Hybrid Cuban-American Crocodiles on the Rise
Rare Cuban species in danger of being bred out of existence.
Christine Dell'Amore,National Geographic News,Published June 24, 2011
Editor -something old that I missed when it first was published and was sent to me Wed. and is definitely worth publishing)
There's a new Cuban crisis-the island country's rare crocodile is being loved to death by its American cousin, a new study suggests.
Mating Cuban crocodiles and American crocodiles are creating hybrid offspring that threaten the survival of the Cuban species, which has dwindled to about 4,000 wild animals in two isolated Cuban swamps. The ten-foot-long (three-meter-long) reptile is listed as critically endangered by the International Union for Conservation of Nature (IUCN).
"That means any loss of animals-be it loss in fact or loss through hybridization-is a grave concern," said John G. Robinson, executive vice president for conservation and science at the Wildlife Conservation Society.
American crocodiles, which are found throughout the Caribbean, are not considered threatened by IUCN. The animals have increasingly moved into the Cuban crocodile's remaining freshwater habitat as it becomes more brackish-or salty-due to agricultural activities, said Robinson, who was not involved in the research.
The Cuban crocodile is the most terrestrial of the crocodiles-walking instead of waddling on their bellies like other croc species, he added. "They're very cool beasts."
For the study, scientists led by Yoamel Milián-García, of the University of Havana, took DNA samples from 89 wild-caught crocodiles and 2 captive crocodiles.
Surprisingly, the results showed that American crocodiles living in Cuba are more closely related to Cuban crocodiles than to other American crocodile populations in Central America.
This suggests that the American and Cuban species are mating much more than thought. When different species mate to create hybrids, genes mix, and eventually one lineage can cause the extinction of the other.
The scientists haven't done behavioral studies to find out if the hybrids are stronger or more aggressive, which can sometimes happen when species interbreed.
Yet the study "will be a wake-up call" for conservationists in Cuba, who have already put a lot of effort into protecting the Zapata swamp-home to about 3,000 of the Cuban crocodiles, WCS's Robinson said.
One obvious strategy, he said, would be to restore the flow of fresh water into the swamps, which would make the habitat less palatable for the American crocodile.
Cuban-American hybrid crocodile research published in the spring issue of the Journal of Experimental Zoology.
Showing posts with label american crocodile. Show all posts
Showing posts with label american crocodile. Show all posts
Saturday, November 19, 2011
Sunday, August 7, 2011
Unhappy snaps
A photographer has been quizzed by police after the crocodile he brought to a lake for happy snaps with holidaymakers escaped terrifying hundreds of swimmers.
The six foot long reptile - at Lake Shira in Siberia, eastern Russia - gave his owner the slip as he haggled with tourists over the price of a souvenir photo, reports local media.
Horrified swimmer Anna Luneva said: "I was swimming and suddenly realised there was a crocodile in the water. I was so frightened I almost lost my mind.
"Everyone was panicking," she added.
A special police wildlife unit eventually recovered the crocodile, which is recovering at a nearby aquatic centre.
"It was quite a young crocodile and there is plenty of food in this lake - swimmers. We didn't want him to escape and grow any bigger," commented an officer.
http://web.orange.co.uk/article/quirkies/croodile_snaps
The six foot long reptile - at Lake Shira in Siberia, eastern Russia - gave his owner the slip as he haggled with tourists over the price of a souvenir photo, reports local media.
Horrified swimmer Anna Luneva said: "I was swimming and suddenly realised there was a crocodile in the water. I was so frightened I almost lost my mind.
"Everyone was panicking," she added.
A special police wildlife unit eventually recovered the crocodile, which is recovering at a nearby aquatic centre.
"It was quite a young crocodile and there is plenty of food in this lake - swimmers. We didn't want him to escape and grow any bigger," commented an officer.
http://web.orange.co.uk/article/quirkies/croodile_snaps
Wednesday, July 20, 2011
Threat to Cuban Crocodiles
DNA study confirms that wild populations of critically endangered Cuban crocodiles
are breeding with ubiquitous American crocodiles
Hybridization may threaten Cuban crocodiles--Study shows that Cuban and American crocs more closely related than previously thought
NEW YORK (June 22, 2011) WCS Press Release - A new genetic study by a team of Cuban and American researchers confirms that American crocodiles are hybridizing with wild populations of critically endangered Cuban crocodiles, which may cause a population decline of this species found only in the Cuban Archipelago.
Cuban crocodiles and American crocodiles have been confirmed to interbreed in captivity and were suspected to hybridize in the wild. This is the first genetic study that confirms wild hybridization.
The study, which appears in the spring issue of the Journal of Experimental Zoology, is by Yoamel Milián-García of the University of Havana; Miryam Venegas-Anaya of the Smithsonian Tropical Research Institute; Roberto Frias-Soler of the University of Havana; Andrew Crawford of the Smithsonian Tropical Research Institute; Roberto Ramos-Targarona, Roberto Rodríguez-Soberón, and Manuel Alonso-Tabet of Empresa Nacional para la Protección de la Flora y la Fauna; the late John Thorbjarnarson of the Wildlife Conservation Society; Oris I. Sanjur of the Smithsonian Tropical Research Institute; Georgina Espinosa-López of the University of Havana; and Eldredge Bermingham of the Smithsonian Tropical Research Institute.
Known for their leaping ability and aggressive disposition, Cuban crocs are a charismatic and culturally significant species to Cuba. Exact population estimates for the species remain unknown, though scientists believe that a minimum of 3,000 individuals remain in the Zapata swamp. A smaller population exists in the Lanier Swamp on the Island of Youth. The species was extensively hunted from the middle of the 19th century through the 1960s resulting in drastic population declines.
The team collected and analyzed DNA from 89 wild-caught Cuban and American crocodiles in the wild and two samples from crocodiles in zoos.
The genetic data produced an unsuspected result: American crocodiles in Cuba are more closely related to Cuban crocodiles than other American crocodile populations found along mainland Central America. The study found just a 1 percent genetic sequence divergence between Cuban crocodiles and American crocodiles in Cuba yet an 8 percent divergence between American crocodiles in Cuba and other American crocodile populations living in mainland Central America.
This finding indicates that Cuban crocodiles and American crocodiles in Cuba may represent two evolutionary significant units (ESU's) - populations considered distinct for conservation purposes and represent an important component of the evolutionary legacy of the species.
The team collected and analyzed DNA from 89 wild-caught Cuban and American crocodiles in the wild and two samples from crocodiles in zoos.
The authors say that hybridization may be one of the most important threats to Cuban crocodiles, along with illegal hunting and habitat modification. Hybridization can result in both replacement and genetic mixing, and one lineage may cause the extinction of another.
Based on evidence of hybridization between the two species, the authors strongly urge that efforts to avoid anthropogenic causes of hybridization be taken into account for future management plans of Cuban crocodiles.
The authors acknowledge the following: Faculty of Biology, University of Havana, Cuba; Marine Research Centre, Havana, Cuba; National Enterprise for the Conservation of Flora and Fauna, Cuba; Smithsonian Tropical Research Institute, Panama, Republic of Panama.
CONTACT: Stephen Sauter: (1-718-220-3682; ssautner@wcs.org)
John Delaney: (1-718-220-3275; jdelaney@wcs.org)
are breeding with ubiquitous American crocodiles
Hybridization may threaten Cuban crocodiles--Study shows that Cuban and American crocs more closely related than previously thought
NEW YORK (June 22, 2011) WCS Press Release - A new genetic study by a team of Cuban and American researchers confirms that American crocodiles are hybridizing with wild populations of critically endangered Cuban crocodiles, which may cause a population decline of this species found only in the Cuban Archipelago.
Cuban crocodiles and American crocodiles have been confirmed to interbreed in captivity and were suspected to hybridize in the wild. This is the first genetic study that confirms wild hybridization.
The study, which appears in the spring issue of the Journal of Experimental Zoology, is by Yoamel Milián-García of the University of Havana; Miryam Venegas-Anaya of the Smithsonian Tropical Research Institute; Roberto Frias-Soler of the University of Havana; Andrew Crawford of the Smithsonian Tropical Research Institute; Roberto Ramos-Targarona, Roberto Rodríguez-Soberón, and Manuel Alonso-Tabet of Empresa Nacional para la Protección de la Flora y la Fauna; the late John Thorbjarnarson of the Wildlife Conservation Society; Oris I. Sanjur of the Smithsonian Tropical Research Institute; Georgina Espinosa-López of the University of Havana; and Eldredge Bermingham of the Smithsonian Tropical Research Institute.
Known for their leaping ability and aggressive disposition, Cuban crocs are a charismatic and culturally significant species to Cuba. Exact population estimates for the species remain unknown, though scientists believe that a minimum of 3,000 individuals remain in the Zapata swamp. A smaller population exists in the Lanier Swamp on the Island of Youth. The species was extensively hunted from the middle of the 19th century through the 1960s resulting in drastic population declines.
The team collected and analyzed DNA from 89 wild-caught Cuban and American crocodiles in the wild and two samples from crocodiles in zoos.
The genetic data produced an unsuspected result: American crocodiles in Cuba are more closely related to Cuban crocodiles than other American crocodile populations found along mainland Central America. The study found just a 1 percent genetic sequence divergence between Cuban crocodiles and American crocodiles in Cuba yet an 8 percent divergence between American crocodiles in Cuba and other American crocodile populations living in mainland Central America.
This finding indicates that Cuban crocodiles and American crocodiles in Cuba may represent two evolutionary significant units (ESU's) - populations considered distinct for conservation purposes and represent an important component of the evolutionary legacy of the species.
The team collected and analyzed DNA from 89 wild-caught Cuban and American crocodiles in the wild and two samples from crocodiles in zoos.
The authors say that hybridization may be one of the most important threats to Cuban crocodiles, along with illegal hunting and habitat modification. Hybridization can result in both replacement and genetic mixing, and one lineage may cause the extinction of another.
Based on evidence of hybridization between the two species, the authors strongly urge that efforts to avoid anthropogenic causes of hybridization be taken into account for future management plans of Cuban crocodiles.
The authors acknowledge the following: Faculty of Biology, University of Havana, Cuba; Marine Research Centre, Havana, Cuba; National Enterprise for the Conservation of Flora and Fauna, Cuba; Smithsonian Tropical Research Institute, Panama, Republic of Panama.
CONTACT: Stephen Sauter: (1-718-220-3682; ssautner@wcs.org)
John Delaney: (1-718-220-3275; jdelaney@wcs.org)
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