Hetero-specific Alarm Call Eavesdropping in Non-vocal, Whitebellied Copper-striped Skinks (Emoia cyanura)
- Author(s): Fuong, Holly
- Bulut, Yasemin
- Keeley, Kathryn N
- Advisor(s): Blumstein, Daniel
- et al.
Many species benefit from listening to the vocalizations of their predators as well as the alarm vocalizations of other species. This eavesdropping is an important way to acquire information of predator location and threat magnitude. Eavesdropping is commonly studied in mammals and birds, and it has only recently been reported to occur in reptiles. Studies that examine lizard responses to playbacks of both predatory calls and heterospecific alarm calls are absent, even though eavesdropping may be especially important in non-vocal species. We broadcast predator vocalizations, alarm calls from a non-predatory bird (red-vented bulbul, Pycnonotus cafer), and social vocalizations from red-vented bulbuls to determine if non-vocal white-bellied copper-striped skinks (Emoia cyanura) could discriminate between them. Upon hearing red-vented bulbul alarm calls, white-bellied copper-striped skinks reduced their rate of looking compared to a baseline period. However, they did not respond significantly to red-vented bulbul social calls or vocalizations from their potential predators. Pairwise analyses revealed that upon hearing red-vented bulbul alarm calls, skinks reacted significantly differently than when they heard social calls or predatory calls. Our study is the first to look at the responses of both predator and heterospecific alarm call playbacks in lizards. White-bellied copper-striped skinks most likely depend on heterospecific vocalizations for predator information because they are non-vocal and found low on the forest floor, making it harder to identify predators directly than through alarm calls of avian heterospecifics.