December was another quiet month for the choughs, and it seems, for now at least, their exploratory days are over. The birds rarely ventured further than half a kilometre from the aviary, apparently content probing for insects in the grazed fields near the aviary. The ten juveniles were at least a little more adventurous than the older six birds however, and for the first few weeks in December, could faithfully be found every morning, perched on the muddy cliffs at the mouth of Mourier Valley, digging furiously, doing what looked like some impressive excavation work!
Chickay, Bean and co digging on their “favourite” cliff. Photo by Harriet Clark
Quite what the birds were finding there is unclear, but our pitfall trapping showed that there were still plenty of insects about, including rove beetles, ground beetles, minotaur beetles, earthworms and leatherjackets. Leatherjackets (crane fly larvae) are known to be a favourite food item for choughs, and this is certainly evident with our birds as they excitedly, and rather comically, chase each other when one chances upon the prized invertebrate prey.
Unsurprisingly December brought more downpours, fog, gale force winds and hail, but I am thrilled to say that the choughs have battled through, all in good health. We only had one morning of heavy frost, and interestingly, early that day the birds were nowhere to be seen in the usual grazed fields.
Handfuls of leatherjackets to be found! Photo by Harriet Clark
We eventually tracked the flock to Mourier Valley, and found them foraging amongst the dead stands of bracken. We hadn’t observed the birds foraging there before, but closer inspection revealed the soil was very soft, and presumably easier to probe for insects in than the harder ground of the grazed fields. Will, Jennifer and I also adapted to the windier, wetter weather and located several “good” gorse bushes to huddle beneath or, in Jennifer’s case, lie flat on her back underneath, just to have a bit of a break from the pounding, relentless wind!
The choughs weighing themselves in the aviary. Photo by Harriet Clark
December marked seven months of living free for the older birds, and three months for the juveniles. Faecal samples were submitted to the laboratory at Durrell as part of our continuous post-release health screening. The results were very encouraging and showed that the birds’ parasite load has decreased since their last screening in October. We also monitor their health by weighing them, and we now have a second set of scales so that when the weather allows we can weigh as many individuals as possible. Despite halving the quantity of dry mix and insects that we feed the choughs in October, regular weighing shows that the birds definitely aren’t suffering from lack of food, with several even putting on weight. This and their low levels of parasites, indicates the birds are clearly maintaining good body condition and are acclimatising well to their environment.
Sorel is ideal habitat for minotaur beetles, which prefer short grazed turf and plenty of sheep dung for the larvae to feed on. Photo by Harriet Clark
The older choughs developed a new habit this month; during feeds they would collect several mealworms or a “beakful” of dry mix and fly out of the aviary, disappearing out of sight to a nearby field. At first we wondered whether they were simply taking their food away from the group to eat it in peace, but careful observation revealed that although sometimes they were eating it, other times they were digging a hole and hiding the food in there. Choughs caching mealworms has previously been observed by Eric Bignal in his study of supplementary feeding wild choughs in Islay (report published in British Wildlife), and the birds there were seen marking their caches with different objects such as feathers, to aid finding them later. Although we feed our choughs twice a day, they don’t receive a huge amount and it is quickly consumed, so perhaps the adults are caching food so that they have access to it later in the day.
Evidence of choughs at work. Photo by Will Campbell.
At the beginning of the month we started to notice several muddy patches scattered randomly across the sheep grazed fields. We quickly discovered the culprits- the choughs of course. They seem to have developed a penchant for tearing up the grass, and we’ve observed the group many times this month energetically flinging clumps of grass into the air, no doubt searching for soil invertebrates to feed on.
Icho and three of the adults tearing up the grass in search of insects. Photo by Harriet Clark
The adult female Mauve, finally gave up pursuing her previous partner Green this month, focussing her attention instead on the two-year-old male White. We monitor the location and activity of the birds hourly throughout the day, and White and Mauve are almost always found foraging close together, often separate from the rest of the group. During supplementary feeds the pair also feed from the same dish, and regular roost checks throughout the month revealed that rather than returning to the aviary with the rest of the group at sunset, they roost together in the quarry. Fingers crossed we may now have two potential breeding pairs to keep an eye on in 2015!
Regular visitors to Sorel will undoubtedly have noticed significantly fewer sheep out and about on the north coast towards the end of the month. Unfortunately several young sheep were taken ill and because it was not clear at first what the problem was, the flock was moved into the fenced-off aviary field for close monitoring and care by their shepherd Aaron Le Couteur (CS Conservation). Test results revealed the sheep had a gastro-intestinal problem, and, being a primitive breed, they have physiological differences so often respond differently to parasites compared to commercial sheep breeds. The flock has now been treated with a novel drug and are fortunately well on the road to recovery.
We sadly said goodbye to Will at the end of December, after four months on the project. He started volunteering one week after the juveniles were released and has been following their progress ever since, spending many hours radio tracking the birds across the island and observing their antics on the cliff tops at Sorel. Will has been a huge help both in the field and in developing our invertebrate monitoring project. We wish him every success as he moves to England to pursue a career in wildlife conservation. You can read his brilliant piece about his time on the project here
In October Adam wrote about his time with the choughs on the sunny north coast of Jersey. However, it’s not all sunshine and calm days on our coastline and here Will recounts his time following the choughs into a Jersey winter.
My toes are numb as I squeeze my way past gorse bushes and through muddy fields, arm and radio antenna outstretched, feverishly waiting for the reassuring ‘pip’ from the SIKA that indicates a nearby chough. Because, once you have found one chough (the ‘Judas chough’ as fellow volunteer Jenny calls them), you can be pretty sure that the others are nearby.
I trudge, stooping into the wind, to a high point and wave the antenna in every direction for what seems like the hundredth time. At last a faint ‘pip’ comes through the SIKA slung over my shoulder. I look anxiously ahead into the wind and rain but instead of the familiar acrobatics of a chough I see nothing but a thick sea mist. Dejectedly I trudge on, in the vague direction of the ‘pip’ in order to pinpoint their location.
It’s at times like these when some people might ask, ‘Why?’ And I tell them that although data collection isn’t easy, no matter how minute and irrelevant it may seem, it is absolutely necessary to build the bigger picture. A big part of my time with the choughs was spent radio tracking them – essentially finding out where they were and how far they were from their mates. Doing this up to eight times every day allows you to amass a huge amount of data, which can in turn help answer loads of questions in matters such as social sub-groups, home range, and even potential breeding pairs and nest sites come the spring.
Although I’ve painted a pretty grim picture at the start of this piece, I did in fact experience all four seasons in my four months up on the north coast, sometimes, it seemed, in the space of one day. At 8am I might be huddled with the sheep in what little shelter there was from the wind and rain, and by 11am I could be sunbathing in a field, cursing myself for forgetting my sun cream.
The most extreme weather I faced up at Sorel was during gale force 8/9 winds where simply walking from A to B was a challenge. Even the choughs were wisely sheltering in the aviary from the onslaught. Harriet and I noticed an upturned kayak in the sea and, fearing the worst, she called the Coastguard. It didn’t take long for a search plane to arrive and start scouring the sea. Luckily, it turned out the kayak had never been occupied and the plane turned back to what must have been a very bumpy landing.
It was during the warmer half of my placement that the choughs decided to clock some air miles and check out what the rest of the Island had to offer. This left us frantically driving around the west of Island, but ‘as the chough flies’ is a much quicker way of getting around than ‘as the Skoda drives’. It was only due to the very welcome tip-offs from local bird-watchers that we were able to find the choughs down at Beauport probing amongst the cliffs; apparently oblivious to the panic and excitement they caused us. It was incredibly rewarding to see the previously captive birds exploring the island and always making it back to the aviary with impeccable timing to demand their lunch.
The choughs seem to have an uncanny ‘spider sense’ when it comes to feeding time. The idea is that, once you have put out the dishes, you give a tinnitus-inducing blow of a whistle and the choughs appear in unison to merrily scoff all the food. The birds have been trained to the whistle to try and give us an element of control, for example if they need to be shut in the aviary. In practice, however, the choughs are canny little birds and seem to react to the subtlest of cues such as the gentle clinking of dishes, the opening of a door or even a Durrell jumper walking towards the aviary. The result is always the same. By the time you have put the dishes out and raised the whistle to your lips all 16 birds will be lined up along the exterior aviary shelf, begging with their wings open and squawking to express their irritation at having to wait for their dinner. During the afternoon feed, when insects are scattered and hidden in pine cones and under logs, you have the delight of witnessing an ‘Easter Egg Hunt’ as the birds frantically waddle around the aviary trying to be the first to find the delectable wax moth larvae.
Another ongoing study that I was involved with was a pitfall-trapping survey in order to gather information about the choughs’ available food sources. Unfortunately I didn’t have the chance to look into the other end (literally) and sift through chough poo to see what they were actually eating. As I have a weird fascination with invertebrates and had gained some experience in stream-dwelling bugs during my degree, I was appointed the authority on all things creepy and crawly and was instructed to create a pictorial guide to the invertebrates previously found at Sorel. This soon turned into an 80+-page monstrosity that I sincerely hope will be of use to the other volunteers and staff (other than to prop up their computer screens).
It was a challenge at first to identify the unique coloured rings around the legs of each bird, let alone remember which bird the rings belonged to. But after a while you can even guess which birds hang out together and, at the risk of anthropomorphizing our feathered friends, understand their individual characters. The love triangle between Dingle, Chickay and Caûvette (and Caûvette’s incessant whining) wouldn’t be out of place in an episode of EastEnders.
Although you shouldn’t choose amongst your children, Chickay is definitely my favourite. When you watch the choughs for as many hours as I have you see them do some pretty bizarre things. It always seemed to be Chickay that would hang upside-down from the aviary netting like a bat, groom a sheep or chase butterflies with her peculiar waddle.
Reluctantly, my time with the choughs has come to an end. It has been a great experience working on the reintroduction project, and to be part of such an important and exciting project in its infancy. All that is left to say is a big thank you to Liz, Harriet, Glyn, Jenny and everyone at Durrell for making my placement unforgettable. And, of course, thank you to the 16 choughs (you know who you are) that kept me company up on the cliffs. Oh, and thanks of course to the sheep for sharing their best spots to shelter from the rain. I sincerely hope that all the hard work, dedication and frostbite bears fruit once it comes to the breeding season!
Last month we gave you an insight into Cornish choughs and what people are doing there to help them. This month we continue our travels and will take you north across the border to Wales. Known for its lush valleys and majestic mountains, Wales is also home to about three-quarter’s of the UK’s choughs.
www.visitwales.com
The Welsh name for a chough is brân goesgoch meaning ‘red-legged crow’.
Wales is broadly categorised into four regions; north, mid, west, and south. Choughs can be found more or less along the entire Welsh coastline from the Gower Peninsula in the south to the isle of Anglesey in the north.
They can also be found inland from the coast nesting in abandoned quarries or mineshafts. Most famously at the Llechwedd slate caverns , North Wales, where a pair are known to nest much to the delight of the tourists deep underground. A video made by the RSPB gives you more of an insight and can be viewed here.
Over the past two decades researchers working with these choughs have seen more and more inland nests becoming abandoned and breeding pairs disappearing. Ceredigion had five breeding sites in the late 1980s. Ten years later it was down to one. Montgomeryshire has seen a complete loss. It is believed that the boom in natural predator numbers, namely peregrine and goshawk, has not helped matters.
Silurian shale coastline in Mid Wales.
Coastal nest sites are also under threat, but in this case it is due to natural erosion. A lot of the coast is limestone, sandstone, or shale and easily erodes. Looking at the photo on the right you wouldn’t think a bird would chose to build a nest on these cliffs. Yet they do, often with success, although a few years down the line the ledge might give way falling into the sea and a new nest will need to be built.
Nest-site availability is a very strong limiting factor in population expansion. In the late 1980s Scottish researchers had already shown the effectiveness of providing choughs with artificial nest-sites. Wales took on board this advice and started providing nest-boxes or ledge supports at various coastal sites. Within a few years just over two thirds of the artificial sites were being used. As of 2008 choughs at 22 artificial nest-sites successfully raised a total of 335 fledglings!
On a recent holiday to Wales I had the privilege of meeting Tony Cross, a champion chough supporter and the person responsible for designing the artificial nest-boxes (which we use at the Wildlife Park). Tony very kindly spared time to show me around some of the sites and teach me more about the Welsh choughs. Having ringed over 4,000 choughs and followed many individuals for several years there is a lot we can learn from him.
This area was once used by choughs to raise chicks, but has now been abandoned.
An abandoned mine shaft once used by nesting choughs.
The first stop was at an abandoned mining area where a pair of choughs used to nest. It is hard to see from the photos, but they chose a spot down a deep shaft which kept them fairly well protected from nest predators.
The land around looks quite healthy in terms of insect availability with cattle grazing pastures and its away from built up areas.
This is probably one of those sites which ‘suffered at the talons’ of the goshawk (although great news for the goshawk I guess).
As it was outside of the breeding season we didn’t disturb any nesting choughs. Tony is a licensed ringer and licenced to approach nests. I would not have been able to do this without him.
We then drove to the coast to take a look at some of the nest-boxes Tony and his colleagues have fitted to the cliffs. It is quite a challenge as they have to find a site that they can access, but at the same time deter egg collectors and the like from reaching it. In recent years Tony has sadly found activity at boxes suggestive of human raids rather than natural predators (and we thought those days were over). One clue being that ravens don’t need to use ropes!
Nest-boxes are positioned away from potential land predators in areas where choughs are trying to breed naturally but fail.
Tony Cross indicating how far back the nest-box reaches. This one is unusual in that it is positioned on top of the cliff.
The front of the box has and overhang which, apart from acting as a deterrent to something trying to reach in, makes it feel a bit more enclosed and sheltered for the birds.
An chough nest-box facing the sea (the black dot in the sea is a seal, trust me)
One factor Tony did not consider when first designing these boxes was how badger-proof they would need to be. Don’t be alarmed, Welsh badgers have not adapted to have opposable thumbs and learn rope skills. They do, however, burrow and at one particular sight they have given the nest-box a bit of a battering pushing it out of place.
One nest-box needs re-positioning after a run in with badgers.
The boxes need to be checked each year as they do suffer from being exposed to the sea air. As long as the roof remains dry and there is no risk of collapse the boxes can be used for several years. It normally takes a year before a breeding pair move in to a new box. Lots of HSE forms to fill in, quality control tests, and the long wait for the Royal Court date (Jersey in-joke sorry).
It is clear that the work Tony and his colleagues are doing has made a great difference to the Welsh chough population. Jersey’s choughs may well benefit from the same practices as these birds have no experience of wild nest sites and will need some encouragement.
Choughs at South Stack, Anglesey
Many thanks once again to Tony for taking time out. You can find out more about his work at www.ecologymatters.co.uk
They steal, raid nests, and keep the company of witches. But the unpopular crow may not be the menace people think.
A new study, published in the BOU’s journal IBIS (here), has found that crows – along with their cousins the magpie and the raven – have surprisingly little impact on the abundance of other bird species.
Collectively known as corvids (a group that includes choughs, jackdaws and even jays), these birds are in fact being menaced by mankind in the mistaken belief that removing them is good for conservation. This new study found that in the vast majority of cases (82%), corvids had no impact at all on their potential prey species.
“Many nature lovers have been distressed to witness a crow or magpie raiding the nests of their beloved garden songbirds, stealing their eggs or eating their defenceless chicks,” said study co-author Dr Arjun Amar from the Percy FitzPatrick Institute for Ornithology. “Although this predation is entirely natural, these observations can be upsetting to witness and often leave people wondering if these predators might be reducing bird numbers.”
“However, our global review suggests that we should be cautious before jumping to conclusions over the impacts these species may have. Just because a predator eats something occasionally does not always mean that they have an impact,” Dr Amar said.
The study reviewed all published evidence on whether predation by corvids actually reduces the overall breeding performance of birds or, more importantly from a conservation perspective, reduces their numbers. Data were collated from 42 studies of corvid predation conducted across the globe over the last 60 years.
Not only were corvids unlikely to have any impact on their potential prey species, if there was an impact it most often affected the breeding success of the prey species rather than their subsequent numbers. Half of cases found that corvids reduced breeding success whereas less than 10% of cases found that they reduced prey numbers in the long term.
“These results have big implications for the likely benefits of corvid control,” Dr Amar said. “They suggest that killing corvids will be of most benefit to those interested in gamebird shooting rather than conservationists.” He added: “Bird hunters are usually most interested in increasing numbers of birds available to shoot immediately after the breeding season and this appears to be where corvids have most impact”. “Conservationists on the other hand, are usually interested in increasing a species population size and our results suggest that only in a very few cases did corvids have an influence on this aspect of their prey,” Dr Amar said.
The review analysed the impact of six corvid species on a variety of prey species including gamebirds, songbirds, waders, herons, cranes, sea birds, wildfowl and raptors. The 42 studies incorporated into the review included 326 cases of corvid – bird prey interaction Most of the data stemmed from field research in the UK, France and the United States. The impacts were determined partly by comparing bird counts before and after corvids were either removed or their numbers reduced.
The review also found large differences between the impacts of crows, historically considered the most ‘cunning’ corvid, and magpies which are sometimes killed by home owners hoping to protect songbirds in their gardens. Crow species were six times more likely to have an impact on bird prey species than Magpies.
Mistaken assumptions about corvid predation were possibly explained by the birds’ diurnal nature and the fact that they are conspicuous nest predators: “Their importance in prey population regulation is often assumed prior to any assessment of the evidence,” the study warned.
Chrissie Madden, the lead author on the paper, hoped that the review would challenge the perception that all corvids were bad, thereby preventing needless killing: “Our results suggest that this is a mistaken belief and that generally speaking people would be wasting their time killing corvids to increase bird numbers”.
“Overall therefore, our study points to the fact that we are often too quick to jump to the conclusion that crows and magpies may be the cause of bird population declines,” she said.
You can download A review of the impacts of corvids on bird productivity and abundancehere
Thanks to the blanket fog, gales, and torrential rain we have been experiencing, plus the reduced daylight hours, November’s report is probably the shortest on record. Both the chough team and the equipment have taken a bit of a battering. A few tracking sessions have been cancelled whilst we shelter in cars or with the choughs in the aviary.
To be fair the start of the month was fairly pleasant. A bit bracing in the wind, but the sun was out and the chicks were on the move. Considering how much of the Island a chough can cover in just a few minutes the tracking team tried to be cunning and set up at three strategic vantage points; Sorel, Devil’s Hole/Crabbe, and Grantez.
Dawn tracking at Grantez.
Without sounding too bitter our plan failed on all but one occasion. Since I returned from holiday on the 8th the chicks have only flown south once…on my weekend (there is probably opportunity for a research paper into that correlation).
They decided to start exploring the north-west corner of the Island. Only ever seen flying, never touching down to feed, and only really on a few occasions. As the weather started to turn they hunkered down in Mourier Valley and haven’t really left since.
Juvenile choughs probing for food on the cliffs at Mourier Valley. Photo by Liz Corry
Thanks again to everyone who sent in sightings this month. They have definitely helped to solve one mystery disappearance and have now made it onto five of 22 bird monitoring transects in Jersey.
To distract from the lack of content this month here are some photos and a video of what the choughs have been up to….
Seconds before the shutter clicked three choughs had been perched with the kestrel, exchanging daily gossip perhaps.
Cauvette and Dingle having a squabble over a prize insect Cauvette had dug up.
Dingle begging for food from Bean (she wasn’t too impressed).
This summer we travelled to Cornwall to collect six chough chicks from Paradise Park. Whilst we were there we took the opportunity to meet up with Claire Mucklow, RSPB Cornwall chough project manager, and Nicola Shanks, RSPB chough project officer. They very kindly drove myself and Harriet around the picturesque countryside in the hunt for the Cornish legend that is the red-billed chough.
Choughs have a long standing history with Cornwall dating back to the 13th Century and even feature on its coat of arms. In the 19th Century the population of Cornish choughs came under immense pressures from egg collectors, people shooting for fun or misidentifying them as pests, and people taking chicks to tame as house pets.
All that on top of the continually degrading habitat in which livestock were being moved inland for easier farming leaving once grazed cliff top pastures to become overgrown and unmanaged.
By the 1950s choughs were failing to breed in Cornwall and by 1974 the population was no more. Throughout the 1970s and right up until the Millenium Cornwall would only be visited by outsiders passing through. It was not until 2001 when three of these ‘tourist’ choughs (from Ireland) decided conditions were favourable enough to stay. In 2002 two of the birds nested and for the first time in over fifty years Cornwall once again had its own wild chough chicks. Now, twelve years later, there are seven pairs of chough nesting in Cornwall (or should I say ‘attempting’ since one is a male-male pairing). Check up on Cornwall’s choughs through their own website
A view from Lizard Point where choughs returned to breed in 2001. Photo by Liz Corry
The three birds who returned in 2001 chose Lizard Point on the south coast of Cornwall to become their new home. With suitable grazing and dramatic cliff tops it is easy to see why. As part of their conservation management Claire organises volunteer nest watches each year so the eggs and subsequent chicks can receive round-the-clock protection. Sadly, egg-collecting still threatens choughs and many other species today. In 2006 police seized a collection of over 7,000 wild bird eggs including chough, the largest case to date. For more information on this case click here.
A volunteer chough watch point at The Lizard this year manned by National Trust (in red). Photo by Liz Corry.
Choughs are protected by UK law to the extent that a licence is needed in order to photograph and access nests. The volunteers watch from a distance and gauge breeding activity according to what the parents are doing. With an incubation period of around three weeks and a further six to seven weeks before the chicks leave the nest, the volunteers are often in for a long wait to see the chicks fledge. Happily the breeding success and survival of these Cornish birds is very good.
It doesn’t have to be the breeding season for you to see choughs at Lizard Point (although from personal experience it helps!). And don’t be put off by the thought of standing out in blustery, icy winds at this time of year. The Polpeor Café has a great view and heating. You can get even ‘warmer’ by stopping off at The Witchball in the village and sampling the delights of the Cornish Chough Brewery.
Cornish Chough Brewery ales on tap at The Witchball.
Just north of Lizard Point is Kynance Cove a very popular destination in summer for both people and choughs. People are attracted to the turquoise water, white sands, and café cream teas.
Chough habitat at Kynance, Cornwall. Photo by Liz Corry
The choughs…cow pats. In 2010 local farmer Roland Hill, in partnership with Nature England and the National Trust, started grazing ruby red cattle (sometimes, and whisper this, called North Devons) at Kynance and Lizard Downs in order to restore the coastal grassland including rare plants such as spring sandwort. Of course they also benefit the choughs by allowing insect communities to thrive in the grazed land and their dung provides an almost endless supply of beetle larvae. Ruby reds happen to be one of the most docile and prettiest breeds of cattle, Jerseys aside of course, which make them quite an attraction in their own right at Kynance.
Ruby red cattle grazing the cliff tops at Kynance Cove. Photo by Liz Corry.
Ruby reds grazing in amongst the visitors to Kynance Cove. Photo by Liz Corry.
As chough numbers started to increase the birds began slowly dispersing further along the coastline. An hour’s drive west of Lizard Point is Cape Cornwall and where we based ourselves for the two day trip. We asked Nicola to recommend accommodation in the area with a tongue in cheek challenge to find somewhere we could photograph a Cornish chough with the sun setting in the background over picture perfect calm seas. Hats of to her she did it, but I don’t think Nicola expected us to be quite so lucky (Claire says she did. It was test to see if we were going to put beer or choughs first that evening!).
Cape Cornwall and a view of the Heniz Monument. Photo by Liz Corry.
After checking in at the hotel on the first evening we walked down to the end of the headland to Heniz Monument. Very soon we heard the unmistakeable call of a chough and, on following the sound, spotted three birds coming in to land. Oblivious to the two over-excited, binocular clad, girls jumping up and down twenty five metres away, the choughs went about their business foraging in the grass around the headland and preening on the wall surrounding the pubic car park.
One of three choughs spotted feeding around Cape Cornwall. Photo by Liz Corry
After a while the choughs took to the air and flew off north. As we watched the birds disappear into the distance we began to make out tiny black specks on the slopes below Kenidjack. Following the footpath around to get closer the tiny specks began to take shape and we soon realised we were looking at choughs. Not just dirt on the lens or rabbit holes (trust me it happens).
Choughs gathering near a communal roost site. Photo by Liz Corry.
Pre-roost preening ritual. Photo by Liz Corry
In total we counted fourteen choughs scattered across the rocks on the other side of the valley. We sat and watched them until the sun had set. Clearly we had found a communal roost site and had been fortunate enough to watch them all bed down for the night.
Sunset at Cape Cornwall. Photo by Liz Corry
The next morning when we met Claire we worked out that we had been observing two family groups and the all male pairing. During the breeding season these three groups tend to keep their distance from one another. Once breeding is over groups will flock together sharing roosts and feeding sites.
Coastal farmland grazed by longhorn cattle to improve chough feeding sites. Photo by Liz Corry
To help us learn more about the habitat preferences of the choughs Claire and Nicola drove us to sites either side of Cape Cornwall. Our first stop was an area called Nanjulian where longhorn cattle are being used to graze the headland. The farmer here is so pleased with the way things have gone he is looking to expand is herd although as with many projects of this kind he is limited by time and resources.
Slightly less huggable in appearance than ruby reds, yet just as likeable and important, the longhorns keep the grasses short, scrub at bay, and allow the insect comminuties to thrive.
Longhorn cattle graze land as part of chough conservation measures in Cornwall. Photo by Liz Corry.
With food supplies in check, chough parents-to-be need secure nest sites. Generally these are in caves or deep crevices along the cliffs. Cornwall’s coastline is abound with such features and the choughs often choose the most dramatic of sites, many of which cannot be accessed on foot by people providing the birds with a certain amount of security. We were taken to see a few such sites and marvelled at how Claire spotted the site in the first place, followed by how the licensed ringer accesses the nests in order to collect data on the chicks.
Abandoed tin mines, such as Botallack, are a common feature of the Cornish coastline. Photo by Liz Corry.
Choughs are quite resourceful and take advantage of Cornwall’s other offering of nest sites in the form of abandoned mines, adits, and other stone buildings. Our final stop on the guided tour was the Botallack Mine complex north of St. Just. These are abandoned tin mines built in the 1860s which run about 400m into the Atlantic Ocean. The area is now managed by the National Trust and home to Cornish choughs. The National Trust have secured all the old mineshafts, but it always pays to be careful where you walk in old mining areas. The deepest shaft at Botallack runs about 500m down into the ground. It is advisable to stick to designated footpaths. Choughs rarely like to abide by rules and where they nest in this area is certainly off the beaten track, barely accessible by humans. A perfect spot to safely raise chicks.
Before heading home we couldn’t resist one final check of Cape Cornwall’s offerings. We only counted twelve choughs that evening as they dropped off the cliff edge out of sight down to the roost below.
Choughs flying along the Cornish coast. Photo by Liz Corry.
Whether one, twelve, or twenty-two it was amazing to see a bird that has been able to return home and breed once again. The population is nowhere near the numbers it used to be. However, thanks to the conservation efforts of the RSPB, National Trust, Nature England, the farmers and the people of Cornwall the number of choughs has gone from three to thirty-three in little more than a decade.
October marked six months since the release hatches were first opened in 2014 and five months of living free for the six older choughs. I am, therefore, delighted to report that they are doing amazingly well. Even more pleasing is their decision to return to the aviary to roost with the juveniles each night.
They are behaving exactly the same as any wild chough. Foraging for insects, sheltering on cliff ledges, and fully aware of potential predators. The only difference being that they return for extra food at the aviary when we call them in. Although if you are a Scottish chough living in Islay this isn’t that unusual. Eric Bignal’s work with supplementary feeding is once again being highlighted in the UK media.
Supplementary feeding study of wild choughs living in Islay showed an increase in juvenile survival rates over-winter. Bignal, E., & Bignal, C. Supplementary feeding of sub-adult choughs. British Wildlife 2011: 315-319.
Eric and the Scottish Chough Study Group started a programme of controlled supplementary feeds providing wild choughs with a daily ‘top up’ of mealworms. Survival rates in juvenile choughs during their first winter are very low due to limited availibility of insects at that time of year; insect numbers are lower, ground frosts block access to the soil. After several years of supplementary feeding, the choughs on Islay have increased in breeding pairs from 39 in 2013 to 46 this year (report published in British Wildlife). Still a long way to go to get back up to the 95 they had in 1986, but evidence that this sort of management in the wild can work. Click here to learn more.
This work has been critical in how we planned the Jersey project and we fully expect to continue with some form of supplmentary feeding in the future. At present the Jersey choughs are receiving two feeds a day from staff. Without knowing exactly how many calories each of our choughs are getting from the wild it is difficult to quantify how much extra to give them.
Bean’s bill a tell tale sign that the choughs are probing for insects, but are they finding enough? Photo by Liz Corry
We tried reducing the quantity of insects and drymix per feed by half this month. We gave them a week to adjust, continued to monitor their body weights, and their general behaviour. Constant hounding of staff by the choughs suggested that they weren’t finding enough in the wild. We tried to leave it long enough in order to rule out complaicancy of not getting an easy meal. I’m still not convinced, but don’t have enough will-power to crack the whip just yet.
Invertebrate sampling at Sorel
To try and get a handle on what the choughs are eating out in the wild we have set out pitfall traps and randomly selected sites within the choughs’ current foraging area. These will be checked once a day for five days and repeated every month. This will allow us to assess seasonal variations and help us to indentify the insects we found in the faecal samples that we have collected. This month we are starting to see a lot more beetles in the feacals and pellets as opposed to ants and hawthorn seeds back in September.
Pitfall traps in the ground at chough feeding sites to study insect abundance. Photo by Liz Corry.
Will and our new student, Jennifer, have been creating an identification guide for the invertebrates we are likely to find based on existing studies and what is found in the traps. For image copyright reasons this report will only be for internal use for the time being. However, we would be very keen to see this developed into a much wider available publication for Jersey.
New six-month student placement
New student Jennifer began her six month placement studying the choughs…not the sheep! Photo by Harriet Clark.
Jennifer Garbutt joined the chough team this month for a six month placement on the project. Jennifer has just finished her Master’s Degree at Bristol and hopes to further develop her research skills for a career in conservation.
As a new arrival to Jersey the first few weeks of driving green lanes to follow choughs has been quite daunting, but a welcome challenge.
Jennifer is our first student who has been able to commit to longer than the minimum three-month requirement.
Often by the time you have learnt the ropes it is time to leave. By committing longer term there is undoubtedly a greater benefit for all. We will be inviting people to apply for our student positions in the New Year. The placements are currently full until March 2015. For more information and how to apply please click here or phone 01534 860045.
Maladies, mysteries, and muck
Faecal samples were submitted to Durrell’s lab this month as part of our post-release health monitoring. This coincided with the Wildlife Park’s bi-annual screening programme in which every animal at Durrell is sampled. To save Ann’s, our lab technician’s, sanity we treated the post-release samples as their bi-annual check as well so she only had to do half the amount of testing. Thankfully nothing came back on the results to cause Ann even more stress and the birds seem happy. That said, we did have two veterinary cases this month which have left us all somewhat baffled.
Egg, a five month old female chough. Photo by Liz Cory
On the last Saturday of the month at a supplementary feed Egg (red leg ring) seemed a little off colour. When the rest of the group had eaten and flown off to play on the cliff tops she stayed in the aviary. Her body weight was average and she showed no external signs of injury. She was observed closely for the rest of the day but showed no improvement and was not eating.
Egg was locked into section 1A of the release aviary and the vet was called up to examine her. Both vet and keepers drew a blank. Egg’s faeces showed no sign of infection and there were no other clues to suggest a reason for her depression. She was kept in the aviary for the next two nights with the other chicks roosting next door, and monitored closely. Egg started to eat and her mood had picked up. On the Monday morning she was released back out of the aviary and joined the others straight away. Egg’s condition will remain a mystery. We just hope this is a one off for her.
Our most alarming mystery this month, however, involved Jean (white leg ring). On the morning of the 11th they was no sign of her at Devil’s Hole foraging with the others. We found her perched alone in a roost box in the aviary at 08:20. She flew out in alarm when we approached and joined the others who had also flown over to Sorel by that point. When they were all back in the aviary for lunch Jean’s left eye was closed. When the others had finished eating and flown out she remained perched. We shut the aviary hatches so we could get a closer look without her flying away. It was clear that something was up with her eye and on the vet’s recommendations she was caught up and examined.
Staff noticed something wrong with Jean’ eye so she was isolated for veterinrary care. Photo by Liz Corry
The surface of the eye was very cloudy suggesting severe inflammation and no menace reflex was observed which indicated that Jean could not see with the left eye. Thankfully there was still perfect vision in the right eye. No signs of ulcers in the surface of the eye were noted and no conjunctivitis was observed. Additionally she was not showing any signs of pain and discomfort at this point. Medications were administered topically and orally given in insects, in order to decrease the inflammation to allow a more detailed examination of the eye. This meant that she had to be confined to the aviary for at least five days. Photos were sent off to a veterinary ophthalmologist for a second opinion. Five days later the eye was examined again in more detail as most of the inflammation was resolved. Jean was still unable to see and an opacity was noted in the lens inside of the eye, suggesting the formation of a cataract. The posterior portion of the eye was still not visible and an ultrasound of the eye was performed to evaluate this area – having a portable ultrasound machine allowed the veterinary team to perform this examination at the Sorel aviary after applying a topical anaesthesia on the eye. No problems were noted in this section of the eye and we decided that the cataract formation was the result of trauma to the eye.
Ocular opacity in left eye covering entire lens (left) began clearing up after five days of treatment (right). Photos by Harriet Clark.
Jean continued to be confined to the aviary and given anti-inflammatory drugs for the next three days. Weighing up the options with careful consideration for Jean’s welfare we decided it would be in her best interest to release her again. We would continue to monitor her closely and if we felt there was a concern over her mobility due to the loss of binocular vision we would consider confining her to an aviary permanently. Follow up examinations have showed a decrease in the size of the cataract so there is the possibility that Jean will regain some vision in the future but it is very early to say.
Durrell vet, Alberto Barbon, performing an ultrasound on a Jean’s eye. Photo by Harriet Clark
Having seen her response to a peregrine the day she was initially confined to the aviary we had faith that she would stand a good chance of survival if the choughs continued to act as a group. Choughs are a social animal and remain in continuous contact with each other whether by calling or by displaying a flick of a wing feather. They show each other where to feed and when to stop feeding if a potential threat is approaching be it peregrine or person. She had already gained enough experience to know the lay of the land around the release site and would still roost in the relative saftey of the aviary. If she had a been a bird of prey who is reliant on pin-point 20:20 vision to hunt or a solitary species left to fend for herself our decision would have been different.
We are pleased to say that Jean was released back out to Sorel on the 20th, joined the flock straight away, and has been with them ever since. She has shown no concern when flying or feeding. At first, and with strong winds, she found it difficult to judge distance going through the hatches to get to food inside the aviary. Very quickly she learned to adapt and flew in sideways using her good eye for judgement. I hasten to add that we provide food dishes outside as well as in the aviary, she was just greedy and wanted to go to all the dishes. It is clear that she is an intelligent bird and has the ability to learn to adapt qucikly. Only time will tell if the damage is permanent and we may never know what caused it in the first place. This was a huge learning experience for us, the vets, and avian husbandary in general. Let us hope that November has fewer surprises in store!
Juveniles reunited after Egg and Jean’s mystery illnesses (Cauvette is a little camera shy). Photo by Liz Corry
Aviary maintenance
We have had to add more food shelters to the aviary to protect the choughs from the driving rain which hits in all directions. The roof alone does not provide sufficient protection and, with twice as many birds as last winter, we need extra spaces. Will and Harriet fitted the plywood shelters and watched contently as the choughs put them to good use.
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Juvenile choughs on a windy day in Jersey.
Trick or Treat: Juvenile dispersal
The choughs now seem very settled at Sorel. They have been bathing in the stream at the mouth of Mourier Valley, sheltering on the cliff when it rains, and probing in the Conservation Fields. All of which are new sites for both the juveniles and adults.
Choughs at Devil’s Hole rock face. Photo by Liz Corry
The biggest change came at the end of the month. At 07:30 on the 27th the team went to Sorel and counted 16 choughs. They continued to observe the choughs playing, feeding, preening, until 08:45 when nine juveniles took to the air and flew out of sight over Devil’s Hole (nb: Egg was still confined to the aviary at this stage due to her malaise).
In the last few weeks when they have flown beyond Devil’s Hole we have been able to watch them fly over Crabbé, maybe dip out of sight behind the gun range, then reappear. This time they never reappeared!
The radio trackers set off the best they could trying to follow signals. However, it appears that motorised vehicles and Jersey’s 15mph, winding, green lanes are no match for a chough. Thanks to reports from members of the public, the team were informed that the choughs had reached the south-west of the Island within fifteen minutes of ‘dropping off the radar’. Sticking rigidly to Jersey’s speed limits Harriet made her way down only to find the choughs had gone….back to the aviary.
By 10:50 the nine juveniles were visible flying in west along the coast from Devil’s Hole towards the aviary. They joined back with the adults, who had stayed around the release site, and all came down for their lunchtime feed a few minutes later. Egg was released back into the group at this point. The group spent the afternoon around the aviary, although four adults left for the quarry at 16:30. All the juveniles roosted in the aviary.
The next morning there was not a single chough in sight at Sorel. Phone calls and text messages came in from the public once again, placing the adults around St Ouen’s Bay (perhaps checking out the best spot for breakfast) and the chicks even further south. This time the chicks were not just flying but foraging on the ground around Beauport and Ficquet Bay. This is a really interesting development as this part of the coast was the last known breeding location for Jersey’s choughs over 100 years ago.
Choughs return for supplementary food twice a day. Photo by Liz Corry.
The chicks didn’t stay long, returning to the aviary by 11:00. The adults had returned ninety minutes earlier. They spent the rest of the afternoon around Sorel and roosted in the aviary again.
We think that five of the adults might have spent the night in the quarry. One was spotted flying back from the quarry to the aviary at 16:45, but after sunset it was hard to tell if others had followed suit.
For the next few days leading up to the 31st, the chicks would follow a pattern of leaving Sorel first thing after sunrise, heading to Beauport to explore the headland, then return to the aviary in time for the lunch feed and weigh-in. The adults showed no further interest in leaving stretch of coast between Sorel and Devil’s Hole. See report here
We will have to wait to see if this is going to become a permanent pattern of dispersal with the chicks or whether they were just tricking us. Well it was Halloween after all.
Speaking of which, an interesting article about Channel Island folklore was sent to the chough team recently. It turns out that we might be dabbling in the dark arts! In the Nineteenth Century when choughs were found across the Channel Islands people were very superstitious about the red-legged bird. Why? Witches wore red stockings as a means of identification and, therefore, in the days when logical thought was questionable, choughs were also, by association, witches. The infamous Guernsey witch Marie Pipet, was even said to be able to turn herself into a chough.
Witch burning. Image taken from www.theislandwiki.org
Georges Métvier explained the link in the Dictionnaire Anglo-Normand translated in a Guernsey magazine in April 1883 (de Garis – Folklore): ‘… a certain Sieur Job, the venerable owner of the property found some Marie or Judith in his cow house in the shape of one of these birds, which he wounded in the leg with a pitchfork. Soon after the good woman sent for the doctor, who was called upon to tend exactly the same wound which had been inflicted on the bird, and so ill was she that for 6 months she was confined to her bed.‘
Scientific proof if ever one needed it! Thank you to Sarah Nugent for sending this our way and to Guernsey Birds for reference material regarding the choughs.
Well, it had to happen. After staying patiently around the release aviary at Sorel for several months, the choughs have begun to explore the Island’s coastline. On Monday (27th October) we received the first reports of choughs away from the north coast. At first slightly sceptical, it quickly became obvious that all 16 birds had left to do some exploring. It also, very quickly, became apparent that the birds were not all together.
The 10 young birds (all reared this year) had gone down to the Island’s south-west, to cliff sites where choughs once bred. The chough team had recorded all the birds at Devil’s Hole shortly after dawn so were surprised to hear that they were now several miles away. The older six birds had also gone on an expedition but only got about half way along St Ouen’s Bay before heading home. The team caught up with the very settled young birds and watched them head north again in time for lunch! All the birds remained at Sorel throughout the afternoon and roosted there.
Come Tuesday, we were interested to see what would happen. The 10 flew south again and were tracked quickly. Again they flew home for lunch. On Wednesday we lay in wait for them, watched them leave the north coast and saw them arrive in the south-west. We also timed them leaving and arriving back ‘home’ for their lunch. The pattern seemed set and we have a good idea of the route they were taking and the landmarks they were using. The commuting flights were taking around 15 minutes although an impressive 11 minutes was recorded on Thursday.
While the younger birds were roaming a little like a gang of teenagers the older birds were pretty well staying put. Except for a brief wander west along the north coast. The pattern seemed set. Until Sunday, when, in heavy early morning rain, no one moved! It will be interesting to see what happens next. We wondered exactly how the 10 found the traditional sites in the south-west when, thanks to the team, we knew roughly where the birds were each day and couldn’t see when they had had time to find the new spots. Then, we thought, if they soar (as they often do) above Sorel they can see all the Jersey coastline. Is that how they knew where to go? It makes sense too when you realise that the commuting flights are direct and not following the coastline.
We received several very important sightings of the birds during the week and would not have put the whole story together without them. We are grateful to everyone who sent in sightings through the website, by phone or through social media. The wanderings are, no doubt, going to increase from now on so please carry on with the sightings. Even with transmitters on the younger birds we can lose track of them if they are moving fast. Your sightings can help us piece together the birds’ activities and the routes taken. You can use the webpage here, through the Birds On The Edge email address birdsote@gmail.com, social media, directly to the team or through Jersey Birds.
At the end of August the aviary quarantine restrictions were lifted and the birds there were poised ready for release. On 1st September the release hatches were opened at 17:00 allowing the chicks to have 30 minutes access outside.
Release hatches opened for the chicks. Photo by Liz Corry
The hand-reared chicks were the first to leave. Already having experienced the joys of ‘free-flying’ they headed straight to the cliffs to join the adults. Not wanting to be left behind, the parent-reared chicks followed.
Having never flown outside of an aviary before, their flight was noticeably sluggish compared to the hand-reared chicks. This changed very quickly once they got used to using the air currents.
Grace and Helier seemed a little confused by the situation and didn’t fly out of the aviary straight away. They watched the others flying around and both groups called back and forth. Grace and Helier eventually ventured out once the other chicks returned to the aviary for a respite.
The chicks were obviously very excited about being on the other side of the aviary netting. Hard to say if the adults felt the same? One could infer that feelings were mixed from the fact that three decided to fly off to Sorel Point once the chicks arrived.
The chicks started to follow them flying a couple of hundred feet high in the sky, but decided to turn back and returned on their own accord to the aviary. Eight of the chicks went inside and their keeper locked them in at 17:30. Considering Grace’s reluctance to leaving the aviary she was one of the last to return.
Grace and Jean remained outside. It was not clear whether this was out of choice or because they could not work out how to get back in. The team called them down to the outside target-boards to encourage them in. It worked for Grace, but Jean remained outside preferring to stay on the roof.
Adults and chicks hanging out at the aviary. Photo by Liz Corry
The adults reappeared at the aviary. Possibly responding to hearing the call for food. This seemed to encourage Jean away from the roof down to the release hatches where the adults were. She calmly landed on the shelf and walked inside the aviary looking for food.
The team were then faced with an unusual problem in that the adults were sat either above the hatches, or on them as was the case for Mauve. This hasn’t happened before.
Normally the adults fly off as soon as they see someone make an attempt to reach the hatch wires. They were probably waiting for their last supplementary feed of the day. The hatches had to be closed, which caused the adults to take to the air, but at the same time their keeper called them back for food and they happily returned to feed. That meant that the last chick was locked in for the night at 18:45. Cutting it a bit fine before roost time yet still this was a very successful first day.
Chickay out of the aviary. Photo by Liz Corry
The next few days proved even more successful with all the chicks going out, flying around and exploring the cliffs, feeding in the grazed fields and returning to the aviary to be locked in before roost. Each day the time of release was brought forward by one hour.
There was only one close encounter with a peregrine during this soft-release. The peregrine had swooped down on a mixed flock of pigeons, crows, and gulls feeding in the conservation fields. It had claimed one victim, but dropped it before reaching the aviary. It then spotted the flock of choughs by the cliffs and flew at them. Luckily it missed. When they fled to the aviary it gave up and flew off empty ‘handed’ out to Sorel Point.
The rest of the soft release was fairly uneventful in the drama stakes. There was a visit by a short-eared owl on two occasions. The quarry’s blasting sirens rang loud and clear during one release. The birds showed no reaction; the team did find it a little surreal though.
An interesting turn of events, however, was the adults’ reaction to having access to the aviary again. They loved it. So much so that by the end of the week it was getting quite difficult trying to get the adults out of the aviary at lock-in time. We ended up leaving them in on Day 7. There was no real concern over fighting or stress within the group, yet the team were still relieved to see everyone ok the next morning. We locked them all in again on the 8th night. On the morning of Day 9 the group was called for food in the aviary first thing then the hatches were opened. They have stayed open ever since.
The trial release programme in 2013 had less than a dozen release days spread over a six-week period and then had to be postponed because of bad weather and an injured bird. When these birds were let out again in April it took twenty-five release days over a six-week period before we could confidently let them out full-time. For the group of ten chicks it took one week! Obviously the chicks had an advantage of having other choughs out at Sorel as role models, yet no one would have predicted the process to happen quite so quickly.
In some respects that is the easy part over with. We now need to monitor these birds closely, ensure that they have enough food over the winter, and have all their needs catered for when next year’s breeding season rolls around.
Please feel free to send in any of your sightings or encounters to the website. We always appreciate extra eyes on the ground (or air!) and we are very keen to hear how the residents of Jersey are taking to their new neighbours.
Dawn til Dusk
Radio-tracking at dawn. Photo by Liz Corry
Once the chicks had 24-hour access outside, our radio-tracking study got underway. We follow one bird per tracking session recording location, behaviour, and proximity to other choughs. We alternate the focal bird so as not to bias observations. Since we are recording proximity we are, in effect, checking up on all 16 birds per session.
There are six tracking sessions per day starting at 07:30. The last session of the day is set at 19:00 to give us an idea about roost site selection. Obviously, as the days get shorter, this late session will become redundant.
Both sunrise and sunset can be quite spectacular at Sorel and shed interesting light on chough behaviour. For the first week or so of living at liberty the choughs would be enjoying breakfast either at the aviary (provided by the team) or on the grazed land probing for wild insects. We then started to notice the birds flying around Mourier Valley and only returning to the aviary when we blew the whistle for food. We decided to stop providing them with breakfast as they were obviously beginning to explore and learn where other sources of food were.
Probing holes in the ground where the choughs have breakfast. Photo by Liz Corry
Next thing we knew, they are shooting out of the aviary at the crack of dawn and feeding over at Devil’s Hole before meandering back to Sorel for lunch and an afternoon hang-out. We have also watched them take several flights over to Crabbé and over Rouge Nez. We have never observed them land, but we are sure it won’t be long before they start investigating the short grass at the gun range.
Sunset checks can be frustrating because the choughs’ behaviour can vary each day. Some nights they want to head to their roost site before sunset. Sometimes they can be probing for food right up until the last slither of light.
The adults returned to roost at the aviary the first night we left the hatches open for the chicks. It is a lot harder to know where the adults roost now they have moulted their transmitters. We have to spend a good thirty to forty minutes before sunset watching them to see where they go.
We are now seeing our external roost-boxes being used more. Not surprising with sixteen birds competing for a roost spot. Fortunately Sorel is quite quiet at roost time with most tourists and dog walkers having headed home meaning that the birds can settle down for the night at the aviary and not be scared away.
Hello and Goodbyes
Max and Adam sadly had to say goodbye to us this month. Max returned to University in Germany to continue his studies. Adam finally bowed out after six months on the project, having initially volunteered for three! Both have been an immense help on the project and have, we are sure, learnt a lot in the process. A special thank you must be given to Adam who stood in when Harriet and I went to Cornwall in July. Not to mention the endless search effort for the missing birds in April and being the one to find Yellow’s signal 9km away from the aviary! Adam’s time on the project is documented on our website, shortly to be followed by Max’s story.
New student Will Campbell joined the project in September. Photo by Harriet Clark.
Will Campbell, our new graduate student from Jersey, shadowed Adam in his last week and was thrown straight into radio-tracking the chicks. The success with the chick release meant that Will missed the entire soft-release, but he has been following them ever since. Will had the added pressure of being the only student during most of September. We are hoping he will rise to the challenge and not do a runner like Yellow and Cerise!
Bean loses it!
Bean’s radio transmitter fell off this month. Photo by Liz Corry
….her transmitter that is. All the choughs were accounted for on the morning of the 27th, yet Bean’s transmitter was silent. The team eventually found the signal emitting from the roof of one of the quarry store-sheds by the offices. The transmitter has not yet been recovered and we are waiting for one of the gulls who sits on the roof to kindly dislodge it for us. Thankfully, Bean is quite a communal chick and hangs out with the others so she has been easy to follow. It does make it a little bit more difficult when they are flying as we cannot see the leg rings. We used to be able distinguish adults from chicks by presence of the tail transmitter.
Not to be upstaged, exactly a week later, Caûvette’s transmitter started playing up. At first it was just the pitch that had altered then very quickly the battery died. We have contacted the manufacturer to try and understand why this would have happened so soon. Normal battery life for this model is nine months. With the transmitter still attached to the bird it is a little difficult to diagnose. Hopefully the other eight will hold out over the next six months and stay attached to the birds.
Ménage a trois
Green preening Blue much to the apparant disapproval of Mauve. Photo by Liz Corry
The intriguing trio of Green, Mauve, and Blue continues. On the whole, Green spends more time with his new interest, Blue, than his old partner Mauve. Yet still they feed together and Green will preen both as they stand together in their sordid triangle. We think Mauve might be starting to take offence (finally) and has been seen alone on occasion several hundreds of metres apart from the rest of the group.
This behaviour started on the morning of the 15th when Mauve didn’t show for breakfast and returned to the group and the aviary four hours later. There was no sight or sound from her in between. Maybe at the start of the breeding season, as hormones start playing their part, Mauve’s stubbornness will shine through and she will win back her ‘man’. That or she will pair-up with a younger chough and we will have two potential breeding pairs to look out for.
Back at the park
All of Durrell’s captive choughs have been moved off-show whilst their aviary awaits major repair work. Gianna loves the attention she is getting from Academy staff watching her from their offices and from the Security staff who walk past every day.
Tristan has been demonstrating unusual behaviour suggestive of breathing issues. However, after inspection in the hand and faecal and blood testing, no conclusive diagnosis could be made. He is on an anti-inflammatory drug and will continue to be monitored carefully by keepers.
Diet analysis
Our study into what the choughs are eating in the wild got into full swing this month. Will is working on an invertebrate key based on previous studies specific to Le Don Paton. Faecal samples are starting to be picked apart in the lab to first separate into animal, plant, mineral, and then to genus level. We will be setting out pitfall traps to help ascertain what is available at this time of year and to help with our identification of faecal finds. We hope to extend the invertebrate survey to study monthly and seasonal variations in prey availability.
The excitement of sheep faeces. Photo by Liz Corry
Choughs don’t just eat insects in the ground. Our choughs have taken a great interest in sheep faeces. We know that in the UK choughs probe cattle dung for larvae but we were quite surprised at how much can be found in smaller sheep faeces. And we were completely taken aback when we watched our choughs playing with the poo! Caûvette, for example, was seen on her back, legs kicking in the air, tossing a piece of poo around with her bill. And, no, she wasn’t stuck!
Chough drinking from the sheep’s water trough. Photo by Liz Corry.
An unexpected benefit of having the sheep around is that the choughs have learnt to drink from the water bowser left out for the sheep. We provide them with two sources of fresh water at the aviary, cleaned out every day.
Understandably then it is a little bit insulting to the team when the choughs choose the water pans left out, green with algae. We have started scrubbing out the pans to keep the water clean.
Hopefully the choughs are sensible and drink from these because they are shallow. There have been a couple of reports in the past where UK choughs have fallen into horse troughs and drowned because the sides are too steep and slippery to get out of.
The choughs unexpectedly talking refuge in trees. Photo by Liz Corry
The birds have also been in the hawthorns by the aviary picking at the berries and the bark. We have found pellets containing undigested seeds suggesting that they are eating the fruit.
Presumably when they are pecking at the bark they are looking for woodlice and other such invertebrates. At the same time choughs are highly inquisitive and could just be investigating.
Chickay and friends investigate the new camera on their food stand. Photo by Liz Corry
It should be pointed out that choughs are classed as a non-perching bird. You don’t normally find choughs in trees. Choughs do like high vantage points and these trees are the best option within close proximity to the aviary field. Consider it a Jersey adaptation
We would like to use next-generation sequencing to look more closely at the question of prey selection by released choughs. This would feed into answering (no pun intended) how much the choughs are reliant on our provision of food throughout the year. This sort of genetics study requires funding and institutional support potentially incorporated into an MRes or PhD.
Weight watchers
Choughs weighing themselves during lunch. Photo by Liz Corry
With the choughs flying free it is more important than ever to know how well they are adapting to finding food in the wild, how necessary the supplementary feed is, and to monitor their general body condition. We do this by checking their weights each day and their physical appearance at feeding times.
Now we have sixteen birds flying to one weighing scale it is very difficult to get daily weights from every individual. To compound the problem certain individuals, not naming names… Dingle, Chickay, and Caûvette…head straight for the scales and push off anyone else who tries to feed. We will be looking to purchase a second set of specialist scales (approximate cost £200) to allow simultaneous weighing. This might not solve the problem, but will certainly alleviate it.
‘Behavioural problems’
We have tried to continue the behavioural observations to see how group cohesion prior to release, affects behaviour post-release. The obvious obstacle to continuing observations is that the birds are no longer confined to the aviary. Thankfully with the way choughs flock together at this time of year we can focus on feeding sites and simply adapt the methodology.
Skills are put to the test trying to spot and identify all sixteen choughs out at Sorel. Photo by Liz Corry
What we can’t manipulate though is the choughs’ penchant for rabbit holes. The terrain at the feeding sites often means that the birds’ leg rings are hidden. Or, in the case of a rabbit hole, the whole chough can be blocked from view. The birds also tend to spend only a few minutes feeding in one area. With the two issues combined, and our other project commitments, we end up only getting 10 to 15 minutes of observations once or twice a day. We may have to discontinue this study unless we can outsource to a student intern who can focus solely on this research.
Paradise Park visit Jersey
Ali and Ray Hales came over to Jersey to watch their parent-reared chicks take to the skies. They missed the first few days when the chicks were having limited time outside but then very quickly five hours became ten hours and on the day Ali and Ray returned home the chicks were given full access outside. Photos from their time here can be found on their website here.
Joe Thompson, Paradise Park, gets a fly past from the chough chicks. Photo by Liz Corry
Ali was so impressed by the choughs’ progress that she immediately started arranging visits for her keepers. Fortunately parrot keeper Joe Thompson is also a pilot! This meant Paradise Park staff could visit Jersey in a day without disrupting their staffing rota too much. The first trip was made on the 23rd after two postponed dates through bad weather.
Joe along with Adam Pollard and Olly Frost, who are responsible for Paradise Park’s choughs, had a whirlwind three and a half hour tour of Sorel and the Wildlife Park.
I think it is safe to say they were suitably impressed with seeing their birds flying around the cliffs. Sadly, bad flying weather and reduced daylight hours have now meant any further trips from Cornwall are postponed until next spring.
Butterfly transects
An annual butterfly transect was setup this year at Sorel and carried out by project staff. The survey runs from April to September counting butterflies on a weekly basis. The transect is a new addition to the Jersey Butterfly Monitoring Scheme (JBMS) run by the States of Jersey Department of the Environment. The overall scheme started in 2004 and uses the same methodology as the UK Butterfly Monitoring Scheme. The scheme is financed by the States of Jersey, but is almost entirely based on volunteer recorders.
Four common butterfly species found at Sorel. Photos by Liz Corry
We are hoping the results will not only inform people about what can be found at Sorel, but show how the conservation crops can benefit butterflies. Data collected this year will be submitted to the States and results published later this year.
Air display
Durrell’s Overseas Team came over to Jersey between 8th and 13th of September for the annual Conservation Forum. After several days of intensive management planning and workshops they were ‘rewarded’ with a trip to Jersey’s International Air Show. A fleeting visit to the not so secret viewpoint at Noirmont to watch the Red Arrows, followed by a close up view of the Lancaster bomber, and finished off with a sunset tour of Sorel.
Our own aerial display team didn’t disappoint and flew over-head, dramatically dive-bombed the cliffs, then obediently returned to the aviary. The visitors were suitably impressed, especially considering last time they were here involved peering into a rain-soaked quarry looking for a lone chough. Many on the team have experience with re-introductions and restoration projects around the world and have advised with the chough project.
We were hoping for the ultimate photo opportunity of Red Arrows and red-billed choughs in one frame. However, on hearing the approaching engines the choughs understandably headed straight for the aviary.
Is it a bird? Is it a plane? No its just Durrell’s Overseas team. Photo by Nik Cole
Since the start of my degree, I have always known that I wanted to become a conservation biologist. In early 2014, I realised I needed to gain field-based experience in this area to complement my knowledge. That’s where Durrell came along. Being Jersey born, I had always hoped to work for Durrell in some form so imagine my surprise when I noticed the red-billed chough re-introduction student placement advertisement! It was a dream come true, an entry level project that would allow me to work with Durrell in the field and gain the necessary skills I would need for my later career. Fast forward five months and I have achieved everything I had hoped for, have made new friends (both chough and human) and have even been allowed to name one of the new choughs which is an honour in itself!
Almost as soon as I had been accepted onto the project, I was thrown into the action. I first met Liz and the eight adult choughs (green, mauve, blue, black, red, cerise, yellow and white) on a sunny but windy Sunday afternoon and only two weeks later I helped with their first release of the season. Standing on the hill now aptly named Mount Dallas by the team in honour of the amount of hours I have spent there tracking choughs from it. I was amazed by the heights the eight birds rose to and the acrobatic displays that they seemed to be able to perform with such ease. Getting them to come back inside the aviary proved to be a problem and by the end of my first full day on the job, one bird had returned home while five were roosting in the nearby quarry and the other two (yellow and cerise) had travelled further afield.
A search of the nearby area for these missing two gave us no clue of their whereabouts so Liz sent myself and Pierre (my fellow student) on countless searches across Jersey armed with our trusty radio receivers and maps taken straight from the phonebook (they are the only ones with all the road names!). Over the next few weeks Pierre and I travelled the length and breadth of the island, both on foot and in my car searching every cliff path and exposed hill we could find, ever hopeful that if we somehow managed to find the missing birds we would be able to return to Durrell as heroes.
Only once did we come close to finding the missing two choughs. It was an uneventful Friday and Liz and I had spent the whole day searching the west of the island with no luck. As dusk approached we decided to end our search at Noirmont Point, only to find that our radio receivers were picking up a signal for one of the birds (cerise). The signal itself was coming from one of the many bays in between Belcroute Bay and Noirmont. Unfortunately, the high tide and the presence of large areas of private land prevented us from searching further. Over the weekend we were able to get slightly closer but then the signal had disappeared never to be heard again. A frustrating end to what was such a hopeful chance.
Soon a month had come and gone and the arrival of four chicks back at the Wildlife Park soon meant that Pierre, Harriet, Liz and I had more work on our hands! I was lucky enough to have been one of the first staff members to see one of the newly hatched chicks having coincidently arrived back from lunch at the perfect time! I was always extremely busy during this time as I would spend my mornings searching for the missing adults, my lunchtime helping staff feed the chicks and my afternoons helping to release the other six adults. As the chicks grew and our searches for the missing choughs grew more and more desperate, my day soon became re-organised. By early June we were spending most of our time back at Sorel “chick-proofing” the aviary by building countless roost boxes and by laying rat proof mesh under the floor.
The chicks moved into to their new home at Sorel in mid-June, by this time the six adults had established themselves in the surrounding area and only relied on us for food. However, they did still spend a great deal of time at the aviary. This meant that a new stage of my placement could start.
One of the main questions the team had at this time was how the adult choughs would react to the new presence of the chicks at the aviary. To test this, I helped Harriet to develop a series of observations that would allow us to watch both the adults and chicks from a nearby field and witness any interactions that may take place. We decided to try and do three one-hour long observations each day: one in the morning, one over lunch (when both the adults and chicks were fed) and one in the afternoon. These observations have continued over summer and the team are still performing them now. One of the great things about being around the birds for such long periods of time is that you begin to recognise and appreciate their individual personalities. I am still amazed by certain birds’ apparent greediness and it still makes me laugh when I see the chicks playing with pieces of wool.
By July, the chicks had matured enough to begin their own series of releases and experience the outside world for the first time. Although these birds were only let out a few times they took to the skies in a manner similar to the adults before them; flying high and testing how far they could test their limits. July also brought me a fresh and exciting challenge as Liz and Harriet had to collect six further chicks from Paradise Park in Cornwall, leaving me and the new student Max alone with the birds for the first time. I had spent the weeks prior to this learning how to feed and train the birds correctly but nevertheless I was still terrified when the dates rolled around. In the end, it was far less stressful then I had anticipated and with the help of everyone in the Bird and Conservation Departments I managed to go three days without harming a single chough!
Looking back so much has changed since I first started this placement. I have learnt so much in my brief time with the choughs and I have really enjoyed every minute of my time with both the choughs and the team from Durrell. If anyone were to ask me if I would do this placement again I would not hesitate to agree and sign up again.
By Harriet Clark
