Through-ice communication by Weddell seals may not be practicable

• Other Authors: TERHUNE, JOHN MOORE (hasPrincipalInvestigator), TERHUNE, JOHN MOORE (processor), Australian Antarctic Data Centre (publisher)
• Format: Dataset
• Language: unknown
• Published: Australian Antarctic Data Centre
• Subjects: biota; oceans; ANIMALS/VERTEBRATES; EARTH SCIENCE; BIOLOGICAL CLASSIFICATION; MAMMALS; ATTRIBUTE; CALL TYPE; CALLS; CASEY; DAVIS; ELEMENTS; FREQUENCY; LEPTONYCHOTES WEDDELLII; REPETITION; TIME; TRILLS; UNDERWATER; VOCALISATIONS; WEDDELL SEALS; HYDROPHONES; FIELD SURVEYS; CONTINENT > ANTARCTICA > GEOGRAPHIC REGION > POLAR; Weddell; Antarc*; Antarctica; harbour seal; Phoca vitulina; Weddell Seals
• Online Access: https://researchdata.ands.org.au/through-ice-communication-seals-practicable/699737; https://doi.org/10.4225/15/55EF991B8EEAB; https://data.aad.gov.au/metadata/records/ASAC_2122-3; http://nla.gov.au/nla.party-617536

Possible communication between territorial male Weddell seals (Leptonychotes weddellii) under the ice with females on the ice was investigated. In-air and underwater recordings of underwater calls were made at three locations near Davis, Antarctica. Most underwater calls were not detectable in air, often because of wind noise. In-air call amplitudes of detectable calls ranged from 32-74 dB re. 20 microPa at 86 Hz down to 4-38 dB re. 20 microPa at 3.6 kHz. Most of these would be audible to humans. Only 26 of 582 amplitude measurements (from 230 calls) ranged from 5 dB to a maximum of 15 dB above the minimum harbour-seal (Phoca vitulina) in-air detection threshold. Seals on the ice could likely hear a few very loud underwater calls but only if the caller was nearby and there were no wind noises. The low detectability of underwater calls in air likely precludes effective communication between underwater seals and those on the ice. See other metadata records and datasets associated with ASAC project 2122 (ASAC_2122) for further information. The fields in this dataset are: Column A: G = grunt, T = trill, CT = constant freq. trill, O = tone, C = chug, AW = ascending whistle, DW = descending whistle, L = growl, R - roar Column B: frequency (Hz) Column C: underwater call level NOTE dB re 20 uPa Column D: in-air call level dB re 20 uPa Column E: in-air background noise level at this frequency dB re 20 uPa Column F: water - air difference dB Column G: location, 1-3, see paper for code Column H: seal in-air threshold dB re 20 uPa Column I: human in-air threshold dB re 20 uPa Column J: seal in-air threshold at this frequency dB re 20 uPa