Most interesting---and what are the primary sources of mercury, as entry agents into the food chain? That would be the next question.
On Sun, Dec 12, 2010 at 11:39 PM, Gordon <[email protected]> wrote: > > > Christine Dell'Amore > > National Geographic News <http://news.nationalgeographic.com> > > Published December 3, 2010 > > Male birds that eat mercury-contaminated food show "surprising" homosexual > behavior, scientists have found. > > In a recent experiment in captive white ibises, many of the males exposed to > the metal chose other males as mates. > > These "male-male pairs did everything that a heterosexual pair would do," > said study leader Peter Frederick > <http://www.wec.ufl.edu/faculty/frederickp/> , a wildlife ecologist at the > University of Florida in Gainesville. > > "They built their nest, copulated together, stayed together on a nest for a > month, even though there were no eggs-they did the whole nine yards." .. > > http://news.nationalgeographic.com/news/2010/12/101203-homosexual-birds-merc > ury-science/ > > > > Proceedings of the Royal Society B: Biological Sciences, published online > December 1, 2010 > > Altered pairing behaviour and reproductive success in white ibises exposed > to environmentally relevant concentrations of methylmercury > > 1. > <http://rspb.royalsocietypublishing.org/search?author1=Peter+Frederick&sorts > pec=date&submit=Submit> Peter Frederick > <http://rspb.royalsocietypublishing.org/content/early/2010/11/24/rspb.2010.2 > 189.abstract?sid=4c63cdc0-93a4-4c67-8633-75275cbcfed5#aff-1> 1, > <http://rspb.royalsocietypublishing.org/content/early/2010/11/24/rspb.2010.2 > 189.abstract?sid=4c63cdc0-93a4-4c67-8633-75275cbcfed5#corresp-1> * and > > 2. > <http://rspb.royalsocietypublishing.org/search?author1=Nilmini+Jayasena&sort > spec=date&submit=Submit> Nilmini Jayasena > <http://rspb.royalsocietypublishing.org/content/early/2010/11/24/rspb.2010.2 > 189.abstract?sid=4c63cdc0-93a4-4c67-8633-75275cbcfed5#aff-1> 1, > <http://rspb.royalsocietypublishing.org/content/early/2010/11/24/rspb.2010.2 > 189.abstract?sid=4c63cdc0-93a4-4c67-8633-75275cbcfed5#aff-2> 2 > > 1. 1Department of Wildlife Ecology and Conservation, University of > Florida, Gainesville, FL, USA > 2. 2Department of Basic Veterinary Sciences, Faculty of Veterinary > Medicine and Animal Science, University of Peradeniya, Peradeniya, Sri Lanka > > > 1. * Author for correspondence ( <mailto:[email protected]> > [email protected]). > > Abstract > > Methylmercury (MeHg) is the most biologically available and toxic form of > mercury, and can act as a powerful teratogen, neurotoxin and endocrine > disruptor in vertebrates. However, mechanisms of endocrine impairment and > net effects on demography of biota are poorly understood. Here, we report > that experimental exposure of an aquatic bird over 3 years to > environmentally relevant dietary MeHg concentrations (0.05-0.3 ppm wet > weight) resulted in dose-related increases in male-male pairing behaviour > (to 55% of males), and decreases in egg productivity (to 30%). Dosed males > showed decreased rates of key courtship behaviours, and were approached less > by courting females in comparison to control males. Within dosed groups, > homosexual males showed a similar reduction when compared with dosed > heterosexual males. We found an average 35 per cent decrease in fledgling > production in high-dose birds over the study duration. These results are of > interest because (i) MeHg exposure is experimentally tied to demographically > important reproductive deficits, (ii) these effects were found at low, > chronic exposure levels commonly experienced by wildlife, and (iii) effects > on reproductive behaviour and sexual preference mediated by endocrine > disruption represent a novel and probably under-reported mechanism by which > contaminants may influence wild populations of birds. > > > > > > > ---- > Join or Leave mou-net: http://lists.umn.edu/cgi-bin/wa?SUBED1=mou-net > Archives: http://lists.umn.edu/archives/mou-net.html > ---- Join or Leave mou-net: http://lists.umn.edu/cgi-bin/wa?SUBED1=mou-net Archives: http://lists.umn.edu/archives/mou-net.html
