Recent research on declines in Afro-Palaearctic migrant birds has primarily focused on conditions in these species’ wintering grounds. However, population changes could also be influenced by factors during breeding and migration, as a new study shows. Read the abstract here
The study’s authors analysed data from the BTO’s Breeding Bird Survey for 46 species of passerine and near-passerine, including residents, short-distance migrants (wintering in continental Europe) and long-distance migrants (wintering in the Arid and Humid Zones of Africa). Overall, they found that species breeding in Scotland are generally doing better than those in England, with several species either declining in England but increasing in Scotland, or increasing in England at a slower rate than in Scotland. These differences were especially stark in long-distance migrants, and in particular those that overwinter in the African Humid Zone, with species such as house martin and garden warbler strongly increasing in number in Scotland only.
Taken together, these results illustrate how population trends can be affected by interactions between breeding season processes, wintering conditions, and the costs of making long migratory journeys. While many migrants may be facing increasingly tough conditions outside the UK, it is likely that these costs are being offset by better breeding conditions in Scotland than in England, which could be related to differences in land-use between the two countries (e.g. lower agricultural intensification in Scotland than in England). Further exploration of such geographical variation is essential to properly understand the demographic processes underpinning population trends of these migratory species, many of which breed in Jersey, are in marked decline and are on the Jersey bird Red List.
In December 2012, BIRDS ON THE EDGE submitted an application to the Countryside Enhancement Scheme (CES) to cover the costs of bracken clearance works in three areas of the north coast.
This application is part of the project’s main strategy of restoring coastal habitats such as heathland, gorseland and grassland which, properly managed, can provide prime breeding and feeding sites for many locally threatened birds from stonechats and whitethroats to puffins and fulmars.
In March, BIRDS ON THE EDGE was notified that the application had been successful, securing the contractor’s fee of £6,665 to carry out this year’s work. This grant only covers the costs of one year’s work and further funds will be needed to continue work for at least three further years. Bracken management does not yield immediate results; each area that needs management requires two annual passes, repeated each year for at least three years depending on many factors such as the local geology and climate.
The three areas that will be cleared are found on areas of National Trust for Jersey land along the coast between Sorel Point and Île Agois to the west. Together these sites represent an area of approximately 50 vergees. The work to be carried out at each site will take place in two separate periods of the year (at the end of spring and end of summer) and will involve a variety of techniques, from cutting, flailing and bruising to spraying and trampling (see bracken clearance) depending on each site’s terrain and state of the bracken.
Two of the sites are within the grazing area of the Manx Loaghtan sheep flock, so the exposed land will benefit from these animals’ trampling action and in turn the sheep will be able to reach new patches of suitable pastures beyond the bracken. Whilst the sheep are not really very keen on eating the bracken themselves, they do graze the grass swards beneath the thick fronds, encouraging the regeneration of natural grassland. Their hooves also trample the bracken’s new shoots, preventing the fern from coming back after it has been removed.
The areas of cleared bracken will be monitored to evaluate which techniques are most effective as well as to detect any changes on the wildlife in the vicinity, such as an increase on the invertebrates and thus on feeding opportunities of
nearby nesting birds such as stonechats, meadow pipits, Dartford warblers and common whitethroats. It is hoped that it won’t take long for the wildflowers, invertebrates and birds to find their way to the clearings that will be opened soon amongst the sea of bracken on our coastal cliffs.
All three managed sites are found within the boundaries of the North Coast Breeding Bird Survey which will provide information on the locally endangered birds and their breeding success in 2013.
What is Birds On The Edge and what has it achieved so far?
Saturday 18th May 2013. Start 10.30 at Devil’s Hole.
Join Birds On The Edge and Action for Wildlife on a fascinating walk along the north coast path from Devil’s Hole to Sorel Point and back with Sally Dalman, Cris Sellarés and Glyn Young.
This stretch of coast is truly beautiful and best shows off the project. Learn here about the birds of the north coast: the importance of the area for breeding, wintering and as a stopover during migration. We will hope to see several species including breeders on the coastal edge and any migrants that may still be heading further north.
We can look too at the bracken, how it has become invasive over large areas of the cliff tops and how we can manage it. I am sure that we will have a chance to meet some of the most stalwart land workers, the Manx Loaghtan sheep doing their best to open up this habitat. We will see the recently planted hedges and look at their importance for birds throughout the year and also the permanent fields and second crops planted out as winter food for birds.
While we are on the cliffs we will look out for the choughs and learn how the programme to return these stunning birds to the Island is progressing. We can see the release aviary and meet the occupants.
The walk will last approximately two hours, on undulating terrain, so good shoes are required and a degree of fitness. Bring drinks as, you never know, it might be hot and there will be a pub on hand for lunch later if you chose!
Please meet in the Upper Car Park (above the Priory Inn) at 10.15.
The breeding pairs were caught up out of the display aviary at the start of the month and moved down to their breeding aviaries. It took three days to get them all. By the second day they were all wary of the catch-up cage and it took Tristan three days before he summoned up the courage and/or his hunger got the better of him.
Nesting material was added to the breeding aviaries almost straight away, but the record-breaking snow blizzard deterred the birds from doing anything. As soon as this past and the weather ‘improved’ they began taking the material into the boxes.
The choughs in the display aviary braved the elements at the start of the blizzard. By the end of the first day the snow had settled on the netting and transformed the aviary into an igloo. They were probably warmer than their keepers.
Thanks to the generosity of Paradise Park we have been given two brand new Sony 700 line nest cameras. With weather disrupting breeding behaviour we took the opportunity to install one of the new cameras. The existing camera in SF3, whilst showing a clear picture, was not suitable in design, size, and position and was removed.
Gianna has started to be a bit more forthcoming towards keepers now she has settled in to the main display aviary. She has started conditional behaviour training and is learning to fly on command. Once this is mastered she will begin learning to weigh herself on scales and enter/exit carrying crates without being handled. Hopefully the other choughs in the aviary will follow suit in the near future
Arrival of Paradise Park’s 2012 juveniles
Three juvenile choughs, hatched in 2012, and the trained adult male, George, were scheduled to arrive by plane in Jersey on the 12th March. Lee Durrell had kindly loaned her Navajo plane for the collection of the choughs from Paradise Park. Colin Stevenson was going to be the pilot.
However, with the unprecedented snow blizzards this plan was thrown into mild chaos. By hook or by crook the birds had to arrive by the end of that week. If not, the next import date would be in mid-April. Having been ‘snowed in’ for two days at the Wildlife Park, keepers were far from optimistic that the birds would arrive.
A decision was needed by the 13th in order for the airport authorities to sign off on the paperwork for a flight on the 14th. Despite the 9ft snow drifts that lined the roads the route to the Sorel aviary was still accessible. The next task was making sure that Lee’s plane could get onto the runway on the 14th, let alone be able to fly. Colin, the pilot, reported that:
“Steve Driscoll, the Ports of Jersey Group Operations Director and André Rabet, the Airport Engineering Director made a significant intervention by diverting their very stretched crews to clear our taxiway.
The Airport snow clearing team themselves, once detached from their normal duties, cheerfully made short work of clearing the snow from our taxiway and had us operational by Wednesday night…..Eric, the digger driver, worked at the hangar for four and a half hours, until half past seven in the evening – after starting to clear snow at the airport at 5am that morning.”
After, what we were told were near perfect flying conditions, Colin, co-pilot Gregory Guida and the choughs touched down in the early afternoon. The choughs were accompanied by David Woolcock, Curator at Paradise Park, who had kindly volunteered his time to stay at Durrell for two days to help settle the birds in and discuss training protocols.
Once the birds arrived at Durrell they were swiftly whisked away to the Vet Centre under quarantine conditions. There the birds had a general health check, blood samples taken, ID rings attached, and radio transmitters attached where appropriate.
On inspection of two of the juveniles it was noted that some of their tail feathers had ‘fret lines’. The central tail feather, where the radio transmitter is attached, had broken off quite close to the base. It meant it was not possible to attach radio transmitters to these two birds. After careful consideration of the options it was decided that these two would not be used in the trial release. Their feathers will be allowed to moult through naturally at the end of the breeding season and we would consider them for a second release if planned.
The two birds involved were still given Jersey addressed metal ID rings in case they accidentally escape over the next few months. It will not make them easier to find but if recovered it will make it easier to identify where they came from. The only one who has not been given a Jersey ring is George due to his leg deformity. All the choughs at Durrell and now at Sorel have transponders implanted under their skin as another means of identification if recovered. These tiny ‘microchips’ were fitted by Paradise Park staff prior to the birds departure for Jersey.
After what must have seemed like a lifetime for the birds they finally got to leave the Durrell Vet Centre and be transported by car to the release aviary at Sorel. Andrew Terry volunteered his time and more importantly his 4WD to transport the birds. Unfortunately the last 100m of track leading up to the field site had not been cleared and the driver faced a 6ft wall of snow. The last leg of the journey had to be done on foot from Sorel car park, but finally with the sun setting the choughs made it to the aviary. They were released into the back half of the enclosure (Sorel1A) where they will stay until the Durrell group get moved up and then mixed together. For the next thirty days quarantine restrictions will apply and only designated staff can access the aviary.
Choughs at Sorel
The first quarantine faecal sample was submitted to the lab on the 18th. For the choughs (and their keepers) to be ‘released’ from their quarantine period a minimum of three pooled faecal samples need to be taken on a weekly basis. Analysis of these samples will determine whether more are needed and/or if treatment is required.
The first faecal sample showed positive for nematodes and coccidians, albeit at low levels. It was decided to not move the Durrell choughs until a second faecal sample could be analysed and a decision made about treatment. The second faecal showed low levels of coccidians and nematodes, but since this would be typical for wild birds as well it was not deemed significant. However, as a standard of good practice we will treat George’s group with a single injection of Ivermectin (anti-parasitic drug) prior to release.
A Bushnell trail camera was installed in the aviary when the choughs moved in. This will act as a security camera as well as documenting the birds’ behaviour when keepers are not present. It has proven very useful so far and we have been able to see how the birds react when dogs, people, and heavy machinery are around. It has shown that like most other corvids, choughs can be active from 05.00 onwards.
The camera has also recorded a surprising, and unprovoked, attack on George by the other male in the group. This might be expected since George has been kept separate from the group over the last 5-6 weeks. From the keeper’s point of view, whenever they enter the aviary, the juveniles hide or are too busy eating to show any animosity towards George. Most squabbles seem to be between the juvenile male and the female without the radio transmitter so it was interesting to be able to remotely observe this behaviour.
Pre-release training
George, having been trained prior to arriving in Jersey, will be the role model for the other choughs when they start their conditional behaviour training. However, it is not a role he can easily jump into. First he needs to adjust to his new surroundings, the new weather conditions (gale force winds are not a common occurrence in Hayle) and, even more challenging, adjust to his new keepers.
Whilst George settled in very quickly (eating straight away) it took him a few days to be confident enough to perch close to the keepers. He will now fly to the keeper when called and can jump onto the scales to be weighed. This last task is quite a challenge in his new surroundings. For a start, on certain days he has to battle against the wind. The scales are a slightly different design to what he is used to which will make him insecure. We have ordered the same scales as Paradise Park, but they have to be delivered from the manufacturer in Germany.
For the keeper to reach the shelving and be at a comfortable height with George a ladder is required. At first George was scared of the long ladder, so they were swapped for a small pair of steps. Gradually he warmed to the ladder, mainly due to the keeper using it a lot to carry out DIY work inside the aviary.
The biggest challenge was in keeper and bird trying to understand each other. George knows the command for “please jump on the scale” and he knows that he will be rewarded with insects. The keeper knows the correct command and the correct reward. But when the bird doesn’t want to jump up in the wind onto a strange object it is very hard for it to convey this. It is a lot easier to hop along to the keeper, look doe-eyed (trust me they can do this) and ‘guilt’ the keeper into giving them insects!
As part of a study on impacts from the world’s most widely used class of insecticides, nicotine-like chemicals called neonicotinoids, the American Bird Conservancy (ABC) has called for a ban on their use as seed treatments and for the suspension of all applications pending an independent review of the products’ effects on birds, terrestrial and aquatic invertebrates, and other wildlife.
“It is clear that these chemicals have the potential to affect entire food chains. The environmental persistence of the neonicotinoids, their propensity for runoff and for groundwater infiltration, and their cumulative and largely irreversible mode of action in invertebrates raise significant environmental concerns,” said Cynthia Palmer, co-author of the report and Pesticides Program Manager for ABC, one of the USA’s leading bird conservation organizations.
ABC commissioned the 100-page report, The Impact of the Nation’s Most Widely Used Insecticides on Birds, that reviews 200 studies on neonicotinoids including industry research obtained through the US Freedom of Information Act. The report evaluates the toxicological risk to birds and aquatic systems and includes extensive comparisons with the older pesticides that the neonicotinoids have replaced. The assessment concludes that the neonicotinoids are lethal to birds and to the aquatic systems on which they depend.
“A single corn kernel coated with a neonicotinoid can kill a songbird,” Palmer said. “Even a tiny grain of wheat treated with the oldest neonicotinoid — called imidacloprid — can fatally poison a bird. And as little as 1/10th of a neonicotinoid-coated corn seed per day during egg-laying season is all that is needed to affect reproduction.”
The new report concludes that neonicotinoid contamination levels in both surface- and ground water in the United States and around the world are already beyond the threshold found to kill many aquatic invertebrates. Data on surface water contamination from surveys to date, most notably from California and from the Canadian Prairies, indicate that concentrations of several of the neonicotinoid insecticides are high enough to be causing impacts in aquatic food chains. Data from other jurisdictions such as the Netherlands show even higher levels of contamination.
Neonicotinoids’ toxicity to bees and other insects has brought them the most attention thus far and has dominated recent concerns of regulatory institutions worldwide. The serious risk to bees should not be understated, as one-third of the US diet depends on these insect pollinators. The ABC assessment makes clear, however, that the potential environmental impacts of neonicotinoids go well beyond bees.
Buglife UK have added that “This highlights the poisonous nature of neonicotinoid insecticides, environmental concerns go well beyond pollinators. They can persist in the soil for many years, leach into aquatic ecosystems and affect birds and mammals. One of the reasons neonicotinoids are so commonly used is because they are promoted as being non-toxic to vertebrates, but this study shows that claim to be false”.
This report has been released shortly after the European Commission failed to agree on a proposed ban on three of the most commonly used neonicotinoids– imidacloprid, thiamethoxam and clothianidin. Representatives from Member States met to discuss a significant ban after the European Food Safety Authority identified a ‘high acute’ risk to honeybees. However, with five countries abstaining from the vote, including the UK, the ban failed to go through.
Buglife said “The ban proposal will now go through the appeals process with the European Commission free to ban the insecticides unless Member States reach a compromise within two months. I am sure that the European Commission will take note of the recommendations of this significant report when making their next decision and enforce a robust ban”.
It should be noted that in Jersey itself, very few of these products have ever been used. However, their use outside of the Channel Islands will undoubtedly have a bearing on our wildlife too.
Jersey musicians of repute Badlabecques have recorded a song with students from Le Rocquier School, to celebrate the new chough release aviary at Le Don Paton, near Sorel Point, on Jersey’s north coast.
The song itself is based on a 1934 Jèrriais poem by Frank Le Maistre, which was set to music by Norman French band Magène and adapted by Badlabecques with the help of local poet Geraint Jennings. Titled “Ma Bouaîs’sie” (My Wood) it evokes walking through Egypt Woods in Trinity and hearing all the birds singing together.
Lyrics
J’connais l’bouvtheu et la rouoge-gorge,
Et touos les mêles mé sûffl’yent beinv’nue,
La grive, lé vèrdreu et l’mouosson.
Et l’rossîngno (tch’est un pînchon).
I’y’a étout lé rouoge linnot,
Lé pique-en-bouais et l’vèrmîngnon,
Lé p’tit raîté – eune vraie dgilouette –
Et la mîngnonne dé cardrinnette.
Dans ma bouaîs’sie j’sis bein èrchu,
Ch’est si pliaîthant d’ouï la musique –
Tout l’ouaîthelîn chante à forte vouaix
A londgeu d’jours parmi les bouais.
J’voudrêmes èrvaie la bouonne caûvette;
J’voudrêmes èrouï étout l’alouette,
Auve sa couôthinne, l’alouette dé mielle,
Par nos falaises rotcheuses et belles.
Pis y’a la d’mouaîselle du Ouaisné,
Lé poffîn épis l’cormouothan;
Y’a l’êteurcélet des mathais,
La rouoge-coue et lé p’tit jaûnouais.
Dans ma bouaîs’sie j’sis bein èrchu,
Ch’est si pliaîthant d’ouï la musique –
Tout l’ouaîthelîn chante à forte vouaix
A londgeu d’jours parmi les bouais.
Birds On The Edge wanted the song to be an educational project, as well as a piece of community art so they are pleased that Le Rocquier School students are involved.
Rick Jones, Durrell Communications Officer says:
“We are delighted that as well as cultural history, Badlabecques are promoting a love of natural history, and taking it to the younger generation. Jersey’s heritage is interwoven with its landscapes, and Birds On The Edge will restore and protect natural areas of the Island’s beautiful coastal regions for posterity. What better way to celebrate this, than to give it an authentic soundtrack!”
Phillip Slater, Head Teacher at Le Rocquier School says:
“Recently at Le Rocquier we have been focusing on the importance of Jersey’s native language, Jèrriais, as well as our natural history. Above the entrance to our hall we have placed our school motto “Our School, Our Education, Our Future” in Jèrriais. We are also developing Jèrriais extracurricular classes and we have also been looking to encourage the speaking, and indeed singing, of Jèrriais in as many ways as possible.”
Kit Ashton, founder and lead singer of Badlabecques is also proud of the song:
“This is exactly what Badlabecques is all about as a band – celebrating our beautiful island, our heritage, and our community through music that is hopefully both entertaining and meaningful. I love it!”
Song details
Released 4th April 2013
Recorded and mixed at Le Rocquier School, Jersey, featuring students from Year 8.
Download of the song Ma Bouaîs’sie in your choice of high-quality MP3, FLAC, or just about any other format you could possibly desire here.
BIRDS ON THE EDGE has highlighted the threats to our finches and other songbirds from diseases such as the parasitic trichomonosis and avian pox being spread among the birds. The larger population consequences of these parasitic diseases, however, are rarely documented. A recent study in the journal Ibis has looked at the extent to which the trichomonosis epidemic affected the Finnish population sizes of European greenfinch, chaffinch and a control species, great tit, and the body condition of greenfinches.
The disease was first documented in Finland in 2008 and epidemics were observed mainly in south-western Finland. Greenfinches showed a significant decline of 47% in breeding numbers and 65% in wintering numbers in southern Finland during 2006 – 2010. Breeding chaffinch numbers showed a slight decline (4%) during the same study period that was significant only in central Finland. Great tit did not show a significant change in breeding numbers. During the initial disease epidemic the body condition of all demographic groups of greenfinches decreased equally, suggesting that the disease was not selective in respect of age or sex. There were no encounters of Finnish ringed greenfinches or chaffinches in the UK, which could indicate that the parasite has not necessarily been transferred directly from the UK, but perhaps by migrants from Sweden and Germany.
In conclusion, the Finnish greenfinch population has faced rapid and severe population decline due to an epidemic of finch trichomonosis, but the effect on chaffinches has been minor. The decline of greenfinches has been greater than in neighbouring Sweden and of the same order as in UK, where the epidemic was first observed. The study further emphasizes the importance of annual monitoring schemes now and especially in the future in order to detect rapid population changes in common bird species that may be caused by disease epidemics. Bird counts in Jersey have repeatedly shown a very rapid and dramatic decline in numbers of greenfinches in recent years.
As part of the BIRDS ON THE EDGE habitat restoration strategy the National Trust for Jersey is working to restore important bird habitats on the north coast between Mourier Valley and Sorel Point.
Whilst the flock of Manx Loaghtan sheep are busy opening patches through the bracken that is being cleared, and preventing it from coming back, further inland the conservation fields of Le Don Hodges are being enhanced by planting trees for hedges. These 14 fields, comprising a total of 50 vergees of land, were purchased by the National Trust for Jersey through a donation in 2012, and are being managed to enhance the local wildlife. An agreement was established with the Jersey Royal Company to allow for the utilisation of some of these fields for potato crops in exchange for a management regime more sensitive to wildlife and the planting of wildlife crops in the fields once the potatoes are harvested. Some of these fields are cultivated in rotation to create a mosaic of spring cereals and seed mixes, while others will never be cultivated and have been sown with wildflower mixes to create permanent, insect-rich grasslands. Many farmland birds rely on these crops as a source of food during the cold months of winter, when insects are less abundant or in hibernation. If it wasn’t for these crops many chaffinches, goldfinches, greenfinches and linnets would not make it through the winter.
With the permanent grassland and wildflower fields providing insects during spring and summer, and cereals and other seed-rich crops on the fields to provide the winter food, the hedges are the last piece of this puzzle. Hedges provide cover from predators near their feeding grounds, nesting opportunities, food for many insects that the birds will feed on, and buds and berries for the birds to feed on from spring to autumn.
Last year the NTJ was awarded funding to buy 8,000 trees for hedges, of which almost 5,000 have already been planted around the Le Don Hodges fields by participants of the Back to Work Scheme and teams of volunteers during weekend community events. It is hoped that the remaining trees will be planted over the next few weeks and that within the next few years they will grow into thick, luscious and berry-loaded hedges that will provide the birds with a safe breeding habitat.
With the last piece of the puzzle in place, let’s hope that the restored habitats can soon provide our threatened birds with all they need to survive and thrive throughout the year.
PS. If you would like to help with planting hedges sign up for the volunteer mailing list by e-mailing Cris Cris@nationaltrust.je
In March 2013 one hundred and seventy-five pairs of Atlantic puffins will return to the small island of Burhou which is situated two kilometres north-west of Alderney to breed. The seabirds will live and raise their young on the rocky coastline for a few months before they return to sea with their young, in the puffin’s case their ‘puffling’ chicks.
A Puffin Season on Burhou is an exciting project offering schools in the South East of England and the Channel Islands the opportunity to bring the fascinating life of the puffin live into their classrooms. Using the charismatic puffin as a focal point, this project links directly to the Keystage 1 & 2 curriculum, and is an effective way of teaching Science and Literacy skills, and promoting pupil creativity. This website will provide schools with daily 24 hour updates, live streamed video and a range of other excellent features to keeps schools and pupils informed about developments on the island of Burhou.
Teaching & Learning Resources
To support the project teachers and pupils will be able to access and download a range of excellent Teaching & Learning resources from the project website. Schools can opt to follow the 12 week project plan or select activities from the project menu. Designed for use with Key Stage 1 and 2 pupils these include:
Science activities linked to popular topics including adaptation, life cycles, food chains, habitats, caring for the young and conservation and protection
Daily and weekly mathematical data providing pupils with information about puffin numbers, frequency, location, climate and daily weather reports
Literacy activities – including opportunities to work with our project author
Geography & History – Information about the relief, climate and history of Alderney
Plus Art/Design and ICT activities for pupils of all ages.
Interested in taking part in this exciting science based project?
The project will commence at the start of the Term 5 and run until the end of the first week in July.
Please note, spaces for Channel Island schools are now fully booked. If you would like to be kept informed about the project please contact Living Islands: Live
The Centre for Ecology & Hydrology has been receiving reports of an Atlantic puffin wreck (multiple unusual deaths) on the east coast of Scotland and the north-east of England.
It appears that, while the exact causes of these deaths are currently unknown, the birds have died of starvation, unable to feed in the recent bad weather and strong easterly winds. This incident is likely to be the biggest ‘wreck’ since 1947 and research will be done this summer to see how it affects the northern colonies of puffins. Numbers of guillemots and razorbills have also been picked up after, presumably, suffering the same fate. The RSPB have added that as we are fast approaching the start of the seabird breeding season, where tens of thousands of seabirds return to their colonies to raise their young, the recent events could have an impact on the success of this year’s puffin breeding season. Puffins are already suffering population declines.
No reports of a puffin wreck have occurred in the lower regions of the species range, and the Channel Islands have not received as much bad weather as the north of the UK.
Although the puffins arrived back on Burhou, Alderney, later this year than last, a good number were recorded by the remote camera (see Living Islands Live). It is unlikely that the wreck will affect Burhou, but in the event that anyone does find any dead puffins washing onto shorelines in the Channel Islands, particularly Alderney, please report them immediately to ecologist@alderneywildlife.org. Thank you.
Recent research on declines in Afro-Palaearctic migrant birds has primarily focused on conditions in these species’ wintering grounds. However, population changes could also be influenced by factors during breeding and migration, as a new study shows. Read the abstract here
Taken together, these results illustrate how population trends can be affected by interactions between breeding season processes, wintering conditions, and the costs of making long migratory journeys. While many migrants may be facing increasingly tough conditions outside the UK, it is likely that these costs are being offset by better breeding conditions in Scotland than in England, which could be related to differences in land-use between the two countries (e.g. lower agricultural intensification in Scotland than in England). Further exploration of such geographical variation is essential to properly understand the demographic processes underpinning population trends of these migratory species, many of which breed in Jersey, are in marked decline and are on the Jersey bird Red List.
