Research published today in Molecular Ecology shows that female hawksbill turtles mate at the beginning of the season and store sperm for up to 75 days to use when laying multiple nests on the beach.
It also reveals that these turtles are mainly monogamous and don't tend to re-mate during the season.
Because the turtles live underwater, and often far out to sea, little has been understood about their breeding habits until now. The breakthrough was made by studying DNA samples taken from turtles on Cousine Island in the Seychelles.
The hawksbill turtle (Eretmochelys imbricata) was listed as critically endangered in 1996 by the International Union for Conservation of Nature (IUCN), largely due to a dramatic reduction in their numbers driven by the international trade in tortoiseshell as a decorative material – an activity which was banned in the same year.
The Seychelles are home to the largest remaining population of hawksbill turtles in the western Indian Ocean. Cousine Island is an important nesting ground for the hawksbill and has a long running turtle monitoring program. It is hoped that the research will help focus conservation efforts in future.
Lead researcher Dr David Richardson, from UEA's school of Biological Sciences, said: "We now know much more about the mating system of this critically endangered species. By looking at DNA samples from female turtles and their offspring, we can identify and count the number of breeding males involved. This would otherwise be impossible from observation alone because they live and mate in the water, often far out to sea.
"We now know that female turtles mate at the beginning of the season - probably before migrating to the nesting beaches. They then store sperm from that mating to use over the next couple of months when laying multiple nests.
"Our research also shows that, unlike in many other species, the females normally mate with just one male, they rarely re-mate within a season and they do not seem to be selecting specific 'better quality' males to mate with.
"Understanding more about when and where they are mating is important because it will help conservationists target areas to focus their efforts on.
"It also lets us calculate how many different males contribute to the next generation of turtles, as well as giving an idea of how many adult males are out there, which we never see because they live out in the ocean.
"Perhaps most importantly, it gives us a measure of how genetically viable the population is - despite all the hunting of this beautiful and enigmatic species over the last 100 years.
"The good news is that each female is pairing up with a different male – which suggests that there are plenty of males out there. This may be why we still see high levels of genetic variation in the population, which is crucial for its long term survival .This endangered species does seem to be doing well in the Seychelles at least."
Lead author Karl Phillips, a PhD student in UEA's school of Biological Sciences, added: "This is an excellent example of how studying DNA can reveal previously unknown aspects of species' life histories."
The research was funded by UEA and the Natural Environment Research Council (NERC) Biomolecular Analysis Facility (NBAF).
'Reconstructing paternal genotypes to infer patterns of sperm storage and sexual selection in the hawksbill turtle' by David S. Richardson, Karl P. Phillips, and Tove H.Jorgensen (all UEA) and Kevin G. Jolliffe, San-Marie Jolliffe and Jock Henwood (Cousine Island) is published by the journal Molecular Ecology on Monday, February 4, 2012.
Lisa Horton | Source: EurekAlert!
Further information: www.uea.ac.uk
More articles from Ecology, The Environment and Conservation:
New rearing method may help control of the western bean cutworm
09.12.2013 | Entomological Society of America
The invasive Turkestan cockroach is displacing the oriental cockroach in the southwestern US
09.12.2013 | Entomological Society of America
The molecular architecture of three key proteins and their complexes reveals how plants fine-tune their immune response to pathogens
Plants rarely get sick in their natural environment. When the threat of infection arises, a quick decision is made about the necessary countermeasures. The course is set by a protein which forms complexes with its partner proteins for this purpose.
Jane Parker from the Max Planck Institute for Plant Breeding ...
Researchers studying speciation of butterfly orchids on the Azores have been startled to discover that the answer to a long-debated question "Do the islands support one species or two species?" is actually "three species".
Hochstetter's Butterfly-orchid, newly recognized following application of a battery of scientific techniques and reveling in a complex taxonomic history worthy of Sherlock Holmes, is arguably Europe's rarest orchid species. Under threat in its mountain-top retreat, the orchid urgently requires conservation recognition.
A lavishly illustrated publication, titled "Systematic revision of Platanthera in ...
Researchers from Brown University and the University of Hawaii have found some mineralogical surprises in the Moon's largest impact crater.
Data from the Moon Mineralogy Mapper that flew aboard India's Chandrayaan-1 lunar orbiter shows a diverse mineralogy in the subsurface of the giant South Pole Aitken basin.
The differing mineral signatures could be reflective of the minerals dredged up at the time of the giant impact 4 billion years ago, ...
In power electronics systems bonded connections create the central electrical connections between adjoining surfaces.
The quality of these bonded connections is one of the main factors that determines the reliability and availability of drive systems in electric vehicles, and hence constitutes a major design challenge for German auto manufacturers aiming to electrify their vehicles.
Now the partners participating in the RoBE (Robust Bonds in ...
International team of scientists develops new feedback method for optimizing the laser pulse shapes used in the control of chemical reactions
In many ways, traditional chemical synthesis is similar to cooking. To alter the final product, you can change the ingredients or their ratio, change the method of mixing ingredients, or change the temperature or pressure of the environment of the ingredients.
Like an accomplished chef, chemists have become very skilled ...
11.12.2013 | Information Technology
11.12.2013 | Life Sciences
11.12.2013 | Agricultural and Forestry Science
11.12.2013 | Event News
10.12.2013 | Event News
05.12.2013 | Event News