water and the background noise this presents. During the day, individuals of this species usually crouch on rocks near the stream rapids or on stone walls near the waterfalls. Occasionally, they stay in the water for brief periods of time and then float on the water surface. At night, individuals of A. torrentis can be found on rocks near the streams or on leaves of nearby shrubbery and weeds. Reproduction Females of A. torrentis lay eggs at rocky and fast flowing sites in the stream, specifically in holes or openings in the rock piles where the follicles can be anchored to the stones or to nearby soils to prevent the eggs from being washed away. Tadpoles also inhabit similar locations. Mating Male calling Mating in this species occurs via calling, as calls are transmitted across and around streams. The call sounds like a sharp and high "squeak, squeak, squeak" as males produce calls that consist of a series of identical repeated notes throughout the day and night during breeding season. Males of this species change their call frequency in response to noise but not their call intensity or amplitude. Researchers investigating this utilized recordings of stream noise to determine how stream noise changes characteristics of male calling. The lack of an increase in call amplitude with increased background noise is a contradiction to the Lombard hypothesis, which states that animals are expected to increase both their call frequency and their call amplitude in response to noise in the environment. The calling behavior of A. torrentis instead supports the theory that calling with a higher frequency helps prevent their calls from being lost in the background noise. This may be due to the fact that stream noise (the primary background noise for these frogs) is mainly in lower frequency ranges, so the upward shift in call frequency could be more adaptive than increasing the lowest frequencies. Males of this species prefer to call from stones in the river that have the same background color as the frog’s body and different than the white color of the vocal sac, so vocal-sac inflation is conspicuous in the environment. Female preference Females of A. torrentis prefer higher-frequency calls over lower-frequency calls regardless of background noise levels. In addition, females prefer calls with high amplitude noise added over calls with low amplitude stream noise added, but stream/background noise is not attractive to females by itself.