CHARLES DARWIN RESEARCH STATION NEWS BULLETIN
- More Galapagos petrels discovered
- New colonies of rare endemic rice rat found on Santiago Island
- Alcedo volcano rich in invertebrate species
- Darwin Day 2005: linking science and community
- More teachers and students discover the Galapagos Islands
An exhaustive exploration of potential nesting sites of the Galapagos petrel, Pterodroma phaeopygia (also known as the dark-rumped petrel) found around 300 new nests on Santa Cruz Island. With this exciting new discovery, we are thrilled with the possibility that the seabirds which nest on this island may be extending their nesting areas.
"The information that was available on the distribution of the species on Santa Cruz Island was restricted to well-known colonies on Cerro Media Luna," said Juan Carlos Valarezo, a volunteer with CDF. "Now, following three months of intensive exploration of the Santa Cruz highlands, we have new information on their distribution on the island and the recovery of their population."
At Cerro Media Luna, 385 nests were known, over an area of nine hectares. The largest and most abundant of the newly identified colonies was discovered within the National Park where they are now benefiting from a protection programme aimed at reducing the impacts of invasive species on their reproduction. Of the 200 nests in this colony 180 were being used when found.
Galapagos petrels nest solely in the highlands of Santa Cruz, Santiago, San Cristobal, Floreana and Isabela Islands. This new research has almost doubled the known population of these rare and endangered birds on Santa Cruz.
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Two new populations of the endemic rice rat, Nesoryzomys swarthi, were discovered on the northern coast of Santiago Island during a monitoring expedition in March this year led by Oxford University student Stephen Gregory. Stephen has been involved in a study of this species since 2002, in association with the CDF Vertebrate Ecology team.
Three of the seven species of rice rats endemic to the Galapagos Islands are extinct. The four remaining species are N. narboroughii and N. fernandinae on Fernandina Island, N. swarthi on Santiago Island, and Oryzomys bauri on Santa Fe.
The two sites on Santiago Island where Nesoryzomys swarthi were detected are near the previously known population, at the site called La Bomba. The population densities of the endemic rice rats at the two new sites are lower than at La Bomba, but they represent a significant increase in the known population of the species. This range extension does not alter the highly endangered status of this unique species. No other populations of N. swarthi were found while searching for potential sites on western Santiago. Only the black rat, Rattus rattus and the common mouse, Mus musculus, were found in the baited live traps.
At the sites where the endemic rice rat species was found, there was also a large quantity of the endemic cactus, Opuntia galapageia. Marjorie Riofrío, CDF volunteer, says: "This tends to confirm results from recent research that a relationship exists between this plant and the presence and survival of the rice rat N. swarthi."
She adds: "While the endemic and introduced rodent species can coexist in the same habitat, the population of endemic rice rat is small compared to the introduced black rat. These population numbers underscore the grave threat posed to the endemic rat population by the presence of the more aggressive black rat, which can compete with it for resources. Research indicates that the endemic rice rat may be able to resist a prolonged drought while the introduced rat cannot. We believe it is important to continue to look for evidence of N. swarthi populations on the eastern part of the island because of its drier environment."
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Alcedo Volcano, on Isabela Island, was until recently one of the largest and most intact volcano ecosystems in the Galapagos. Currently under restoration from the impacts of feral goats, Alcedo also has been the site of a long-term invertebrate monitoring program. Entomologists from the CDF monitored an entire altitude gradient of the volcano between 1997 and 2001 to collect baseline information about invertebrate species distribution and populations. CDF scholarship student, Ana Maria Ortega, analysed the monitoring results as her thesis project.
"I collected the work of the many people who have worked in invertebrate research in Alcedo over many years," says Ortega. "This was a fascinating project that has so many positive outcomes - for conservation in general, new data are now available to other scientists and, for my own academic development."
Ortega prepared 25,624 specimens from among the 670 species that had been collected. The work showed that the transition zone found at 550 metres above sea level (masl) had a larger variety of species compared to the low and summit dry zones, at 0 masl and 1,120 masl.
The analysis of the presence and distribution of different species contributes to the knowledge about the diversity of invertebrate species found at the Alcedo volcano and to understanding the distribution patterns of invertebrates along the altitude gradients which will help scientists and park managers develop strategies for protecting these areas.
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Darwin Day 2005 provided an excellent opportunity to strengthen the link between science and the local community, showing island residents the importance of science in their daily lives. The event, which took place on Santa Cruz Island from 8 - 10 September, attracted nearly 3,000 visitors, including students from local schools and community members.
This year's event featured a new, interactive educational exhibit with displays related to marine environments, lobster fishing, and sea cucumber harvesting. Other science projects featured in the exhibit included the monitoring of the Dengue mosquito Aedes aegypti, the restoration of the Scalesia pedunculata forest at the site Los Gemelos (twin craters in the highlands of Santa Cruz Island highlands), the study of plant diseases, the monitoring of bird mortality due to traffic along the highway that crosses Santa Cruz from the coast town of Puerto Ayora to the Itabaca channel, and more.
CDF Executive Director Graham Watkins, praised the local community for its interest in conservation and biodiversity in the Galapagos. "We're very happy with this year's attendance which represents about 20 percent of the Santa Cruz community," said Watkins. "CDF couldn't carry out its research without the support of the local communities."
Darwin Day 2005 marked the 170th anniversary of Charles Darwin's arrival in the Galapagos archipelago. This annual event showcases the decades of research and collaborative work by CDF. During the three-day event, CDF staff members were on hand to provide support and answer questions from visitors, playing a vital role in linking the scientists with their neighbors and bringing research into the daily life of our towns.
CDF plans to hold similar events on other islands in the near future. "We look forward to community involvement on San Cristobal and Isabela Islands in similar events to highlight the work being carried out in collaboration with community leaders and institutions on each island," said Watkins.
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In 1998, Lindblad Expeditions launched the "Teachers on Board" programme in the Galapagos Islands to give local teachers and students the opportunity to experience the natural richness of the islands and to foster an understanding of the importance of maintaining their ecological balance. The Lindblad Expeditions ship Islander recently hosted 43 teachers and 32 students from primary and high schools on San Cristobal, Isabela and Santa Cruz islands for a five-day tour of the archipelago. The group, which also included two local radio journalists, visited Genovesa, Bartolome, and Santiago islands, and the northwest of Isabela and Fernandina. For many it was the first time they had visited these locations or even their first time on other islands.
"The Lindblad Expedition ships, Polaris and Islander, take the teachers to the other side of Galapagos to give them a greater appreciation of the place where they live," said CDF staff member Sandra Tapia, who helps coordinate the programme.
CDF entomologist Piedad Lincango assisted with the on board activities and said that the passengers were enthusiastic and delighted throughout the trip. "They felt fortunate to see blue- and red-footed boobies, Nazca boobies, frigate birds, iguanas, sea lions, dolphins, turtles and mangroves, as well as the geological and scenic beauty that makes the Galapagos Islands an earthly paradise," said Lincango.
Using the trip's slogan of "You can't love what you don't know", the teachers discussed the benefits of conservation and recreation in the islands, and how to promote the protection and restoration of the environment. During an action-packed five days, the guests took part in a wide range of activities that included mural painting and a coastal clean up.
At the end of the journey the teachers and journalists pledged to continue conservation efforts for the archipelago with students and the community to ensure the continued wellbeing of the natural habitat and citizens on the islands.
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