Researchers in Minnesota studying Cope’s Gray tree frogs - Hyla chrysoscelis
– now have a better idea of how female frogs select their mates.
It turns out that the females of this species prefer their male mates be capable of multitasking
, those who can perform two or more difficult tasks at the same time. Displaying this ability shows that the male frog of the species is of higher quality compared to those who aren’t able to multitask so easily.
The female frogs pick up on the male’s abilities to multitask by their calls
The male gray tree frog produces "trilled" mating calls
that are made up of a string of pulses. Each of their calls can range from 20 to 40 of these pulses and there are five to 15 of these calls per minute.
Most male frogs can either perform longer or more frequent calls, but being able to do both can be difficult. But the females prefer males who can do both, perform longer and more frequent calls.
"It’s kind of like singing and dancing at the same time," says Jessica Ward, a researcher at the University of Minnesota
who is lead author for the study.
The study, published in August issue of Animal Behavior
, backs up the multi-tasking theory, which suggests that females prefer multi-tasking males.
Ward says that this multi-tasking theory, which has considered how a male’s multiple mating signals affects female behavior, is a new area of interest in animal behavior research
By listening to the recordings of 1,000 frog calls, the researchers were able to determine that males often trade-off the duration of their calls for frequency and vice-versa. In other words, the guys were able to perform either relatively longer calls at slower rates or more frequent calls that were shorter in duration.
"It's easy to imagine that we humans might also prefer multi-tasking partners, such as someone who can successfully earn a good income, cook dinner, manage the finances and get the kids to soccer practice on time,” said Ward.
The study by Ward and her colleagues was done as part of larger research project that is being conducted by Mark Bee, a professor in the Department of Ecology, Evolution and Behavior
at the University of Minnesota. The goal of Bee’s research
is to get an understanding of how female frogs are able to tell apart one male’s individual mating call from a cacophony of sound produced by a large chorus of male frogs
With humans, especially as we get older, we lose our ability to distinguish individual voices in a crowd, something that is at times referred to as the "cocktail party effect”
. Doctors and hearing specialists often look at this as the first sign of hearing loss. The researchers who are involved with these studies feel that improved hearing aids could be developed by better understanding how frogs hear.