Lizard Love

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Anolis lizards have a thing or two to teach humans about love — or in scientific speak, sexual selection — at least when it comes to territoriality.Decades of behavioral research on the lizard’s mating systems have resulted in near-unanimous agreement among scientists that the males maintain restricted, static territories to defend exclusive mating access to females within these territories and are consequently polygamous.
However, recent genetic data shows that female Anolis sagrei — a brown lizard native to Cuba and the Bahamas but well established in Florida — also have multiple partners.
UC Santa Barbara behavioral ecologist Ambika Kamath and colleague Jonathan Losos of Washington University in Saint Louis eschew the framework of territoriality. Rather, they quantify movement patterns of the lizards and estimate encounters between potential mates. Their finding: The species’ movement behavior can be more dynamic than previously thought, leading females to frequently encounter multiple males and suggesting the possibility that female mate choice may be an important selective force.
Kamath’s and Losos’ research is published in the Proceedings of the Royal Society B.
“Understanding animals’ movement patterns and the encounters they bring about is a key step in characterizing a population’s mating system and essential for determining how behavior both facilitates and is subject to sexual selection,” explained Kamath, a postdoctoral scholar in UCSB’s Department of Ecology, Evolution, and Marine Biology. “The movement patterns of these lizards revealed not only that a majority of males (60 percent) encountered multiple females but also that most females (78 percent) encountered multiple males over the first three months of the breeding season. This suggests potentially complex mating patterns with ample scope for female choice.”
The researchers characterized sexual selection by examining the predictors of male reproductive success at two levels. First, they asked whether the number of potential mates encountered by males was associated with their phenotype (the spatial extent of …

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