What is the aim of the Release?

The aim of Operation Chough is the re-establishment of the Chough in Cornwall. The aim of this first release of birds is to establish a group in an area which is a former site for Chough. This birds would be the closest to the Lizard birds, so individuals could eventually meet and could eventually breed together. However, the species is known to be sedentary, dividing off into pairs during the breeding season and flocking togther the rest of the time, but generally staying within an established range if there is food there to support them.

Occasional vagrant birds may travel further afield, usually as singles but exceptionally more, like the three which came to the Lizard. Therefore, if they do meet, then it is not likely to be soon. We believe that 'disturbance' to the birds on the Lizard has been mimimised because any meeting will be in the usual, natural way that any travelling birds might meet each other. The released birds are displaying very normal, natural behaviours and after just a few days we are very reassured that they 'know' what they should be doing out there. After say, six months, a year or maybe three, the released birds or even their offspring could make ideal mates for the young Lizard Choughs.

James Gilardi PhD one of our team, who has observed releases previously, aptly sums up:

"The recovery of locally extirpated English wildlife should be a central goal for us all. With hundreds of miles of Cornish coast deprived of native Choughs, restoring this important aspect of our coastal ecosystems is a local and regional priority. To sit back and wait for a "natural" recolonization event places the scientific curiosity about this process above the conservation of our native ecosystems. Because the tools to facilitate this process are readily available, it makes good conservation sense to encourage this recovery over a period of years, rather than sitting back and hoping that it takes place over decades."

How were the birds prepared for the release?

The birds for release had been living in a large aviary built in an exposed situation at Paradise Park for almost two years before their release. They had shelters with multiple openings to mimic natural shelters, ledges in high positions and rocks to wipe their bills. This aviary allowed the birds good flying space and access to the ground which was grazed by animals. The aviary also gave them a good viewpoint to become familiar with birds of prey, which often fly over. Click here for aviary pictures.

They were given regular veterinary checks by our own vet, as well as thorough pre-release checks by a vet from the International Zoo Vet Group. The birds' general health was monitored and all the birds were declared fit and parasite-free before the final release. Click here for pictures.

In the months before the release an enclosure was built on private land in sight of the coast. This had an inner aviary and an outer flight area, which would allow release of some birds while keeping others in.

In this enclosure and the previous aviary the birds had become used to being fed by having food on the ground, or hidden amongst rocks. A call system was used (not given publicity) so that they could be alerted to feeding times, with the expectation that they would recognise this when released, allowing us to provide them with supplementary food.

The birds have also been fitted with unique radio tracking transponders, allowing them to be tracked from a distance. Each bird has a combination of coloured leg rings, also to enhance recognition from afar.

How was the release timed?

The date chosen to release the birds was timed to be after the breeding season, then allowing time for moulting to occur. This meant that the birds would be equipped with fresh feathers, both for flying and to assist the attachment of a radio tracking device. Furthermore, other species would also be out of their main breeding season with the expectation of less territorial behaviour towards the Choughs.

We also made sure that the birds on the Lizard had finished breeding.

The original date was to be July, but this was changed as long-range weather forecasts showed that the weather was not favourable at that time.

Why was it only publicised later?

We chose to keep the release private for a week as we wanted some quiet time to study the first important days. We judge this to have been a useful way allow us to prioritise the welfare of the birds during this time.

We also felt that the release would generate a lot of local interest, with a possible influx of people wanting to see the birds. It is standard practice with bird/animal releases. The same is true of rare birds nesting - hence the secrecy in the first year of the Choughs nesting on the Lizard.

Did the released birds show natural behaviours after release?

Dr Richard Meyer, who instigated Operation Chough by writing his thesis ‘The feeding ecology of the Red-billed Chough and the feasibility of re-establishment in Cornwall’, has written the following summary of the first week after the release:

"The initial release was successful. The birds reunited after the initial separation of one male. They remained together for at least three days until subsequently separating again. They initially responded well to the soft release technique used, coming down at feeding times and settling in two sites within easy contact range of each other. In between feed times, they behaved naturally - feeding amongst the granite clitter and at the rock-soil-vegetation interfaces, and taking many flights around the area, performing well and flying confidently. Later they dispersed, and tracking became more difficult. They spent more time at coastal sites, which could be seen as reversion to more natural behaviours although the 'inland' behaviour was reminiscent of Choughs feeding at upland sites elsewhere."

Field biologist Jamie Gilardi PhD., who was observing at the release made the following notes:

1. From day 1, the birds socialized with their own kind and other corvids in an appropriate manner.

2. They foraged effectively in habitats appropriate to the species, with evident success.

3. They flew strongly, yet returned to familiar points.

4. Although one bird separated from the other three, they joined up within 48 hours, and continued to forage and socialize together.

5. They selected a variety of appropriate perching sites including exposed rock, coastal heath, and man-made structures, thus they show comfort with the kinds of habitat they will need to use over the long term to survive in Cornwall.

How is the release being monitored?

Staff and associates of Paradise Park have monitored the birds since their release. The birds were monitored by Richard Meyer PhD and his team, from dawn to roosting each night for the first week. As the birds movements settled into a regular pattern, the monitoring has been reduced. A minimum of two hours per day, but often more, will continue for the time being.

As previously mentioned, radio-tracking devices were attached to a tail-feather of each bird before release. This tracking equipment, enabled observers to follow the birds movements without causing any interference to natural behaviour.

What people and skills were used to set up the release project?

The full range of people involved in Operation Chough is quite formidable. At the head of the project is Dr Richard Meyer PhD, author of the definative work - "The feeding ecology of the Red-Billed Chough in West Wales, and the feasibility of re-establishment in West Cornwall". There is also Dr James Gilardi PhD, Director of the World Parrot Trust (a charity based at Paradise Park). He has been envolved in many projects including releases in many parts of the world.

Many members of staff from Paradise Park are also actively involved in the release. These include staff members who have worked with Carl Jones in Mauritius (Echo Parakeet, Pink Pigeon and Mauritius Kestrel). Other staff members have worked on the Kakapo project in New Zealand.

The staff at Paradise Park are a dedicated group who have many thousands of hours experience, both with captive and wild birds. Many are also keen ornitologists, and have an expert knowledge of local birds and their habits, and have spent time observing the Choughs on the Lizard.

Outside of the Park, we have strong support from wildlife experts, local farmers and the good will of the people of Cornwall. We can call upon the expertise of such people as Vic Simpson (who has worked for many years at the VI Centre in Truro). He has carried out post mortem work on the Chough which perished on the Lizard earlier this year, and has provided some valuable data.

In setting up our release avairies, we have strongly relied on the help of local people, and their intuitive knowledge of their surroundings. The foremost of these being Paul Carter, who has constantly monitored the progress of the birds in their pre-release aviary, and has spent most of his free time making this event possible.

Were the IUCN Guidelines followed?

The IUCN - The International Union for the Conservation of Nature - is an organisation committed to communicating species conservation information to resource managers, decision makers and others whose actions affect the conservation of biodiversity.

All the scientific guidelines laid down by the IUCN have been followed. Paradise Park, and it's charity the World Parrot Trust, are well aware of the guidelines, having worked closely with the IUCN in producing the Parrot Action Plan - "Parrots, Status Survey and Conservation Action Plan 2000-2004". This lays out detailed proposals for the management of endangered species of parrots in crisis throughout the world.

The guidelines are long and complex, and their meanings can often be ambiguous. Conservation organisations often quote the main points of the guidelines.

For example, the following is from the RSPB website with reference to their introduction of Red Kites, and can be found at http://www.rspb.org.uk/birds/redkite/conservation_action.asp

"Reintroduction would only be considered if the IUCN (International Union for Conservation of Nature) criteria were met in full:

• Existence of good historical evidence of former natural occurrence.
• A clear understanding of why the species disappeared. Only if the disappearance was due to human action and the species was unlikely to recolonise naturally, would it be considered.
• The factors causing extinction have been rectified.
• Suitable habitat is still present to support a viable population.
• Birds intended for release are genetically as close as possible to the former indigenous population.
• The removal of birds for the project does not jeopardise the survival of the population from which the birds are taken."

Each of the above has been thoroughly investigated by Operation Chough, and the project has fulfilled its obligations on every point.

Can the released birds be harmful to the wild birds?

There has been speculation that the West Penwith birds could "teach bad habits" to the wild birds on the Lizard, and it would be important to remember these points:

• We believe that any risk to the wild birds from the released birds would be identical to any risk from them meeting a vagrant from Wales, for instance.
• Any meeting is unlikely to be soon as the species is known to sedentary, dividing off into pairs during the breeding season and flocking together the rest of the time, but generally staying within an established range if there is food there to support them.
• Occasional vagrant birds may travel further afield, usually as singles but exceptionally more, like the three which came to the Lizard. We believe that 'disturbance' to the birds on the Lizard has been mimimised because any meeting will be in the usual, natural way that any travelling birds might meet each other. The released birds are displaying very normal, natural behaviours and after just a few days we were very reassured that they 'know' what they should be doing out there. After say, six months, a year or maybe three, the released birds or even their offspring could make ideal mates for the young Lizard Choughs.
• Although the West Penwith Choughs have been programmed to respond to a specific signal for purposes of supplementary feeding, the birds show no signs of begging behaviour, and are developing a healthy disrespect of human beings. It is heartening to see true instinct taking over.
• Choughs are preferentially insectivores, there is no point in them begging for food from people. (Unless they happen to be carrying earwig sandwiches!)

The birds were given a full health check prior to their release, along with medication to protect them against immediate threats of common parasites, such as gape worm.

What did the DNA testing show?

In the winter of 2000, staff from Paradise Park took samples from taxidermy specimenskept at the Royal Cornwall Museum, Truro, for DNA analysis. Click here to see page.

These birds would provide the necessary DNA testing evidence for Karen Matthews, who at the time was writing her thesis "The Molecular Ecology of the Chough". Her work was carried out at Cardiff University, and has been overseen by Professors M W Bruford and Dr S Casey.

Ms Matthews compared the DNA of the Truro samples with those taken from Choughs in Wales. These samples were also tested against samples taken by Tomaskovic and Bruford, which were taken from the Natural History Museum in Tring.

Tomaskovic's samples included birds from Swanage, Polperro, Monmouthshire, The Isle of Islay, Co Maoy, and Co Kerry. The samples also included DNA from Alpine Choughs from the Haute Pyrenees, Morocco and Macedonia. All in all, these samples represent a significant part of the Chough's range.

When the Mitochondrial DNA was tested, it was found that the Truro samples matched those of all other samples. Ms Matthews Writes:

"The sequences were aligned and compared with sequences from study by Tomaskovic, 2000 (see Table 1, Appendix III).

All the samples sequenced from blood samples from Paradise Park, Cornwall were of the same haplotype.

This matched with the haplotype Pp01, of all extant birds from Wales. Sequences are shown in Appendix IV."

In simpler terms, all Choughs, including Alpine Choughs, are genetically identical, and therefore share common ancestry.

This view is shared by Derek Goodwin, ex Natural History Museum, author of "Crows of the World"

What are the origins of the released birds?

We believe that most of our original birds would have had Welsh or Irish origins, having come from various individuals and collections around Britain. The released birds, which included some bred here at Paradise Park, had a cross section of bloodlines to ensure gene diversity within the group. They were aged between 4 and 11 years old.

Operation Chough has been involved in research on the genetic ancestry of Choughs. This has included taking samples from the birds at Paradise Park and taxidermy specimens held at the Royal Cornwall Museum, Truro and the Natural History Museum at Tring. DNA from the birds was tested (at Cardiff University), with others from extant populations around the UK and Europe, and the results show that all Choughs are genetically similar.

This is understandable if you consider that only a few hundred years ago the populations of the Chough around the coast of Britain (and further afield), would have been much greater. This would have allowed for these mainly sedentary birds to disperse and mix with neighbouring populations.

See also: What did the DNA testing show?