Meeting Abstract
Vocalizing animals exploit certain behaviors to differentiate themselves among conspecifics. One mechanism is the jamming avoidance response (JAR), where individuals adjust the frequency of their signals relative to nearby conspecifics to avoid signal overlap. This behavior is utilized by animals that rely on signaling, such as weakly electric fish and bats. Male oyster toadfish, Opsanus tau, establish nests in mid spring and emit advertisement calls (boatwhistles) with distinct fundamental frequencies to attract females. The males appear to alternate calls to avoid temporal overlap, however, on occasion, the fundamental frequency of the callers are quite similar. The aim of this study was to investigate boatwhistle parameters among multiple males in a natural competitive environment. An in situ hydrophone continuously recorded vocalizations in Eel Pond, MA, from mid-June through late July 2016. Individual toadfish were distinguishable by waveform patterns, call duration, and amplitude. During a 36 hour calling period, the variation in fundamental frequency of an individual toadfish (e.g. 203 – 219 Hz) was closely correlated with water temperature change (22.5 – 24.0 °C) (R2 = 0.59). In contrast, when conspecifics were also calling, toadfish with similar signals appeared to implement the JAR; when the fundamental frequency of one calling toadfish progressed toward the fundamental frequency of another, the individuals shifted their fundamental frequencies away from each other. This is the first time that this putative jamming avoidance behavior had been observed in the wild and demonstrates the complexity of these intraspecific interactions.
