We have an apology to make to our faithful readers. We have not been entirely honest with you over the past month. In May we reported that there were two nests in the quarry and that Mauve and White’s nest had not produced any chicks. What we didn’t tell you is that, in the same week of visiting their nest, we also took a sneak peek into Green and Blue’s nest.
Looking at potential chough nest sites in the quarry. Photo by Liz Corry
On 12th May we were taken to the nest site by Matthew Sharpe, (then Assistant Quarry Manager) of Ronez quarry. The position of the nest and its careful concealment meant that there was no way we could see into it.
We knew from the female’s daily routine that she was incubating. Not wanting to disturb her we patiently waited. The incubation period is about 19 days from the last egg being laid. We could only guess a start date for laying and allowed a couple of days error either side. Add to that a few more days post-hatch so we don’t spook mum and risk the nest being abandoned.
We had a long wait.
Accessing the nest required a scissor lift or cherry picker to be brought into the quarry. Site foreman Kevin Gray very kindly and efficiently juggled their work schedule to allow their pre-made plans to hire in the machinery to coinincide with our availability to check the nest.
On the 29th, with hard hat, high vis, safety specs, and a 1001 butterflies in the stomach I went up to find out exactly what Green and Blue had been up to over the past three weeks.
Green and Blue’s nest. Photo by Liz Corry
The first thing I saw was a very cleverly constructed nest, exactly how you woud expect a wild chough pair to build one.
Watchful parents. Photo by Liz Corry
Very proud of Green and Blue, who were watching on from above, my journey upwards in the cherry picker continued (at a comical pace) until I was level with the top of the nest.
It was a very proud moment as I gingerly peered in and said hello to a little naked chough chick.
The first sighting of Green and Blue’s chick. Photo by Liz Corry
From our experience with the captive choughs at the Wildlife Park we judged the chick to be about 4-5 days old. It is slightly tricky to judge as you are comparing hand-fed to parent-fed chicks housed in different conditions. However, the lack of emerging pin-feathers allowed for fairly accurate dating. All chough chicks hatch with a bit of ‘fluff’ on them, as can be seen in the photo above, but these are not the feathers.
Whilst this might seem like the perfect time to celebrate we had to be cautious. It takes about 42 days from hatch to the point of flying. In the last week or so before that flight the chick will be ‘bouldering’ around. This could be quite a tricky feat in an active quarry building especially when the nest is built on an overhanging steel girdle. There were potential hazards inside not to mention those outside. What if something happened to the parent(s)? Will there be adequate food for a chick?
Harriet with the free-living choughs waiting for their supplementary feed. Photo by Liz Corry
The latter was easy to control. Our supplementary feeding at the aviary meant the parents knew when and where to get food for the chick even if wild supplies dried up (quite literally as the weather gets hotter and the ground becomes harder). We can’t control what happens to the parents when they are out and about. We simply monitor their behaviour and look out for any signs of problems. Ronez helped where they could by keeping an eye on the parents and nest in the quarry.
Even lunchtimes became occupied with nest watches. Photo by Liz Corry.
When the chick was approxiately three-weeks old we paid another visit to the nest. This time to give the chick leg rings, take morphometric measurements, and get a blood sample for sexing. This is the best age to do this as the chicks are almost fully grown but not at risk of jumping out of the nest in panic. Licensed ringer Dave Buxton accompanied myself and Harriet into the quarry. This time Ronez had arranged the use of a scissior lift. We knew from the parents’ behaviour that they had still been taking food to the nest and as soon as we were underneath we could hear the chick calling away.
Once again with parents watching, I went up to the nest, this time to remove the chick so we could process it on the ground in a calm and safe environment. It was amazing to see the size difference between our hand-reared chick and this one. This chick was 70g heavier! We felt shamed as surrogate parents, but it is to be expected as chough parents are bound to be better feeders.
David Buxton rings Dusty at Ronez Quarry. 16-6-2015. Photo by Liz Corry
We will not know the sex until the DNA results come back from the lab, although we have started placing in-house bets based on weight and leg length. Regardless, the team at Ronez have already taken this chick to heart and proudly named it Dusty.
Dusty was returned to the nest as soon as possible and we quickly left the area so the parents could return to see that their chick was fine. Quarry staff fitted a hammock-style tarpauline underneath the nest to act as a safety net in case the chick was to fall out. Each day they would check the site at the start and end of their working day to make sure Dusty was ok.
Then on 2nd July I received an urgent text message from Harriet to call her as soon as I could. Two days after we lost our foster chick ‘Special K’ on the operating table I naturally feared the worst.
After a quick chat, and strict instructions never to leave me hanging like that again, my fear subsided and I rushed over to Sorel. Dusty was out!
Without us knowing, Dusty had left the nest-building and moved to the tallest building it could find. The parents were the give-away as they flew to feed it and then spent several hours trying to coax Dusty back down so they could roost in the safety and familiar home of the ‘crusher’ (that is the actual working name of the building!).
Like all toddlers Dusty was intent on ignoring its parents and stayed put. It will probably take a week or so of short practice flights before Dusty spreads its wings further. We fully expect Green and Blue to bring Dusty to the aviary and teach it about the supplementary food as well as how to probe for wild insects. We will be there every step of the way and as ever will keep you posted on its progress…we promise.
Thank you to everyone at Ronez whose support throughout the project has helped tremendously. We would also like to thank Paradise Park, all our colleagues in the Birds On The Edge project and all of the students and volunteers over the last two years as without them Green and Blue would not be flying free and have the resources they need to successfully breed in the wild. This is the first successful breeding attempt by choughs in the Channel Islands since the 1920s. With the continued help of the team and the people of Jersey we hope we can truely see the red-billed chough return to its full glory in the years to come.
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 30th 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 10th 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 30th 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…