The restoration of choughs into Jersey will pose a number of challenges. The release of intelligent social birds is potentially complex and an area of reintroduction biology requiring further applied research. To achieve the aims of the project we need to trial management and release techniques.
A trial release
Birds should probably be released as young as possible; however, birds a year old or older may fare better than juveniles. Weather conditions and food abundance, including those imposed by the advancing winter on relatively recently released first year birds, may affect survival prospects. Therefore, it is not yet obvious whether summer/autumn releases or spring releases would be best. Releases may need to be timed to avoid breeding periods for peregrine Falco peregrinus and raven Corvus corax, two potential predators that nest at coastal sites in Jersey. The pre-release choughs may need to be taught to recognise these predators and to react accordingly to other species alarm calls.
It is planned to undertake a trial release of a small number of birds habituated to their keeper/manager near Sorel Point. Around 6-8 birds will be acclimatised in a pre-release aviary on site where thay can also undergo a full veterinary screening before release. In the pre-release aviary the birds will get a good introduction to the weather conditions and be trained to live together and learn to come to food provided by the manager.
The birds were first released in August 2013, read updates on their progress here
All the choughs will carry individually numbered and coloured rings on their legs so that each one can easily be identified. They will be further tracked very closely using radio tracking devices attached to the birds that will provide insight into the success of the trial as we can see where birds chose to visit in Jersey including which fields and which coastal spots they prefer. We hope that Islanders will report in sightings of the birds to help us get a better understanding of their movements and activities and to encourage support for the project.
After the trial release, the research and acquired skills will be collated and documented to produce protocols for release of further choughs. It is assumed that birds will need to be released every year for 5-7 years until at least 50 birds are established. The release phase of the project will end when the population is breeding freely in the wild. It may, however, be that we will continue to provide the wild birds with small amounts of supplementary food in order to monitor their progress and to ensure that they are getting a well balanced diet.
We plan to re-establish the red-billed chough in Jersey and use this highly charismatic bird as a flagship for extensive restoration projects on our Island’s coastline. The first, trial, release of birds will be undertaken at Le Don Paton near Sorel Point. Six birds will be released and monitored closely to understand better their behaviour, use of the available habitat and daily movements. The trial release will allow us to develop plans for the further release of more birds over a 5-10 year period until the species once again breeds wild in Jersey.
Approximate costs for the first year of the trial release included:
- Construction of temporary release aviary £15,000
- Radio-tracking equipment for six birds £5,000
- Chough manager (six months) £12,000
- Consultant £2,500
- Expenses (petrol etc) £1,000
- Food for birds £1,000
- Veterinary expenses £1,000