Carotenoid deprivation and beta-carotene's effects on male and female turtle color.

Carotenoid-colored integuments commonly function as sexually selected honest signals because carotenoid pigments can be costly to obtain, ingest, absorb, metabolize or transport before being deposited into the integument. As such, carotenoid pigmentation is often sexually dichromatic, with males being more colorful than females. Sexual dichromatism may also occur in ultraviolet (UV) wavelengths, which is visible to organisms who possess UV-sensitive photoreceptors.

The effect of dietary carotenoid increase on painted turtle spot and stripe color.

Determination of how carotenoid-based color patches change with pigmentary access is important to understanding color patch function in animals. We performed a carotenoid addition experiment on male painted turtles (Chrysemys picta) to determine if an increase in dietary carotenoids led to location-specific changes in painted turtle spot and stripe color. Turtles fed large quantities of carotenoids had increased yellow chroma in chin stripes and increased red chroma in the neck and carapace stripes, as well as reduced ultraviolet (UV) chroma in the neck (orange to the human eye) and fore -limb (red to the human eye) stripes.

Host stress response is important for the pathogenesis of the deadly amphibian disease, Chytridiomycosis, in Litoria caerulea.

Chytridiomycosis, a disease caused by Batrachochytrium dendrobatidis, has contributed to worldwide amphibian population declines; however, the pathogenesis of this disease is still somewhat unclear. Previous studies suggest that infection disrupts cutaneous sodium transport, which leads to hyponatremia and cardiac failure. However, infection is also correlated with unexplained effects on appetite, skin shedding, and white blood cell profiles.

Perch-height specific predation on tropical lizard clay models: implications for habitat selection in mainland neotropical lizards.

Predation has been hypothesized to be a strong selective force structuring communities of tropical lizards. Comparisons of perch height and size-based predation frequencies can provide a unique window into understanding how predation might shape habitat selection and morphological patterns in lizards, especially anoles. Here I use plasticine clay models, placed on the trunks of trees and suspended in the canopy to show that predation frequency on clay models differs primarily according to habitat (canopy vs.

A field test of female mate preference for male plumage coloration in eastern bluebirds.

A growing body of evidence shows that female birds use male plumage coloration as an important criterion in mate choice. In the field, however, males with brighter coloration may both compete better for high quality territories and be the object of female choice. Positive associations between territory quality, male-male competitive ability, and female preferences can make it difficult to determine whether females actively choose the most ornamented males.

How dewlap color reflects its carotenoid and pterin content in male and female brown anoles (Norops sagrei).

Sexually selected colors in animals can be created by multiple pigments (e.g., carotenoids, melanins, pterins), but how these pigment classes interact to generate intraspecific color variation has rarely been tested, especially in reptiles.

Contributions of pterin and carotenoid pigments to dewlap coloration in two anole species.

Animals can acquire bright coloration using a variety of pigmentary and microstructural mechanisms. Reptiles and amphibians are known to use two types of pigments - pterins and carotenoids - to generate their spectrum of colorful red, orange, and yellow hues. Because both pigment classes can confer all of these hues, the relative importance of pterins versus carotenoids in creating these different colors is not always apparent.