By Liz Corry
On 3rd October the choughs inside the release aviary were given access outside to join the free-living flock. Chick S is still missing presumed dead so the radio-tracking study will focus on the eleven remaining captive-bred juveniles of 2016. This includes Trevor, Durrell’s parent-reared male, already at liberty with the older birds. However, our primary concern during the first week of the October release was ‘simply’ making sure the six Paradise Park birds survived.
The four foster chicks knew what to expect due to their summer outing shortly after fledging. The six birds from Paradise Park had to take a leap of faith. For a few it was obvious that the situation was overwhelming. The physical stress of flying outside of the aviary parameters started to show quite quickly.
Earl took to the air after a period of contemplation on the outer shelf. His flight was quite laboured compared to the birds with several months flying experience. He flew continuously making several loops high above the aviary and started flying open-mouthed implying shortness of breath. When he finally landed back at the aviary it took him several minutes to compose himself, standing on the shelf, mouth wide open, before venturing back inside to feed.
One of the females, Yarila, acted in a similar fashion. She flew non-stop for almost an hour flapping back and forth between Sorel Farm and Mourier Valley whilst the other 34 choughs paid her no attention. Almost certainly peregrine fodder, fortunately for her they were occupied elsewhere. Yarila is the name of a Russian deity symbolising spring (and an anagram of Ali and Ray). Fingers crossed she makes it through to the spring if she keeps up antics like that.
The foster chicks also appeared to have had a hectic first half hour. Hopefully more out of excitement than stress. Very quickly they settled back into life outside the aviary, foraging together or joining the adults in flight around Sorel. They chose to roost back at the aviary which helped calm the nerves of the tracking team.
Duke and Earl are two males from Paradise Park and very important for the future of the wild population. No surprises then that these two deviated from the plan. After recuperating in the aviary, Earl took flight again following a group leaving the aviary towards the quarry. Radio signals suggested he was with the group flying around the quarry which put the tracking team at ease and allowed the focus to shift to Duke who had wandered off to the cliffs.
The radio signal for Duke suggested he was part of a trio hanging around the top of Sorel Point. As the team crept closer with binoculars primed, the choughs took flight and dropped behind the point. Half an hour before sunset Duke reappeared, alone, on the cliff-top near the aviary. We know from previous releases, that if the bird is not at the aviary as the sun is setting on their first night out they start to panic. They look for an alternative roost site within their immediate vicinity which might not be appropriate, but it is the only option they see. Duke had settled in an area where we have a nest box secured on the cliff face. When his signal disappeared at sunset we had to hope he had found the box and was sheltering at the back.
Returning at sunrise we found that Duke‘s signal was coming from the same area. We tried to scour the area as best as possible, bearing in mind sections of shear cliff and thick vegetation physically blocking areas and the cliff structure bouncing/blocking radio waves. We started to fear the worse after two hours of the signal behaving as if the bird (or transmitter) was stationary. Suddenly a chough flew up out of nowhere, called, then disappeared. Was this Duke or one of the others who had been foraging nearby? At 10:30 the student went off to prepare the dishes for the morning feed at the aviary. Much to everyone’s surprise Duke was at the aviary flanked by the other Paradise Park chicks. He didn’t seem quite at ease, but must have been as relieved to be back as were we.
At the same time as searching for Duke we had to find out what had happened to Earl. His signal was still at the quarry despite all the other quarry roosting choughs dispersing at dawn. Trevor and sixteen other choughs had entirely vanished. No sign of them at Devils Hole or Crabbé. The three breeding pairs and their chicks were foraging with the newbies at Sorel. Earl was alone. As with Duke his signal was not changing location but it was behaving as if he was moving. Possibly short flights back and forth. Yet not a single chough in sight. The good news was that he had gone to the side of the quarry where others have in the past and we can get supplemental food to them (via a catapult). The bad news was that it was also the same place where Ronez perished last year.
As the sun was setting 24 hours after Earl had first arrived at the quarry, a large group of choughs flew into the quarry. They started foraging for food in the same area where Earl‘s signal was coming from. A total of 27 choughs were there including the foster chicks. He had to be in that group. Surely this meant he would roost with either the quarry group or follow the foster chicks when they headed back to the aviary to roost.
Nope. Day 2 began like groundhog day. Earl alone in the quarry, Trevor and a large group off travelling the Island, and the remainder at the aviary. The major difference was at 9am when suddenly Earl appeared, sat on a rock. Jumping into action, chough food was catapulted over the fence towards Earl. Initially he seemed oblivious, then noticed the food and started eating.
We paid him another two visits making sure he kept his energy levels up throughout the day. Then at 3pm a group of 19 choughs flew in from the direction of the quarry and landed at the aviary. One of which was Earl. Unfamiliar with the concept of walking on netting he edged his way slowly across the roof to re-join the Paradise Park chicks.
The rest of the first week outside was relatively uneventful. The newbies stayed around Sorel along with the breeding pairs with occasional visits to the quarry or Devil’s Hole. It was Trevor and other choughs who caused fun and games for the tracking team. We knew the older birds had been visiting other areas along the north coast thanks to a couple of public sightings. Once we started radio-tracking again from dawn until dusk it was evident the visits were common place.
Even before the sun had risen over the horizon a group had set off to find breakfast at Les Landes. They visited the race course at Les Landes last autumn. This time round there are more of them and the consistency of their visits is fairly promising. They are expanding their range and who can blame them with managed grassland potentially rich in invertebrates thanks to the dung produced from the resident cows in the middle of the track and the visiting horses.
It is a difficult area to keep track of exactly how many choughs are present. It may look flat, but there are plenty of dips, dents, and barriers to visibility. The most challenging being when they land in amongst the heather as you can see below.
Public sightings of choughs
Other areas regularly visited by the choughs this month have been Crabbé shooting range, L’Etacq just south of the race course and the Model Aircraft Field. There is a prize up for grabs to the first person to get a photo of a chough taking off from that runway! They have also been seen flying over Plémont to get to or from Les Landes. No one has yet reported seeing a chough feeding at Plémont. The habitat restoration work carried out at Plémont by the National Trust for Jersey should make it more attractive to the choughs over the next few years. If not sooner.
We are starting to collect a few intriguing sightings in areas where we wouldn’t typically expect to see the choughs, but not impossible considering the size of the Island. They tend to be a single bird flying overhead, making it impossible to identify the individual. It also means we cannot be certain if they are using that area or just flying over en route to another location. Either way we are urging Islanders to keep an eye out in St Lawrence and Trinity!
Of course it doesn’t help matters when the birds you are tracking drop their radio-transmitters. After only two weeks Zennor lost her radio-transmitter. It dropped close to the aviary with the feather still attached. The quill was damaged. This could be an indication of why the feather came out before their natural moult. Equally the damage could have occurred after it dropped by feet (or hooves!) unknowingly trampling the feather.
Zennor tends to stay close to the other juveniles which means her movements should be relatively easy to follow. Hopefully this is a one off and the others stay attached until the birds moult naturally in May/June.
Patience is a virtue
We finally succeeded in trapping the sick wild chick, PP003, in the aviary towards the end of the month. Her condition had not worsened, but it certainly wasn’t improving. After an injection of wormer and visual inspection by Durrell’s vet nurse she was released and re-joined the group. We have noticed a considerable improvement and will continue to monitor in case a second dose of wormer is required.
The end of British Summertime saw a shift in daylight hours and has meant that the supplemental feed in the afternoon has been brought forward to 15:00 from 30th October. Our roost checks will now occur daily at a more amenable time as sunset becomes earlier and earlier.
With the choughs successfully released and settling down into their new lives in the wild it was time for a day off. What better way of relaxing than taking a boat trip with Jersey Seafaris to see….the choughs.
To be fair, the two hour trip along the north coast from St Catherine’s Breakwater to L’Île Agois promised sea caves and dolphins and nothing (strictly) to do with choughs.
That being said it did provide a unique opportunity to scour the coastline thinking about future breeding sites when competition in the quarry forces new pairs to look elsewhere.
There are plenty of caves and crevices along the north coast, but many are cut off at high tide. Devil’s Hole has always looked appealing and resembles may of the Cornish breeding sites. On this particular day the choughs were flying high above Sorel Point, but they frequently visit Devils Hole. The boat trip does not go as far round as Les Landes and Plémont. Even if it did, we would have run out of time that day. A pod of dolphins complete with baby, kept crew and passengers engaged a lot longer than anyone anticipated both there and back.
It is well worth hopping on board a Jersey Seafaris excursion and seeing the Island from a completely different perspective. It becomes clear, very quickly, why it is important to protect Jersey’s natural heritage on both land and sea.
Below is a video of the trip filmed by Mark Errington. You won’t be able to ‘play spot the choughs’, but there is a split second cameo by yours truly.
Visitors to Sorel
Durrell and the National Trust were proud to host Maggie Walker from the Audubon Society and her sister Jane Kramer on 5th and 6th October. Maggie and Jane visited Durrell’s Wildlife Park and the choughs before getting a guided tour of the National Trust conservation fields and other areas of their work.