Sex violence threatens female lizards

There are too many guys surrounded by a disadvantage for female lizards. Scientists have found that excess males will cause lizards to experience violent mating, reducing their ability to survive and reproduce.

The violence of males during mating is in many species. For example, red striped snakes often make children choke when coping. But this is the first study to show that it affects population, said researcher Xavier Lambin at the University of Aberdeen, Scotland.

The researchers tracked the reproduction of two groups of Lacerta vivipara lizards in a field. In one group, 78% of adults are female, while in the other group, 78% are male. After one year, the group with more children increased from 73 to 118. In contrast, in the excess group, the number dropped to 35, and more males than before. Children in the male-dominated group also died 4 times more than normal, and gave birth to 3-4 children per year compared to the usual 5.

Researchers surmised that the children had died from stress because they had to constantly "mate" their partners. " The children living with more males will suffer more violent mating ," explained Jean-François Le Galliard, the head of the study.

He also said that male lizards often bite their partners when excited, causing her to lose a piece of skin on her back. In the excess male group, the surviving females lost three times as much skin as the other females.

Researchers have found that male redundancy can eventually push the population to death. This means that some species of precious animals whose sex ratio has been disproportionately difficult to regain balance, once the males are not gentle with their partners.

MT ( Nature )