Why does the female Eastern Fence Lizard find the blue patches on the undersides of the male Fence lizard so sexy? And why is the male Eastern Fence Lizard turned off by blue females?
Sounds like a mystery, doesn’t it?
A team of biologists from Pensslyvania State University, headed by Tracy Langkilde, has revealed some insights on this mystery. The team of scientists has tried to evaluate how the blue color affects female lizards. According to their study, which was presented recently at the annual meeting of the Society for Integrative and Comparative Biology, despite some disadvantages, the blue female Eastern Fence Lizard will usually run faster and have stronger offsprings that survive better than fence lizards that are not blue.
Who is the Eastern Fence Lizard?
Known also as the Prairie Lizard, Gray Lizard, and scientifically as Sceloporus undulatus, the Eastern Fence Lizard is a medium-sized lizard found on rocks and tree stumps in the eastern region of the United States. The gray (female) or brown (male) lizard has keeled scales with a dark line stretched along its thigh. They will grow to lengths of between 4-7 inches. A remarkable study from 2009 revealed that the Eastern Fence lizard has evolved in 70 years and developed longer legs, in order to escape the red fire ants, which can easily kill the fence lizard. Several years ago, Biologist Tracy Langkilde conducted a research on native fence lizards and their adaptive reactions to the presence of the invasive fire ant.
Watch this video and interview with Tracy Langkilde:
Back to the new study on how blue rules their lives, the biologists suggest that various traits can have different costs and benefits for the two sexes of lizards.
According to the study, the blue patches of the males appeal to females, while on the other hand, males prefer to mate with non-blue females. They sometimes even mistaken blue female fence lizards for other males, and therefore do not harass them. Further more, blue females are slower to lay their eggs, which also weigh less than the clutches of eggs of non-blue females. However, the blue female fence lizard runs faster, according to the study, and reaches speeds of 1.5 meters per second, compared to only 1.2 m/s for non-blue females.
For those interested, here is some more info about the leading biologist in this study, Tracy Langkilde.