Abstract
When acoustic signals sent from individuals overlap in frequency and time, acoustic interference and signal masking may occur. Under the acoustic niche hypothesis (ANH), signaling behavior has evolved to partition acoustic space and minimize overlap with other calling individuals through selection on signal structure and/or the sender’s ability to adjust the timing of signals. Alternately, under the acoustic clustering hypothesis, there is potential benefit to convergence and synchronization of the structural or temporal characteristics of signals in the avian community, and organisms produce signals that overlap more than would be expected by chance. Interactive communication networks may also occur, where species living together are more likely to have songs with convergent spectral and or temporal characteristics. In this study, we examine the fine-scale use of acoustic space in montane tropical wet forest bird communities in Costa Rica and Hawai‘i. At multiple recording stations in each community, we identified the species associated with each recorded signal, measured observed signal overlap, and used null models to generate random distributions of expected signal overlap. We then compared observed vs. expected signal overlap to test predictions of the acoustic niche and acoustic clustering hypotheses. We found a high degree of overlap in the signal characteristics (frequency range) of species in both Costa Rica and Hawai‘i, however, as predicted under ANH, species significantly reduced observed overlap relative to the random distribution through temporal partitioning. There was little support for acoustic clustering or the prediction of the network hypothesis that species segregate across the landscape based on the frequency range of their vocalizations. These findings constitute strong support that there is competition for acoustic space in these signaling communities, and this has resulted primarily in temporal partitioning of the soundscape.
Highlights
Acoustic signaling is a major form of social behavior in many terrestrial and aquatic organisms
We identified the species associated with each recorded signal at multiple recording stations in each community and measured observed signal overlap within and among species
There was a total of 2,880 vocalizations with a duration of 1,614 s from Costa Rica and 4,489 vocalizations detected with a duration of 6,097 s from Hawai‘i. According to species accumulation curves the recording length (10–15 min) was long enough to capture species diversity at a location (Figure 1)
Summary
Acoustic signaling is a major form of social behavior in many terrestrial and aquatic organisms. Acoustic Hart Niche Partitioning (ANH; Krause, 1987, 1993), signaling behavior has evolved to minimize overlap with heterospecific calling individuals through selection on signal structure and the sender’s ability to adjust the timing of signals. This hypothesis may be viewed as an extension of the niche theory of Hutchinson (1957) whereby acoustic space is a resource that organisms may compete for and that can be partitioned both spectrally (frequency range of the signal) and temporally. Acoustic signals are relatively constrained in the way their spectral characteristics can vary to reduce interference with other biotic and abiotic sounds
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
