• Press Releases (225)
• Local Events (119)
• Animals (170)
• Jersey (247)
• Global Projects (109)
• Promotions (26)
• Madagascar (15)

Rarest of Charles Darwin's iconic finches in trial translocation

19^th July 2010

Durrell’s Francesca Cunninghame, Mangrove Finch Field Manager working with the Charles Darwin Foundation has just returned from the isolated coast of the Galápagos island of Isabela having undertaken the first trial Mangrove Finch translocation. This project constitutes an important gain for the management and future conservation of this critically endangered species.

The aim of this project, a partnership between Durrell Wildlife Conservation Trust, Charles Darwin Foundation and the Galápagos National Park is to restore the rare Mangrove Finch to areas they historically inhabited and where they may hopefully increase their population size. The project has been funded by Defra’s Darwin Initiative – which draws on the wealth of biodiversity expertise within the UK to help protect and enhance biodiversity around the world.

The Mangrove Finch currently survives in two small patches of mangrove located in Playa Tortuga Negra and Caleta Black in the west of Isabela Island, there is also a small remnant population of around 5 individuals on the South Eastern coast of Isabela. The birds have also been observed in Fernandina Island (Punta Espinoza). At present population numbers stand at approximately just over 100 individuals. The objective of this translocation programme was to move a limited number of finches in the hope that they adapt and breed in an area quite similar to their original habitat.

Thus this programme saw the movement of nine birds to the formerly inhabited site of Bahia Urvina which is an area of approximately 30 hectares very similar to Playa Tortuga Negra and Caleta Black.

Initially a radio transmitter was placed on each bird in order for the team to track their movement and determine their behaviour. Shortly after their arrival two adult finches took up residence in a stand of mangroves 3km away from where they were released, but one juvenile bird returned to Playa Tortuga Negra, after flying across 12km of bare lava field.

Ongoing monitoring will continue to assess how the birds adapt to the new habitat and also inform future decisions which may help to recover this population.

More information

• The Mangrove finch is listed in the Red List of the International Union for Conservation of Nature (IUCN) as critically endangered
• The habitat of this species is mangroves where they forage in dead wood and leaf litter as their diet consists of insects and other invertebrates and larvae, spiders and moths, and fruits if available.
• The finch is threatened by rats, cats and the parasitic fly Philornis downsi.
• A field team of eight people, from the Charles Darwin Foundation, Galápagos National Park and Durrell Wildlife Conservation Trust took part in this translocation project which commenced in May 2010.
• Nine mangrove finches were captured using mist nets at Playa Tortuga Negra on the north western coast of Isabela Island over three days.
• The birds were translocated to a suitable mangrove forest 22km to the south at Bahía Urbina.
• Birds were transported in purpose-built transfer boxes to the release site by small boat on the same day that they were caught.
• A total of five juveniles and four adults were translocated.
• Because this is the first time Mangrove finches have been held in cages it was essential to assess their reactions.  Birds reacted very well during their time in captivity with juveniles feeding during transport and all birds arrived at the release site in excellent health.
• All birds were fitted with radio transmitters and colour bands to enable monitoring and individual identification after their release.
• The transmitters weighed 0.41 grams and were glued in place to the feathers on the birds’ backs.
• The transmitters weighed less than 3% of the smallest bird’s body weight, which is the internationally accepted benchmark.
• Birds flew directly out of the transfer boxes upon arrival.  Some individuals were observed feeding immediately following their release.
• All birds were found to be alive 48 hours after release.
• Four people, staff and volunteers from the Charles Darwin Foundation and Durrell, remained in the field for two weeks after the release to monitor the movement of the birds.
• Monitoring of individual birds lasted between two to 14 days depending how long the transmitters remained attached to the birds.
• Two adults have taken up residence in a stand of mangroves 3km away from where they were released.
• One juvenile bird returned to Playa Tortuga Negra, after flying across 12km of bare lava field.
• Introduced ship rats (Rattus rattus) are knows predators of mangrove finch eggs and chicks, 60 bait stations have been put in place and filled so that this predator can be controlled  before the breeding season starts in December.
• Now that the battery life of the transmitters has run out and the birds are no longer singing, locating them will be very difficult and we will not have confirmation that they have remained in the area until they begin to call again later in the year.
• The fact that mangrove finches have now been successfully transported and released in a new site shows that translocating and reintroducing this species across its historic range can be used to secure its future.  We now have a powerful tool in our armament for helping combat the processes of bird extinction in the Galápagos Islands.

---

Post comments on this article

Jump to latest post

« Return to News