Silverstone’s Poison Frog
When he reaches sexual maturity, a male Silverstone’s poison frog uses the subgular vocal sac in his throat and vocal slits in the mouth to make mating trills to attract females.
Silverstone’s poison frog males are territorial during the breeding season. When they reach sexual maturity, males begin mating trills to attract females.
There have been recordings of Silverstone’s poison frog calls, which have been described as retarded trill calls, the fourth class of dendrobatid vocalizations to be defined. Their call is a series of short, similar abrupt whistles, distinctly spaced and produced at 4-6 notes per second.
Only adult males possess the small, shallow, subgular vocal sac in the throat rarely indicated externally by weak longitudinal crease (not a definite fold) on each side of throat and well-developed vocal slits on the floor of the mouth.