Discover the astonishing diversity of frog vocal sac structures, which have evolved to amplify calls and convey nuances of male quality in a fascinating symphony of sounds.
A pair of blue bulges puffs outward as a male Indian bullfrog calls. Side puffs are just one of 20 patterns that male vocal sacs evolved for amplifying the calls of frogs and toads.
Male frogs have long been depicted in literature and media as croaking with their mouths, but this is only half the story. Herpetologist Agustín Elías-Costa reveals that there is a staggering diversity of body parts used by frogs to ribbit, with some species using up to 20 different patterns.
Frogs belong to the order Anura, comprising over 6,000 species worldwide.
They have a streamlined body, typically green or brown in color, with webbed feet for swimming.
Frogs undergo metamorphosis from aquatic eggs to terrestrial adults.
Their diet consists mainly of insects and other small invertebrates.
Some species, like the poison dart frog, possess toxic secretions on their skin.
Frogs play a vital role in ecosystems, serving as both predators and prey.
The diversity of vocal sacs among frogs is astounding. Some males serenade with paired puff-out disks, while others have sacs resembling ‘balloon Mickey Mouse ears in khaki’ . Still, about 18 percent of the 4,358 species examined didn’t have vocal sacs at all.
Elías-Costa and her colleague Julián Faivovich studied over 777 specimens from museums around the world, including the Smithsonian’s National Museum of Natural History in Washington, D.C. They used these collections to understand the evolutionary history of vocal sacs among frogs.
The survey showed that vocal sacs disappeared between 146 and 196 times across the very twiggy evolutionary branchings of the frog and toad family tree. Despite their disappearance, frogs still emit sounds from their larynxes, which can convey nuances of male quality and sexiness but also alert predators.
The researchers hope that their findings will shed light on ecological questions surrounding vocal sacs, such as how different environments influence the evolution of these structures. Frogs shop for mates in a wide range of habitats, each with its unique risks and acoustic challenges.
Females in some species also vocalize, but it is mostly a male endeavor. The loss of vocal sacs has significant implications for how we understand the biology of frogs and toads. By studying these structures, researchers can gain insights into the complex interactions between these animals and their environments.
The study’s findings have important implications for our understanding of the evolutionary history of vocal sacs among frogs. The loss of these structures has occurred multiple times across different branches of the frog and toad family tree, suggesting that there are common pressures driving this process.
By examining the diversity of vocal sacs among frogs, researchers can gain a deeper understanding of the complex biology of these animals and how they adapt to their environments. This research highlights the importance of continued exploration into the natural world, where scientists like Elías-Costa and Faivovich continue to uncover new insights into the fascinating world of frogs and toads.
- sciencenews.org | Frog ribbits erupt via an extravagant variety of vocal sacs
