Dear colleagues, We are pleased to announce the publication of the following article in the journal Bioacoustics: *Whistling in a noisy ocean: bottlenose dolphins adjust whistle frequencies in response to real-time ambient noise levels* (Chantal van Ginkel, Danielle Becker, Shannon Gowans & Peter Simard).
The paper is available on the following link (or by contacting me): http://www.tandfonline.com/eprint/fmkdYaCfGbWt9I747EQy/full Abstract: Common bottlenose dolphins (*Tursiops truncatus*) use complex acoustic behaviours for communication, group cohesion and foraging. Ambient noise from natural and anthropogenic sources has implications for the acoustic behaviour of dolphins, and research shows that average ambient noise levels alter dolphin acoustic behaviour. However, when background noise levels are highly variable, the relationships between noise and acoustic behaviour over short time periods are likely important. This study investigates whether bottlenose dolphins altered the temporal and spectral qualities of their whistles in relation to the ambient noise present at the time the whistles were produced. Dolphin groups were recorded in Tampa Bay (western Florida) between 2008 and 2015. Six whistle parameters were analysed in spectrogram software (minimum frequency, maximum frequency, bandwidth, peak frequency, duration and number of inflection points) and ambient noise levels were calculated immediately prior to each whistle. Linear regression analysis indicated that the minimum, maximum and peak frequencies of whistles had significant positive relationships with the ambient noise levels present at the time of the whistles. These models suggested that for each 1 dB increase in ambient noise, minimum frequency increased by 121 Hz, maximum frequency increased by 108 Hz and peak frequency increased by between 122 and 144 Hz. As ambient noise is typically low frequency, this suggests that bottlenose dolphins increased whistle frequency in response to real-time noise levels to avoid masking. Future research to determine the fitness consequences of noise-induced changes in the communication behaviour of dolphins would be an important contribution to conservation efforts. On behalf of the co-authors Peter Simard -- Peter Simard, Ph.D. Visiting/CPT Professor, Environmental Studies Eckerd College Dolphin Project http://www.eckerd.edu/dolphin-project https://www.eckerd.edu/environmental-studies/faculty/simard/ Office: 119A, Galbriath Marine Science Laboratory Eckerd College 4200 54th Ave. South St. Petersburg, FL 33711
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