If they want to be the biggest frog on a pond's lily pad, male frogs need to speak up. Lady frogs
prefer "talkative" males, according to Sunny Boyd, Notre Dame professor of biological sciences.
It seems the ladies judge Kermit on the basis of his vocal talents, with the more pulses and the
longer the call equaling the more desirable male. Girl frogs aren't interested in the strong silent
type; the studs are the guys belting out the long "ribbids."
"Females choose the longer-call males because it's an energetically costly behavior that
correlates with a more fit male, and that translates into producing more fit tadpoles," Boyd says.
For the ND biologist, whose work focuses on understanding behavior down to its most
basic level, the biochemical pathways that regulate the action are the most intriguing thing about
the frog call. In particular Boyd has studied the role of arginine vasotocin (AVT), a chemical
produced in the frog brain that plays a variety of roles in frog behavior, including mating call
conduct. Among other things, AVT has been shown to increase mate call frequency in male
frogs and to increase female attraction to males.
In her study of what controls behavior, Boyd also looks at how individual cells
communicate by analyzing the production of particular chemical messengers in the brain. She
also is researching how individual parts of the brain contribute to behavior and is attempting to
understand interactions of animals in the field.
John Monczunsk is an associate editor of this magazine. Email him at monczunski.1@nd.edu.
(April 2008)
