Reptiles Make a Surprising Amount of Noise. Here's What Those Sounds Might Mean, From Pops to Hoots to Bellows

Reptiles are increasingly being recognized as more vocal animals than their reputation suggests. Turtles, lizards and crocodilians have often been treated as comparatively silent beside birds and mammals, but their calls are drawing renewed attention. The emerging picture is not of a single kind of reptile sound, but of a varied acoustic world that can include sharp pops, hooting calls, deep bellows, chirps, squeaks and roars. Scientists are still working out what many of these signals convey and when they matter most.

One striking example comes from the Chambal River in northern India. Gharials, the long-snouted relatives of crocodiles, can move almost unnoticed along its sandy edges and through its water. That calm can change when an unfamiliar animal appears. A male may answer the encounter with a run of abrupt popping sounds, turning a nearly silent moment into an audible display. The calls have only recently registered as a subject of scientific interest, despite the conspicuous effect they can have in the river setting.

The gharial’s pop is produced through an unusual action rather than a simple voice-like call. A male takes water into its nasal passage and then forces it out quickly. The rush passes through a swollen structure at the end of the animal’s elongated snout, producing a report likened to the release of a champagne cork. Females do not make this sound. The sex-specific behavior makes the pop especially notable among the many different noises now associated with reptiles.

These pops commonly arrive in a sequence rather than alone. Available observations suggest that the arrangement of a male’s sounds may identify him: individual gharials appear to have their own recognizable pattern. That interpretation remains important to distinguish from a final decoding of the signal. A repeated pop sequence may carry identity, but the precise information heard by another gharial, and the circumstances in which it changes behavior, are questions that still need closer attention.

The larger point extends beyond one river and one species. Reptile communication has traditionally received less public attention than songbirds or calling mammals, yet reptiles are not simply passing through their environments without sound. Their noises range from small, high calls to more forceful vocal displays. Listing those sounds is less revealing than recognizing their possible purposes: a call can be part of an encounter, a territorial exchange or a search for a mate, rather than mere background activity.

Tokay geckos offer another indication that reptile calls can be responsive rather than fixed. In noisy surroundings, a tokay gecko alters a call that is generally connected with attracting a partner or defending space. That adjustment places the sound in a social context and shows why recording an animal only under quiet conditions may offer an incomplete view. It also complicates the old assumption that vocal flexibility belongs chiefly to animals better known for elaborate sound-based communication.

There is a reason for caution in turning these examples into a simple claim that every reptile call has been explained. The very fact that gharial popping is newly appreciated underscores how much can be missed when attention is centered on more familiar animal voices. Calling a sound communication does not settle every aspect of its meaning. Researchers must separate what is directly observed—such as a male’s patterned pops or a gecko’s shift in loud settings—from interpretations about the message received.

What happens next is likely to depend on listening as carefully as researchers watch, and on repeated observations across different conditions. The sounds already described invite broader questions about identity, courtship, territory and reactions to other animals, while the diversity of chirps, squeaks, hoots, bellows and roars suggests that no single explanation will fit all reptiles. For general audiences, the revision is straightforward: creatures once imagined as quiet inhabitants of wild places may be contributing more actively to those places’ soundscapes than previously understood.

Source: Smithsonian Magazine