The Evolution of Acoustic Signals in Poison Dart Frogs

By: Lia Casey, Jenna Cuzziere, and Rofail Wassef (Stonehill College, BIO 323: Evolution, Spring 2024)

Overview

Poison dart frogs, belonging to the Dendrobatidae family, are a fascinating group of amphibians renowned for their vibrant colors and potent toxins. These frogs are native to the tropical rainforests of Central and South America, where they inhabit diverse habitats ranging from leaf litter on the forest floor to the canopy of trees. Their striking hues, which include shades of red, blue, yellow, orange, and green, serve as a warning to potential predators of their toxic nature. Along with changing colors, poison dart frogs also can utilize acoustic signals (noises animals produce) to attract potential mates. Despite their small size, these frogs can produce a wide array of calls, ranging from simple chirps to complex series of notes. Male poison dart frogs often use their calls to establish and defend territories, as well as to attract mates during the breeding season. Each species has its unique call, which helps in species recognition and mate selection. Additionally, acoustic signals may also serve as a form of communication between males and females during courtship rituals, or mate selection, aiding in the coordination of reproductive behaviors. The frequency, duration, and intensity of these calls can convey information about the caller’s size, health, and vigor, influencing the outcome of mating interactions. Furthermore, studies have shown that environmental factors such as temperature and humidity can impact the acoustic properties of these calls, highlighting the intricate interplay between biology and the environment in the vocal behavior of poison dart frogs. Feel free to tune into the podcast to learn more about this exciting topic!

Short podcast summarizing the paper. Image of a Poison dart frog. Acoustic signals in poison dart frogs serve as vital communication tools for territorial defense, mate attraction, and courtship rituals within their diverse rainforest habitats. https://www.britannica.com/science/animal-communication/Signal-production
Podcast Music: https://www.youtube.com/watch?v=498HcLwcjxs
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Sexual Selection: Big-brain vs. Small-brain

Gianna Amatucci, Nick Mulvey, Caitlin Welsh, & Cayleigh Shufelt (Stonehill College, BIO 323 Evolution, Fall 2019)

Predominantly residing in the tropics of South America, guppies are small and colorful freshwater fish. They are omnivorous animals, primarily consuming algae and brine shrimp. Unfortunately, guppies are preyed upon by a number of larger creatures, including birds, larger fish and mammals. While constantly having to avoid such predators, guppies are always in search of a suitable mate to spread their gene pools to future offspring. Alberto Corral-López and colleagues studied how predation pressure, in addition to cognitive ability and brain size, affected sexual behavior and sexual selection in guppies. The actions of both large-brained and small-brained female and male guppies were observed by Corral-López in order to study this phenomenon.

Domestic male guppy in an S-curve mating display. Image credit: “older guy 22feb08” by Alice Chaos is licensed under CC BY-NC-SA 2.0
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Why do birds get divorced?

Divorce in Savannah Sparrows of Kent Island

by: Michael Calcagno, Meghan Ghazal, Lizzie Poyant & Zarir Sidhwa (Stonehill College Evolution Fall 2017)

In Savannah sparrows (Passerculus sandwichensis) that reside on Kent Island, New Brunswick, Canada an understanding of divorce rates within the species was analyzed to determine the molecular basis of the phenotypic trait. As well as, to determine if divorce is an adaptive strategy for greater fitness for females. In this species, approximately 47% of pairs in which both partners survived to the following breeding season ended in divorce. Neither the lifetime number of divorces nor whether an individual had ever divorced affected the fitness of either sex, thus suggesting little to no sexual selection for the trait. Divorce in the Savannah sparrows appeared to be an inheritable behavior in which expression depending primarily upon an individual’s age, mating status, sex, and size.

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Dad’s social status effects offspring personality in zebrafish

Dad’s social status effects offspring personality in zebrafish

By: Colleen O’Donnell, Lauren Smith, and Courtney Walsh (Stonehill College Evolution Fall 2017)

Ever wonder if fish have personality? If fish have a social hierarchy?

Well, news flash, they do! Dr. Susanne Zajitschek had the opportunity to study Zebrafish, otherwise known as Dario reno, and manipulate their social hierarchy in order to determine whether or not this would affect the offspring of the Zebrafish. She focused on the paternal aspect of rearing offspring. Dr. Zajitshek combined this manipulation with the genetic onset of personality traits of the fathers. As a result of her research, she was able to find that both social status and personality traits do in fact affect the behavior of the offspring.

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