A short breath extends the mating calls of male tokay geckos

October 3, 2026 feature A short breath extends the mating calls of male tokay geckos Ingrid Fadelli Author Gaby Clark Scientific Editor Robert Egan Senior Editor Tokay geckos (Gekko gecko), large and mostly nocturnal geckos native to parts of Asia, are among the few nonbird reptiles that make sounds to attract potential mates, defend their territory and signal distress. Male tokay geckos' calls typically begin with quieter rattles, followed by louder two-part sounds that can sound like "ge-ko" or "to-kay." Past studies suggest that in noisy environments, male tokay geckos can produce more of the louder "GE-KO" sounds and make them last longer. How they manage to extend these sounds while breathing had remained unclear. Researchers at the University of Southern Denmark recently set out to better understand the physiological processes that allow male geckos to extend their two-part calls. Their findings, outlined in a paper published in Proceedings of the Royal Society B: Biological Sciences, revealed that geckos take a brief breath between the two parts of a call and add pulses to the second part to make it last longer. "Although previously considered inflexible, male tokay geckos exhibit vocal plasticity by switching to longer, louder call types in noisy environmental conditions," wrote Mathilde S. Fuglsang Thastum, Danuta M. Wisniewska, Jakob Christensen-Dalsgaard and Coen P.H. Elemans in their paper. "However, they seem to face respiratory constraints limiting longer duration calls. To test this hypothesis, we combined acoustic analysis with deep learning-based pose estimation to quantify respiratory dynamics during spontaneous advertisement calling." Analyzing the mating calls of male tokay geckos Male tokay geckos typically use calls to attract potential female mates or communicate with other males. The researchers collected and analyzed 16 video clips of seven captive male tokay geckos spontaneously making sounds. "Calls were produced exclusively during expiration at a constant rate, supporting the hypothesis that respiratory constraints limit call duration," wrote Thastum, Wisniewska and their colleagues. "Tokays use two mechanisms to increase bi-note call duration. First, bi-notes contain an inspiratory 'mini-breath'—a feature previously associated only with songbirds. Second, bi-note duration is increased by adding terminal pulses, whose acoustic signatures suggest vocal fold oscillation in the air-efficient vocal fry register." The researchers also tracked movement in the geckos' backs, bellies and ear openings. This helped them identify when the animals breathed in and out and when their ear openings narrowed. Finally, they searched the recordings for acoustic signs of "vocal fry," a low, creaky mode of voice production also observed during human speech. Clues to the physiology of gecko mating calls The researchers observed that male geckos produced the audible parts of their calls while breathing out. Between the first and second parts of their calls, however, they appeared to take a very short, silent breath in, lasting approximately a tenth of a second. The team found that the mini-breath may provide more air for the two-part call. Successive two-part calls also became longer as the geckos added pulses to the end of the second sound. The geckos' ear openings narrowed while they called. This could help protect their hearing by reducing exposure to their own loud calls, although future research will be needed to test the hypothesis. "These findings suggest that tokay advertisement calls function as honest signals of respiratory capacity," wrote the authors. "We also observed slow closure of the ear opening during vocalizations, indicating a mechanism for protecting the auditory system from self-generated loud sounds. Unlike the reflexive auditory attenuation mechanisms of birds and mammals, this response appears tightly coordinated with vocal–respiratory activity, representing an additional evolutionary innovation associated with tympanic hearing." This study offers new insight into the physiology of reptile calls, which could guide further research. Other teams could investigate how female tokay geckos respond to male calls of different lengths or determine whether wild tokay geckos use the same calling techniques. Written for you by our author Ingrid Fadelli, edited by Gaby Clark, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive. If this reporting matters to you, please consider a donation (especially monthly). You'll get an ad-free account as a thank-you. Publication details Mathilde S. Fuglsang Thastum et al, Mini-breaths and vocal-fry-like laryngeal register alleviate respiratory constraints on tokay ( Gekko gecko ) mating vocalizations, Proceedings of the Royal Society B: Biological Sciences (2026). DOI: 10.1098/rspb.2026.1077. Journal information: Proceedings B Key concepts vocalization methods© 2026 Science X Network