April 29, 2009 -- Females of an Australian species of lizard rely on testosterone for a most unusual method of keeping amorous males off their backs, researchers have found. Evolutionary ecologist Devi Stuart-Fox of the University of Melbourne and colleagues report their findings online ahead of print publication in the Journal of Comparative Physiology A. In most animals that use colorful displays for attraction, such as the peacock, it's usually the male that's flashy. But the female Lake Eyre dragon lizard (Ctenophorus maculosus) is an exception. She displays a bright orange belly and throat during parts of her breeding season, which researchers think is driven by the hormone testosterone. Related Content:
Interestingly, the color features prominently when the female wants to put off a male from copulating with her. Stuart-Fox and colleagues took a close look at a number of female lizards taken from Lake Eyre in South Australia and observed what happened when they were in the company of males. When Lake Eyre lizards copulate, the male bites the female's neck, climbs on top of her, wraps his tail around hers and inserts one of his two penises. This can be hazardous to the health of the female, because when the males bite them on the neck they can pierce the female's spine, killing her. Therefore, once the female's eggs have been fertilized, she will try to avoid mating. But males aren't easily put off. Get More NewsSpiders, Scorpions Among World's Oldest CreaturesMany creepy crawlies have been on Earth much longer than previously believed.Blood-Sucking Vampire Bats Sing DuetsWhite-winged vampire bats "harmonize" with separated roost mates.Oldest Hebrew Writing Possibly FoundAncient inscriptions on a 3,000-year-old pottery shard could make history.Rare, Prehistoric-Age Reptile Found in N.Z.A tuatara has been spotted on the New Zealand mainland for the first time in 200 years.Iceman Has No Living RelativesOetzi, the 5,300 year-old frozen mummy, left no living genetic legacy.SLIDE SHOW: Landscapes of TerrorWhat makes a place feel scary? There are scientific explanations.It's Official: People Are Warming the PolesHumans are conclusively to blame for polar warming, say scientists.Eight-Armed Animal Preceded DinosaursWhat may be one of Earth's first animals was no bigger than a coaster and had eight arms.Phoenicians Live on in People's GenesOne in 17 Mediterranean men may be descended from ancient Phoenicians.Pesticides, Fertilizers Linked to Frog DeclineA pesticide is found to promote parasites among amphibians.Hubble Telescope Taking Photos AgainThe Hubble Space Telescope is once again snapping stunning photos of the universe.Andean Mummy Hairs Show Hallucinogen UseScientists find direct evidence of hallucinogenic drug use among ancient Andeans.Opals on Mars Reveal Planet's Long Wet PastOpals found on Mars suggest the planet has been wet for much longer. |
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