March 17th, 2015
The Mangrove Finch project team, led by the Charles Darwin Foundation (CDF) and the Ecuadorian Ministry of Environment via the Galapagos National Park Directorate (GNPD), in collaboration with San Diego Zoo Global and Durrell Wildlife Conservation Trust, are once again captive rearing mangrove finches – giving this critically endangered Darwin Finch a further “head start”.
From February 3 to March 3, 2015, 30 mangrove finch eggs were collected from the wild at Playa Tortuga Negra, on northwestern Isabela Island in Galapagos. The eggs were then transported 80 miles by boat to the artificial incubation and captive rearing facility at the Charles Darwin Research Station (CDRS) – the operating arm of the Charles Darwin Foundation in Puerto Ayora, Galapagos. This is a quarantine facility, which minimizes the nestlings’ susceptibility to disease.
The first eggs have now hatched, and chicks are being cared for around the clock by the project team.
The mangrove finch (Camarhynchus heliobates), the rarest of “Darwin´s Finches”, has an estimated population size of less than 100 individuals — with fewer than 20 breeding pairs remaining. Research shows that the introduced parasitic fly, Philornis downsi, is one of the primary causes of high nestling mortality, with up to 95% of nestlings dying during the first months of the breeding season in natural conditions.
Intensive conservation management to increase the number of fledglings produced each year was initiated in 2014 by the Mangrove Finch Project team when, for the first time in Galapagos, eggs were collected from the wild, transferred to Puerto Ayora and then captive reared. Fifteen fledglings were successfully released back into the wild in May 2014. Due to the tiny population size of the mangrove finch, and with no viable technique to protect wild nests from parasitism by P. downsi at present, the collection of eggs and the captive rearing of nestlings is a successful strategy that warrants repeating.
Following last year’s success, this season the field team was faced with unexpected challenges. Mangrove Finch Project lead Francesca Cunninghame explains: “It was exceptionally dry at Playa Tortuga Negra, and the mangrove finches were slower breeding. Consequently, we only identified 12 nesting pairs. We also experienced two days of high wind gusts, which made climbing trees up to 60 feet into the canopy overwhelming and dangerous.”
The incubation and captive rearing team, led by staff from San Diego Zoo Global (SDZG) with the support of Ecuadorian trainees, placed the eggs in incubators installed within the quarantined facility at the CDRS. Eggs have been hatching over the past two weeks. Chicks are being fed 15 times a day on a diet of scrambled egg and papaya, introduced wasp larvae, moth innards, and passerine pellets.
Nicole LaGreco, a lead aviculturalist from SDZG, said “With the success of last season, we were excited and eager to be asked to participate again this year. While this year has presented more challenges than last year, we are hopeful for another successful season.”
Once the chicks have fledged and are feeding independently, they will be released back into the wild at Playa Tortuga Negra by the project team.
The Mangrove Finch Project is a bi-institutional project carried out by the Charles Darwin Foundation and Galapagos National Park Directorate in collaboration with San Diego Zoo Global and Durrell Wildlife Conservation Trust. The project is supported by Galapagos Conservation Trust, The Mohamed bin Zayed Species Conservation Fund, Durrell Wildlife Conservation Trust, The Leona M and Harry B Helmsley Charitable Trust, Galapagos Conservancy, and The British Embassy in Ecuador. Thank you also to Lindblad Expeditions and Metropolitan Touring for providing their tourist boats to help transport the eggs to the incubation facility.
Reprinted with permission from the Charles Darwin Foundation.