Behaviour 2019
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You scared the piss out of me, or did you? Disturbance cues not likely from bladder emptying in tadpoles
Gabrielle H. Achtymichuk1, Adam L. Crane2, Theresa E. Wrynn1, Maud C.O. Ferrari1. 1Western College of Veterinary Medicine, Saskatoon, SK, Canada; 2University of Saskatchewan, Saskatoon, SK, Canada

One of the many sources of predation-related information available to aquatic prey are disturbance cues – chemicals known to increase vigilance when detected by conspecifics. These cues or signals are nitrogenous wastes, hypothesized to be released voluntarily when an individual is chased by a predator, although their release mechanism remains unknown. If the signal results from bladder emptying, individuals could deplete the cues after being disturbed, thus requiring a ‘refill’ period before more cues can be released. To test this, we obtained disturbance cues from larval woodfrogs (Lithobates sylvaticus) following a standardized chasing event. Then, a second round of disturbance cues was collected after either a 5-min or 2-h refill period. Tadpoles showed the same antipredator response regardless of whether they were exposed to disturbances cues obtained from donors after a 5-min or 2-h refill period, or cues collected after the first release event (postive control). This indicates that the effects of disturbance cues are not constrained by production, and thus might not be released via bladder emptying, further supporting the theory that these cues may be released voluntarily.