Tuesday, August 9, 2011
Protecting the Galapagos Islands' wildlife
Endangered breeds like the giant tortoise, which can live for over 150 years, are protected by the conservation programme.
John McIntyre reports from the reserve.
watch video here:
http://news.bbc.co.uk/1/hi/programmes/fast_track/9554939.stm
Monday, June 20, 2011
Giant tortoise bachelors Al and Tex find romance at long last
Al and Tex, two giant tortoise buddies who hadn't been around a female in more than 20 years and were in sad need of a date, appear to have discovered lust at first sight with a couple of hotties from Atlanta, the Knoxville News Sentinel reported.
At first glance, Al and Tex don't sound like George Clooney and Brad Pitt. Al is 130 years old and weighs 250 kilograms while Tex, a mere 90, tips the scale at 160kg.
Al last saw a female tortoise in 1983 and Tex, whose memories are a little more recent, was last around a lady friend in the late 1980s.
Both residents of the Knoxville Zoo, "the boys" needed some matchmaking help.
Enter the zoo's assistant curator of herpetology Michael Ogle, who helped arrange a hookup with two Zoo Atlanta female tortoises, Patches and Corky.
The temptresses are both younger (60 to 70) and svelte (90-115kg).
But first, the News Sentinel reported, the male and female tortoises had to spend four to five months apart to successfully reproduce - it's a tortoise thing, don't ask.
So the boys and girls switched zoo homes for a while, since neither had enough space to house all four separately.
On Wednesday, Mr Ogle drove Al and Tex back from Atlanta to meet Patches and Corky, alluringly awaiting them in a clover-filled exhibit.
For Al, romance blossomed instantly and he moved much faster than normal tortoise speed to mate with Patches.
Tex, who has an arthritic-like leg condition, paced himself more slowly but at least seemed interested in the tantalising twosome.
The goal, of course, is baby tortoises, to be shared between the two zoos. But it will have to be a fleeting summer romance - Corky and Patches are due back in Atlanta come October.
Tuesday, April 26, 2011
Giant tortoises show rewilding can work (Via HerpDigest)
'Rewilding with taxon substitutes', the intentional introduction of exotic species to fulfil key functions in ecosystems following the loss of recently extinct species, is highly controversial, partly due to a lack of rigorous scientific studies.
In a paper published today in Current Biology, Christine Griffiths of Bristol's School of Biological Sciences and colleagues present the first empirical evidence that rewilding can work.
Exotic giant Aldabra tortoises, Aldabrachelys gigantea, were introduced to Ile aux Aigrettes, a 25-hectare island off Mauritius, in 2000 to disperse the slow-growing ebony Diospyros egrettarum (Ebenaceae), which once covered the island, but today is critically endangered following intensive logging for firewood that lasted until the early 1980s.
To highlight the extent to which the ebony forest had been decimated, the researchers surveyed and mapped all ebony trees in an island-wide survey in 2007 and located a total of 3,518 adult trees. However, large tracts of the island remained denuded of ebony, particularly in the northern and eastern coastal areas nearest to the mainland where logging was most intense.
There had been no regeneration in these areas even though logging ceased thirty years ago because, with the extinction of the island's native giant tortoises, there were no large fruit-eating animals left to disperse the seeds of these critically-endangered trees.
The introduced Aldabra tortoises not only ingested the large fruits and dispersed large numbers of ebony seeds, but the process of passing through a tortoise's gut also improved seed germination, leading to the widespread, successful establishment of new ebony seedlings in the heavily logged parts of the island.
Christine Griffiths said: "Our results demonstrate that the introduction of these effective seed dispersers is aiding the recovery of this critically endangered tree whose seeds were previously seed-dispersal limited. Reversible rewilding experiments such as ours are necessary to investigate whether extinct interactions can be restored."
Professor Stephen Harris, co-author of the study, said: "Ecological restoration projects generally involve the plant community, as more often the animal components are extinct. There is, however, increasing evidence that restoration ecologists should be most concerned with the decline of species interactions, rather than species extinctions per se. Species interactions structure ecological communities, and provide essential ecosystem processes and functions such as pollination, seed dispersal and browsing, that are necessary for the self-regulation and persistence of a community."
Contact: Hannah Johnson
hannah.johnson@bristol.ac.uk
44-117-928-8896
University of Bristol
Wednesday, June 2, 2010
Giant tortoises released onto Pinta Island for the first time for 40 years
June 2010. 39 tortoises have been released into the wilds of Pinta Island, in the northern waters of the Galapagos Archipelago, as part of an ongoing effort to restore the ecological integrity of Pinta ecosystems. This is the first time that tortoises have inhabited the island since the removal of Lonesome George, the last known Pinta tortoise, in 1972.
The return of tortoises to Pinta is considered an essential step towards re-establishing ecological processes on the island. The Ministry of the Environment of Ecuador is overseeing this vital step in the implementation of the plan for the ecological restoration of Pinta.
Lonesome George last of his kind
Giant tortoises on Pinta are thought to have numbered between 5,000 and 10,000 before pirates and whalers began removing them for food. As a result of the over-exploitation in past centuries, tortoises were believed to be extinct on Pinta during much of the twentieth century. The discovery of Lonesome George on Pinta in 1971 surprised scientists and park managers alike. George was transported to the Tortoise Center on Santa Cruz Island in the spring of 1972 to ensure his safety. While park rangers, scientists and the thousands of tourists who have visited George hope that one day a mate will be discovered-on Pinta, in a zoo, or in a private collection-no female Pinta tortoise has yet been found.
In addition to the removal of giant tortoises, which are known to play an important role as "ecosystem engineers" through movement patterns, herbivory, and seed dispersal, Pinta also suffered large-scale degradation by introduced goats. Three goats released onto Pinta in 1959 eventually resulted in a population of more than 40,000 animals, which destroyed much of the island's native vegetation. After the GNP achieved eradication of the goats from the island in 2003, the vegetation recovered rapidly. However, full and balanced island restoration required the presence of Galapagos giant tortoises.
Hybrid tortoises sterilized and releasedWhile ongoing genetic studies are helping to determine the best species with which to repopulate the island, it is important that tortoises be released onto Pinta as soon as possible. The decision was made to use the hybrid tortoises held in corrals of the GNP on Santa Cruz and Floreana for this purpose. These tortoises are the offspring of tortoises of unknown origin held in captivity during the early years of the GNP. Given that one of the main goals of the GNP is to conserve the evolutionary integrity of the archipelago's biodiversity, release of hybrid tortoises into the wild is unacceptable. Therefore, these tortoises were destined to spend their entire lives-as much as 150 years or more-in captivity. By sterilizing these tortoises, they can now be released into the wild on Pinta as non-reproducing contributors to the restoration of the island's ecosystem.
A group of veterinarians from the United States, led by Drs. Steve Divers (College of Veterinary Medicine, University of Georgia), Sam Rivera (Zoo Atlanta), and Joe Flanagan (Houston Zoo), worked with the GNP to sterilize the tortoises in November 2009. Since that time, the tortoises have been held in quarantine in a corral separate from all other captive tortoises. Their health is monitored and their faeces are also inspected to determine if they have consumed any seeds. It is essential to ensure that the tortoises do not introduce any plant species to the nearly pristine island. The tortoises will also be fitted with satellite and telemetry tags so that scientists can monitor their movements on Pinta.
This project has been made possible by funding from the Galapagos National Park, and generous contributions of the Panaphil Foundation, Continental Airlines, Buffalo Exchange, SUNY-ESF, the Houston Zoo, a number of veterinarians who have donated their services, and approximately 1,000 Galapagos Conservancy members.
Galapagos Conservancy is dedicated exclusively to the long-term protection of the Galapagos Islands. This single focus allows us to maximize the impact of the financial investments of our members, who include individuals and institutions that care deeply about the Galapagos Islands and understand the scientific importance of preserving this extraordinary ecosystem.
Under the leadership of the Minister of the Environment, the tortoises' release was carried out by a team of park rangers, herpetologists, botanists, and veterinarians-from the Galapagos National Park (GNP), Galapagos Conservancy, the State University of New York College of Environmental Science and Forestry (SUNY-ESF), and the Houston Zoo.
