[Location: Location_Category='CONTINENT', Location_Type='ANTARCTICA', Detailed_Location='Davis']
Stereotyped Calling Patterns of a Male Weddell Seal (Leptonychotes weddellii)Entry ID: ASAC_2122-5
Abstract: From the abstract of the attached paper:
Underwater calling behaviour between breathing bouts of a single adult male Weddell seal (Leptonychotes weddellii) was examined with respect to call type and timing late in the breeding season at Davis Station, Antarctica. Underwater calls and breathing sounds were recorded on 1 and 8 December 1997. Thirty-seven sequences of calls ... prior to surfacing to breathe and 36 post-submerging sets of calls were analysed with respect to probability of call type occurrence and timing. Dives were 461 plus or minus 259 seconds (mean plus or minus standard deviation). The seal called every 29.7 plus or minus 56.2 seconds throughout a dive. The first call after submerging was usually (n = 29 of 36) a low frequency (less than 0.8 kHz) growl. Three patterns of three- to five-call type sequences were made following 28 of 36 breathing bouts. Call type patterns after submerging exhibited fewer different sequences than those before surfacing (chi-squared = 61.42, DF = 4, p less than 0.000001). The call usage patterns before surfacing were diverse and did not indicate when the seal was going to surface, a time when he would be vulnerable to attack from below. Our findings suggest the hypotheses that territorial male Weddell seals call throughout each dive and use stereotyped call patterns to identify themselves while vocally asserting dominance.
This work was completed as part of ASAC project 2122 (ASAC_2122).
The fields in this dataset are:
Sequence per tape
Sequence entire data
Count since last breath
Last breathing bout number
Count prior to next breath
Time in tape (seconds)
End time of last breath
Start time of next breath
Time since dive
The 'sequence' relates to the sequence of call types that are given between the end of the last breath of a breathing bout and the beginning of the first breath the next time the seal surfaces to breathe. Essentially the report relates to the stereotyped nature of the call types, especially just after the dominant male dives after finishing breathing.
Each time the animal surfaced, that was identified as a breathing bout. They are numbered sequentially. At the very start of the data set the seal had to surface before the breathing bout could be counted (as number 1). This procedure enabled us to identify the order and timing of the calls that occurred immediately before and immediately after each breathing bout. Thus, the 'count prior to the next breath' gives the order of the calls before the seal surfaced to breathe again (third last, second last, last,).
The call types were analysed with respect to the following pattern:
third last, second last, last, breathing bout, first, second, third, etc. to
third last, second last, last, next breathing bout.
(Click for Interactive Map)
Start Date: 1997-12-01Stop Date: 1997-12-08
Quality Paraphrased from the Materials and Methods of the referenced paper:
In early December 1997, we conducted an opportunistic study of the transmission of underwater calls through sea ice. Simultaneous recordings were made underwater and above the ice near a breathing hole. A male seal (identified by his use of trills) frequented the breathing hole during the two ... days that recordings were obtained. In addition to recording sound levels of the underwater calls just above the ice, the in-air microphone recorded the breathing sounds when the seal surfaced in the hole. it seemed likely that all of the recordings were from a single adult male Weddell seal.
Recordings were made on landfast sea ice (68.5699 degrees S, 77.9266 degrees E), 1.55km from the shoreline of Davis Station, Eastern Antarctica, on 1 and 8 December 1997. The water depth was 23 m. The ice in this area had been broken up and refrozen following the arrival of the R.S.V. Aurora Australis to the station two months earlier. Recordings were made on an opportunistic basis at two different breathing holes (one per day).
Simultaneous recordings in air (using a Radio Shack 33-2050 sound level meter as a microphone) and underwater (Bruel and Kjaer 8100 hydrophone with a Bruel and Kjaer 2635 charge preamplifier) were made using a Sony TCD-D7 DAT recorder. the microphone was 1.0 to 3.0 m from the breathing hole, and the hydrophone was deployed through the breathing hole to a depth of 3.0 to 3.8 m. To reduce possible human disturbance, 2 hour DAT tapes were used and after the equipment was operating, the observer left the area.
Access Constraints The dataset is available for download rom the provided URL. The dataset includes a pdf of the referenced paper and an excel spreadsheet of data.
Use Constraints This data set conforms to the PICCCBY Attribution License
Please follow instructions listed in the citation reference at the provided URL when using these data.
Data Set Progress
Distribution Media: HTTP
Distribution Size: 24 KB
Distribution Format: excel
Distribution Media: HTTP
Distribution Size: 408 KB
Distribution Format: pdf
Role: TECHNICAL CONTACT
Phone: +1 506 648 5633
Fax: +1 506 648 5811
Email: terhune at unbsj.ca
Department of Biology PO Box 5050 University of New Brunswick
City: Saint John
Province or State: New Brunswick
Postal Code: E2L 4L5
Role: TECHNICAL CONTACT
Ancona University Department of Marine Biology
Role: DIF AUTHOR
Phone: +61 3 6232 3244
Fax: +61 3 6232 3351
Email: dave.connell at aad.gov.au
Australian Antarctic Division 203 Channel Highway
Province or State: Tasmania
Postal Code: 7050
Terhune, J.M. and Dell'Apa, A. (2006) Stereotyped Calling Patterns of a Male Weddell Seal (Leptonychotes weddellii), Aquatic Mammals, 32(2), 175-181
Creation and Review Dates
DIF Creation Date: 2002-05-29
Last DIF Revision Date: 2010-07-26