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: June 2018

By Liz Corry

Breeding success

The choughs have been busy ‘behind the scenes’ resulting in a record-breaking breeding season. By the end of June, we had found four active nests with a total of ten chicks. We knew four chicks had hatched at the end of May. We didn’t have to wait long before Ronez Quarry sent photos of a second nest with chicks.

Dusty and Chickay’s nest with three chicks safely tucked away in a quarry building. Photo taken under license by Toby Cabaret.

This nest belonged to Dusty and his partner Chickay: an astonishing and heart-warming sight. This was their third season nesting, finally they had chicks, and from the looks of things they were at least three weeks old.

The icing on the cake is the uniqueness of the coupling. Chickay was hand-reared, proving that our choice of methods worked, and Dusty is himself a wild-hatched chick.

Ronez hired equipment to access the chough nests under license. Photo by Liz Corry.

A site-visit was arranged for 16th June when the quarry was not in operation. Ronez hired a cherry picker to access the nests. What we found was a mixed bag of good news and bad news. Some nests had failed, some succeeded beyond expectations. And then one complete surprise; a nest we had no idea about.

This nest contained one chick approximately four weeks old. We also noticed twigs in a nest-box we had put up in 2014. This is the first time the birds have tried to use this box. Either they decided it wasn’t a suitable place to continue or the pairing just didn’t work out.

The table below aims to answer any queries the dedicated reader has about which pairs succeeded.

Pair Bred before? Nest status
Green & Black Yes empty
Dingle & Red Yes empty
Kevin & Bean Yes 3 chicks
Dusty & Chickay No 3 chicks
Q & Flieur Yes empty
Lee & Caûvette Yes 2 chicks
White & Mauve Yes empty
Trevor & Noirmont No no nest found
Pyrrho & Percy No empty
? & ? 1 chick
Total 9 chicks

 

However it also throws up a few queries, like “didn’t Kevin and Bean have four chicks in May”? Yes they did. Sadly one is no more, probably the runt of the clutch, but to have three chicks still alive and well is a first for Jersey’s choughs.

The nest belonging to Lee and Caûvette was found to contain two chicks. Photo by Liz Corry.

You might also be tempted to ask “does the mystery chick not belong to Trevor and Noir“? That, dear reader, is something I still don’t have the answer to a month after the site visit. And one that is driving me insane so lets return to June 16th; life was simpler then.

We had taken a licensed ringer into the quarry with us so we could ring the chicks and get DNA samples for sexing. This is supposed to be done when the chick is around three weeks of age. Clearly from what we were seeing these chicks were older. We did not want to risk disturbing them for fear they prematurely left the nest once we put them back. It is a long way to fall!

That is ok, we thought, we can just ring them once they reach the aviary. We can see which adults feed them and work out ownership that way.

How naive we were.

Fledged chough chicks reach the aviary

Below is a montage of footage taken during the supplemental feed once the chicks had fledged. Imagine having a baby that can fly and walk and scream for food whilst doing said actions. Then multiply by two or three. That is what it’s like for a chough parent for the first few months. Note how loud the begging starts off then trails away. Always lingering, never stopping.

From appearances, Chickay was not keen on parenthood. She left most of the feeding duties to Dusty. One of our daily reports records an observation of Kevin “karate kicking” a chick in response to the constant in-your-face begging. Quite often at the feeds you would see chicks accidentally push the parent off the food-stand or shelf in the frenzy to beat its sibling to the food on offer. You also saw them beg at non-breeding individuals who looked more than a little perplexed by the situation.

Throughout all this, the three newbies (Han SoloChewy, and Skywalker) remained locked in quarantine in one half of the aviary. We could not attempt to catch-up and ring the wild chicks until the three had been released. That was scheduled for July.

All we could do in the meantime was try and figure out how many chicks each set of parents had. Lee and Caûvette made things easy as they continued to visit Les Landes and Grosnez, taking their chicks away from the mayhem for a few hours each day. We knew both of their chicks seen on the 16th had survived and arrived at the aviary the last week of June.

Family portrait: Lee and Caûvette with their two chicks at Grosnez. Photo by Mick Dryden.

Lee with his two noisy chicks. Photo by Mick Dryden.

Dusty and Chickay were tending to three chicks (well Dusty was at least). They would take them back and forth between Sorel and the south-east corner of the quarry. Initially there was concern over one of the three chicks as it looked relatively lethargic. We put this down to the heat and that it could be the youngest, struggling to keep up. Dusty was always very sensible, taking his chicks into the shade to rest.

Dusty and Chickay keeping their chicks in the shaded parts of the quarry. Note the chick lying down next to dad whilst the other two preen next to mum. Photo by Liz Corry.

Kevin and Bean‘s three also made it from nest site to Sorel. However, they made it a little harder. Most of the time their chicks were kept around Sorel Point. Often out of sight, but not earshot. 

View across the quarry from Sorel Point. Photo by Liz Corry.

Then the mystery deepened. Q and Flieur turned up to the supplemental feed with two chicks. “But their nest was empty?” you cry. Yes, yes it was. “And the surprise nest only had one chick in it?” you answer back. Yes, yes it did.

The Plémont pair

Earl and foster-reared Xaviour, or the Plémont pair as we call them, are still roosting out at Petit Plémont. Their amazing choice of nest site has made it impossible to tell exactly what they have been up to this breeding season. We did suspect, from the couple’s behaviour out of the nest, that the female was incubating eggs.

Earl taking a break on the WW2 bunker ruins at Petit Plémont. Photo by Liz Corry.

One was seen carrying something white away from the nest. An optimistic observer thought it was a faecal sac. These ‘sacs’ are produced by chicks and carried away from the nest by the parents. He changed his mind when he saw the adult pecking away at it. The white object started to look more like an egg, but smaller than a chough egg. Out of reach of the observer, we will never know the true-identity of the object.

In the days the followed, hope of a successful nesting attempt began to fade. Xaviour was spending more time away from the nest. Foraging around the headland and neighbouring cliff tops to feed herself rather than take back to an expectant nest.

The pair are young. This year should be taken as a positive step forward in their development. They remain the first pair to set up a territory away from the release site. As they mature they will no doubt see success with their nest.

Star Wars saga continues

Han Solo, Chewy, and Skywalker continue to adjust to life at Sorel whilst in quarantine. Faecal samples from the two Paradise Park birds tested positive for nematodes.

Staff began to hear sneezing from the confined group a week or so after their arrival. Nothing to cause alarm, but enough to warrant a wormer pre-release.

This was scheduled for 20th June. On the 17th the Bird Department received a call to say that there were only two choughs locked in the aviary. Skywalker was missing. Scanning the aviary, it became apparent that he had not used Jedi mind tricks to escape. He had in fact managed to squeeze out through a hole in the netting, no doubt created by rodents.

He was not with the free-living choughs at Sorel. Well not in plain sight at least. The following day he couldn’t be any more obvious if he tried. Skywalker was on the roof of the aviary alongside Zennor a young female.

Since the boys arrived at Sorel, Zennor has shown a keen interest in them. She sits, on the opposite side of the netting during every feed whilst everyone else is tucking into their meal. We thought her interest was in Han Solo as they had touched bills through the netting; fiction becoming reality? Alas, it was Skywalker she wanted which worked to everyone’s advantage as he had another chough to follow, returned to the aviary, and we managed to get him safely back inside.

Return of the Jedi: Skywalker shortly after being trapped back inside the aviary. Photo by Paul Pestana.

All in time for the vet to visit on the 20th, give all three a wormer, and fit Han Solo with a transponder chip just like all the other captive-bred birds have. Bird Department staff also kitted them out with shiny new leg ring combos to make it easy to tell them apart once released.

Luckily the States Vet agreed that no extra time needed to be added to their quarantine period. Once complete, at the end of June, they can be released.

May the force be with them.

Aviary maintenance

Despite the recent rodent-proofing at the release aviary there are still weak points in the defences. As exemplified by Skywalker’s escape. Without a major overhaul of the aviary design there is not much to be done.

Mind you, that overhaul may come sooner than imagined. The shelving has now warped so badly that bolts keeping the hatches closed no longer reach. The hinges on the external keeper door snapped right off due to rust.

This is the first year the pre-release group have not had full access to the flight tunnel in a bid to avoid further premature releases. Once the new boys have been released and settled into life at Sorel we can start repair work.

Supplemental feeds

The choughs have seen a few changes to the menu this month due to food shortages. There is still no Remilline pellet in stock in Jersey, so the egg-based diet returned to the menu. The live-food manufacturer has been experiencing issues with their mealworm stock resulting in fewer or no insects being delivered. Not the best of timing. We had to increase the amount of supplemental food this month in response to an increasing demand. Obviously with mouths to feed, the breeding pairs become more dependent on the aviary feed.

Lights, camera, action

Ronez Quarry very kindly funded young film maker Sam Hertzog to fly to Jersey and produce a short film about the chough reintroduction project. Sam had four days to try and sum up the last five years into a seven minute documentary. To make the challenge that little bit harder we threw in rolling sea fog, a field manager dying of hay fever, and birds that never paid attention to the script.

Sam succeeded. You can view his film below. We are very grateful to his friend Elin Cunningham for proposing the idea and for being the boom operator, gaffer, assistant director, chauffeur….