CHARLES DARWIN FOUNDATION NEWS BULLETIN
CDRS entomologists Lazaro Roque and Alejandro Mieles collected specimens of a rare endemic moth species, Epiplemma becki, which was once common on Isabela Island but last collected in 1971. This rare species was found during a field trip to Wolf Volcano on Isabela Island in June. "Only five museum specimens existed worldwide until now," says Lazaro Roque, entomologist and curator of the station's invertebrate museum.
Another new Galapagos species record is Diatraea saccharalis, a serious sugar cane pest commonly known as the sugar cane borer, and which originated from the Caribbean and has spread throughout South America. CDRS scout Jose Loayza spotted the species, which hatched out of corn, during a routine quarantine and inspection check in San Cristobal. Bernard Landry, a lepidopterist taxonomist at the Muséum d'Histoire Naturelle in Geneva, Switzerland with 15 years experience on Galapagos fauna, identified the insect.
The diamond back moth Plutella xylostella, a serious cabbage pest, was also recently registered in Galapagos though there is no indigenous plant of the cabbage family present in Galapagos. Entomologist Lazaro Roque found the insect in his house in Bellavista, and Bernard Landry confirmed its identification.
Setomorpha rutella, the tropical tobacco moth, was detected in the fly pupa of a Darwin finch nest. "The moth was developing inside the fly pupa, an unusual and interesting phenomenon," says Dr. Helmuth Rogg, head of the invertebrates department, who discovered the moth.
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The guides and crew of Lindblad Expedition's cruise ship Polaris welcomed 65 happy, curious Galapagos children on board for a three-day tour of the islands in May, organised by the Charles Darwin Research Station (CDRS) and the Santa Cruz Island municipality. The children, many of whom have never visited the other islands of their world-famous archipelago, visited Bartolome and Santiago islands, swimming with sea lions and penguins, exploring lava formations, and learning how volcanic islands are formed. Each child was given a disposable camera to photograph their favorite sights and a personalised video of their time on board the Polaris.
"This trip gave these children an opportunity to discover the wonders that draw tourists and scientists to Galapagos from around the world, and is helping to cultivate a new generation of Galapagos conservationists," says Sandra Tapia, an educator with the station's environmental education center on Santa Cruz Island who coordinated the trip.
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Local journalists saw the damage caused by introduced goats in Northern Isabela and learned how the Isabela Project is helping restore the area's fragile ecosystem during a five-day visit in late May to Alcedo Volcano. The 11 journalists from the islands of Santa Cruz, San Cristobal and Isabela toured the dog kennels at the park facilities in Puerto Ayora where hunting dogs are reared and specially trained in goat tracking and bailing techniques. Felipe Cruz, the project's technical coordinator, briefed the reporters.
The group traveled to Isabela Island by boat where they were met by project hunters and taken to the rim of Alcedo Volcano. The journalists visited the volcano's rim and fumaroles, home to one of the archipelago's rare Galapagos giant tortoise species and many other unique plant and animal species, where they saw firsthand the devastation caused by introduced goats in the area. After a two-day visit, a helicopter transported the group back to the base camp giving them an aerial view of the extent of the damage and the large numbers of goats roaming the area. Following the trip, several journalists reported on their experiences in local television and radio spots, and newspaper articles.
The visit, coordinated by the communications departments of CDRS and the Galapagos National Park Service (GNPS), is part of a campaign to build local support for the Isabela Project, the goal of which is the ecological restoration of the northern part of Isabela Island.
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In July, CDRS and GNPS launched a one-year pilot study into the post-larval and juvenile phases of the red spiny lobster in Galapagos, one of the key species in the local fishing industry. The project's short-term goal is to develop a spatial and seasonal model for post-larval lobster recruitment and associated settling fauna for the red spiny lobster Panulirus penicillatus off the island of Santa Cruz that incorporates physical oceanographic parameters such as temperature and currents. The model will provide the basis for a long-term study of the relationships between climate, oceanography and recruitment and juvenile and adult numbers. The results will be incorporated into a predictive model to aid decision-making regarding fishing activity and climatic events.
"Increasing fishing pressure and the unique nature of the Galapagos Archipelago, and its vulnerability to large-scale changes such as El Niño events, demand an understanding of the early life history of these key species in their habitats as a tool for their conservation and protection," said Dr. Alex Hearn, coordinator of fisheries research at the station. "Regardless of whether we obtain lobster pueruli, the organisms on these collectors are going to provide us with interesting data on distribution of certain species, and may also help to increase the biodiversity count of the islands."
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In late June, dive guide Santiago Insuasti of the Aggressor fleet observed thousands of dead and moribund fish floating past his ship as it anchored off Darwin. Two specimens delivered by the guide to the CDRS marine research and conservation department were later identified as Lagocephalus lagocephalus, the oceanic puffer, by Dr. John McCosker acting director of the Steinhart Aquarium at the California Academy of Sciences and Dr. Jack Grove, marine biologist and author of Fishes of the Galapagos.
The puffer inhabits oceanic surface waters, and is not commonly encountered near the coast. Meanwhile, the cause for the observed die off remains a mystery. Although no fishing boat was observed in the vicinity, the fish may have been captured by fishermen and released as undesirable by-catch, or their death might have been caused by some undetermined environmental condition.
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CDRS herbarium curator Patricia Jaramillo visited Spain's University of Malaga in April to complete the latest phase of a three-year project to establish a pollen reference collection for all the endemic and selected other plants of Galapagos. "The aim is to create a pollen atlas for Galapagos that we can use in studies about pollinators, plant taxonomy, historical pollen records (fossil pollen) and the process of pollination," says Patty.
Pollen samples brought from Galapagos were prepared and then photographed under the electron microscope in the lab at Malaga. The samples were mainly endemic species and "doubtfully native" species, so named because of their cosmopolitan distribution in the world, a wide distribution in Galapagos and early records of them by the first botanists to visit Galapagos. Botanists are unsure whether these species arrived naturally, or were accidental introductions by the earliest human visitors to the islands.
"We hope that pollen data collected from sediments in lagoons and bogs may help us to answer that question," says Jaramillo. During 2004 to 2006, collaborating research groups will collect new sediment cores to try and determine the origin of some of the doubtful natives. Scientists will also investigate the question of whether humans visited the islands before their discovery by Europeans in 1535, which also has implications for the history of plant introductions to Galapagos.
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Santa Cruz Island is now free of feral pigeons (also known as rock doves), and the majority have been removed from San Cristobal Island. The remaining eight pigeons estimated on San Cristobal will be removed this year. Though CDRS and GNPS have not yet eradicated all pigeons from the archipelago, the project is regarded as highly successful as it provides an extremely useful model for future projects given its mix of survey, practical control methods, use of legislation, cooperation between public authorities, and quarantine and community participation.
The transfer of two pigeons from Isabela Island to Santa Cruz Island last year reinforced the need for inter-island quarantine and the urgency of completing the work to remove pigeons from the entire archipelago to reduce further risk of reinvasion. Building on previous successes, CDRS and GNPS will initiate an eradication campaign on Isabela Island to remove the last rock doves from the archipelago in 2005. In addition, GNPS will continue to use new local government by-laws implemented for the control of domestic animals to discourage residents from having pets that are detrimental to local conservation, agriculture or public health. CDRS, with the help of Dr Nicole Gottdenker, a veterinary pathologist from the St. Louis Zoo in the U.S., is currently documenting infections in rock doves, such as Salmonella, that could threaten native bird species or affect humans.
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GNPS personnel have contained introduced tree frogs in Isabela within a relatively small area though attempts to eliminate them from the areas where they are most abundant have not been successful to date. Research by Dr. Brian Cooke, an invasive species specialist with CDRS and Leo Zurita, a student of the University of San Francisco in Quito, has shown that the tadpoles of these frogs do not have a high tolerance of saline water. As a result frogs are restricted to areas where water is generally of good quality and only breed all year round in a few lagoons.
"We are investigating the idea that we could restrict frogs to even smaller areas by manipulating the level of salinity in some of the larger lagoons by pumping in sea water or applying raw salt crystals," says Dr. Cooke. "The changes necessary to affect frog tadpoles are relatively small so we anticipate that they will not greatly affect other wildlife, such as flamingos, that feed in hyper-saline pools as well as fresh water lagoons."
Recent studies on the frog-infested "Las Diablas" lagoon show that the lagoon remains relatively fresh because there is an inflow of very fresh water on its northern edge. This water probably originates as rainfall in the higher parts of the island and eventually reaches Las Diablas through cracks and fissures in the lava. Basic hydrological studies, such as estimating the volume of Las Diablas, water inflow and evaporation are essential for deciding on possible strategies for frog control.
"We need to know how much salt water must be pumped in from the sea, how well it would mix and distribute itself in the lagoon and how effective it would be in restricting frogs to limited areas where alternative, more costly control measures might be applied to finally eradicate them," says Dr. Cooke.
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An article submitted recently to Weed Technology by CDRS Botany staff consolidates 20 years of old unpublished trials and 5 years of recent control trials that led to the discovery of an effective control method by CDRS and GNPS for the red quinine tree, a very serious invasive tree on Santa Cruz Island. Quinine, known locally as cascarilla, now dominates vast areas of the island's highlands, areas formerly dominated by native shrubs, ferns and grasses.
"We are seeing a complete shift from natural shrubland and fern-sedge zone to introduced tall forest," says Chris Buddenhagen, a specialist in the control of introduced plants at the CDRS.
One of the methods, the application of a mix of two herbicides (picloram and metsulfuron) to machete hacks around the trunk of individual trees was shown to be the most effective of the methods, achieving nearly 100 percent control. This method showed promise in 2001 (before the study was finished) and has already been implemented to control more than 100 hectares near Cerro Crocker and Media Luna.
In cooperation with GNPS, a number of botanists, including Sarah Wilkinson, Mark Gardener, Alan Tye, Monica Soria, Patricio Yanez, Jorge Luis Renteria and Chris Buddenhagen, carried out the most recent trials. Rene Valle of GNPS and his control team were involved for a number of years and Rene is a coauthor of the article.
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CDRS botanists have reached an important milestone in their efforts to carry out a complete survey of introduced plants covering all of the inhabited zones of Galapagos. Since late 2002, Ana Mireya Guerrero, Paola Pozo, Anne Guézou and Sussy Chamorro of the botany department have been documenting the occurrence of introduced plants in Puerto Ayora, Santa Cruz Island. The group visited more than 2000 properties and completed the fieldwork in early 2004 where they recorded more than 300 species, at least 40 of which were not previously registered in Galapagos. More than 600 specimens were added to the herbarium collection.
Some of the species found on Santa Cruz may be invasive, though it should be feasible to eradicate some of these in consultation with landowners before they become established. Others may become the focus of community campaigns to encourage local gardeners to grow non-invasive and native plants.
To complete the surveys, botany staff will visit every property in the urban and agricultural zones of Isabela and San Cristobal islands and record or collect the introduced species that occur there. These properties are source areas from which introduced species escape into the Galapagos National Park. Complete knowledge of the introduced species present in the islands will help the Station and Park plan research and management strategies for the control of those that pose the greatest threat.
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Preliminary results of a study on a potential biocontrol agent to control the widespread invasive Lantana camara (locally known as supirrosa) in the CABI Bioscience laboratories in Ascot, England are promising. The results were outlined in an article recently submitted to Sida, Contributions to Botany by CDRS botanist Jorge Luis Renteria and Carol Ellison from CABI.
Lantana camara is a thorny, woody and smelly invasive shrub widespread on Floreana, forming huge dense patches, and is patchily problematic at sites on San Cristobal and Santa Cruz and present in a few sites on Isabela. The plant is dispersed by birds because of its small black fruit and by gardeners because of its pretty flowers. On Floreana Island it dominates nesting areas of the rare Galapagos petrel, and competes with native and endemic plant species, some of which are threatened.
Lantana camara plants from Galapagos and a number of plant species related to it were inoculated with Puccinea lantanae, a fungus isolated from Lantana camara in Peru. The plants were grown in special high humidity dew chambers at CABI and checked for the development of symptoms. The fungus did not attack any species apart from the target strain of Lantana camara, and most importantly, it did not attack Lantana peduncularis, a species endemic to Galapagos. Of all plant species tested in the study, only Lantana camara was infected by the rust - the plant lost its leaves and its shoot tips died. Further trials need to be carried out with more native and endemic species before the fungus can be seriously considered for release in Galapagos. This research phase will probably require at least two years of more work.
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