Chough report: May 2019

Breeding success for 2019

At the start of May, Toby Cabaret and myself carried out the first nest check in the quarry. It took a lot longer than last year (4 hour). Along with more nests to check there was a small addition of a film crew.

Action man Toby being filmed for a documentary. Photo by Liz Corry.

Tune in around autumn to hear more about that. Back to the nests…

We recorded eleven potential nests including one new location thanks to Kevin at Ronez who had been keeping an eye on a pair. He is also the ‘guardian’ of Red and Dingle’s building and has successfully convinced them to use the nest-box rather than the hot pipes. The negotiations have paid off – two chicks were visible in the nest on 23rd May!

Chough chicks, only a few days old, in a quarry nest box. Photo by Toby Cabaret.

PS. the camera in the photo has been knocked out of position by the parents so we can’t monitor remotely. The box was accessed at a predetermined time under licence. These chicks were too young to ring this month. We will return in June.

Quarry staff also confirmed Dusty and Chickay’s nest had hatched and that Green and Black looked to be feeding chicks. The former cannot be accessed without some dodgy ladder work. We have to wait to see what will fledge. Green and Black’s nest can be accessed only if you have a hydraulic crane and Ronez generously paid to hire one as there are several nests that require it. On 25th May Operation Test-out-Toby’s-crane-driving-skills was carried out. 

Kevin and new partner Wally (he must have a thing for hand-reared birds) have chicks. Her nest is one of the easiest to access and with the aid of a smartphone easy to check too…

Operation Test-out-Toby’s-crane-driving-skills

We checked Green and Black’s nest first; 3 chicks! They looked about four weeks old. We decided it would be too intrusive to fit leg rings as they could prematurely jump to their death if disturbed so we backed down (literally in the crane). Mum and Dad were watching over us and went straight in to feed them once we left.

Lee and Caûvette’s nest also contained three chicks. Toby managed to manoeuvre the crane tantalisingly close to the nest, but we were short by a few inches. My finger tips could just about touch the base of the nest if I stretched and leaned out of the cart. Actually removing a chick safely from the nest (not dropping it onto the rock pile 20ft below) was out of the question.

A frustrated Toby drove on to the next site. This time with more success. We checked the nest site belonging to Trevor and Noir. Last year they raised one chick but it failed to fledge successfully. This year they had three chicks in the nest. Licensed ringer Dave Buxton and trainee ringer Paul Pestana helped process the chicks with leg rings, biometric measurements, and DNA sexing. Hopefully all three chicks will fledge in a few weeks time.

Licensed ringer Dave Buxton training Paul Pestana to ring a chough chick. Photo by Liz Corry.

An exciting discovery at the start of May was finding out who was responsible for the ‘Mill nest’. We watched as Percy flew to the top of the external nest-box and fed a demanding Icho who had been waiting patiently inside. When he left, she went back inside the nest and we could hear chick begging noises. Toby had reported hearing chick noises previously, this visit appeared to confirm it.

On the 25th, with the assistance of the crane we went to access the nest to ring the chicks. This was the last nest to be checked that day and had been surprisingly quiet. As we slowly rose closer to the nest  entrance the only sound to be heard was that of the crane’s motor. Looking inside all we found were three cold, unhatched eggs. The nest had failed and the parents had abandoned.

A check of Percy and Icho’s nest found the chick to be missing and the remaining eggs had not hatched. Photo by Liz Corry.

I can’t end this section without talking about Tony’s mad crane skillz (with a ‘z’ like all the cool kids, sorry kidz). We wanted to check the building Kevin had been keeping an eye on. The day before Operation Test-out-Toby’s-crane-driving-skills (sorry skillz), Toby had spotted where the nest was located inside the building. Accessing it definitely required the crane. The trouble was how do we get the crane to the site with the various gangways and structures in the way. With mere millimetres to spare Toby drove the crane through the obstacle course and started taking us up. Removing the chicks from the nest safely was questionable as it required a fair bit of stretching. However, the dilemma was solved by taking a photo of the nest – the chicks were way too young to fit leg rings. And Toby had to tackle the obstacle course once again, this time in reverse!

The people on the ground managed to get a good glimpse of the leg rings on one of the parents. It was Pyrrho. We believe she is partnered with Skywalker. We give them another four weeks or so to see what leaves the nest. May the force be with them!

The Plémont family

There have not been many opportunities to monitor the Plémont nest. What we have seen has all been positive. Paul Pestana has kindly volunteered his free afternoons to keep an eye on them and has experienced a few cherished moments. Like watching Earl remove a faecal sac from the nest. To some, gross. To others, a happy sign that there must be a chick in the nest to produce the faeces in the first place!

Typical habitat to the east of Plémont – home to a pair of choughs. Photo by Liz Corry.

As the days passed and the chick(s) got older you could hear begging noises coming from the cliffs. Only of course if there was little to no wind and you were prepared to get perilously close to a cliff edge. By the end of May this nest was not far from fledging. If and when they do, we will need to monitor the site as closely as possible. The headland is accessible by the public who may pose a threat to bumbling fledglings, the nesting peregrine pair certainly pose a threat, and the steep plummeting drop to the rocky seas below…well that is all part and parcel of being a chough!

Catch-ups at the aviary

There have been several catch-ups at the aviary this month mainly due to health reasons. Two of the breeding females, Caûvette and Wally, managed to get their hind toes caught in their plastic leg rings. As has become the norm, it took a few attempts to get each female. Luckily no injuries had been sustained making it a simple case of unhook toe, refit ring, and release bird.

Wally was one of two adults needing to be caught this month to free their hind digit caught in their leg ring. Photo by Liz Corry.

Chewbacca was also looked at in the hand after presenting signs of lameness and general lethargy. Clinical diagnosis – attention seeking. That may be an unfair assumption he could have just been run down. Although the ‘lameness’ suspiciously swapped each day between left and right. Personally, it looked more like he was playing the ‘oh woe is me card’ at the supplemental feed resulting in more food being thrown his way. Remind me again, is it the choughs that are trained or the keepers?

Zoo chicks

Tristan and Penny’s eggs hatched at the start of May. As with all corvids it can take a day or two between eggs, so keepers had to wait a week before knowing how many chicks would hatch. Only one egg didn’t make it, leaving the parents with three hungry mouths to feed.

Everything was going well, both parents very attentive, until one day Tristan turned. Keepers watching the nest-camera footage could see that one of the chicks had died. Mum carried on feeding the remaining two chicks with the dead one left in the nest. Tristan started being aggressive towards Penny each time he returned to the nest to the point he was endangering both chicks and mum.

Keepers caught up Tristan and moved him to a separate aviary. They discovered he weighed 400g. Considering captive males normally weigh around 350g this may have been a clue to why he was behaving as he was. With some species, if the male takes on too much protein during the nesting season they become ‘randy’ for want of a better word. Eager to keep breeding even when the female has chicks which results in aggression often directed at the female and/or chicks. He might have been trying to tell Penny to get rid of the dead chick. We will never really know. Keepers are always trying to second guess their animals acting as chef, interior designer, GP, and psychologist on a daily basis.

Continued work at the aviary

The boring stuff – there are still several jobs that need to be done at the aviary. Net trimming, replacing rodent-proof mesh around doors and hatch frames, and replacing the fixtures removed when the old timber was ripped out. A lot of these require working at height with power tools therefore a second person and special ladders are essential for health and safety. By the end of May these jobs were still outstanding as it has been difficult to fulfil the H&S requirements.

Not helped by the additional job of net repairs. Deja vu? Yes, rodents have chewed holes in the brand-new netting. Apologies for any walkers at Sorel and beyond who heard my cursing that day. In just one night, eighteen small holes were chewed into the new netting along the north facing side of the tunnel. Whilst waiting for the guttering to be transported back up to the aviary another two holes appeared overnight on the other side of the tunnel. The guttering, unsightly as it is, is now back on preventing the rodents from reaching the netting from the outside. There is also a large hole in the middle partition at ground level. I suspect a rodent had become trapped inside the aviary when the rebuild happened and chewed their way out.

It is getting harder to capture the entire flock in one shot these days – a sure sign of success. Photo by Liz Corry.

Volunteer request

An advert went out asking for a volunteer to help with the gardening at the aviary. During the spring and summer months the grass in and around the aviary needs cutting on a weekly basis.

The bank around the perimeter also needs maintaining for the benefit of the wildlife and to keep the path for staff accessible. There is a considerable drop on one side that becomes hidden when the bracken grows up. One step the wrong way and it’s an undignified fall into bramble and blackthorn.

Volunteer needed for vegetation clearance at aviary. Sheep need not apply. Photo by Liz Corry.

Despite hay fever allergies I enjoy this job, but it does demand time and with no student placement this year I am finding it hard to keep on top of it. Several people have shown interest in the position, few can commit on a regular basis. Hopefully by June we will have found a suitable volunteer.

Private donors

We are very grateful to the De Lancey Foundation who gave a generous donation towards the running of the chough project. In return, a group from their board of trustees had a private tour of Sorel and our facilities. Their passion for conservation and knowledge on the subject was evident as we discussed the challenges faced and the achievements made to date. The Foundation is also supporting the head-starting of Jersey’s agile frogs at the Zoo.

Last but not least

A colleague took his young family to Sorel to see the choughs and Manx loaghtans. His son, a huge fan of the computer game Minecraft (no me neither), was inspired to create his very own red-billed chough character for the game. I think this has to be a world first! Well done Sam. Watch this space for the development of more Birds On The Edge characters.

A Minecraft chough created by Sam Wright after his visit to Sorel.

 

 

Chough report: May 2017

Wild flowers at Sorel. Photo by Liz Corry.

Jersey’s coastal habitat was home to spring lambs, wild flowers, and baby choughs this month. Here is what the choughs got up to. Or, as we can now call them, what the award-winning choughs got up to!

May the 4th be with you

On May the 4th the first of the three eggs in Issy and Tristan’s nest hatched. Staff were naturally excited and considering the date, the geeks amongst us (i.e. everyone), started putting bids in for Star Wars related names for the clutch.

Chough eggs hatch sequentially so we expected it to take a few days. However, the days passed and it became clear that this would be the only egg to hatch.

Han Solo was duly christened.

The parents were keen to remove one of the failed eggs. The other was left in the nest for quite sometime.

With only one chick to care for, Han Solo was well fed and grew steadily day by day.

Breeding in the wild

This year’s wall planner had a rather colourful month in store with various predicted hatch dates starred and scribbled in colour-coded marker. First off the blocks were to be Red and Dingle (hand-reared) who raised their first chicks last year. This year’s eggs were due to hatch around the first week in May. A change in Red‘s behaviour on 4th May suggested the eggs might have started hatching. Instead of waiting for the cue from Dingle, she was already waiting at the aviary for food in the morning. As soon as she picked up a mouthful of mealworms she zoomed back to her nest.

We asked Kevin le Herissier, responsible for ‘their’ building (Ronez naively still believe that the buildings are theirs not the choughs’), to check the nest the following week. This was to allow time for the entire clutch to hatch and so that the parents were not as sensitive to disturbance.

To our bemusement the photo he sent back was of a perfect nest containing four eggs.

Kevin_le_H_photo of Red nest

Red and Dingle’s nest early in May. Photo by Kevin le Herissier

A follow up check on the 19th also found four eggs. Guess what was found when the nest was checked for a third time on the 31st? Sadly, not a case of third time lucky. Still four eggs. Under license by the States of Jersey, these eggs were candled in the nest to find answers to what had happened, why they hadn’t hatched. One egg had failed during embryonic development while the others looked like they contained almost fully developed chicks. The eggs were returned to the nest.

New nest-site discovered

Student John Harding and Ronez operational assistant Toby Cabaret checked on the nests in the quarry on the 19th. Armed with a GoPro and a very long pole they checked nest-boxes and known nest sites. One of the nest-boxes we fitted in the quarry in 2015 had nesting material in it. What flew out wasn’t a chough though. It was a kestrel!

Most of the nests were just centimetres out of reach of the pole and suspiciously quiet. The team did, however, spot a female on a nest in a building not previously used by the choughs. With no wish to disturb her the nest was left alone. We now have the task of trying to work out which pair this nest belongs to.

A neighbouring building was also found to have a nest. This one didn’t have a female on it, but from the begging noises it was clear there were at least two chicks in there. Again this is a new site and new pairing.

This video shows Toby and John trying to use the GoPro to check the cheeping nest. They didn’t realise at the time how close they were to the nest. You can see the chicks.

They look extremely young. Normally we would avoid disturbing a nest at this age. From our calculations we expected any chicks to be a few days older. From their begging they look strong.

All nest checks are done under license from the States of Jersey.

Chick ringing and revelations

On the 31st we returned to the nest sites. This time with Channel Island ringer Dave Buxton in case the chicks were old enough to fit with leg rings. We were also armed with a new piece of equipment…a USB endoscope camera. It doesn’t provide HD images like the GoPro. However, it is equipped with LED lights and a lot more manoeuvrable (and only cost £25).

Toby Cabaret checking a chough nest with the Potensic endoscope. Photo by Liz Corry.

Three chicks could be seen with the endoscope plugged into a smartphone. Photo by Liz Corry.

Due to health and safety concerns, two nest-sites were out of bounds. We were able to check the nest with the cheeping chicks. This time eerily silent, although it was clear from the endoscope image that there were three bills. They still had pin feathers on their heads and from their size they looked no more than two weeks old. Too young to fit rings.

Before leaving the building John and Toby went a checked the next floor up on a hunch that there could be something. They were right! They found a nest tucked away behind girders.

Spot the nest? Photo by Liz Corry.

Despite a grainy image, the colour and shape of a bill could be seen and possibly a second body. The image below is a snapshot from the endoscope. The image is less clear than in realtime. You will be forgiven if you can’t spot the head of a chick.

Screen grab of endoscope view in nest showing the pale bill of a chick (far right). Photo by Liz Corry.

Whilst checking this nest Kevin and Bean flew in and appeared slightly aggrieved that we had discovered their little secret. The disappointment of the chicks once again being too young to ring was quickly overshadowed by this news. Bean is one of our hand-reared females released as a juvenile in 2014 and now, three years later, rearing chicks of her own!

Chough-watch

We received several reports of choughs out and about this month from members of the public. Of interest was a report of a pair from Tabor Park, St Brelade. They had been seen on the allotments, but flown before leg rings could be read. Five days later another report came in of a chough calling at the desalination plant by Corbiere.

We have radio-tracked choughs to the south-west before in 2014 and 2015. Since then there have been a handful of sightings around Gorselands, Le Creux and Red Houses.

Choughs on the move. Photo by Liz Corry.

Regular chough watchers Mick Dryden, Tony Paintin, and Piers Sangan reported choughs at Crabbé, Île Agois, and Grosnez during the day. We assume these are the sub-adults and non-breeders who don’t have commitments at the quarry. Without leg ring records we can’t be sure.

Grosnez to Plémont with Sorel point in the far distance: areas visited by the choughs this month. Photo by Liz Corry.

Personality research with Nottingham Trent University

Guille Mayor arrived this month to start his MSc research looking at personality traits in released choughs. He is trying to see if personality relates to dispersal distances and success in the wild. Part of his work will involve behavioural observation at the release aviary and how individuals react to a novel object.

The trickier part of his study requires him to find where the choughs go each day. He obviously likes a challenge since only three in 34 have radio tracking devices and Guille is on a bicycle. If you do spot a chough away from Sorel please as also let us know. Send an email, call 01534 860059, or post on Jersey Wildlife Facebook page. Location, date, time, and, if possible, leg rings need including.

And finally

British and Irish Association of Zoos and Aquariums (BIAZA) held their annual awards at The Deep in Hull this month. Durrell had entered four categories and came away with three gold and one silver. We are delighted to announce that the return of choughs to Jersey was awarded gold in the conservation category.

Many thanks to everyone involved over the years that have helped plan, raise, release, monitor, and protect the choughs, many of which have volunteered their free time to do so. And of course our partners at the National Trust for Jersey, Department of the Environment, and our extended chough family at Paradise Park.

BIAZA award 2017

Choughs at Sorel Point May 2017. Photo by Mark Sleep