Paola Lahuatte, Junior Investigator at CDF, is working to find a control method for the highly damaging Philornis downsi parasitic fly.

When I first arrived in the Galapagos Islands in mid-2013, I was thrilled to have the opportunity to do an internship with the Charles Darwin Foundation (CDF). As odd as it sounds, I was involved in reproducing and raising an invasive fly in captivity. The particular fly we were working with, Philornis downsi, may look like an ordinary house fly, but it is far less innocent. The larvae parasitize endemic landbirds, sucking the blood of chicks and often causing all the chicks in a nest to die. In other words, if you’re one of Darwin’s finches, this fly is a living nightmare.

There are currently 1,476 introduced species established on the Galapagos Islands, of which many are harmful for the endemic flora and fauna. The Philornis fly is one of the most dangerous species because it parasitizes at least 17 endemic bird species including the critically endangered mangrove finch, with less than 20 breeding pairs left in the world. In order to find a control method for the fly, we must first breed the fly under laboratory conditions and understand its lifecycle.

 

Philornis downsi, an invasive fly.
Philornis downsi, an invasive fly. Photo by: Sam Rowley.

Having just completed my undergraduate classes at the Central University of Ecuador, rearing flies was a new experience for me. On the mainland I had studied ticks and mosquitos, but here I needed to figure out how to raise the flies in captivity. Believe me, it’s not easy to take care of a fly, especially one that relies on blood and a live animal host. One of the main reasons we needed to raise flies in the lab is that scientists only had access to flies during the five months when birds breed and we were losing out on seven months of valuable research time every year!

I remember being frustrated when I saw how many Philornis flies were found in bird nests and yet in the laboratory it was so difficult to create the correct conditions to rear them for our studies. Despite the challenges in breeding flies, I succeeded in creating a new system specifically designed for rearing larvae, which became the subject of my undergraduate thesis. I continue to be inspired by the thought that this work may save Galapagos land birds, even though I feel a large responsibility on my shoulders. Fortunately, I have had the continued trust and support of Dr. Piedad Lincango and Dr. Charlotte Causton.

 

Fieldwork, collecting larvae from the wild. Photo: Liza Diaz Lálova
Fieldwork, collecting larvae from the wild. Photo: Liza Diaz Lálova.

As I was still interested in Philornis downsi flies, I wrote to Dr. George Heimpel at the University of Minnesota, lead researcher of a program investigating the possibility of using natural enemies to control Philornis downsi (known as biological control). I traveled to Minnesota to work with him and was overwhelmed by the subzero climate and language difficulties. However, thanks to the Heimpel family, who hosted me, I was able to adapt and I learned a lot! Upon completing my internship, I got a job as junior researcher at the Charles Darwin Foundation and returned to Galapagos in 2015 to continue this cutting-edge scientific investigation.

We are now able to raise small numbers of flies in captivity, but our goal is to rear large numbers of flies for our studies to develop control methods. This is particularly important now that two wasp species have been found parasitizing Philornis downsi on mainland Ecuador. These wasps exhibit characteristics that suggest that they would make good candidates for a biological control program and the hope in the next year is to confirm these preliminary findings through additional research.

I have learned a lot thanks to the opportunities given to me by the Charles Darwin Foundation and I definitely think that accepting an internship in Galapagos was the best decision I ever made.

The Charles Darwin Foundation depends entirely on the generosity of our supporters. If you would like to support us in finding a solution to this invasive parasitic fly, please donate today.

Van Straelen Interpretation Center on the way to the Charles Darwin Research Station.

With more than 80,000 visitors annually, the Charles Darwin Research Station (CDRS) is one of the most visited places by tourists in the Galapagos Islands. The Van Straelen Interpretation Center, part of the visit to our Research Station, is a space where different exhibits about Galapagos have been showcased since its construction. The name of this building is in honor of the renowned Belgian Conservationist Victor Van Straelen, first President of the Charles Darwin Foundation (CDF), from 1959 until his death in 1964, year in which the CDRS was inaugurated in the Galapagos Islands.

Thanks to the support of Save Our Seas Foundation and the work of our outreach and marine biology teams, this iconic site will feature a new exhibit that will present relevant information on the importance of sharks for marine ecosystems and for the community. Questions gathered since 2014 through communication and environmental education campaigns about sharks, will be answered in different sections of the exhibit. This information will include data on prehistoric sharks, ecological role, anatomy and senses, scientific studies carried out in partnership with the Galapagos National Park Directorate (GNPD) and collaborators, among other interesting topics.

Daniela Vilema making a map of marine currents and marine protected areas in process.
Daniela Vilema making a map of marine currents and marine protected areas in process. Photo by: Joshua Vela.

Staff members of the CDRS have volunteered their time to design a garden with endemic plants and fix parts of the infrastructure. We will replace the old furniture with some furniture donated by the Galapagos National Park. Together with our group of Shark-Ambassadors, we carried out several beach clean-ups in which we collected a large amount of marine garbage that includes plastic bottles, bottle caps, micro-plastics, glass, rubber, plastic bags, fishing nets and much more. With a little creativity and the artistic hands of our team, these materials are being reused in the new exhibit at the Center.

“The materials that we are reusing are things that are commonly used in Galapagos. They are materials that take many years to degrade, for example, plastics, glass, rubber, cardboard and paper. Most of this garbage goes directly to the sea when it is not treated properly, contaminating marine life"
— says Jonathan Atiencia, local volunteer and project artist.

Jonathan Atiencia building a mangrove forest with recycled materials, rocks and lose branches.
Jonathan Atiencia building a mangrove forest with recycled materials, rocks and lose branches. Photo by: Joshua Vela.

In addition to the new exhibition displays, we will have teaching materials, a small library and a space to carry out educational activities with the groups of students that visit us. The center will be open to the public and everyone who wants to learn about sharks and the marine world will be welcome. Soon we will have more updates!

Class and library of the Van Straelen Interpretation Center in process.
Class and library of the Van Straelen Interpretation Center in progress. Photo by: Joshua Vela

Thank you to those who are supporting us to re-open the Van Straelen Interpretation Center for the community! To support projects like these at the Charles Darwin Research Station, please donate now.

Young mangrove finches in the rearing facility at the Charles Darwin Research Station.

The Mangrove Finch (Camarhynchus heliobates), one of Darwin’s iconic finches, is a bird species found only in the dense mangrove forests of the western Galapagos Islands. At one time, these birds were found on two Galapagos Islands, Fernandina and Isabela. Today, primarily due to threats from invasive species, they are restricted to just two mangrove forests, scarcely larger than 30 hectares on Isabela, and their total population is estimated to be no more than 100 birds. Since 2000, the Mangrove Finch has been listed as Critically Endangered; it is currently considered to be one of the rarest birds in the world.

Mangrove Finches face extreme threats to their survival. The two major threats come from an introduced predator, the black rat (Rattus rattus), and an introduced parasite, the Philornis downsi fly, both of which impact the bird’s nesting success. When uncontrolled, black rats will invade 70% of the nests, where they prey upon the eggs. If the eggs survive this threat and succeed in hatching, they may then be affected by Philornis downsi, parasitic fly that lays its eggs in the nest. When the fly larvae hatch, they feed on the blood of the Mangrove Finch nestlings; few nestlings survive this parasitism. Past studies have shown that nestling mortality is higher at the start of the breeding season with up to 95% of nestlings being lost to parasitism and adult pairs laying up to five clutches a season to rear at best one or two chicks late in the season.

Juvenile Mangrove Finch.
Juvenile Mangrove Finch. Photo by: Francesca Cunninghame / CDF.

In order to combat these threats and prevent the extinction of the species, The Charles Darwin Foundation, together with the Galapagos National Park Directorate, began a formal long-term conservation project in 2006. The Mangrove Finch Project began with introduced rat control and bird monitoring, and has since expanded into a captive-rearing and reintroduction program. This program, established in 2014, is a collaboration with San Diego Zoo Global, Durrell Wildlife Conservation Trust and the Auckland Zoo and seeks to bypass the most lethal period of the finches’ lives and give them a head start for survival. The program’s personnel collect eggs in the wild, incubate them in a safe controlled environment and return the young birds to the wild.

Francesca Cunninghame gets ready to collect a Mangrove Finch nest on Isabela Island.
Francesca Cunninghame gets ready to collect a Mangrove Finch nest on Isabela Island. Photo by: Liza Díaz Lalova / CDF.

Good News for the Mangrove Finch in 2017:

  • 2 of the captive raised birds have paired up with wild raised birds and bred in the wild.
  • 100% of the 14 chicks that hatched in nests in the wild survived (in parasite treated nests).
A graph of mangrove finch statistics from 2011 to 2017.
A graph of mangrove finch statistics from 2011 to 2017.

Over the years, the Mangrove Finch project has had many successes, with 39 young birds (fledglings) released back into the wild. Many of these birds have shown that they are capable of lasting survival in their natural habitat. For example, in the 2016-2017 season, two of the released birds began breeding. Also in 2016-2017, a new parasite-control technique, in which nests were injected with permethrin (an insecticide), was given a trial run on Mangrove Finch nests after some success was achieved with a more common species on another island. The early results of the nest injections are encouraging: 14 chicks from these nests hatched and survived in the wild. In 2018, the team will focus on obtaining more data to determine the success of nest injections as, if effective, it presents a more viable long-term conservation technique than captive rearing.

Feeding a newly-hatched chick.  Young chicks are fed a high protein mixture that includes introduced wasp larvae and egg with papaya. Photo: Liza Diaz Lalova.
Feeding a newly-hatched chick. Young chicks are fed a high protein mixture that includes introduced wasp larvae and egg with papaya. Photo: Liza Diaz Lalova.

The success of the Mangrove Finch project is extremely exciting. It provides hope that, with long-term help from the Project’s hard-working field crews, supporting organizations, and generous donors, threats to the Mangrove Finch can be effectively controlled and their population will increase. Please donate today.

The Mangrove Finch Project is a bi-institutional project carried out by the Charles Darwin Foundation and the Galapagos National Park Directorate in collaboration with San Diego Zoo Global, Auckland Zoo and Durrell Wildlife Conservation Trust. The project is supported by the Leona M. And Harry B. Helmsley Charitable Trust, Galapagos Conservation Trust, Marguerite Griffith-Jones, GESS Charitable Trust, Decoroom Limited, Holbeck Charitable Trust, and Friends of Galapagos Switzerland.

Bottom left: Lenyn Betancourth (Entomology: CDF), Jandry Vásquez (Galapagos Verde 2050: CDF), Edgar Segovia (Entomology: CDF), Diana Flores (Galapagos Verde 2050: CDF), Paul Mayorga (Galapagos Verde 2050: CDF), Brandon Polzin (Galapagos Verde 2050: CDF), Freddy Azuero (GNPD Park ranger).

Between July and September 2017, the Galapagos Verde 2050 (#GV 2050) team, together with the entomology team of the Charles Darwin Foundation and park guards from the Galapagos National Park Directorate carried out ecological monitoring of the Opuntia echios var. echios seedlings present on the island (without water-saving technology). Pitfall traps and Berlese funnels were placed in order to evaluate the mesofauna present in the ecosystem as part of the process of ecological restoration on the island.

Ecological monitoring was carried out in three study sites, with a total of 45 Opuntias monitored including those that were controls and also those that used water saving technology. The kind of information recorded includes environmental and biological data such as: height of the plant, state, presence/absence of new leaves (cladodes), presence/absence of herbivory, presence of flowers and fruits, biological observations (such as soil and geographical location).

Ecological monitoring on Plaza Sur.
Ecological monitoring on Plaza Sur. Photo by: Diana Flores.

During this expedition of approximately six months, the water boxes (Groasis technology) were completely refilled at the three study sites on Plaza Sur; in order to achieve this, large containers filled with water were transported from Santa Cruz Island and with the help of the GV2050 team and one park guard from the Galapagos National Park.

Mobilizing the water containers to specific places on the island.
Mobilizing the water containers to specific places on the island. Photo by: Liza Díaz Lálova.
Filling the Groasis technology with water.
Filling the Groasis technology with water. Photo by: Diana Flores.

With the objective of protecting the Opuntia echios var. echios seedlings from the herbivorous land iguanas of the islands, from the beginning of the ecological restoration large steel fences were placed around each Groasis Technology water box. These fences will be removed once the cacti can survive on their own.

Mobilizing the protective steel fences.
Mobilizing the protective steel fences. Photo by: Diana Flores.
Replacing the protective fences.
Replacing the protective fences. Photo by: Diana Flores.

As part of the ecological restoration of the island, we considered starting various sample sites at different stations of the year starting in April until now with “Analysis of edaphic mesofauna present on Plaza Sur Island”.

During this expedition, four Pitfall traps were placed in different zones of the island, such as the ravine near the coast, cliffs, shrubby areas and the dock with the end goal of capturing terrestrial invertebrates present at different substrates.

Pitfall traps.
Pitfall traps. Photo by: Diana Flores.

Additionally, we carried out the collection of six soil samples (approximately 18 kg) to analyze them at the Charles Darwin Foundation’s laboratory, with the help of the Berlese methodology, under a specific temperature and constant artificial light so that the invertebrates will move downwards to the container with alcohol and get stored to later get identified and analyzed.

Soil samples collected on Plaza Sur, collected in Berlese traps.
Soil samples collected on Plaza Sur, collected in Berlese traps. Photo by: Diana Flores.

So that the analysis of mesofauna is more complete, we also carried out manual capture of terrestrial invertebrates in specific parts of the island during the daytime.

Manual capture of terrestrial invertebrates.
Manual capture of terrestrial invertebrates. Photo by: Diana Flores.
Mapping the distribution of traps on Plaza Sur Island.
Mapping the distribution of traps on Plaza Sur Island. Created by Byron Delgado with information from GV2050.

At the Charles Darwin Foundation’s laboratory, we proceeded with an analysis of the samples collected with Pitfall traps and the soil samples processed through Berlese methodology with the goal of evaluating the edaphic mesofauna present on the island.

The procedure for the analysis of Pitfall traps was as follows: separation of organisms (invertebrates) by morphotype with the help of a stereoscope and taking photographs of each individual; afterwards the organisms were identified by categories and categorized taxonomically to include them in the invertebrate collections of CDF (ICCDRS) and obtain a registry of the invertebrates present on the island.

The procedure to analyze the soil samples was as follows: the samples from the soil were collected in Berlese funnels, after approximately a week the funnels were removed to analyze the invertebrates present; then, with lab tweezers the present organisms were separated to later be identified and included in the invertebrate collection.

Thanks to the support of Biologist Edgar Segovia (museum volunteer) and Lenyn Betancourt, technical curator of the invertebrate collection, 122 specimens were found in total were found, pertaining to 39 species/morphotypes that had been identified, within 17 families of morphotypes identified. In each sample, the groups that dominate are Formicidae (Tetramorium lanuginosum) y Agromyzidae (Ag1 posiblemente Phytoliriomyza sp., seguidos de Tenebrionidae (Stomion sp), all following the quarantine procedures established in the plan of action of the project. (Jaramillo et al. 2017a; Jaramillo et al. 2017b).

Identifying the oganisms present in the Pitfall traps with the support of Gustavo Morejón at the office of GV2050.
Identifying the oganisms present in the Pitfall traps with the support of Gustavo Morejón at the office of GV2050. Photo by: Jandry Vásquez.
Separating organisms present in the soil with the support of national and international volunteers and field assistants of the Galapagos Verde 2050 Project.
Separating organisms present in the soil with the support of national and international volunteers and field assistants of the Galapagos Verde 2050 Project. Photo by: CDF Archive.

Additionally, the remains of leaves and seeds were separated from the soil samples and identified to later be included in the collections of the herbarium as auxiliary samples and as part of this project.

Seeds found in soil samples.
Seeds found in soil samples. Photo by: Diana Flores.
Leaves found in the soil samples.
Leaves found in the soil samples. Photo by: Diana Flores

Land iguana excrement was randomly collected on the surface of the entire island and it was later transported to the laboratory of the Charles Darwin Foundation with protocols established by the Galapagos National Park Directorate and guided by the Action Plan for the ecological restoration of Baltra and Plaza Sur. This collection was carried out to obtain sees of Opuntia echios var. echios and continue with the germination tests ex situ and viability tests, in addition to obtaining seeds of different species, identifying them and integrating them in the herbarium (CDS) of the Charles Darwin Research Station.

Collecting land iguana excrement.
Collecting land iguana excrement. Photo by: Diana Flores.

Galapagos Verde 2050 project is implemented by the joint work of the Charles Darwin Foundation and the Galapagos National Park Directorate. The continuity of the project is possible thanks to the support of the COmON Foundation, The Leona M and Harry B. Helmsley Charitable Trust and Bess Forest Club.

Opuntia echios var echios, after three years of growth thanks to the water saving technology on Plaza Sur Island.
Opuntia echios var echios, after three years of growth thanks to the water saving technology on Plaza Sur Island. Photo by: Diana Flores.

This project is one of many conducted by the Charles Darwin Foundation and depends entirely on the generosity of our supporters. Please donate today.

References

Jaramillo P, Tapia W, GIbbs J (2017a) Action Plan for the Ecological Restoration of Baltra and Plaza Sur Islands. 2:1-29

Jaramillo P, Tapia W, Romero ML, Gibbs J (2017b) Galápagos Verde 2050: Restauración ecológica de ecosistemas degradados y agricultura sostenible utilizando tecnologíaS ahorradoras de agua. Fundación Charles Darwin, Puerto Ayora, Isla Santa Cruz.

The “Charles Darwin Foundation for the Galapagos Islands”, in French “Fondation Charles Darwin pour les îles Galapagos”, Association International sans but lucratif (“AISBL”), has its registered office located at Drève du Pieuré 19, 1160 Brussels, and is registered under the trade registry of Brussels under the number 0409.359.103.

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