Influence of social stimulation intensity on male túngara frog calling
Poster Number
54
Faculty Mentor Name
Faculty mentor is Dr. Gridi-Papp, reachable at mgridipapp@pacific.edu
Research or Creativity Area
Natural Sciences
Abstract
Male túngara frogs (Engystomops pustulosus) emit energetically expensive mating calls to attract females. In the field, males form choruses in which competitor proximity pushes them to adjust their calling strategy to increase their likelihood of finding a female mate. The influence of stimulus proximity, and therefore calling amplitude of nearby competitors, however, remains unclear. This study aims to characterize the effect of stimulus intensity on call amplitude, frequency, and number of calls emitted by a focal male. Forty seven males were placed in 1 of 6 acoustic isolation chambers with shallow water, conditions that mimicked their natural pond habitat to encourage calling. Each acoustic isolation chamber was fixed with a microphone, speaker, and insulated with layers of plywood, mass loaded vinyl, and cellulose fiber. Males were repeatedly administered 5 minutes of silence and 5 minutes of playback stimulus over a 24-72 hour period. 13 different audio tracks were used for playback, 10 based on natural calls and 3 based on synthetic calls with increasing complexities (whine, whine + chuck, whine +3 chucks). Playback amplitude ranged from natural intensity down to -54 dB in 6 dB decrements.
A preliminary analysis showed that within the silent 5 minute periods, the amplitude, frequency, duration, period and number of calls exhibited modest variability. During the stimulated 5 minute periods, however, the number of calls emitted by the focal males increased significantly, and was positively correlated with call amplitude while negatively correlated with period. The response to increasing stimulus amplitude shows a marked inflexion followed by a plateau as opposed to a gradual increase. These results may help explain the dynamics of the chorus. Discrimination of differences in stimuli intensity may allow male túngara frogs to adjust their calling strategy to males in their immediate area, without interference by the sounds of the remaining frogs calling at the pond.
Location
University of the Pacific, DeRosa University Center
Start Date
24-4-2026 11:00 AM
End Date
24-4-2026 2:00 PM
Influence of social stimulation intensity on male túngara frog calling
University of the Pacific, DeRosa University Center
Male túngara frogs (Engystomops pustulosus) emit energetically expensive mating calls to attract females. In the field, males form choruses in which competitor proximity pushes them to adjust their calling strategy to increase their likelihood of finding a female mate. The influence of stimulus proximity, and therefore calling amplitude of nearby competitors, however, remains unclear. This study aims to characterize the effect of stimulus intensity on call amplitude, frequency, and number of calls emitted by a focal male. Forty seven males were placed in 1 of 6 acoustic isolation chambers with shallow water, conditions that mimicked their natural pond habitat to encourage calling. Each acoustic isolation chamber was fixed with a microphone, speaker, and insulated with layers of plywood, mass loaded vinyl, and cellulose fiber. Males were repeatedly administered 5 minutes of silence and 5 minutes of playback stimulus over a 24-72 hour period. 13 different audio tracks were used for playback, 10 based on natural calls and 3 based on synthetic calls with increasing complexities (whine, whine + chuck, whine +3 chucks). Playback amplitude ranged from natural intensity down to -54 dB in 6 dB decrements.
A preliminary analysis showed that within the silent 5 minute periods, the amplitude, frequency, duration, period and number of calls exhibited modest variability. During the stimulated 5 minute periods, however, the number of calls emitted by the focal males increased significantly, and was positively correlated with call amplitude while negatively correlated with period. The response to increasing stimulus amplitude shows a marked inflexion followed by a plateau as opposed to a gradual increase. These results may help explain the dynamics of the chorus. Discrimination of differences in stimuli intensity may allow male túngara frogs to adjust their calling strategy to males in their immediate area, without interference by the sounds of the remaining frogs calling at the pond.
