KNOXVILLE, Tenn., May 13 (UPI) -- U.S. ecologists have discovered rare traits persist in a population because predators prefer common forms of prey and ignore variations.
University of Tennessee Assistant Professor Benjamin Fitzpatrick, who led the research, found birds will target salamanders that look like the majority -- even reversing behavior in response to alterations in the ratio of a distinguishing trait.
He worked with Kim Shook and Reuben Izally in studying the effects of the prevalence of a dorsal stripe among a group of salamanders on the foraging behavior of a flock of Blue Jays.
The researchers said they put a selection of model salamanders into a field for six days, with striped models outnumbering the unstriped by 9-to-1, or vice versa. On test days, the numbers were evened. They discovered in each case the birds were more likely to attack salamanders that had been most prevalent during the previous six-day period.
"We believe the different color forms represent different ways of blending in on the forest floor," Fitzpatrick said. "Looking for something cryptic takes both concentration and practice. Predators concentrating on finding striped salamanders might not notice unstriped ones.
"Thus," he added, "the maintenance of color variation in terrestrial salamanders might be explained by the oldest and most obvious hypothesis -- rare form advantage arises because predators tend to overlook rare prey."
The study appears in the journal BMC Ecology.
