File:Sophisticated-Communication-in-the-Brazilian-Torrent-Frog-Hylodes-japi-pone.0145444.s006.ogv

English: Hylodes japi couple during the elaborate courtship ritual. Movie starts showing female approaching the male and the exact moment when the female adopts the acceptance position, touching the male’s dorsum with her gular region. That couple position is kept during the acceptance courtship step. Then, we can observe the male emitting peep and squeal calls with only one vocal sac inflated, the one nearer the female (his left vocal sac), demonstrating the visual component of his bright whitish vocal sacs. Next, we can observe two events whereby the female triggered the male’s courtship calls via bimodal stimulation (visual plus tactile); first by arm lifting display plus tactile stimulation and second by arm waving display plus tactile stimulation. The movie is slowed down for better observation (rate 0.25). Finally, once male and female reach the fast-flowing stream margin, we can see the exact moment when, while maintaining physical contact with the female, the male slightly moves his body forward, consequently moving the female body as well; then the male dives followed by the female, marking the beginning of the underwater part of the courtship (leading to the oviposition site). Recorded on 6 March 2012, using the camera’s ‘NightShot’ function (infrared sensitivity).