While the classic “croak” is frequently associated with frogs, toads also produce a range of distinct calls. Understanding these vocalizations reveals a fascinating aspect of toad biology, moving beyond simple assumptions about their acoustic world. This article explores the diverse sounds toads make and the reasons behind them.
Toad Vocalizations: More Than Just Croaks
While the term “croak” can broadly apply to amphibian sounds, their calls are often quite specific and varied. Unlike the iconic “ribbit” sound, which is typically associated with certain frog species, toad vocalizations encompass trills, chirps, barks, and even buzzing noises. For instance, the American toad is known for its long, musical trill that can last five to thirty seconds. Each male in a chorus may call at a slightly different pitch, creating a complex soundscape.
Fowler’s toads produce a nasal, buzzy trill that often sounds like a wailing scream or a crying baby, typically lasting one to five seconds. Meanwhile, the common toad has a higher-pitched, stark call described as a rough “qwark-qwark-qwark,” which some listeners might even mistake for a duck or goose. These distinct calls allow for species recognition, ensuring that toads attract mates of their own kind even within a noisy environment.
The Reasons and Ways Toads Make Sounds
Toads vocalize primarily to attract mates. Male toads use these calls to signal their availability, especially during breeding seasons. The intensity and frequency of these calls increase when breeding activity is at its peak. Beyond reproduction, toads also use sounds to establish and defend their territories, warning off rival males.
Additionally, toads can produce distress calls when they feel threatened by a predator or are injured. While male toads are the main vocalists, research suggests that female toads may also vocalize, though their calls are generally less frequent and distinct, sometimes serving mating or territorial functions.
To produce these sounds, toads utilize vocal cords in their larynx. A specialized structure, a vocal sac (an inflatable pouch), amplifies these sounds.
A toad initiates a call by inhaling air and closing its nostrils. It forces air between its lungs and the vocal sac, causing the vocal cords to vibrate. The vocal sac inflates, creating a resonating chamber that amplifies the sound, allowing it to travel further. Different species of toads can have single median throat sacs, paired throat sacs, or paired lateral sacs, contributing to the unique characteristics of their calls.