Dear all,

We are pleased to inform you that our article

Synthetic communication signals influence wild harbour porpoise (Phocoena phocoena) behaviour
has been published on Taylor & Francis Online.
It is available at: http://www.tandfonline.com/doi/full/10.1080/09524622.2015.1023848.

Boris Culik^a^*, Christian von Dorrien^b, Vailett Müller^c & Matthias Conrad^d^e

We used our novel and programmable Porpoise Alarm (PAL, patd.) to synthesize life-like, electronic harbour porpoise communication signals based on those described for captive animals. In the Little Belt, Denmark, we employed PAL (source level 158 ± 1 dB p–p re 1 μPa@1 m; centroid frequency 133 ± 8.5 kHz) to synthesize three aggressive click train types termed “A”, “F3” and “M1” to naive, free-living harbour porpoises. Via theodolite tracking (372 h of total visual effort spread over 10 expeditions) we found that, depending on signal type, porpoises either avoid or become attracted to PAL: Signal types “A” and “F3” are slight deterrents, porpoises increasing minimum range (+23 to 32 m, respectively), whereas “M1” attracts porpoises, reducing range (by − 29 m). As determined via archival acoustic detectors (AADs), both signals “F3” and “M1” led the animals to significantly intensify their click rate (by +10% and 68%, respectively) while signal “A” led to a significant reduction ( − 59%). We propose that equipping fishing gear with PAL emitting signal “F3” could potentially reduce porpoise by-catch by increasing (1) awareness through enhanced echolocation and (2) distance to the nets. Detection probability and radius of PAL/AAD tandems could be improved by emitting signal “M1” to focus porpoise echolocation signals on the AAD. The signal may also be useful in luring animals away from hazards, which may be helpful for conservation measures prior to the onset of harmful acoustic activities such as pile-driving, seismic exploration or ammunition clearance.

Kind regards,
Boris

-- 
___________________________________
Boris Culik
Prof. Dr. rer. nat. habil.
F³: Forschung . Fakten . Fantasie
Am Reff 1
D- 24226 Heikendorf
Tel.: +49 (0)431 2378 588
Fax.: +49 (0)431 2378 589
Mobil.: +49 172 750 4192
Email bculik@fh3.de
Web.: www.fh3.de
___________________________________