Article Review: "Larger females are choosier in the gray treefrog (Hyla versicolor)"

This article was published on November 28, 2016 in the Behavioural Processes Journal . It was written by Michael C. Kuczynski, Thomas Getty, and Eben Gering. The article examines how the choosiness of the larger females of the H. versicolor impacts the species' trait diversity and the evolution of sexual traits. They tested the relationship between female choosiness and female body size, physical condition, and age with how far the different females were willing to travel to reach the attractive male call. They collected 50 (30 young and 20 old) sexually mature females of varying lengths and placed them in a chamber for the playback trials of male calls, which were created from recordings made in the summer of 2014. The unattractive call was set for a "near" amplitude for every test, and the speaker was placed opposite of the attractive speaker. The distance the female traveled was observed and their response time between the first and last trial was recorded after they were played four different call samples. They were able to vary the amplitude of the calls to simulate calls that were close or far away, so they did not have to move the speakers. After testing, length, weight after laying eggs, and physical condition of each female was recorded. Based on their weight and size the female frogs were placed into either the old or young category after testing. Female motivation was constant during the trials and no relationship was observed between response time and female length, weight, or condition through out the trials. Length of the female was the only strong predictor of choosiness. It was found that as predicted, the large female gray tree frogs were more likely to travel longer distances to reach the attractive male call than the small females were. Contrary to the prediction, female age and physical condition was not a concrete predictor of choosiness.

This research shows that there is deliberate size-dependent variation in choosing a mate in the gray tree frog species. Female preference can alter the population's sexual characteristics, this can help us to understand how certain male secondary sexual characteristics, like male calling properties, came about in this population, or how speciation was influenced. It is interesting to see how strong the influence of the general female preference of a frog population is and how it is able to determine the sexual trait  characteristics of the males in this species. This may open up new opportunities to understand how the influence of genes and the environment influence characteristics, like body size, to mold female's mate choice and the characteristics of the males and the evolution of female preference.
Link: https://www.researchgate.net/profile/Eben_Gering/publication/311158568_Larger_females_are_choosier_in_the_gray_treefrog_Hyla_versicolor/links/5a1ac2280f7e9be37f9be03d/Larger-females-are-choosier-in-the-gray-treefrog-Hyla-versicolor.pdf