Volunteer field assistants required – radio-tracking the red-billed choughs

Jess, chough field assistant, radio-tracking at Sorel. Photo by Liz CorryBackground

Birds On The Edge needs your help. We will be releasing the small group of young choughs to the north coast of Jersey very soon now. This is a trial release and each of the birds will be radio-tracked and monitored closely for a period of six months (see our monthly reports here).

The position

Choughs in the Sorel aviary. Liz Corry. April 2013 We require the support of keen volunteers to work alongside our Field Manager to carry out this radio-tracking and monitoring. So, we are looking for people who are able to commit to up to six months starting in early August 2013 and ending no later than 31st January 2013, although the end date depends a little on the birds themselves.

Volunteer activities will be focused around intensively tracking and, if necessary, searching for released choughs and recording basic behavioural data in the field. Training will be given in radio-tracking, habitat assessment and understanding chough behaviour.  Volunteers will also be responsible for entering some of the data collected into the field database.

Le Don Paton. Photo by Mick DrydenRequirements

Applicants will need to:

  • Have a background in biological sciences
  • Be happy to work outdoors and have some previous birdwatching experience
  • Have flexibility, commitment and determination to work, under sometimes uncomfortable or frustrating conditions, combined with good physical fitness
  • Provide careful attention to data recording
  • Be able to commit 18 hours per week for 6 months
  • Be resident in Jersey
  • Have transport within Jersey, personal equipment and insurance but the project will assist with money for petrol used if the birds need following.

This is the ideal opportunity for someone looking for practical conservation experience working with this very exciting re-introduction project for such a highly charismatic bird.

If you wish to apply, please contact volunteer@durrell.org

Closing date for applications: Friday 19th July 2013

Getting rid of Hottentot fig does bring results!

Former Hottentot fig covered ground. Photo courtesy of Alderney Wildlife Trust 2013One year after clearing an area of coastline of Hottentot fig in Alderney, look at this display of native flowers coming into their own!  This site now has kidney vetch Anthyllis vulneraria, cat’s ear Hypochaeris radicata, stemless (dwarf) thistle Cirsium acaule and bastard toadflax Comandra umbellata all coming back into their own!

This change of fortunes has been brought about by the hard work of the local conservation volunteers. If you are visiting Alderney, you can join in too, there’s no need to attend regularly or even be a resident on the Island, just go along to one of the Wednesday or Saturday afternoon sessions (contact info@alderneywildlife.org). But don’t fear if you are not planning to visit the northern island in the near future, there are plenty of opportunities on the other islands to get after those figs and other invasive plants. A few hours here or there can make a huge difference and who needs a gym when you can keep fit and help our biodiversity! In Jersey, look out for the activities of our own Jersey Conservation Volunteers

Farmland bird monitoring – four new transects and two new birds

Farmland at St Catherine's. Photo by Mick DrydenThis month saw the further extension of our Farmland Bird Monitoring programme. Four new sites, relatively close to each other in St Martin, were brought in to the overall scheme. Birds recorded at each of the sites will be entered into the project database but will also be used for farmland management trials aimed for 2014 as part of a joint project by the Department of the Environment and Game & Wildlife Conservation Trust. These four farmland sites join two woodland sites (at Rozel Manor and Le Saie) in the trial.

La Coupe - Fliquet_1013m. Photo courtesy of Department of the EnvironmentThe four new sites are at Ville es Nouaux/La Fosse (a single 1,037m transect), Rozel Mill (1,203m transect), Gibraltar/St Catherine’s (1,027m transect) and at La Coupe/Fliquet (1,170m transect).

The new sites bring the total number of monitored sites in this programme to 20 with two of those having two separate transects (22 transects in total). We count all the birds along 25,439 metres of transect every fortnight. That’s 15.8 miles birdwatching at least twice a month in all weathers!

Common quail in Jersey (May 2011). Photo by Mick DrydenDuring this month we have also recorded two new bird species on the transects. On 2nd June, Harriet Clark recorded a very rare common quail on the new transect at Gibraltar/St Catherine’s. Quail are a migrant species breeding in Europe and wintering in Africa. Sadly, quail are becoming rarer through hunting and loss of suitable breeding and wintering habitat. We record single birds in most years in the Channel Islands but they are still a very good sighting. Harriet’s quail became the 159th bird species recorded during the monitoring project.

Oystercatcher. Photo by Mick DrydenThe 159th species was very quickly followed by the 160th. We finally found an oystercatcher! Oystercatchers can be heard at some sites during every single visit, but, as they are typically either at the base of the cliffs or flying at sea (they are very, very noisy and their voices carry) but, as they aren’t really using the site we are monitoring, they haven’t been counted. However, on 11th June, Tim Liddiard found an oystercatcher actually walking on the path we use as the Les Blanche Banques transect. This bird was presumably one of the pair nesting at the nearby sandpits.

Gannets don’t share their food

Rouzic island - 7 îles archipelago. Photo by Régis Perdriat

From Birdguides and University of Leeds. Many thanks to Chris Bunting, University of Leeds for extra material.

Gannet. Photo by Mick DrydenNew research published this month in the journal Science shows that gannets only feed in areas belonging exclusively to their colony, preferring to leave those belonging to neighbours alone. The study was an international project led by the universities of Leeds and Exeter. The researchers used small satellite tracking devices attached to 184 gannets from different colonies around the UK, Channel Islands and Brittany to build up maps showing the birds’ flight paths. Dr Keith Hamer, from the University of Leeds and principal investigator of the project, said: “It quickly became clear when we started mapping the data that something interesting was happening. Areas of sea used by birds from adjacent colonies were neatly abutting but not overlapping, with no spaces between them either”.

Gannet foraging areas. Map courtesy of University of LeedsThe team think there are two reasons that the birds follow such set routes. The first is a question of maths. Dr Ewan Wakefield from the University of Leeds explained: “gannets dive from the air into the water and feed on prey close to surface. But once gannets start diving in, the prey take evasive action, so feeding opportunities don’t last long. The important thing for gannets is to be one of the first arriving at the feeding area. If other birds from another colony are more likely to get there first, there’s no pay-off.”

Dr Thomas Bodey, from the University of Exeter, says that competition for food cannot be the only explanation for such clear differences between the colonies’ feeding patterns. “It’s likely that cultural differences also play a part in the birds’ behaviour. As with humans, birds have favoured routes to travel, and if new arrivals at a colony follow experienced old hands then these patterns can quickly become fixed, even if other opportunities potentially exist.”

“There’s no conscious realisation that the bird feeding next to them is from their own or another colony. Some colonies have 60,000 birds so it would be impossible for a gannet to tell. At sea they’re just looking out for themselves,” Hamer explains. “Natural selection will favour individuals who can find good feeding opportunities, but if a gannet keeps going somewhere that other birds from another colony are getting to first, it won’t do very well.”

All gannet tracks. Map courtesy of University of LeedsInterestingly, the study suggests that gannets seen from the west coast of Jersey are most likely to be from the Sept Îles colony and those feeding off the east coast are from Alderney.

The research could have wider implications for our understanding of animal behaviour as, until now, individual colonies having exclusive access to small foraging areas was a trait known mainly among insects. Professor Stuart Bearhop of the University of Exeter said, “If you look at some species, like ants, individuals aggressively defend an area around their colony to keep others away. That results in a way of foraging in ant colonies where feeding areas meet but don’t overlap, as the aggressive behaviour means they all steer clear of each other.”

Drama among Cornwall’s wild choughs

From Claire Mucklow, RSPB’s Cornwall Projects Manager

Cornish chough. Photo by Bob Sharples www.bobsharplesphotography.co.ukThe last week has been one of both tremendous highs and lows for the chough team in Cornwall. They were very sad to have to report the loss of the wonderful male chough from Southerly Point on the Lizard. Just over a week ago a volunteer witnessed two choughs locked in combat for the most part of the day, and it appears that the new younger bird has ousted and possibly killed the older male. He may not be dead but he has certainly been usurped. Claire says “I always joke ‘they will live forever’ when people ask me how long the pair at Southerly Point will be around, but sadly choughs are not invincible and nature in all its rawness has won the day. An end of an era, and the loss of a very special bird”.

What a legacy that chough and his mate have left Cornwall with though. Since they returned in 2001 they have brought so much joy to those lucky enough to spend time with them and a real sense of Cornish pride enveloped them. The pair together raised 44 chicks and many of those birds have gone on to breed themselves, securing a future for choughs in Cornwall. Proper job!

But, there is a happier, and unexpected, twist to this tale. The new male, a bird often seen in the company of the Lizard pair, has adopted the old male’s new chicks – extraordinary as normally a bird would try to kill any chicks that were not his. This is new behaviour, possibly not previously recorded for choughs. The female having invested so much time and energy in her new brood has accepted this new male and together they are feeding her two chicks, which are around two weeks old. Here’s hoping the female and her new mate will live for many a year.

There is further news of chicks in Cornwall where there are already chough fledglings this season; five more youngsters took to the skies last week in Penwith. The crazy weather has really affected this year’s breeding season and, with six weeks between first and last broods, the last chicks will not fledge until early July. The total number of young for this season so far is 16, two broods of five, and three broods of two. There are a further three pairs of choughs that have shown signs of breeding but they are too young this year.

Follow news of Cornwall’s choughs on the project website here and on Twitter at @cornishchoughs. Find where to watch wild Cornish choughs here

Chough report: May 2013

Red-billed chough at Sorel. May 2013. Photo by Andrew Koester

Report by Liz Corry

Choughs at Sorel

Pre-release training

Choughs on target boards. May 2013. Photo by Liz CorryTraining this month experienced another learning curve for both choughs and keepers. During training sessions the birds were becoming sluggish and/or lacked motivation. Keepers noticed that with the change in season more and more insects were starting to emerge. The choughs were spending more time probing the ground between sessions and we quickly realised that the birds were just not hungry enough to bother finding out what the whistling keeper was bringing them. With food rations imposed the motivation returned!

Choughs on target boards. May 2013. Photo by Liz CorryAt the same time another behavioural issue arose. As the group becomes more settled in the aviary their personalities start to show and social structures form. When training first began every bird was in the same position. Once they understood what was expected of them and what reward they would receive they would flock to the target boards. Now with a pecking order established (pun fully intended) the dominant ones make sure that the shy ones wait their turn. Which means either very little or no reward at all for some birds and the desired behaviour is not reinforced. To break this pattern more target boards were added to the aviary to spread around the food reward. It took a day or two for the birds to realise they didn’t have to go to one spot for food. Once these considerations were taken into account the choughs’ response time between whistle and reward improved dramatically.

Sorel and release aviary from the air 26-5-2013. Photo by Tony PaintinThere was another dip later in the month when two of the seven choughs had to be separated from the group. These two will not be released as they don’t have radio transmitters. Through positive reinforcement training and a lot of sheer luck the two choughs were shuffled across into section 1A. This is where the first target board was set up and the group have formed a strong association with it. The first few days of training after the separation saw the group of five fly down to the shelves outside and peer in at the target board bewildered by the mesh blocking them. They gradually learnt that they could use other target boards and training is back on track.

As well as flying on command the birds have been undergoing training to jump onto scales and weigh themselves. Their first response to the weighing scale being introduced was to fly to the shelving and peer down in judgement. Soon their desire for food overcame their conflict with change and they jumped on the scales. It takes patience and a basic grasp of maths for the keeper to obtain individual weights when five will jump on at once. However, this was achieved and we learnt that the choughs have maintained healthy weights.

Radio-tracking update

Radio transmitter recovered from floor of aviary. Photo by Liz CorryAround the middle of May keepers found a couple of feathers on the floor of the aviary. This isn’t particularly unusual in a group of that size. However, as the days went on and more were found, alarm bells started ringing. Checking in with the juveniles at Durrell a similar case was being seen and the alarm bells grew louder. It was suspected that the juveniles were going through a moult. Shedding feathers results in shedding radio transmitters and on the 26thMay this was nicely demonstrated by ‘Red’ losing her transmitter. Both birds carrying dummy tags have also dropped them. The first was likely due to over preening of the tail feathers the second which happened more recently was through a natural moult.

Normally choughs will not moult until their breeding season is finished. The earliest we have recorded moult for juveniles at Durrell was July. There are a few possible reasons for an early moult, such as abnormal weather patterns, transmitter attachment causing excess preening, and nutritional factors. Either way the team now needs to consider what this means for the timing of the release. Moulting can be a relatively stressful time for a bird and their welfare is top priority. A delay in release is inevitable, but the question being addressed now is ‘for how long?’

Choughs at Durrell

Captive breeding behind the scenes

Nest camera monitor showing parent feeding chough chicks. Photo by Liz CorryAfter an agonizing wait, for both parents (Tristan & Issy) and keepers, the first chough eggs hatched around the 16th May. Two chicks could be seen on the nest camera monitor begging strongly and the parents were feeding well. The next day a third chick was seen, then a fourth the following day. Extra insect feeds were taken to the aviary from around 7am until 7pm each day. Feeds consisted of mealworms, small crickets, and ants/ant larvae.

On the 19th there was some concern as only two chicks could be seen actively being next to an unhatched egg were. The quality of the camera image at that time was not very clear so the nest was left undisturbed.

However, on the 21st keepers noticed flies hanging around the nest. Concern rose and a decision was made to check the nest. Unfortunately one decomposed chick and an egg were found in the nest. Two other bodies were found on the floor of the aviary. The fourth chick was not recovered. Post mortem analysis by Durrell’s vets showed evidence of a respiratory infection. Further analysis is underway to identify the exact infection. This of course if a huge disappointment for staff considering the efforts undertaken by everyone to achieve success this year. There is a slight chance that Tristan and Issy might lay again, but it would be very late in their season if they did.

Arthur and Gwinny’s nest was checked at the same time and found to be empty. It appears that they have done nothing except build the nest this year.

Update on George

Vets perform surgery to heal George’s bumblefoot infection. Photo by Liz CorryGeorge continues to be held in the Durrell Veterinary Centre whilst his health issues are being treated. The quarantine period finished on the 22nd so in theory he can now be moved into Durrell’s collection at any time.

It was noted that when George finished his course of painkillers he began to hold up his foot again and looked in discomfort. He was immediately put back on medication and re-examined under anaesthetic by the vets.

There were a couple of pecking sores on his left foot and new cracks in the skin. The vets think the fractured middle digit might fall off naturally through necrosis and would prefer this than invasive surgery.

The main focus of this examination was to treat the bumblefoot on the right foot. The vet removed the scab, drained the infection site, cut away excess tissue, and sutured the skin tighter together. This had the effect of reducing the foot pad to a more normal size. With the aid of a pressure bandage it was hoped that George would begin to use his foot normally again and gradually correct his posture. However, upon waking up from the anaesthetic George showed an intense dislike to the bandage and made every effort to remove it. After five days of mental anguish George had the bandage removed. The wound was still healing but as it wasn’t presenting any problems, the bandage was left off and antibiotic ointment applied.

About ten days later George had pulled out his claw on the injured digit of the left foot. There was not much that could be done for this except make sure any bleeding had stopped and clean the wound. A week after that he tore the skin on the end of this digit. The vet sutured the wound with two stitches and George was put back on a six day course of antibiotics and painkiller. However, for all our concerns, George is a born fighter and was moved into the display aviary at the start of June to continue his recovery.