Chough report: May 2021

Broken and faded leg rings used on choughs. Photo by Liz Corry.

By Liz Corry

Housekeeping

Another ‘catch up’ with the choughs this month. This time BoPercyTrevor, and Chickay all needed replacement leg rings. It provided an opportunity too to check their general health through body weights and visual inspection of feather and body condition.  

Happy to report they all looked well and it’s always nice to reconnect with Chickay again who we hand-reared back in 2014.

In contrast, we declared six adults and four juveniles (< 12 months of age) as missing, presumed dead. A few had been missing for a while; in particular, the juveniles who in this species tend to struggle to get through their first winter. Others like Beanie Baby had suddenly gone from their territory making it more obvious to detect the loss. An updated ID list for the Jersey flock is available here. 

Mystery chough in England

Of course one or more of the missing list may have taken flight off-island. No COVID-restrictions for them! A chough of unknown origin was spotted in Dorset early on in May. The video below was taken at Portland Bill near Weymouth. There was a later possible sighting on the Isle of Wight.  

 

The bird in Dorset was unringed and likely to be a Cornish bird dispersing along the coast. Devon have carried out a lot of habitat management to try and encourage choughs to disperse east from Cornwall, which might have helped this one to reach Dorset.

Whilst doubtful it was a Jersey traveller; I contacted the Portland Bird Observatory just in case. All our captive-bred released birds are fitted with transponders. A quick scan with a pet microchip reader would detect if a transponder had been fitted. This requires the bird to be in the hand, a long shot for Portland, but at least they now know about our project and can bear it in mind next time they have a surprise visitor. 

Choughs travel with Blue Islands airline

England did receive one influx of Jersey choughs this month though. The three males we bred in the Zoo last year finally secured passage to Paradise Park, Cornwall. Ever changing COVID travel restrictions in both the UK and Jersey had placed the export on hold for several months.

Pre-export checks include checking the chough’s transponder number matches the paperwork. Photo by Liz Corry.

Export routes are limited now because only certified ports are permitted live animal transfers. Portsmouth (ferry), Heathrow and Gatwick (plane) are the usual routes we use to transfer zoo animals between the UK and Jersey. Neither were an option this time around and after a lot of ‘blue sky thinking’, red-tape cutting, paperwork signing, and (I imagine) a magic 8-ball, our Animal Registrar managed to open up a route via Exeter. This relied heavily on the generosity of Blue Islands airline who have previously supported Durrell’s work. Port staff handling the transfer at Exeter were equally helpful and handed over the birds to David Woolcock who then drove them down to Hayle.

Once they clear quarantine, these males will join the non-breeding flock housed at Paradise Park and eventually be paired up for 2021. They may even find themselves travelling back past Exeter on to one of the planned reintroductions in Kent or the Isle of Wight.

Hatching underway in Jersey

The wild Jersey breeding pairs became very active at Sorel as hungry bills started to hatch out. We think that the first nests to hatch belonged to  Betty and Pyrrho and Percy and Icho. The males would be waiting at the aviary for the supplemental feed, snatch what they could and zoom back to their quarry nests. They would then return with the females to repeat procedure and spend the next hour or so flying back and forth roughly every five minutes.  

Females tend to stay on the nest for the first week post-hatch when the chicks are most vulnerable. Once they get their body feathers, mum will help in collecting food such as ant eggs/pupae, beetle larvae and, in Jersey, the supplemental diet of mealworms. 

Ronez Quarry reported a new nest in a building the choughs have not used before. We suspect this is Betty and Pyrrho since her last known nest site no longer exists. Ronez also sent through photos on 11th May confirming Dusty and Chickay had succeeded in hatching three chicks. These were the first to be accessioned in 2021 and given temporary names of PP066PP067, and PP068. Whilst not the most attractive of names it signifies that they are the 66th, 67th, and 68th chicks to hatch in the wild since the reintroduction began. 

Chough chicks around 17 days old) in the quarry. Photo taken under license by Toby Cabaret.

I should add that some chicks hatch out, die, and get discarded from the nest without us knowing, therefore, the total number hatched is likely to be higher. The same day we were given the good news about Dusty’s family, Ronez called again to say they had found three other chicks prematurely out of their nest.  

The nest these chicks were from is in a box in the secondary crusher building used by Green and his new partner Vicq. Standard procedure would be to return the chicks to the box and hope the parents continue to feed. This option was off the cards as access to the box requires a scissor lift and at 5pm, with hire companies closed, we had to think outside the box. Sorry, even I just sighed at that pun.  

Luckily Ronez had a spare nest box which they placed on the elevated walkway inside the building. One chick was wobbly to say the least when he was picked up. The other two seemed ok despite the fall. Whilst not ideal it meant the chicks were off the ground out of the way of gulls, predators, and morning site traffic. 

Unfortunately, the three chicks did not survive the night. I collected the bodies on the way to work for the Durrell vet to carry out post mortems. He believes at least one was still being fed by the parents judging by the quantity of undigested mealworms he found.

We don’t know how or why the chicks found themselves on the floor. I suspect the nest box is too small to provide adequate air flow in that quarry building which can lead to over-heating, aspergillus, and/or compromised breathing. We had planned to replace the box with a bigger one for the 2020 breeding season. Lockdown stopped that then and again in 2021.  

Even more of a mystery was what happened next with Green and Vicq. The day after the nest failed, Green was seen flying around with his old partner Pyrrho. Then Vicq reunited with her ‘best friend’ Lily who she spent most of 2020 preening and hanging out with.  

Plémont hatch-trick

Plémont Bay. Photo by Liz Corry.

We all needed some good news after that which is where the Plémont pair come in. Minty and Rey started behaving like new parents desperately looking for food around 14th May. There is sparse foraging habitat within the immediate vicinity of the nest. 

Bracken smothers most of the land in the immediate vicinity of the Plémont chough nest. Photo by Liz Corry.

However, 800 metres away at Les Landes there are fields grazed by horses and the racecourse next door. The male could be seen making regular visits to this site whilst the female remained with the nest. 

The Plémont pair source food for their chicks from paddocks like these around Les Landes. Photo by Liz Corry.

On a visit to the nest on the 19th, I heard the unmistakable sound of a begging chough chick. Too young to be visible. The parents on the other hand were visible. Especially if the raven family flew past. Minty has done a sterling job of keeping the nest predators away shouting at any who dared to go near.

Choughs are expert rock-climbers. Photo by Liz Corry.

By the end of the month, we had visual confirmation of chicks in the nest. Minty and Rey were still busy feeding and nest visits every five minutes gradually changed to every twenty minutes or so as the chicks grew and gained strength. The site of a parent carrying away a faecal sac from the nest is a joyous one. To a select few I guess. We are extremely excited to see what June has in store.

Rey, the female chough brooding chicks at Plémont. Photo by Liz Corry.

 

Chough report: April 2018

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Choughs are now frequently foraging on the southwest tip of Jersey. Photo by Dave Warncken .

by Liz Corry

There is a hashtag floating around the social media stratosphere at the moment, #conservationoptimism, which pretty much sums up this month’s chough report.

When the reintroduced choughs started breeding in the wild in 2015 there were just two males and four females. Three years later we have twelve pairs all eager to contribute to the growing population. Furthermore, two of those pairs have decided to branch out and nest in other parts of the Island.

Nesting ambitions of Jersey’s choughs

A male displaying to his female to encourage ‘sexy time’. The female reciprocating with a suitably unimpressed look. Photo by Elin Cunningham.

We have been able to identify a record number of ten nest sites this year.

Specific details of nest localities will remain guarded in order to protect the pairs. I can, however, let you in on some of the ‘highlights’ we have witnessed in April.

All of last year’s sites in Ronez Quarry are being used again with slight tweaks here and there.

There is concern for Red and Dingle as they are using the nest located on hot piping again. Ronez Quarry are helping us look into ways of raising the nest off the pipes without destroying the integrity of the nest. We wouldn’t want their eggs to overheat like last year.

Red and Dingle’s nest guarantees chicks won’t fall out – providing the eggs survive the heat from pipe work underneath. Photo by Liz Corry.

Dusty has strengthened his bond with Chickay after Egg died and continues to use the upper quarry away from the hubbub of the other nest sites. They have built a very nice nest which should be easy for us to monitor.

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Ronez Quarry with Sark in the background. Photo by Liz Corry.

The first nest located away from Sorel was discovered by one of our zoo keepers on their day off. Anyone visiting Plémont in April will more than likely have heard if not seen a chough or two. In the months leading up to the breeding season we had assumed it was the Les Landes pair. And more often than not it had been. However, on reading the leg rings of the twig-carrying choughs it was clear we had a different pair.

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Plémont Headland. Sorel Point lighthouse just about visible in the background. Photo by Liz Corry.

Finding the nest was a little trickier and not for the faint hearted. It is within the Plémont seabird protection zone which imposes public access restrictions from March to July. Plémont’s cliffs, notorious amongst Jersey’s rock climbers, are described as being ‘Weetabix’ like in structure and to be avoided at all costs. All in all there should be little human disturbance at this site adding to our growing optimism.

Not only is this the first nest discovered away from the release site, it is the first to belong to one of our foster-reared females – Xaviour! She has partnered with a male of her own age, Earl, and as such we are not expecting too much from them. At two-years old they are first timers with no knowledge of exactly what is involved in parenthood.

Regardless, this is a small victory for the project; foster-reared birds can pair up, they can build nests, and not just any nest, a truly wild nest. Fingers (and primaries) crossed for the next few weeks.

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A male chough displaying his ‘excitement’. Photo by Liz Corry.

The record-breaking didn’t stop there. The choughs added a third parish to their tick list of breeding sites. Mary and a wild-hatched male from 2016 were found to have moved roost site 7km to the parish of St Peter. They have been a fairly permanent feature of Simon Sand & Gravel Ltd since last year. Jason Simon, Managing Director, reports seeing three choughs around, but of late one had been ‘pushed out’ by the pair.

Simon Sand & Gravel Ltd located in St Ouen’s Bay is home to sand martins and now choughs too. Photo by Liz Corry.

Two choughs have taken up residence at Simon Sand & Gravel Ltd in St Ouen’s Bay. Photo by Elin Cunningham.

Twigs are visible in the location where the pair roost. It could be a red herring as the site is also used by pigeons. From observations, Mary appear’s quite faithful to that particular spot.

The pair continue making the return trip to Sorel for the supplemental feed. You would assume from this that they are not finding what they need in the wild travelling at least 14km a day for the guarantee of food.

Not so. Thanks to several public sightings, and wonderful photographs, we know that this pair are frequenting Corbière, the southwest tip of the Island.

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Wild-hatched chough hanging out at Corbière 21st April 2018. Photo by Dave Warncken.

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Mary and a wild-hatched chough have become permanent residents of the southwest corner of Jersey. Photo by Dave Warncken.

Funding for nest monitoring awarded by the Ecology Trust Fund.

JerseyEcologicalFund

We are very proud to receive funding this month from the Ecology Trust Fund.

This is a Jersey-based  fund established in March 1991 by the States of Jersey with a sum of money received in an insurance settlement from the Amoco Cadiz oil tanker disaster of 1978. Annual interest accrued is used to finance multiple projects each year within the environmental sector.

The money will be used to purchase equipment to help the team monitor chough nests around Jersey. Increasingly important as our birds ‘leave the nest’ and set up home around the Island.

Island Insurance Corporation awards

CaptureStaying on a funding and monitoring theme, we are very honoured to hear that Ronez Quarry have nominated the chough project for the Islands Insurance Corporation Conservation Awards. The choughs have frequented the quarry since the trial release in 2013 which is now permanent residence for several pairs.

There are prizes to the value of £1000 and £500 available. If awarded, we will be able to cover the costs of monitoring, ringing, and sexing the wild-hatched chicks. DNA sexing tests, for example, cost £14 per bird.

With 10 potential clutches this year the costs could soon spiral.

Judges will visit the short-listed projects in May after which voting will open for the People’s Choice Award. We will circulate details as soon as voting opens.

Replacement rings

This chough had lost both plastic leg rings. The unique metal ring is impossible to read at a distance. Photo by Liz Corry.

As previously reported, several of the choughs have been losing their plastic rings. Or in the case of Zennor switching them around. As if the team needed more of a challenge to monitor breeding pairs!

On 26th April a group of choughs were caught up at the supplemental feed. Nine of the 25 birds arriving for food were caught up, weighed, and given new replacement rings. White was the only exception in that we had run out of white rings and given grey instead. Off-White if you like.

They all looked to be in good health. None of the females sported brood patches to suggest they had started incubating. I suspect that will have happened towards the end of the month or early May.

We still have two birds requiring replacement rings. They happen to be two of the four now living away from Sorel. Unlikely we wil get them in the aviary anytime soon.

Zoo news

Change is afoot with the Zoo choughs. We are exchanging chough pairs with Paradise Park, Cornwall, as part of our wider departmental collection plan. Paradise Park have kindly agreed to take Lucifer back after loaning him to us in 2012. Hopefully they can address his egg-smashing behaviour.

Jersey Zoo will continue to house two breeding pairs; Tristan and Issy and a new established pair. The move has been delayed until May which will disrupt the breeding season. With a quarantine period of thirty days it is unlikely the new pair will breed at Jersey this year.

Tristan and Issy remain in the Zoo’s on-show aviary and have already started nest building. Keepers found a discarded egg and the nest-liner on the floor of the aviary towards the end of April. Something obviously unsettled them, but they have started gathering wool again to repair their nest.

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Tristan and Issy collect wool to line their nest in the Zoo. Photo by Liz Corry.

Foster rearing might not be on the cards this year

Gianna is making good progress since her cataract operations. It was clear that she had regained sight post-op, but she was not her normal self. At lot was due to a knock in confidence. Living in the dark for several months and then placed in a different enclosure must be disorientating. She also behaved in a way that suggested her depth perception was a little off. Over time she has improved although it could take a couple more months to be fully adjusted.

 

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Gianna enjoying her morning preen. Photo by Liz Corry.

She is now in the off-show foster aviary allowing her to go through the motions of nest-building and such. A great deal of enthusiasm has been expressed although she still doesn’t have a complete nest. By now she would have finished and be eager to start laying.

Tristan and Issy did not need any assistance last year with raising their chick. As the only active breeding pair this year it is unlikely we will need Gianna’s help. Only time will tell.

That, and May’s monthly report!