From Gharial Pops to Gecko Calls, Reptiles Have More to Say Than Scientists Thought

Reptiles may be quiet compared with birds and mammals, but they are far from silent. A Smithsonian Magazine report describes a growing body of research into the chirps, squeaks, hoots, bellows and explosive pops reptiles use in social situations. One of the strangest examples comes from male gharials along India’s Chambal River. When a gharial encounters a stranger or a potential rival, it may produce a rapid popping sound resembling a champagne cork. The animal fills its nasal cavity with water and forcefully exhales through the bulbous structure at the end of its snout, known as a ghara. Researchers working with the Gharial Ecology Project recorded different sequences of pops in different contexts, including alerts, territorial patrols and courtship. Each male appeared to have distinctive patterns for those situations. The signals may help gharials identify one another, and could also provide females with information about potential fathers. Scientists still do not know precisely how the ghara generates the sound. Other reptile noises begin before the animals even hatch. Baby crocodilians call from inside their eggs, apparently helping siblings hatch together and prompting their mother to assist. Studies of turtles have found a similar pattern in some species. South American river turtle hatchlings, which emerge from clutches containing more than 100 eggs, are more vocal and more likely to leave the nest together than hatchlings from species with much smaller clutches. Researchers suggest the group may cooperate while digging out. Lizards also use sound in varied ways. Chameleons can hoot and bark, while anoles may squeak or growl when distressed. The Chilean tree iguana produces more complex, urgent calls when danger becomes especially severe; nearby lizards respond by remaining still longer and taking more time to escape. Tokay geckos, whose calls are commonly linked to mating and territorial defense, adjust their vocal patterns when exposed to white noise. Rather than simply becoming louder, they reduce their soft introductory cackles and extend the louder “geck-o” portion of the call. Smithsonian Magazine reports that this flexibility surprised the researchers and suggests reptile communication can be more intricate than previously recognized.