‘greens’ to eat throughout the winter. Increased numbers appear to have spilt over into gardens, where plentiful food and nesting opportunities are being utilised. 

BTO can also reveal that woodpigeons are reaching deep into towns and cities, now being seen more often in suburban than in rural gardens. Despite bringing a welcome sense of the countryside with them, their large appetites make woodpigeons divisive garden guests. Woodpigeons. Photo by Mick DrydenWe see the same picture here in Jersey where woodpigeon numbers are going up and the birds themselves seeming to become more confiding each year.  Not only is this bird very common all through the year but in autumn we see remarkable numbers overflying the Island as some populations escape the colder northern winters. These migrants don’t seem to join our residents and often huge flocks can be seen heading out to sea from Noirmont. See updates during the migration

Back in the gardens, there are steps that householders can take, however, to ensure that there is enough food left over for smaller birds. Feeder sanctuaries, for example, which are metal cages through which smaller but not larger species can pass to access food contained inside, are a useful tool. Smaller perches might also dissuade woodpigeons from trying to act like a blue tit on hanging feeders.

There is, however, also much to love about this quirky species. Did you know, for example, that woodpigeons are one of very few bird species that produce crop milk – which is similar to mammalian milk – to help them rear their young? They are also true breeding champions, having been recorded nesting in every month of the year!

Planning application for chough release aviary submitted

An application for planning permission to construct the chough release aviary was submitted to States of Jersey on 13th August. Application P/2012/1033 and all supporting documents can be viewed in full on the States of Jersey website.

Chough release aviary plans. Photo by Naish Waddington ArchitectsThe aviary will be constructed in Field 6, La Rue de Sorel, St John. This field belongs to the National Trust for Jersey and is adjacent to Le Don Paton. The aviary will house the choughs for at least six weeks before they are released into the wild. The birds will be fed in the aviary while acclimatising to their new environment before being allowed to fly free. After release the birds will still be fed in the vicinity of the aviary and may even return to roost inside at night. If any of the birds have difficulty acclimatising to their new life, or if Field 6, Sorel. Photo by Glyn Youngweather conditions become difficult for them, they may be returned to the aviary.  

We are extremely grateful to Naish Waddington Architects who produced all the plans for the aviary and have provided support throughout the planning process. Please check the BIRDS ON THE EDGE website for updates on the aviary and the release programme. Details on the choughs and their management can be found here.

Are Jersey’s cirl buntings back to stay?

Cirl bunting at Les Landes 7th June 2011. Photo by Mick DrydenOn 7th June 2011 a single male cirl bunting was, rather surprisingly, found singing merrily on the perimeter fence at Les Landes racecourse. Not only had this bunting, whose decline and disappearance from Jersey been one of the catalysts to BIRDS ON THE EDGE, not been recorded here since 2004 but Les Landes was not a typical site for the species. As the excitement of this find settled a pair of buntings were located on the golf course in Grouville on 24th June. There may have still been time for these birds to breed in 2011 but there were no signs of activity so we settled down to watch over them through the winter.

Male cirl bunting at Grouville feeder. Photo by Richard PerchardOne of the possible causes for this bunting’s decline in the UK has been identified as a lack of winter food. The RSPB supplied us with details of feeder designs and good seed mixes and several hardy volunteers maintained the feeders through the winter months. After apparently ignoring the feeders for several weeks the buntings, who remained in the area throughout, began to feed on the seed provided and, while not a very hard winter, this may have helped them survive. If nothing else it may have stopped them wandering away from this traditional site.

Cirl bunting chick, Grouville, 24th July 2012. Photo by Mick DrydenThis year we watched as the pair remained in the area and gave tantalising hints of a breeding attempt. The weather, however, may have contrived against them as heavy rain in spring washed out lots of our birds. Then, on 24th July, Mick Dryden, one of the pair’s active monitors, found a single chick – the first hatched on the Island since possibly 12 years ago. A subsequent visit found a second chick and the female may be attempting to nest again.

It may take more than one pair to spur on recolonisation but it is a positive start. Thanks are due to the many people who helped out with feeding the birds, to the RSPB for their advice and to the Royal Jersey Golf Club for their support throughout.

‘Citizen science’ shows that protected areas allow wildlife to spread in response to climate change

Press release from University of York 

Dartford warbler. Photo by Mick DrydenA new study led by scientists at the University of York has shown how birds, butterflies, other insects and spiders have colonised nature reserves and areas protected for wildlife, as they move north in response to climate change and other environmental changes.

The study of over 250 species, led by researchers in the Department of Biology at York, is published online by the Proceedings of the National Academy of Sciences of the USA (PNAS). The conclusions were based on the analysis of millions of records of wildlife species sent in predominantly by members of the public.

The work represents a major new discovery involving collaborators in universities, research institutes, conservation charities, and regional and national government but – crucially – fuelled by ‘citizen science’.

Many species need to spread towards the poles where conditions remain cool enough for them to survive climate warming. But doing this is complicated because many landscapes across the world are dominated by human agriculture and development, which form barriers to the movement of species.  The mainstay of traditional conservation has been to establish protected areas and nature reserves to provide refuges against the loss of habitats and other threats in the surrounding countryside. 

But this method of nature conservation has been questioned in recent years, partly because of continuing degradation of habitats in reserves in some parts of the world.  Increasingly, however, the value of protected areas is being questioned because climate change is taking place – wildlife sites stay where they are while animal species move in response to changing conditions.

However, the new research shows that protected areas are the places that most animal species colonise as they spread into new regions. “Protected areas are like stepping stones across the landscape, allowing species to set up a succession of new breeding populations as they move northwards,” said lead author Professor Chris Thomas, of the University of York.

Co-author Dr Phillipa Gillingham, now a Lecturer at Bournemouth University, calculated that species are on average around four times more likely to colonise nature reserves than might be expected.  “For the seven focal species of birds and butterflies that we studied in greatest detail, 40% of new colonisations occurred in the mere 8.4 per cent of the land that was protected,”  she said.  “Similar patterns were observed among more than 250 invertebrate species.”

But the study showed that species vary greatly in how much they need reserves. “Some species, such as the Dartford warbler and silver-spotted skipper butterfly, are largely confined to nature reserves,” said Dr David Roy, of the NERC Centre for Ecology & Hydrology. “Whereas others like the nightjar and stone curlew are less dependent on these sites.” 

Dr Richard Bradbury, of the RSPB, said: “Sites of importance for wildlife stand out like beacons in otherwise impoverished landscapes. This study shows that the hugely important role they play now will continue undiminished in the future. Protecting these arks, as well as restoring and re-creating new ones where we can, will provide the vital network enabling more species to survive the spectre of climate change.”

This study is a great example of how volunteer recorders and national monitoring schemes together provide the information to answer key conservation questions of global importance, such as how we can help wildlife cope with climate change,” said James Pearce-Higgins of the British Trust for Ornithology. “Only through the dedicated effort of so many people can we undertake the scale of long-term monitoring required.”

Chough report: June 2012

Captive breeding at Durrell

There has been nothing to note since the loss of the chick. Both pairs seem very disinterested now.

Captive breeding at Paradise Park

All three parent-reared chicks survived to fledging age. Hopefully, these will be brought over to Durrell in the autumn to be used in the trial release.

Display flock at Durrell

On the 30th June morning routine B6977 (Wt-R ♀) was found entangled in wire zoo-mesh on top of the catch-up cage. There were two large holes, one of which she had got stuck in. It is not known when, or how, the holes first appeared, but it is likely that the choughs made them bigger by pecking at the metal. They are very inquisitive birds and are attracted to shiny objects. The bird was cut free and examined for any injuries but she appeared fine and was released straight back into the aviary to avoid further stress. Unfortunately, we didn’t get a weight for her but her body condition looked good: not too thin or too fat.


Non-Native Species in Britain

Press release from the British Trust for Ornithology

Pheasant. Photo by Mick DrydenA major new report on the establishment and spread of non-native species in Britain was published this week. Many of the Britain’s most abundant birds and mammals are included among nearly 2,000 non-native species currently established, and the number of new arrivals has increased dramatically over the last 50 years. The report has found that there has been a dramatic increase over time in the number of non-native species arriving in Britain. Of nearly 2,000 non-native species known to be established, over 600 species have arrived in the six decades since 1950, and 125 since 2000. This list is dominated by higher plants (1,377) with insects as the next most numerous group (278 species). Most of the established non-native species originate from continental Europe but the proportion of new species coming from Asia and North America is increasing.

As a highly visible and relatively well-monitored group, bird species comprise a significant proportion of the database but although well over 300 non-native species are regularly observed in the wild, only 15 are considered established (i.e. with self-sustaining breeding populations). Several species are among the recent arrivals in the UK (e.g. ring-necked parakeet) and work is continuing to eradicate others (e.g. ruddy duck).

Hottentot fig at La Corbiere. Photo by Henry GlynnAlthough the majority of non-native species are not considered invasive those that are can cause major ecological or socio-economic impacts if they establish themselves in the wider countryside. Invasive non-native species are considered to be one of the five major threats to biodiversity, estimated to cost the UK economy £1.7 billion every year. Overall about 15% of the species established in Britain are considered to have a negative impact. The research team looked at how to enhance the ability to detect and report non-native species, creating a new database of nearly 4,000 species within the GB Non-Native Species Information Portal (GB-NNSIP). Data on all of the species can be accessed through the portal’s website.

An integral part of the GB-NNSIP is a rapid-reporting system whereby particularly important new arrivals can be immediately notified to the relevant bodies. One such species, the Asian hornet, is not yet present in Great Britain but scientists believe could arrive soon, potentially having a serious impact on honey bees and other pollinators on which it preys. Anyone that suspects they have seen this species is encouraged to send in a photograph through the GB-NNSIP’s online recording website ‘Recording Invasive Species Counts’ which can also be used to report sightings of 19 other key species including water primrose, American bullfrog, carpet sea-squirt, tree of heaven, and American skunk-cabbage. 

In relation to birds, John Marchant of BTO said, “Climate change might easily make Britain more suitable for a wide range of non-native species, like sacred Ibis, currently thriving in southern Europe. Escapes and breeding of such species might be the beginnings of the next burgeoning new populations. To integrate non-native species recording more completely, we have ensured that all non-natives are fully recordable for BTO surveys.”

Details of the findings are contained within the report: Non-Native Species in Great Britain: establishment, detection and reporting to inform effective decision making. NERC Centre for Ecology & Hydrology, 110 pp. The report can be downloaded

Sacred ibis (in its native Africa). Photo by Mick DrydenNOTE. Although the report and the Species Information Portal do not include the Channel Islands both are very good guides to what is already happening and what is likely to happen in the future in the islands. Sacred ibis has already been recorded in Jersey, Guernsey and Alderney!

Irish choughs invade Cornwall

Press release from University of Aberdeen released on 2nd July 2012 

Red-billed chough. Photo by Andrew Kelly www.akellyphoto.comThe red-billed chough stands proud on the Cornish coat of arms but the species became extinct in the Duchy in 1947, denuding Cornwall of one of its most charismatic birds and cultural symbols.

That was until three choughs of unknown origin appeared in Cornwall in 2001 and founded a new breeding population, restoring the ‘Cornish chough’ to its historic home and causing great excitement among birdwatchers and conservationists alike.

But where did the three pioneer choughs come from?

Until now, they were speculated to have travelled from chough populations in south Wales or Brittany.

But now some clever genetic detective work has suggested that the Cornish pioneers came from even further afield – Ireland.

Researchers collected moulted feathers that were naturally dropped by the Cornish choughs, and by choughs in other populations across Europe.

Scientists from the University of Aberdeen then extracted DNA from the feather tips, and compared the DNA sequences of the new Cornish choughs with those of choughs living elsewhere.

By far the best match to the Cornish choughs was the Irish choughs, suggesting an unexpected Celtic origin for the new Cornish birds.

Dr Jane Reid, Royal Society University Research Fellow at the University, said: “We would never have known the origin of the new Cornish choughs without the DNA analysis – we didn’t guess that they would have come from Ireland.”

Claire Mucklow, of the RSPB, added: ‘We assumed those intrepid colonists would have come from closer populations, how wonderful that they have turned out to be Irish! The return of choughs to Cornwall has been very significant, not just in terms of conservation but in terms of Cornwall’s cultural heritage.”

The new Cornish chough population is now going from strength to strength; five pairs bred successfully in 2012.  The future success of the population is being ensured by conservation organisations and farmers who are working to provide suitable habitat, and by volunteers who provide round-the-clock surveillance of nests.

With recent sightings of Welsh choughs in north Devon, there is potential for a merging of Celtic chough diversity in southwest England, which researchers say can only be positive for the future prospects of this enigmatic species.