By Liz Corry

Mystery disappearance

Grace, a 2014 parent-reared chough, disappeared on the 18th August 2015. Photo by Liz Corry.

On 18th August one of the 2014 parent-reared choughs did not show up for the supplementary feeds. Grace, so-called because of how choughs manoeuvre in the air, had been around the day before feeding with the others. The group have been exploring different areas of Sorel recently and we hoped she had just split off and become preoccupied. It soon became clear that Grace was no longer with the group. We have not seen or heard from her since the evening of the 17th.

The weather had not been particularly bad at that stage and she had not appeared unwell or underweight. We have not had any reports of choughs being seen elsewhere on the Island in the last two weeks. Our assumption is that she has unfortunately died for reasons we will most likely never know.

Drinking from the water dispensers for the sheep at Sorel. Photo by Liz Corry taken using a digiscope.

This means that of the twenty birds we have released since 2013 we still have fourteen choughs living at liberty around Sorel. The wild born chick brings the flock size to fifteen.

This exemplifies why we need to release several groups of choughs over the years rather than do a one-off release and hope for the best.

The short video clip below gives you an insight of what the choughs were getting up to at the start of August before Grace disappeared. Dusty the wild born chick, learnt to be more independent by the end of the month and, therefore, less whingey.

Preparing the parent-reared chicks for release

The free-living choughs arrive to greet the parent-reared chicks who have now completed their quarantine period. Photo by Liz Corry.

The eight chicks which arrived from Paradise Park in July completed their quarantine period on the 17th of this month. They were given access to the entire aviary which meant the free-living birds were locked out. They need this space in order to build up their flight muscles and practice flying through hatches on command. They also get to see more of the surrounding environment and orientate themselves to some extent in preparation for the first day of release.

The radio-transmitters arrived from Biotrack Ltd on the 24th. High winds and non-stop rain at Sorel delayed fitting the transmitters until the 28th. This in turn postponed the release which we had hoped to start as close to quarantine ending as possible.

Vet nurse, Mel Frost, injects one of the sick choughs with a wormer. Photo by Liz Corry.

During the same week, to further delay their release, certain individuals within the group started sneezing. Soon two of the males were open-mouthed breathing at rest. Not a good sign.

We decided to blanket treat the group (that is, every bird in the group whether sneezing or not) and inject Ivermectin whilst we had each bird in the hand to fit transmitters. They will need catching for a second dose in a couple of weeks.

We aim to give the parent-reared chicks access into the wild once they are healthier.

 Our hand-reared chick heads home.

It was inevitable that our hand-reared chick, CeCe, would return to the Wildlife Park and did so last week after two months living in the release aviary at Sorel.

The other chicks had accepted her as part of the group. Since fledging in the aviary she had become a skilled flyer and very adept at probing for insects (then burying them out of sight of the others); however, her level of tameness around people always raised concerns.

There had been a change in her behaviour from mid-August whereby she was more apprehensive around staff. When the group reacted to anything she would follow. We started to think she might be ok when released. If a peregrine was to attack the group when they eventually fly free she would take cues from the group and avoid attack. As with any other social bird she would stick with the group when they looked for shelter from the elements and find a safe roost site if they choose not to use the aviary.

CeCe, the hand-reared chick demonstrating why she will not be released into the wild. Photo by Liz Corry.

However, our main concern was whether she would fly to members of the public and beg for food as she does with staff who hand-reared her. Whilst I am sure the majority of the public would love this experience there was potential for her to come to harm through her naivety. We enrolled a couple of willing volunteers and put it to the test inside the aviary. CeCe was horribly conflicted. She begged but kept her distance. Although the look of conflict on her face suggested that she would soon change her mind if there was no clear threat.

Her destiny had been determined. She would return to the Wildlife Park to be an ambassador for the restoration project. Once she has completed her quarantine requirements she will join the Durrell flock in the display aviary.

Durrell’s army take up the challenge of the display aviary

The display aviary at the Wildlife Park now has new netting and brand new uprights to create a better flying area for the choughs. The building work has meant that the walls desperately needed rendering, a new coat of paint and the inside needed re-landscaping. A lot of jobs which could drag out the completion date and force the birds to stay isolated in their breeding aviaries even longer.

Durrell’s army of staff and volunteers took up the call to arms on Friday 28th August. Scrapers, paint brushes, and rollers aloft they went into battle. Or at least that’s what any passer-by would have thought considering the amount of paint that ended up on people as opposed to wall! That being said the team managed to achieve a great deal in two hours.

Staff and volunteers and Durrell help with the display aviary renovations. Photo by Jonathan Stark.

In this case sitting down on the job is permitted. Photo y Liz Corry.

Andrew Terry, Head of Field Programmes, got involved. We had a limited number of ladders so his height played an advantage. Photo by Liz Corry.

Team work. Durrell’s Head Vet Andrew Routh and his wife Sorn, renovating the catch up cage. Several requests by Sorn to lock him in were denied. Photo by Liz Corry.

Senior bird keeper, Hester Whitehead, eventually realised that the other keepers’ refusal to paint without left-handed paint rollers was not legit. Photo by Liz Corry.

‘Sea fog at Sorel’ by Alex Roberts. Otherwise known as applying sealant paint. Photo by Liz Corry.

We started after work at 6pm and continued until the sun had set and the paint tins were empty. Café Firefly kindly provided nourishment in the form of Thai green curry (much to the bemusement of people arriving to collect their takeaway orders). And the choughs provided baked goods!

We could not finish everything. A second coat of paint is needed and for the sake of the ibis trying to sleep next door we could not carry on later into the evening. The jobs that could be ticked off the list have meant we can bring forward the completion date. The choughs will be eternally grateful to all those who volunteered their time that evening.

Moving to (grazed) pastures new

Harriet Clark, field assistant and trainee bird ringer, bade farewell to the choughs and Jersey at the end of August. Harriet has been with Durrell on and off for the last five years as student, then keeper, and for the last 16 months as our field assistant. She has been there for all of the 2014 releases, helped hand-rear Chickay, Bean, Caûvette, Dingle, and CeCe, and assisted Gianna in foster-rearing Special K who sadly never made it to Sorel.

Harriet inspecting a chough nest box. Photo by Liz Corry.

Harriet radio-tracking the group released in April 2014. Photo by Liz Corry.

Part-time shepherd. All lamb cuddling carried out under license. Photo by Liz Corry.

There have been highs and there have been some very low, lows. Harriet has persevered throughout and showed incredible professionalism and dedication. Then again she is also probably the only person I know who would go up a metal ladder in a thunderstorm to secure a hole in the aviary preventing the birds escaping. In theory of course. This never actually happened because she never told me!

 I’m sure all of you who have had the pleasure of working with Harriet will join me in thanking her for hard work over the years.

We wish Harriet all the best as she takes on a Masters in Conservation and Resource Management at the University of Liverpool.

Jersey’s first wild chough chick in one hundred years made its maiden flight out of the nest on 2nd July. Well at least we assume that is how it made it up to the top of one of the tallest buildings in the quarry. It was a long time before we actually witnessed a ‘flight’ and even then it was best described as a choreographed fall. Or was it pushed?

Dusty with parents on the first day away from the nest building. Photo by Liz Corry.

Chough chicks spend a while walking and jumping around the nest site learning all the basics before actually taking flight. Dusty, named by Ronez quarry staff, did exactly that only in this case Dusty left the busy quarry building his parents had nested in and chose the very tall ‘climbing frame’ next door to play around on.

Dusty’s parents, Green and Blue, stayed very close to their chick for the first few days. The video below shows them training Dusty.

They would fly up and perch next to Dusty then take a short flight around the building and back trying to encourage the chick to do the same. Time after time they tried but Dusty was having none of it, which is why we are a tad suspicious of that first ‘flight’.

Parents feeding their wild born chick in the quarry. Photo by Liz Corry.

Dusty did make a few flights around the top of the building over the next few days, but didn’t have much need to go elsewhere. Why would you when your parents are bringing you food and you have one of the safest play areas a chough could want?

Green and Blue adopted a different approach to encouraging Dusty away from the buildings. Starvation.

I’m not suggesting this is an appropriate, or legal, parenting technique, but in the case of a chough it worked.

Not quite as extreme as it sounds. It simply meant the parents were spending less time with Dusty and more time foraging with the flock. They would still return with food for Dusty from either the aviary or the grazed cliff tops, just not as often. Instead of short demonstration flights around the buildings they would fly across the bay to Sorel Point.

Exactly a week after leaving the nest site, Dusty ‘s hunger to be with mum and dad (in both senses of the word) overcame its insecurities and the first flight to Sorel Point was made. Then they kept flying! All the way around to the grazed fields by the aviary to join the other thirteen choughs.

Dusty and parents coming into land at Sorel. Photo by Liz Corry.

It wasn’t long before Dusty went to the aviary. At each supplementary feed when we called the birds to the aviary Dusty would be following eagerly begging for food of mum and dad. However, it took a long time for Dusty to pluck up the courage to actually go in the aviary. Initially it might be fair to say the optical illusion of the netting might have confused the youngster.

Dusty on the outside of the aviary begging to parents inside. Photo by Liz Corry.

Very quickly it was apparent that Dusty was wary about going inside. This was actually really encouraging to observe as it meant the chick wasn’t naïve. Having been raised by captive-bred parents in relatively close proximity to people you might think that this chick would be a little too comfortable around potential threats.

Dusty will now go in the aviary visiting the food dishes on the target boards and has even landed on the weighing scales.

Mum and Dad are still feeding on demand although you can see them trying to encourage Dusty to become more independent.

The general method being deny and ignore. It doesn’t always work and we have witnessed a few scuffles between Dad and chick.

Update from the free-living flock

The other choughs have accepted Dusty into the flock. There has not been any change in behaviour due to an additional member. Even one as noisy as Dusty.

They have started exploring new ground at Sorel looking for insects. The grazed headland is quite hard and compact at this time of year as the sun bakes the soil. The insect larvae available in the soil will be quite hard to get to. The grassy slopes leading down to the sea have looser soils and appear to be more inviting for the choughs right now.

They are still going through their moult, as shown by the chough in the flight in the photo below. They look a bit scruffy, but it isn’t stopping them from putting on their famous acrobatic flights of fancy or maneuvering away from an incoming peregrine. The latter has happened on several occasions this month as the young peregrines are out and about learning their trade.

New arrivals seeking Jersey residency

There has been one change at Sorel which effected the free-living choughs more than Dusty‘s arrival and that was the import of eight parent-reared chicks from Paradise Park. The team at the wildlife sanctuary in Cornwall have had another successful breeding season. They kindly agreed to loan Durrell eight of the eleven chicks that had successfully fledged this year (fully expecting not to see them again unless on holiday in Jersey!). Even better news was finding out that the DNA sexing results show we have four males in the group helping to address the balance out at Sorel.

Three of the parent-reared chicks with their parents at Paradise Park, Cornwall. Photo by Alison Hales.

Once again Lee Durrell and Colin Stephenson eagerly stepped up to offer to fly over and bring back the lucky eight. On the 16th July the three-month old chicks were caught up, crated, and driven to Perranporth airport by Ray Hales and curator David Woolcock. We made it through the very localised Cornish fog and cross winds to land around 1pm. After a brief refuelling of a bacon roll, cup of tea, and a catch up with friends, we loaded the choughs onto the plane and taxied off for our return to Jersey. An hour later we had landed and met by Dennis Moseley, Head of Operations, in the Durrell van to take the choughs on their last leg of the journey to Sorel.

Pilots Lee Durrell and Colin Stephenson alongside Liz Corry at Perranporth airfield to collect the chough chicks. Photo by Ray Hales.

Once at Sorel their ordeal wasn’t over as they then had to go through their vet checks which included blood and faecal samples. The quarantine process began as soon as they entered the aviary and lasts for 30 days providing they all pass their tests. Feacal samples are submitted every seven days and tested at Durrell’s laboratory.

For the first week they were kept in section 1A separated from our hand-reared chick to allow them to settle in. We then gave them access in with our chick so they could socialise together.

Initially the parent-reared chicks were very scared as you can imagine. They quickly learnt to associate the arrival of the free-living group at the aviary with food provided by staff. We don’t know yet if they are responding to the whistle as the logistics of training the group and feeding the other sixteen at the same time is very challenging.

Throughout this the free-living choughs could still enter the aviary poly tunnel, but locked out of the shed sections (1A and 1B). This meant that the eight juveniles who normally roost in section 1 were forced to find alternative roost spots. Once the 2015 chicks have access to the entire aviary the free-living group will not be able to go inside the aviary until we start releases.

Sunset at Sorel. Photo by Liz Corry.

A roost check from 19:30 until 21:00 (sunset at 20:50) confirmed that the juveniles were still sleeping at the aviary, but using the external roost boxes next to the parent-reared chicks.

It also highlighted what happens when people get too close to the aviary at the wrong time of day. The birds had already gone to roost by 19:50, spending the rest of the daylight hour to preen and tidy up. A couple approached the field gate and started to open it. This sent the birds out of their roost boxes and off to the other end of the aviary where they watched the couple closely. As the visitors got closer the choughs flight or fight response kicked in and the flew….off to the cliffs out of sight. The birds locked in the aviary started to panic flying around in a confined space.

The couple clearly meant no harm and they have every right to be in the field as there is public access. Once they left the field the birds inside calmed down and half an hour later the juveniles returned.

Whilst very frustrated that my working day had just been extended I do have to thank the mystery couple. If I had not have gone looking for the juveniles on the cliff I would not have seen the small pod of dolphins swimming across the bay!

Update on our hand-reared chick

The hand-reared chick in the release aviary. Photo by Liz Corry.

Last month we reported on how we moved our hand-reared chick up to the release aviary whilst still a nesting so she can fledge in the aviary and learn from the other choughs.

She had a rocky start overwhelmed by her new surroundings and the very loud gang of choughs that would descend en mass at least twice a day on the aviary. She didn’t have any other clutch mates to look to for support and became very dependent on myself and Harriet hand-feeding her.

She fledged at the start of July and started learning to feed for herself. We began weaning her off the hand-rearing diet and teaching her to fly to the target areas for food.

However we quickly started to realise we had a problem. She learnt to fly…on to our shoulders. Last year’s hand-reared chicks started doing this at a similar age. We never encouraged it, didn’t reward them with food, and in the nicest possible way shood them off. They quickly stopped and have not attempted it ever since. They have now attained a nice balance of being comfortable around staff for feeding and management purposes but at a safe distance from any ‘predation’ threat.

This chick has a unique ability to cling to your like some sort of gecko and no matter how hard you try will not leave you. She has imprinted on staff associating them with food and companionship. When the parent-reared chicks arrived she showed no interest in them. When we mixed her with them there was still no interaction. However we did have a problem of the other eight finishing off all the food. Our chick likes to feed when we are present then maybe graze a little throughout the day. When we were not there she had no food.

When we were there she would be frantically begging, following our every move, and throwing herself at the keeper door to get to us. We noticed her body weight going down each day so we increased the daily food allowance and gave extra dishes to reduce competition. When we gave the group access to the poly tunnel they had more time to explore and find food in the grass. Stress levels have been turned down a notch as a consequence. She will feed side by side with the other chicks and there is no aggression. When they react to something she will react and vice versa. There is a level of social cohesion there. Whether it is strong enough for out in the wild is a question we will face closer to the release date. We need to be confident that she will not be completely naïve when faced with a potential threat whether it be falcon, dog, human, etc.

However much her begging down our ear canals might grate and that her clingy nature means it takes at least twice as long to leave the aviary, it is a real privilege to work with a bird like her. She’s made me re-read Corvus: A Life with Birds by Esther Woolfson with greater appreciation.

Durrell display aviary taking shape

If our hand-reared chick is to return to the wildlife park she will get to move into the newly renovated display aviary. There is still a long list of jobs which require ticking off before the choughs can move back in, but the netting at supporting uprights are now in place. Once it is ready Gianna and the other six birds currently off-show to the public can also move back in.

Changing of the guard

Paul Pestana completed his three month placement on the project at the end of June. He extended his time so he could be there when Dusty fledged. Paul is hoping to continue working in conservation, this time in New Zealand a country with lots of experience at re-introductions and restoration work. In the meantime he is off to Kyrgyzstan on holiday! We have set him the challenge of finding a chough and sending back a photo (its not impossible they are resident there).

Before Paul left he spent a couple of weeks helping our new student Erin O’Brien settle in. Erin is returning to Jersey after completing her degree at the University of Exeter. Like Paul, Erin will spend three months with us and help with the release of this year’s chicks.

By Liz Corry

Celebrations and commiserations this month as the chough breeding season begins to wind down. We have only managed to produce two chicks this year through the captive breeding programme at Durrell. It doesn’t mean that we have had to work any less, however, to ensure that these chicks make it to fledging.

Hand-rearing Gwinny’s chick

Gwinny’s chick is being hand-reared by Durrell staff. Photo by Liz Corry

The chick we began hand-rearing in May continued to grow and develop with relative ease. We had a few stressful days trying to keep the chick from overheating. Corvid chicks are prone to overheating when developing in the nest. We had been carefully controlling temperature within the brooder and maintaining a constant room temperature. The problems started when the weather outside improved. Late afternoon to early evening is when the sun is shining directly on the incubation room window. For a couple of days  at the start of June the temperature in the brooder was being pushed up 2-4°C higher than it should have been and the chick would pant excessively. Much like the perils of keeping dogs in hot cars the chick could have easily died. Of course we wouldn’t let that happen.

A makeshift net curtain was put up to shade the chick in the evening and the windows were opened. As this was happening out of hours, open windows posed a security risk, so we stayed with the chick in between the two affected feed times whilst doing our best to cool it down.

Hand-reared chick in the rearing room. Photo by Liz Corry

Fortunately this situation did not last long and a couple of days later, at 17 days old, the chick was large enough to move out of the brooder and into our rearing room.

Here we had to make sure the room conditions best prepared the chick for the imminent move to the release aviary.

Heating was turned off and skylight windows were gradually opened to allow for a breeze to blow through the room. Not quite cliff top conditions, but at least the outdoors will not come as too much of a shock.

There was some preparation to do at the aviary before the chick moved in. The doors and hatches to section 1B (where the rearing box is) were closed a few days before. This allowed the free-living choughs to sort out their new living arrangements. Eight of the juveniles roost in the aviary and we know from droppings that some use section 1B. There are plenty of other options within the aviary, they just need to decide amongst themselves who was going to go where. It also allowed us to check there were no rodent issues to compromise the chick’s success.

We also spent two days strimming, chopping, mowing, and bracken bashing. Basically any job that was going to create lots of noise and disturbance we wanted out-of-the-way once the chick moved in. At least until it had fledged and was more comfortable in the aviary.

Choughs forage around the outside of the aviary looking for insects amongst the recently strimmed grass. Photo by Liz Corry.

With these tasks out-of-the-way we picked a day when we had plenty of staff around and the vets were available to examine the chick. On 22nd June we took the chick to the Vet Centre to have a routine health-check and blood samples taken. We also added plastic leg rings and implanted a transponder. A DNA sample was taken and sent off to discover the sex of the chick.

Vet, Alberto Barbon, examining the chick’s eyes…or is it the other way around? Photo by Liz Corry

A transponder microchip being implanted into the chough for indentification purposes. Photo by Liz Corry

The one thing we had not planned for was the torrential downpour which lasted most of the day. The chick was fine, being kept in either a pet carrier or sheltered in the aviary. We didn’t fare too well, even with waterproofs, giving up by lunchtime. The chick seemed to adjust easily regardless of weather and took food from the tweezers straight away. When the adults arrived for their food it was a little intimidated. By the afternoon it was calling in response to the adults calling. The video below includes a clip taken on a smartphone the day the chick moved in. The adults are outside on the netting calling and looking in to try to see where the noise was coming from.

The next couple of days the weather switched to being really nice. This time too nice and the chick was overheating again. We might name the chick ‘Goldilocks’ depending on the DNA results. Temperatures in the nest box were averaging 21°C, 2-3 degrees higher than the chick was used to. We removed one of the corotherm panels on the side of the aviary next to the box to allow the wind to get through which helped a lot.

The adults have found their own way to cool off this month using the sheep water bowsers in the field next door, or flying around the quarry where the temperatures were cooler.

Choughs post-bathe using the water pans left out for the sheep. Photo by Liz Corry

Water bowsers left out for the sheep are used by the choughs as well. Photo by Liz Corry

The underlying issue was that the chick was stressed by the whole situation. Anything additional, like it being too hot, would feel amplified for the chick. Last year the four chicks we moved in had each other to look to for reassurance. As one person described it “remember what your first day of school was like”. The chick can hear the intimidating ‘big kids’ next door and sometimes see them. We appear with food for reassurance then disappear (we don’t want it imprinting on us).

The hand-reared chick fledged in the release aviary at Sorel. Photo by Liz Corry

Feed times instantly doubled in length. The chick would eat a few bites then get distracted by noises outside of the aviary. During this time it would take food from the tweezers but then spit it back out. It meant it wasn’t eating as much as it had been back at the park and it’s body weight was fluctuating daily.

Captive-reared chough chick exploring outside of the nest box (top right corner). Photo by Liz Corry

When the chick started ‘bouldering’ out of the nest it became even harder to feed with all the new things for it to explore.

If it wandered too far from the nest, most notably onto the top step of the ladder, it would stay there until Harriet or myself guided it back up with the promise of food.

The captive-reared chick investigating its new home. Photo by Liz Corry.

By July the chick should be flying around with confidence and eating for itself.

We are hoping to receive a group of parent-reared chicks from Paradise Park who can then be socialised with our chick.

We will assess nearer the time whether this chick is suitable for release. If it ends up being too dependent on staff we might not release it and find an alternative role for it back at the park.

Gianna and ‘Special K’ the foster chick

Day old chough chick. Photo by Liz Corry

In May we gave Gianna, our tame chough, a chick that we had hand-reared for the first five days after hatching.

Our intentions being that this would be less demanding for staff time compared to hand-rearing.

More importantly the chick gets to be raised by an actual chough and less human contact.

As this was the first time we had attempted foster-rearing, the only surviving egg of Tristan and Issy, and if a successful release candidate to be name something beginning with ‘K’ we decided to give the unsexed chick the nickname ‘Special K’.

Gianna proved to be an attentive first time parent doing everything a mother chough should.

Staff provided Gianna with a regular supply of food from 07:30 until 19:00, sometimes feeding her in the nest as the male would. As always, we ‘preened’ Gianna, but never Special K as that was Gianna’s job. At two weeks old we switched from daily weighing to every few days as it became too much of a disturbance. The chick had become more alert and reactive.

On 30^th May I noticed Special K looking a little unsteady in the nest. I took it out to weigh and instantly saw to my dismay that it’s right leg was bent. Until now the twigs in the nest had blocked our view of the chick’s legs when sat in the nest. When we had handled it there was nothing to suggest there was a problem although we don’t spend long with the chick when weighing to avoid prolonged human contact.

A deformity in the right leg of the chough chick Special K causes it to walk with a limp. Photo by Liz Corry.

The weekend duty vet was called out to examine the chick. There were two possible reasons either the chick had sustained a fracture in the nest and healed incorrectly or, more worryingly, it was metabolic bone disease (MBD) where bones are weakened.

MBD can be induced by inappropriate nutrient levels in the diet namely lack of calcium and/or vitamin D3.

Gianna had been feeding the chick a lot of waxmoths. Her favourite food, but not necessarily one packed with the right nutrients.

A blood sample from Special K was sent away to look at calcium and protein levels amongst other things. The results did not ring any alarm bells although we had to bear in mind the sample was taken after the bones had changed and would not necessarily reflect what was happening in the blood prior to this.

Special K, the foster chick out of the nest but not yet at the stage where it can fly. Photo by Liz Corry

The aviary they are housed in came into question as it is quite shaded in the mornings but full exposed by late afternoon. Lack of exposure to sufficient ultraviolet light can also cause MBD.

For a species which nests in caves and crevices you would expect UV levels to be lower in general compared to say a gull nesting on a chimney top. We were not too sure if UV levels would be a contributing factor.

Out of curiosity we took UV and lux (illuminance) readings at three different locations in the aviary and one in the overspill car park (no shade) over a five-day period. We did find that levels inside the nest box were low or zero compared to elsewhere. However, we don’t have data for wild nest sites or other captive breeding aviaries for comparison so we cannot read too much into this.

One way we would know whether it was MBD or a fracture would be to X-ray. We decided to wait until the chick was independent of Gianna to do this. Any intervention resulting from the X-ray would be better managed at this stage in its life rather than earlier. If it proved to be a fracture it might be possible to reset the bones in which case 5-6 weeks of post-operative care would be required.

Gianna feeding her six week old foster chick. Photo by Liz Corry

Special K was returned to Gianna and stayed in the nest until it started bouldering, i.e. jumping in and out of the nest, on the 10^th June. Special K’s mobility issues meant it took the chick a few days longer than normal to pluck up the courage and skill to get out of the nest.

We aided it by providing a shelf (B & Q’s finest budget pine) to the front of the nest.This way it didn’t have to leap far.

Once it was out it wasn’t long before it was taking short flights and keepers would find it above their heads hanging out on the safety-porch roof.

The bald patch of skin on the chick’s throat is due to Gianna feather plucking. Photo by Liz Corry

It started feeding for itself around 47 days of age. You could sense Gianna was beginning to feel bored and superfluous. She started preening keepers’ hair and demanding more of our attention. Rather worryingly she started feather plucking the chick under the bill. We tried to provide enrichment, otherwise known as distractions, but to little effect. Any other bird would readily take to them. Gianna either ignored or, in the case of the insect culture we spread out for her to probe through, she tidied it all up and dumped it in the corner of the aviary!

On 30^th June the chick was taken to the Vet Department to have X-rays taken. They clearly show the bone deformity along the tarsus which cause the right foot to bend inwards. This could be operated on to straighten the foot and avoid pressure sores and other problems developing in the future. The X-ray revealed a second problem; the femur was also abnormal to such as degree that it would not be possible to fix. This deformity would mean that once the foot was straightened the right leg would be slightly shorter than the left. This would put the chick at a disadvantage on the ground in terms of mobility, but not necessarily impact on its feeding and flying capabilities.

Vet nurse Mel Frost monitoring the chick’s respiratory rate. Photo by Liz Corry

Once vet nurse, Mel Frost, had prepped the bird for the operation the vet, Alberto Barbon, began to operate on the tarsus.  In simple terms the bone had to be broken and then reset using pins to hold it in place. These then stay in place for three weeks until the bone has fused together.

What I am about to describe might seem fairly gruesome to those of a sensitive nature. I have seen my fair share of operations, but as a surrogate ‘parent’ looking on even I found it a challenge. That being said it is astonishing what can be achieved through modern veterinary practice and as an observer you become transfixed.

Any operation in which a small bird is anaesthetised carries a risk. With this particular procedure there was another hazard. To break the bone internally the vet risks damaging tendons and nerves with the scalpel. Externally it is a lot cleaner with regards to infection risk, but the break might not be clean and could fragment. The vet opted for the latter and with precision and strength (and courage!) snapped the bone.

Vet Alberto Barbon and vet student Ben Howitt operating on the chough chick. Photo by Liz Corry

Pins were inserted by pushing through the skin at calculated points along the bone. Again this required a lot of precision and concentration. In total four pins were inserted along the length of the bone.

Inserting pins into the tarsus bone. Photo by Liz Corry

These were then braced either side with another pin and each join wired then glued together. Finally the ends of the pins were trimmed so the frame was less cumbersome to the chick once it was up and mobile.

The metal framework was wired and glued then trimmed to size before a protective gauze covering is applied. Photo by Liz Corry

Throughout this the vet nurse had paid close attention to heart rate and breathing rate. Painkillers were being administered and a precautionary antibiotic given. To the chick that is! Vet and staff had to grin and bear.

The positioning of the foot was corrected once the metal framework was in place. Photo by Liz Corry

Two hours in and the vet had reached the stage where he just need to bandage the framework to protect the chick. The vet nurse started to bring Special K around, out of the anaesthetic. Suddenly the chick’s responses changed and staff jumped into emergency mode. The chick had stopped breathing and heart rate had dropped. An avian form of CPR was started and adrenaline administered as a final attempt to restart the heart. Despite every effort Special K did not recover and sadly pronounced dead on the operating table.

Everybody involved was understandably devastated. It had seemed so promising with preparations underway to set up a vet centre cage for it’s post-op recovery just as the news broke. Having been hand-reared and foster-reared by staff for two months the loss of Special K had a greater impact than simply one less chough to release.

We now know via the post-mortem that Special K was a female.

Special K will always have a special place in our hearts. Photo by Liz Corry

Teaching Through Nature

For a second year running we participated in Alderney Wildlife Trust’s Teaching Though Nature programme. This is an exciting cross-curricular education project offering schools the opportunity to bring nature into their classrooms.

Using the dramatic lives of seabirds and Alderney’s wildlife, 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 and confidence.

For two weeks at the start of June Durrell took over with daily blogs and live webchats about the choughs, Birds On The Edge, and other species Durrell works with. Questions came flooding in; what do choughs eat?, how many choughs do you have?, what is the deadliest bird? We also had lots of lovely feedback and have hopefully helped spur on the next generation of conservationists.

Summer time shenanigans

With summer finally arriving there were changes in the air at Sorel. Some quite literally. The sheep have been sheared to lose their winter coat. Aaron and Ewen rounded them into the aviary field and spent four days working their way through the flock. The streamlined brown sheep are now back out on the cliffs and making new friends.

Three of te raven family with the seep at Sorel. Photo by Liz Corry

The fledged raven family have been spending a lot of time at Sorel in amongst the sheep, patrolling the field edges for food, and generally just hanging out on the cliffs. Considering the size difference, the choughs were probably pushing their luck when they mobbed one for being in their air space. Other than that they have been living happily side by side. The peregrines have been out and about. Thankfully no encounters with the choughs…yet.

With the warmer weather and calmer winds the choughs have largely ignored everything else going on at Sorel and simply concentrated on having fun. Flying high, tumbling, and playing on the thermals.

If you ever wanted to know why the collective noun for choughs is a chattering, here is why…

Nesting advances to the next stage!

By Liz Corry

The merry month of May held true to its poetic title this year and bore witness to the return of breeding choughs in the wilds of Jersey. After the flourish of nest building activity and copulating in April we noticed a change in the adults’ behaviour. Mauve and Blue were often absent or late to the feeds at the aviary. Their respective partners White and Green would be there, hurriedly eat, and then fly off towards the nesting sites. For those of us monitoring the nest sites it was quite tricky to see what was happening. Why? Because they decided to nest in Ronez Quarry!

We could only watch the birds as they flew back and forth between Sorel and the quarry and calculate how much time was being spent at the nest site. This is actually quite useful because as, breeding behaviour changes, so does time allocation at the nest.

Green and Blue head back to the aviary for food whilst White flies back to see Mauve in the quarry…maybe. Photo by Liz Corry

We know patterns of time allocation from breeding behaviour in UK choughs, especially Cornwall where nest monitoring is carried out every year as a form of protection as well as research. The female incubates the eggs and is fed by the male on the nest with the odd flight during the day to stretch her wings and get more food. Once those eggs hatch there isn’t much difference in behaviour as she spends the first week or two brooding the chicks. After which point the chicks are bigger and require much more food so both parents go out and forage.

White foraging alone at Sorel. Photo by Liz Corry

At the start of May we observed the males frequently making solo flights between the nest sites and headland. Combined with the females’ absence along the clifftops it suggested they were incubating!

The really interesting behaviour was watching the male feed at the aviary when we added the supplementary diet. He would then fly back to the nest site, seconds later the female would emerge and then fly together to the aviary. It was as if she was waiting for him to confirm that dinner was ready so she didn’t have to waste energy flying back in case we weren’t there.

I have to say this behaviour was most prominent between Green and Blue. White and Mauve did something similar, but alas White’s young mind would often wander and he would easily be distracted on the flight back if he bumped into another chough, especially Black, the female he was still courting. Mauve had to put a lot of effort in and was often seen at the aviary begging frantically for food from either White or the team.

We decided to increase the amount of food we were supplying since everything was being eaten and the females were obviously needing to maintain their energy stores. The juveniles on the other hand just thought Christmas had come early and revelled in the extra food. We do exactly the same for captive birds at the Park if they are polishing off their food. Our consideration for Sorel, however, is whether this means there is enough food and/or sufficient foraging habitat for choughs during the breeding season. We don’t want the choughs to become reliant on the food we give them. At the same time the fact that we have choughs incubating in the wild for the first time in a century means we would not want to risk starving the birds.

The pattern of behaviour with the breeding pairs continued for three weeks; choughs incubate for 19-21 days. Then change was in the air. On 22^nd May, I received a call from the Quarry, one of their staff reported hearing a ‘cheeping’ noise from Mauve’s nest! We had already paid a visit to the quarry to see exactly where the nest sites were, so we knew that it would not be possible to visually confirm chicks without disturbing the nest. Instead we had to rely on behavioural patterns again. Over the next 48 hours we started seeing Mauve spending more and more time away from the nest site. Due to the Bank Holiday weekend we were not able to access the nest until the Tuesday by which time we were confident that Mauve had abandoned.

White and Mauve at the aviary after their nest failed. Photo by Liz Corry

With assistance from Ronez staff I climbed up and checked in the nest hoping to find something to indicate what had happened. It was spotless.

Impressive engineering from Mauve and White led to one of the first wild chough nests in Jersey in a century. Photo by Liz Corry.

Our choughs have used fibre glass insulation found in the quarry as well as sheep’s wool to line their nests. Photo by Liz Corry.

A perfect nest with twigs, sheep’s wool, and fibre glass insulation (apologies Ronez for any damage to property).

On a more positive note Green and Blue continued as normal and we wait anxiously. I can only hope that the fact their pair bonding is stronger and they are that little bit older means they will have more success.

Dingle and Red

We mentioned last month that Dingle had paired up with Red and started nest building. They are still a pair but never really got anywhere with a nest. Having spoken to quarry staff it appears we had four females trying to nest in various places around the quarry. Moving twigs from site to site with only two finally feeling happy with their choice. This is an amazing achievement for their first year breeding and first year living free in Jersey. It bodes well for the 2016 breeding season.

News from the Wildlife Park

Back at the Park we had a much clearer idea of what was happening. On 1^st May a very punctual chick emerged from the egg that was being artificially incubated. We hand-reared it for the first five days feeding it from 6am until 11pm using the same methods as last year. This time round we were faced with the problem of rearing a chough in isolation. Last year having four chicks together meant they would be socialised and learn from each other exactly what a chough looks and sounds like. With a single chough the chances of imprinting are much higher.

Senior keeper Catherine Francescon feeding the day old chick. Photo by Liz Corry

Staff gently clean chick’s bill after feed. Photo by Liz Corry

We decided to try foster-rearing using Gianna as mum. This was not without its own risks. What is she didn’t take to the chick? Would she know what to do? Would she be able to feed it enough since she had no partner to feed her in the nest? The answer to the latter was easy. We became her partner. We would go in and feed her and if needs be feed the chick as well, but, ideally, she would do it to feel sufficiently bonded with the chick. The first question was the tough one and there was only one way to find out.

When the chick was five days old we moved it in with Gianna. I went in to feed and preen (tickle) her then swiftly switched her egg for a chick. What happened next melted the heart, she went to the nest box as I pretended to leave. I didn’t want to disturb her so walked to the other side of the aviary and watched carefully. She went to sit back on the ‘egg’ then hesitated, looked down puzzled, looked outside (I won’t say ‘at me’ as that is far too romanticised), then very carefully sat down and brooded the chick. The clip below was taken at a later date when Gianna was more confident.

I sat by the safety porch out of sight but still inside in case things turned nasty. It was silent for exactly 28 minutes, then movement.

Gianna removing a feacal sac produced by the chick. Photo by Liz Corry

Heart in mouth I watched, half expecting to see a bill appear with a chick dangling down. Instead it was a faecal sac belonging to the chick. Gianna flew out and across to the opposite corner of the aviary, deposited the faeces, cleaned her bill, then flew back to the nest. Now maybe this is something only a bird keeper can appreciate, but this was one of the most satisfying sights to see.

The next hurdle was seeing if she would feed it. It wasn’t a smooth start. Gianna knew it needed to be fed, she knew exactly what call to make to encourage the chick to beg, but she couldn’t quite work out how she got the food from her bill into the chick’s. It took three feeding attempts throughout the morning as she teased the chick with food overhead. To be fair, a single chough chick in a nest wobbles around a lot when its begging making it a very fast moving target. By the fourth feed something switched on and she figured out what to do.

We continued to support the chick by hand-feeding pinky mice and papaya, but since Gianna did such as great job we left her to it after a few days. We still went in six times a day from 7.30am until 7pm making sure she had enough supplies and, being Gianna, enough attention.

Gianna collecting inscts to feed to her foster chick. Photo by Liz Corry

The foster chick had daily weigh-ins for the first three weeks to monitor its progress. Photo by Liz Corry

It takes 41 days for a chough to fledge so pretty much the rest of May was spent just making sure the chick grew strong and healthy. Once this chick has fledged and is independent from Gianna it will be moved up to Sorel to take part in the 2015 release this summer.

Gianna keeping a watchful eye on her foster chick whilst making sure she is pampered properly at the same time. Photo by Liz Corry

Gianna’s foster chick was the only egg to hatch from Issy’s clutch of five. They re-made their nest but never got around to laying a second clutch for reasons unknown. The second egg being artificially incubated was the one rescued from Gwinny, or more accurately from the Dad who had an aversion to eggs. This pair also failed to lay a second clutch so it was really important that their egg survived.

The incubation period or this egg was an anxious one. It’s weight-loss graph suggested it wasn’t going to survive. Bird Staff worked hard to reduce humidity keeping the incubator and room as dry as possible. In the end a very delicate and nerve-wrecking procedure of drilling a small hole into the shell was carried out. This had the desired effect after which point it was a case of sit and wait. Not long past the due date the chick inside started to chip away at the shell and eventually emerged.

Gwinny’s chick being hand-reared by staff. Photo by Liz Corry

It has responded very well to life outside of the shell and is piling on the pounds in a good way. It now consumes about 20% of its body weight per feed, which equates to a lot of insects. As with the foster chick we hope this one will make it up to the release aviary this summer.

The video below was taken when Gwinny’s chick was only a few days old and had not opened its eyes yet. When the eye slits start to open we feed wearing a black glove and using orange tweezers. The iPod is used to playback the sound a female chough would make at the nest to announce she has food. It isn’t always necessary if the chick is already begging.

Guided chough tours now offered…by choughs. Photo by Harriet Clark.

Moulting begins

We started noticing moulted feathers in the aviary at the start of May. A few days later the choughs at the Park followed suit. For the Sorel choughs this meant that the remaining radio-transmitters started to drop off.

Their batteries are still active so we should be able to find them (unless they fall in the sea). If you are visiting Sorel and happen to find one please pick it up and contact one of the team we can refurbish them for the 2015 release.

Veterinary intervention

Durrell vet Alberto Barbon examining Mauve in the aviary. Photo by Harriet Clark

Digital microscope image of a chough faecal flotation The large dark oval shape in the top left of the image is a syngamus egg. Photo by Ann Thomasson

Shortly after Mauve abandoned her nest we noticed that she started looking a little run down and began sneezing and spluttering quite badly. She was caught up in the aviary and looked at by the Vet. Faecal samples showed she had nematodes and she was under weight. Highly likely to be stress-related, we kept her locked-in for a week and a treatment of Ivermectin. When she was looking better we released her back into the group.

Durrell’s Display Aviary

Thanks to a very kind private donor work can now begin on the renovation work for the display aviary at Durrell.

As you can see from the photos it isn’t an easy job and will take several weeks. Once ready we will once again be able to flock the choughs together over the non-breeding season.

Dismantling netting frame of chough display aviary. Photo by Glynn Bower

Work began this month nf repairing and redesigning the display aviary at Durrell. Photo by Glynn Bower.

And finally…

The Institute of Zoology held a symposium in May entitled ‘Health and disease in translocated wild animals’. Organised by Tony Sainsbury and John Ewen (ZSL), Katherine Walsh and Ian Carter (Natural England), and Matt Hartley (RSPB) the two-day symposium reviewed the impact of disease on species restoration through translocation, and considered lessons learned to guide effective planning and implementation of future translocation projects. Health management of conservation interventions was discussed, including methods of disease-risk analysis, evaluation of disease management alternatives, use of molecular tools to unravel disease risks, mitigation of diseases and methods for post-release health monitoring.

Day 2 of the symposium held at ZSL. Photo by Liz Corry

To kick off the second day Prof. Carl Jones, chief scientist at Durrell, talked about managing behaviour; appropriate socialisation and early learning to enhance survival using our choughs as a case study.

Bean, Dingle and company fulfilled their flagship role that day and brought the Birds On The Edge project to the attention of a international crowd. In a good way I might add!

Proceedings of the talks will eventually be published in EcoHealth and made available upon request.

Here is a tweet from one of the participants:

Jean

March was a bitter-sweet month in the chough project. We start with the sad news of Jean’s mystery disappearance. On a sodden, gale-force Sunday morning when the clock chimes echoed the start of British Summer Time, but nothing else did, only fifteen choughs could be counted at Sorel. Visibility was poor, but the radio tracker was very decisive in telling me that Jean’s signal had vanished. After several hours searching the coastline from Bonne Nuit to Crabbé, two feeds at the aviary without her showing up, and one brief stop in the pub with an open fire to catch some sort of reprieve from the elements, the outlook for Jean was grim.

The radio tracking antennae took a battering in the gales the day Jean went missing. Photo by Liz Corry.

Having said that, I was still quite hopeful. Perhaps the merciless weather had separated her from the group and she was sheltering in a crevice or somewhere blocking the radio signal.

They have experienced wetter days yet rarely a day when they struggle to fly back into the aviary, opting instead to land on the shelving and cautiously side-step through the hatches.

Jean, named after the Parish they all reside in, was the juvenile we treated last year for sudden blindness in one eye (see October 2014 report). Maybe this put her at a disadvantage although for the past six months there has been nothing to suggest this was the case.

Jean at the start of March, pictured here in the centre, waiting her turn for supplementary food.

The search area was extended to include known peregrine hang outs. If she was ‘sheltering’ in a peregrine stomach we should at least find the discarded feathers with transmitter attached still beeping away. Alas the radio receiver just crackled away with white noise.

It is difficult to speculate as to what happened without any clues. The remaining fifteen are behaving as normal (perhaps too normal!) and all appear in good health. Well, at least they were after she went missing.

Jean hanging out with Dingle and the other juveniles shortly before she disappeared. Photo by Liz Corry.

Further news from Sorel

We had a minor scare earlier on the 15^th when Blue flew to the aviary with her right leg hanging down. Harriet had noticed her limping slightly the day before, but now she was clearly affected by it. I called the group into the aviary for food and shut the hatches. This was the first time the group has been locked in together overnight since October. No one appeared to object and the next morning Blue was caught up and driven to the Veterinary Centre at Durrell to have x-rays taken.

When we caught her up we noticed she was thin and the scales confirmed she had lost about 20 grams in weight. It was also clear that there was dried blood on her metal leg ring. We drove her to the Vet Centre where she was anaesthetised and checked over. The metal ring was adhered to the leg, so we cleaned it up and then used specialised ring-removing pliers to take the ring off. Underneath the ring the leg looked remarkably good, with a little swelling and some abrasions to the skin. X-rays were taken.

X-ray of a chough, more specifically Blue. The small object that looks a bit like a bullet is actually her identification microchip implanted into the pectoral muscle.

These showed a little bit of bony reaction under where the ring had been but no other causes for the lameness. We took advantage of her being in the Vet Centre to give her a full check over and took blood samples. Whilst anaesthetised she was given both an anti-biotic and an anti-inflammatory drug by injection to reduce the risk of infection and to ease the pain and swelling.

Blue (adult, female chough) being examined at the Vet Centre by head vet Andrew Routh. Clockwise from top left; she was given a general anaesthetic, then weighed, given injections of antibiotics and an anti-inflammatory, and an antiseptic wound spray was applied to the cut. Photos by Liz Corry.

Once she recovered from the anaesthetic we took her back into the aviary at Sorel. She was locked into one of the back sections so we could continue with her 5-day course of medication given in food. The rest of the birds were given access back outside with the hope that her partner Green would stay close by. The mesh walls allow him to pass food to her and roost almost side by side if he so wished. The thing is, he didn’t!!

The first night Green roosted in his same spot in the quarry. The next day he was hanging around with Red, a lone female who normally roosts with the juveniles. Then came the ultimate insult to Blue, yet outstanding news for the project, Green and Red started showing signs that they wanted to nest. At first activity levels were sporadic: maybe a handful of sightings of a chough carrying a twig over the space of a week. Their breeding instinct had kicked in, but maybe they weren’t too sure what they were supposed to do having never bred before.

Red has never had much luck when it comes to relationships. She was originally paired with Orange, the male who died in the quarry during the trial release. When White arrived in December 2013 she tried to take him under her wing, so to speak, but that failed.

When we moved the hand-reared chicks into the aviary last summer she would often appear at feed times watching what we were doing very closely. On occasion it looked like she was trying to feed the chicks through the mesh. She seems very broody in her nature and a little bit soft-hearted. Her manoeuvre with Green, whilst quite bold, is understandable at this time of year.

We decided to discharge Blue from the ‘hospital wing’ a little early as she was not taking her medication and clearly not liking being separated. I opened her hatches at the lunchtime feed and spent the afternoon observing her integration back into the group. She more or less went to find Green straight away and of course met Red too. The threesome seemed to be harmonious in flight and stayed together all afternoon. Occasionally the other adults would fly in and join them, but never for long periods. The discord seemed to be when Green and Red landed. Red would see off Blue if she tried to search for food near the pair. It seemed like Blue would need to resign herself to a life without Green.

Green and Red foraging alone along Sorel point. Photo by Liz Corry.

Until the next morning, that was, when Green and Blue were flying around together and Red was with the juveniles looking a little sullen. Red roosted back at the aviary and Green and Blue returned to the quarry. Normality resumed. For now anyway.

The other pair with potential to breed this year is White and his partner Mauve. White is now carrying twigs around which is really exciting news.

Green, adult male, flying with a piece of gorse root potentially to use to construct a nest.

None of the pairs have shown much interest in the nest-boxes we put up. Jennifer however did watch the juveniles foraging around one of the sites and spotted Bean investigate inside the nest-box. This is great news for the future as the juveniles are recognising the boxes and will remember that there are sites out there suitable for nesting.

We are not entirely sure what was going through Chickay’s mind when she picked this polystyrene strip off the side of the aviary. We don’t think she knew either!

News from the Wildlife Park

Back at the Wildlife Park the breeding pairs have been busy building their nests. Tristan and Iseult show the most promise now they are back together. They made a perfect nest within a couple of weeks and we now eagerly await eggs. Gwinny is trying to make her nest. However, her young fella seems to object to her choices of twig and removes them. By the end of the month an agreement had been made and the structure of a nest was there.

Tristan and Issy’s nest took about two weeks to construct using materials supplied by keepers on a daily basis.

The first clutch of eggs laid by these two pairs will be partially incubated by the females and then removed for keepers to continue and hopefully hand-rear. The pairs should try to lay a second clutch and we will let them rear that clutch. All offspring will become enrolled in the 2015 soft release ‘squadron’ preparing for take-off this summer.

One other chough busily building a nest is Gianna, our foster-mum-in-training. When she was with the Italian vet students who rescued her, she had attempted to make a nest, but wasn’t really given the right set up and was still quite young. We provided her with a nest-box and started her off with some twigs.

Gianna proudly collecting twigs for her nest. Photo by Liz Corry

I don’t think any of us was prepared for the speed in which Gianna built her nest and for her excitement in doing so. It became very difficult to distinguish whether she was preening my hair or looking for material to line the nest. Normally they use wool or horse hair. I feel like this should be taken as an insult.

Back at Sorel

Other newsworthy events this month include Dingle losing his transmitter in amongst the gorse and the battery on Egg’s transmitter appears to have run out. We expect the other transmitters to wind down in the next month or so before the birds begin their annual moult. Dingle and Egg tend to stick close together, along with the other youngsters. Hopefully we will still be able to keep a close eye on them.

Dan’s time as a student on the project came to an end this month. It is amazing how time flies when counting sheep and tracking choughs. He moves to Wales next month to monitor osprey nests and hang out with the choughs on Anglesey. We wish him all the best and are in no way jealous that he might get to see osprey chicks up close and personal.

If anyone is wondering how the eclipse affected the choughs this month….it didn’t! However, we did see some stunning scenes around the chough release site this month. Here are just a few examples….