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….

By Liz Corry

February, normally a relatively quiet time in the chough calendar, quickly became action packed. It started with the first snow of the season, the first ever for the chicks.

The choughs searched out snow-free ground to probe in this month (they obviously didn’t look behind the gorse!). Photo by Harriet Clark.

It quickly became apparent that the field staff were more excited by this than the birds. All the choughs cared about was finding food.

In the wild, choughs don’t tend to fare too well if the ground freezes because the surface is too hard to probe. There wasn’t much snow in Jersey, but enough for the choughs to start looking for exposed ground.

Even if the birds can dig below the surface, ground temperatures are not particularly favourable to the insect communities. This was evident when the pitfall traps were collected in by the students. Most were empty to the dismay of the sheep who obviously thought they might be full of food.

Naturally the choughs became more dependent on the supplementary food we have been giving them. The fact that no individuals have died over winter due to starvation is in part a testament to how post-release care is important for a successful re-introduction.

Chickay getting stuck in to her aviary feed. Photo by Liz Corry.

Knowing that we want to release more choughs this year and the next, we have started to prepare ourselves, and the choughs, for what happens if there is too much competition in the aviary at feed time or if the original cohort disperse further afield.

Food stands in the aviary field reduce competition for food in the aviary. Photo by Liz Corry.

We continue to use the external food stands in the field to create multiple feeding sites, thus reducing competition.

Especially from the bold, hand-reared chicks who zoom to the bowls first.

Whilst we might have the odd magpie attempt to masquerade as a choughs to get free food we have not had any problems with other species taking food.

Song thrushes arrived back at Sorel this month and spent most of the time in the aviary field filling up on insects. Photo by Liz Corry.

The dozen or so song thrushes who visited the aviary field this month did take a shine to the food stands. I’m guessing their interest was in any spillage underneath.

Or maybe the sheep ‘fertilizer’ has created an insect hotspot which meant they favoured that field over others!

We have started taking portable target boards out onto the grazed headland to get the choughs used to feeding elsewhere. We might get individuals or pairs dispersing far away from the aviary and we want to guarantee we can get the supplemental food to them if they don’t return to the aviary.

Initially we treated it as a test. Have they just become accustomed to being fed in the same places each day or would they recognise a target board at a completely different location? Their corvid intelligence shone through and they eagerly flew to the targets wherever we put them. So far we have only tried relatively close to the aviary. As their success in finding the targets continues we will try further afield.

In the wild, the chough breeding season kicks off at the end of February or early March if the weather is mild. Breeding pairs are gathering materials and building their nests to rear their brood over the following three months if successful. Some of our original choughs released in 2013 are now sexually mature and we have two pairings with potential to breed. Over the next few months we will be following Green and his partner Blue very carefully along with White and his partner Mauve.

To aid in this, as mentioned in January’s report, we have added a radio transmitter to Green, the oldest male in the group. By doing this we were quite surprised to find out that he has been roosting in the quarry buildings. From our observations the previous few months we have always seen White and Mauve fly to the quarry at night and Green and Blue hang around the aviary.

Some of the structures in the quarry that the choughs like to hang out on at weekends. Photo by Liz Corry.

It might be that this move to the quarry is recent. Although what we fear is that the pair have tricked us and quietly sneaked out seconds before everyone else has gone to roost. Visibility at dusk is poor as you can imagine and we watch from a distance to avoid disturbing them. The only guarantee is if we can hear their transmitters beeping away in our headphones. It also helps having ‘spies’, otherwise known as quarry workers, who keep you informed on how many choughs are waiting for them when they start work at 6am.

We were told that four had roosted in the quarry the day we started radio-tracking Green. Presumably the fourth bird is Green’s partner. If not, I think someone needs to break the news to Blue!

Ronez Quarry have been a huge support throughout this project and this month was no exception. They provided funding to build nest-boxes for our inexperienced choughs who might want to nest along the north coast but could be looking for boxes, just like the ones they were reared in, rather than natural crevices. This could be the case for the first year of breeding. Then, as they build in confidence and experience, they will happily use natural sites.

Since we have birds roosting in the quarry already we suspect that they might try to nest on the rock face or in the buildings. If the latter we need to provide them with somewhere safe and sheltered from the dusty working environment.

Glyn Young, Durrell, and quarry site manager Kirsten DuHeaume in Ronez quarry. Photo by Liz Corry

We spent a couple of days surveying the quarry for potential nest sites with manager Kirsten DuHeaume, and foreman Kevin Gray. We also had to consider which sites were feasible from a health and safety perspective.

Blasting rock for quarrying purposes can leave hidden fractures in surrounding rock faces. What might seem stable from the outside is actually far less when it comes to working on it.

Some buildings which looked suitable could not be reached to place the box high enough for a chough to consider using it. We managed, however, to find a few suitable sites and the rest of our boxes were distributed along the north coast.

Ronez kindly provided the use of their machinery as well as their staff to operate it. Not only that, but they paid for Tony Cross to come over from Wales to advise and assist with fitting the boxes. Within seconds and with precision and skill, Kevin Le Herrissier designed a couple of steel supports to aid in fixing the boxes in place. Tony assisted in positioning the boxes and adding handfuls of gravel, the equivalent of ‘soft-furnishings’.

Kevin Le Herrissier and Tony Cross preparing a nest box. Photo by Liz Corry

The boxes, designed by Tony Cross, were built off-site by two volunteers, John and Mo, who work in Durrell’s Maintenance Department and, thanks to Steve Luce, by La Moye Prison. The prison have previously built nest-boxes for other projects but this time it feels more poignant since La Moye was the last recorded breeding site for wild choughs in Jersey.

Due to the sensitivity of the choughs and to safeguard their survival we will not be disclosing to the public the exact locations of the nest-boxes or any natural sites they use. Licences are required in the UK, just to take photos at chough nests as a certain level of legal protection is needed to deter egg-poaching.

Tony Cross watching the choughs for cllues as to where they might nest. Photo by Liz Corry

Of course the choughs are free to choose where they go and sometimes, as with the quarry, it can become quite obvious.

For now, here are a few photos to give you an idea of what we got up to. Needless to say don’t try this at home unless you are equipped with a fully operational Tony Cross. We also had help from our project partners in the form of National Trust ranger, Neil Harvey, and the States of Jersey’s principal ecologist John Pinel, an experienced climber.

I must also add that we have permission from the landowners to erect these nest-boxes. A requirement for anyone wanting to put up a nest-box.

Tony and his colleague Adrienne normally have to risk life and limb abseiling over cliff edges to erect nest-boxes for choughs.

This time Ronez lent a ‘helping hand’….

Kevin assisted in fixing the boxes. With steel brackets and bolts into the rock I don’t think we will have any problems with boxes falling down!

Some boxes just need to be dug into the top of the cliff edge.

Others can be a bit trickier….

…which is where the extra bodies came in useful. Much to the ‘delight’ of Neil!

and always of course under the supervision of the choughs.

In fact I started to get a bit paranoid by their stalking. Hopefully it meant that by the end of the day they had made a mental note of all the box locations.

Preparing for the breeding season in the Wildlife Park

Preparations for the breeding season have also been underway at the Wildlife Park. Once again we hope to hand-rear and parent chicks from our captive-breeding pairs which can then be used in this year’s soft release.

Two breeding pairs have been moved to their off-show aviaries. Gwinny has stayed paired with the same young male as last year. True to the Celtic legend Tristan and Iseult have reunited and, no pressure here, but since they have produced eggs together in the past we have huge expectations for this pair.

At the start of February we imported a new male from Paradise Park. Denzel, named by his previous keepers, moved into our quarantine enclosure where he must remain until he has been given the ok from our vets. We are hoping he will pair up with our single female to make a third couple.

The nest cameras have been switched on and all the birds have now changed to their breeding diet which means more protein is added to the menu. We will have to wait until March to find out if the pairs decide to build nests.

Gianna, meanwhile, is waiting patiently for when they do in case we need to call on her services as a foster mum. We are still at the very early stages of her training. She is starting to allo-preen staff now: a sign of a pair-bonding in the bird world. She might not reach the stage this year in which we are confident with her foster-rearing abilities. However, we would certainly like to think she can aid the breeding programme in the future.