Floreana Mockingbird & Mangrove Finch Stories

Friends of Galapagos New Zealand www.galapagos.org.nz

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October 2014

Floreana Mockingbird Update &
the Mangrove Finch Story

Hola All Friends of Galapagos NZ

The Floreana Mockingbird Project continues and FOGNZ Committee Member Luis Ortiz-Catedral is heading back to Galapagos to head up the annual survey to assess the population status and trends of the species.

The Mangrove Finch Project, headed by Francesca Cunninghame, has been in the news a lot recently and we have a great account of the fight at the Charles Darwin Foundation to combat the introduced parasitic fly Philornis downsi.

Floreana Mockingbird Research Update

Packed and ready to go! In November this year, Luis Ortiz-Catedral will lead the team conducting the 2014-2015 annual survey of Floreana Mockingbirds on Champion and Gardner Islets. These counts provide the best information about population trends and overall population status of the iconic Floreana Mockingbird, officially, the mockingbird with the most restricted distribution in the world. Besides the annual counts, Luis and his team (which includes a Mexican and an Ecuadorian volunteer) will set up 6 motion-sensitive cameras to monitor active nests and document the breeding cycle of the species. These gadgets are small (about the size of a carton of milk) and camouflaged, thus enabling a non-invasive alternative to monitor nesting outcomes. These cameras will help the understanding of what are the most critical periods of survival for nests (i.e. incubation, chick-rearing or fledgling) and will also document potential native or exotic predators of eggs and chicks.

Luis is excited that they will get to see the presentation of a school play "A very special island". This play will be performed by kids of the Tomas de Berlanga School in Santa Cruz as part of their drama classes, under the skilled supervision of Jill Peters and Jo Browne, two very enthusiastic expat teachers from Australia and the UK respectively. "A very special island" is an interactive theatre piece that will show the audience the challenges of being a mockingbird chick, living on an isolated islet. The cast includes a family of mockingbirds, three rats, one cat, one snake and an owl! Photos of the costumes and a short clip of the play will be available online (FOGNZ will provide links when available).

Lastly, a brief training workshop for rangers of the Galapagos National Park will be conducted to strengthen their skills for handling mockingbirds, applying metal bands, keeping records of banded individuals etc. Support for research in the field and the school activities has been generously provided by Massey University, The Mohamed bin Zayed Species Conservation Trust, the Durrell Wildlife Conservation Trust (in kind support) and The Galapagos Conservation Trust.

The Story of the Mangrove Finch Project

Mangrove finch habitat - north west Isabela Photo F Cunninghame
Eggs being transported by helicopter to the hand rearing facility in Puerto Ayora. Photo Beate Wedelin
Nestling on the day it hatched Photo San Diego Zoo Global
Nestling in its individual nest cup in the captive rearing room. Photo Juan Carlos Avila

The critically endangered mangrove finch (Camarhynchus heliobates), one of Darwin´s finches, is the rarest bird in the Galapagos and one of the most range-restricted birds in the world. An estimated 80 individuals consisting of fewer than 20 breeding pairs are found in just 30ha of mangrove forest on the northwestern coast of Isabela Island. Historically distributed throughout the mangrove forests of both Isabela and Fernandina islands their population has declined during the last 100 years.

Current threats include predation from introduced black rats (Rattus rattus) and mortality of nestlings from the introduced parasitic fly Philornis downsi. Additionally the population is at risk from any single habitat altering event due to their restricted range and from potential genetic weaknesses resulting from extremely small population size.

The Mangrove Finch Project, a bi institutional project with the Charles Darwin Foundation and Galapagos National Park Directorate, in collaboration with San Diego Zoo Global and Durrell Wildlife Conservation Trust, has implemented conservation research and resulting management since 2006. This has included the publication of the Mangrove Finch Recovery Plan and successful rat control which saw an increase in nesting success from 13% to 37%.

Francesca & GNPD ranger Wilson Villafuerte watch as nest is collected. Photo Beate Wedelin
Francesca feeds a nestling in the captive rearing room. Photo Tui De Roy

In 2009, New Zealander, Francesca Cunninghame was employed as project leader and tasked with carrying out a trial translocation in response to Recovery Plan goals as an attempt to increase the species’ range. Nine individuals were successfully translocated in May 2010 to a separate 10ha mangrove forest; this was the first bird translocation carried out in the Galapagos. Though there was successful initial establishment, by the following breeding season four birds had been observed to be back in their source habitat and no birds have been sighted at the new site since November 2010. Graeme Loh (Department of Conservation Dunedin) and Sue Maturin (Forest and Bird, Dunedin) came to Galapagos as professional project volunteers for three months from late 2010 to help monitor the translocated birds and conduct nesting success studies.

While these conservation measures have produced encouraging results they have not been sufficient in significantly increasing the population size or range of the mangrove finch. Parasitism by P. downsi, for which there is not yet viable control methods to protect the mangrove finch, coupled with the tendency of translocated birds to return to the source population, required a more intensive approach to conservation management.

Nest success studies carried out from 2010 onwards, showed exceptionally low breeding success (5%) early in the season followed by multiple re-nesting attempts over several months. This resulted in, at best, each pair producing just two fledglings and lead to the development of plans to implement head starting. Head-starting refers to the collection of wild eggs or young birds, consequent artificial rearing and followed by the release of juveniles. Early laid mangrove finch eggs, with a very low chance of survival, could be collected whilst leaving the wild pairs to re-nest and rear their own young.

Mangrove finches had never been raised in captivity before and very few attempts had been made to rear any of Darwin´s finches in captivity. To be able to successfully rear mangrove finches from wild eggs presented several challenges. San Diego Zoo Global (SDZG) became essential project collaborators from late 2013 to lead the incubation and hand rearing by providing aviculture specialists.

Graeme Loh collects a mangrove finch nest suspended from a M rig. Photo Sue Maturin
GNPD ranger Wilson Villafuerte lowers a mangrove finch nest. Photo Sue Maturin
Mangrove finch eggs placed in heated thermos upon arrival to ground. Photo Sue Maturin
Francesca Cunninghame feeds a nestling in captive rearing room. Photo Tui De Roy

Mangrove finches nest in fairly inaccessible places up to 20m high in the canopy and Graeme Loh once again volunteered his time to provide essential tree climbing skills to ensure the safe collection of nests. From February 2014 ten mangrove finch nests were collected from the tree tops and twenty one eggs and three nestlings were transferred to quarantined rearing facilities at the Charles Darwin Foundation where SDZG personal lead the hand rearing and trained local and project staff in husbandry techniques.

Egg hatchability was high (88%) and fifteen chicks were successfully raised to independence (83.3% chick survivability). These fledglings were transferred back to their natural habitat in March where they were held in pre-release aviaries, situated within the mangrove forest, for four to six weeks. During this time the birds adapted to their natural surroundings and were observed interacting with wild mangrove finches. All fifteen birds were released in late April with tiny transmitters (weighing 0.3g) fitted to the underside of their tails to enable initial post release monitoring for a further month. During this time food was provided to the fledglings in the open aviaries and several of them returned daily for food. These visits reduced over time and some of the birds dispersed to other mangrove areas where they were found surviving independently several weeks after release.

The release of the captive reared mangrove finch fledglings in 2014 demonstrates the potential of head-starting to increase the population size. Wild pairs reared only five fledglings in 2014 with the majority of chicks in wild nests killed by P. downsi parasitism.

Nestlings 13 days after hatching in the captive rearing facility. Photo Ana Carrion
Fledgling in captive rearing room prior to being transported to pre-release aviaries. Photo Tui De Roy
Fledglings feed at feed tray in an aviary which was left open 3 weeks after their release so they could return for food. Photo F. Cunninghame
Fledglings upon weaning and close to being transferred to pre-release aviaries in their natural habitat. Photo F Cunninghame

With the help of New Zealanders an important step towards the future conservation of this critically endangered species has been taken and planning is already underway to repeat head-starting in early 2015. This intensive management, coupled with complementary wild population research and management will have to be conducted over several years, potentially re-populating areas within the historic range of the species and helping reduce the extinction risk faced by one of the most specialized of Darwin´s finches.

The head-starting phase of the bi-institutional Mangrove Finch Project between the Charles Darwin Foundation and the Galapagos National Park Directorate in collaboration with San Diego Zoo Global and Durrell Wildlife Conservation Trust was made possible by funding from Save Our Species (SOS) IUCN, The Leona M and Harry B Helmsley Charitable Trust through the International Community Foundation and Galapagos Conservancy

Captive reared mangrove finch feeds on wild casela fruits after its release .PhotoF Cunninghame
A released fledgling shows its radio transmitter aerial. Photo F. Cunninghame
A captive reared fledgling following its release. Photo F Cunninghame
A wild adult mangrove finch interacts with a captive reared fledgling at the pre-release aviaries. Photo F. Cunninghame

Listen to Francesca talk about the Mangrove Finch Project in this Radio New Zealand interview.

In addition to her work with the Mangrove Finch Project Francesca works on a number of other Galapagos projects and played an important in the FOGNZ White-vented Storm Petrel Project lead by Chris Gaskin & Karen Baird.

Lonesome George in NYC
Visitors to New York City over the next few weeks can see Lonesome George at the American Musuem of Natural History

Find more great Galapagos news and stories on our website or Facebook page with these two links below:

http://www.galapagos.org.nz/news/
https://www.facebook.com/FriendsOfGalapagosNZ

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