By Liz Corry

At the start of September the eight captive-reared chicks were released into Jersey. After their thirty-day quarantine and pre-release training they were finally ready to join the rest of the flock. As with the previous chicks released into Jersey we have named them alphabetically with a nod to their new home. We have four males and four females to introduce to the group. Kevin, named after Ronez’s site foreman who looked after Dusty in the quarry, Lee (Durrell), and (St) Mary are the eldest of the group, albeit only by a week or two. Noir, Ormer, and Pyrrho are three girls from the same clutch, and Q and Ronez are the youngest brothers. Each bird has its own colour ring and a radio transmitter attached to their tail feathers so we can monitor them closely after release.

The method for this release had to be tweaked to account for the fact we had  almost twice as many choughs living outside of the aviary. Attempting to call back and lock-in eight specific individuals from a group of twenty-three each night would be a practical nightmare (and most likely cause nervous breakdowns amongst staff). This time we simply let them out on the first night then planned to follow them like hawks, so to speak, and call them back for food as and when. We relied on the social intelligence of the choughs knowing that the outside group would act as mentors and, hopefully, ‘anchor’ the new birds to the aviary site.

‘Egg’ trying to demonstrate her social intelligence. Photo by Liz Corry

The hatches opened on the 7th and, in what now appears to be modus operandi for chick releases, the eight birds stayed firmly in the aviary. Eventually when the outside group were called down for food at the aviary, the newbies flew out to meet them, eat, and cause general pandemonium once they realised they were no longer confined to the aviary.

They also had several distractions to contend with in the form of low-flying light aircraft, a helicopter, and paragliders. Definitely a good day for flying then!

Over the course of the evening the newbies explored the sky above Sorel and the cliff tops. All bar Mary and Q who decided for personal reasons that observing from inside the aviary was a far better option. The other six carried on flying around past sunset clearly trying to decide on a suitable roosting spot on the cliffs instead of the aviary.

The next morning they were still out along the cliffs, very rarely going inland. Q had decided to leave the aviary but got ‘lost’ in doing so. He was probing one of the farmers’ fields at Sorel by himself, calling loudly and not getting any response from the other choughs.

Even Mary, 200m away in the aviary was ignoring him or maybe petrified into silence now she was the last bird remaining in the aviary. Mary made her way out by midday and joined Q, who had now joined the adult flock, and suddenly 23 choughs were swirling around the cliff tops.

The newbies still avoided the aviary even at feed times. On the second night they moved towards Sorel Point to find a better roost spot.

View of sunset from the second roost site. Two choughs are visible on the rocks in the bottom left corner. Photo by Liz Corry

Over the course of the next five days the newbies kept using this roost site, but one-by-one they returned during the day to join the others at the aviary.

All except Q and Ronez who for reasons known only to themselves decided the quarry looked a much better place to hangout in. They didn’t, however, hangout with the other choughs who use the quarry. Instead they went to the rock-face in the south-east corner and stayed there.

We managed to catapult food onto the quarry ledges. We had to battle with the wind. Sometimes it was calm but at other times you were fighting with the wind to merely stay upright.

Sadly for the youngest chough, Ronez, our efforts, and his, to stay alive on the ledges did not pay off. On the evening of the 13th both he and Q were left probing away near the fenceline at the Ronez loop road. The next morning there was only one chough visible. Ronez’s radio signal was loud and clear suggesting he was close by and not moving.

The unstable nature of the rock face prevents access to the site. He may well have been predated if he roosted on the ground. Feral ferrets have been seen by quarry staff and this particular area is very accessible to a predator who takes little heed about Health and Safety regulations. Just as likely he could have become weak without means of getting out and starved. Either way there was nothing we could do further and it is, sadly, part of the course.Q left the quarry shortly after that and rejoined the other choughs. They now roost in the aviary and return for food provided by staff. They are very good at probing for insects as well and have been spending their mornings at Devil’s Hole on the other side of the valley to Sorel.We have even had a report of a group of eight birds at Les Landes Racecourse. We know from photographs that two of the eight were juveniles from 2014. These birds flew to Les Landes last October to explore but didn’t spend much time there. It will be interesting to see where they decide to go this year.

Action for Wildlife Jersey

We can only follow the young, newly released and naïve, choughs as they discover their new surroundings and learn to survive in the wild because they have tail-mounted radio transmitters. Each of these transmitters has to be bought and, unfortunately, doesn’t have a very long life. If the birds don’t lose their transmitter the battery will run out. We are lucky to ever find the old transmitters and anyway we are only able to change the battery once before the transmitter can not be further modified. So, we need a lot of transmitters, and this is a big area of our annual budget and this year we are extremely grateful to Action for Wildlife Jersey for funding our 2015 transmitter needs. In fact, the funds so generously provided, also allowed us to buy a new electronic balance to weigh the birds up at Sorel and check on their health.

A VIP visitor to Sorel

On 30th September we were proud to introduce leading author and journalist Simon Barnes to the chough flock. Simon, author of such notable books as How To Be A Bad Birdwatcher and Birdwatching with Your Eyes Closed (see the full list of Simon’s books here) was in Jersey for the 2015 Jersey Festival of Words and took time out to see the Sorel birds and hear about Birds On The Edge and the work being done to restore our habitats and give local birds a chance to survive.

Congratulations, it’s a….? Photo by Liz Corry

The DNA sexing results for this year’s chough chicks hatched in Jersey finally arrived this week. Less contentious than the recent Labour leadership election and just as tense as any Jeremy Kyle show, we have had to wait several weeks for the samples to be processed before receiving that long anticipated email.

Durrell use MDS (Pty) Ltd, a molecular diagnostics laboratory, for finding out the gender of birds that cannot be distinguished simply by plumage colouration or size alone. This is essential information for a successful captive breeding programme. You don’t want to have to wait several years before finding out Mr and Mrs ‘critically endangered Tweety pie’ are not producing any chicks because they are actually Mr and Mr. It happens.

With the red-billed chough it has been shown that it is possible to identify sexes based on morphometric measurements, namely leg (tarsus) length and body weight. There can, however, be a fair amount of overlap leading to uncertainty. We took measurements when the chicks were just over three weeks old and had already formed our own opinions within the team. We just needed to wait for genetic proof.

We can now reveal that Dusty, the first chough chick to be born in the wild in Jersey in over 100 years is…a boy! This is great news for the Jersey population as it means that in the next few years the potential number of breeding pairs will increase. This year we had two pairs attempt to breed. In a few years time when Dusty matures we could be looking at eight pairs.

CeCe the female hand-reared chick in July 2015 before she returned to the wildlife park. Photo by Liz Corry.

We are also pleased to announce that CeCe, our hand-reared chick, is indeed female as we had suspected. She is far too sweet and innocent to be anything else. Unlike Dusty who seems to be turning into a bit of a bully.

You can find out more about their progress in the upcoming September report.

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.