Orcalab Recordings: 230AB - 231AB 2006
230A (2006):
(photo - A32 Plumper RIP 1964 - 2010, 2004)
The
Cracroft Point recording (
230A, August 13, 2006, 14:26-15:15) by
Orcalab had faint boat noise and calls (N4, n=4). Whales identified included the A11s. A12s, and B boys.
230B (2006):
The
Orcalab recording
230B
from Cracroft Point and Parson's Island, BC (August 13, 2006,
15:15-16:00) had audible calls at the beginning of the tape then boat
noise increased towards the end. The B7 Matriline could be identified
from calls N1 (45%), N16 (18%), and N18 (10%). Other members from A pod
were heard using N4 (18%) and the A12special (10%). A total of 11
discrete calls were identified (n=11).
B10
(b.1979) is a big male with a huge dorsal fin that flops over to the
left and lays flat along the water causing him to swim sideways. The
above photo reminds me of the day I saw him and his two brothers (B12
1984-2006 and B13 b.1987) in 2004. They were on either side of him
guiding him along as B10 swam almost sideways because of his heavy
dorsal fin.
231A (2006):
The orcalab recording starts at 16:21 and ends at 18:39 on August 13th, 2006. Boat noise is heard throughout the recording with faint calls at Cracroft Point, West Cracroft Island, British Columbia. No calls were audible enough for analysis (n=0).
231B (2006):
The orcalab recording starts at 18:40 and ends at 19:26 on August 13th,
2006. Boat noise is heard throughout the recording with faint calls at
Cracroft Point, West Cracroft Island, British Columbia. No calls were
audible enough for analysis (n=0).
PRELIMINARY REPORT (2004 Calls):
Northern Resident Killer Whale Behaviour Calls
(photo - G38 and A36 boys, 2004)
ABSTRACT
The Northern Resident community of killer whales (
Orcinus orca)
in British Columbia is known to swim close to shore and rub on pebbles
at certain beaches. The purpose of this study was to investigate
discrete calls used by the Northern Residents during this unique
behaviour. A total of
983 calls
were identified from thirty
Orcalab digital recordings. Vocalizations from 2004 were analyzed through the
Orchive.
Calls used while rubbing at Main Beach, Robson Bight Micheal-Bigg
Ecological Reserve were compared to calls used at Cracroft Point, West
Cracroft Island during foraging activity. The N1 and N23 calls were
used significantly more during beach-rubbing behaviour. The N4 and N16
calls were used more while foraging. Further research is required to
increase samples from different years to conclude specific calls are
used at higher rates during certain behaviours.
INTRODUCTION
Killer
whales are known to live in long-term family groups. There are three
types of killer whales in British Columbia (Residents, Bigg’s /
Transients, and Offshores). Residents forage on salmon, Bigg’s are
larger and hunt marine mammals, Offshores are a smaller ecotype
specializing on sharks. Morin et. al. (2010) recommended three known ecotypes of Orcinus orca
be named separate species (Bigg’s, Antarctic Types B, and C) the
remaining types be recognized as subspecies. Another new possible
species has been discovered off New Zealand, Type D (Foote et. al. 2013).
There
are two different communities of fish eating killer whales in British
Columbia, Northern and Southern Residents. They are genetically,
morphologically, and acoustically distinct. Structure and use of calls
suggests they serve as contact signals to maintain family cohesion (Ford
1991). Dialects reflect family relatedness with call variation
building over time (Deeke et. al. 2010). Discrete calls contain
abrupt shifts in pitch and wide-band energy content. Variations in
signal structure can reflect emotional state and reaffirm relationships
(Ford 1989). During close proximity and social behaviour there is an
increase in production of irregular calls relative to foraging and
traveling activities. All calls are used during most killer whale
activities (Ford 1989). The N3 and N12 calls are emitted more
frequently during socializing and beach-rubbing activities (Ford 1989).
This
study compared average rate of Northern Resident calls used during
beach-rubbing and foraging activities to determine if vocalizations may
indicate behaviour. Characterization of unique behaviours could assist
sub-species definition of killer whale ecotypes. This information is
notable for killer whale classification and conservation plans. This research increases awareness of the marine environment.
METHODS & MATERIALS
Northern Resident killer whale calls were analyzed through digital recordings on the Orchive database (Ness et. al.
2013, Orcalab 2013). In 2004, I was in Johnstone Strait as a killer
whale researcher on West Cracroft Island. Orcalab log books and
personal field notes were referenced for direction, location, and whale
group identification. Vocalizations were first annotated then aurally
and visually identified. Call classification was determined by
comparing call types with acoustic catalogues (Ford 1987, Ness et. al.
2013) and through spectrogram analysis. Average call use per recording
was compared between the Main Beach rubbing and Cracroft Point foraging
sites.
RESULTS
A
total of 983 discrete calls were identified from 2004 (30 recordings, 2700 min).
Calls used at Main Beach and Cracroft Point included N1, N2, N3, N4,
N5, N7, N9, N16, N23, N24, and N25 (Fig. 1).
Figure1. Frequency of Northern Resident killer whale discrete calls used during rubbing-beach and foraging activities.
The
null hypothesis (Ho) was there is no significance difference in calls
used while beach-rubbing. Average call rate of each type was compared
between beach-rubbing and forging behaviour to determine any difference
in vocalizations (Table I).
Table
I. Results of statistical t-tests comparing call type frequency of use
at the Main rubbing-beach (RB) and Cracroft Point (CP).
Call
|
RB (%)
|
CP (%)
|
t
|
p
|
Ho
|
N1
|
16.9
|
4.85
|
2.054
|
p < 0.025
|
Reject
|
N2
|
1.54
|
3.56
|
0.9035
|
p < 0.25
|
Accept
|
N3
|
0.305
|
5.94
|
1.005
|
P < 0.25
|
Accept
|
N4
|
14.3
|
27.4
|
1.421
|
p < 0.10
|
Accept
|
N5
|
5.80
|
5.93
|
0.02918
|
p > 0.25
|
Accept
|
N7
|
0.152
|
0.8007
|
0.6471
|
p < 0.25
|
Accept
|
N9
|
4.89
|
10.4
|
1.294
|
p < 0.25
|
Accept
|
N16
|
0.152
|
3.50
|
1.675
|
p < 0.10
|
Accept
|
N23
|
34.4
|
11.9
|
1.765
|
p < 0.05
|
Reject
|
N24
|
1.95
|
1.52
|
0.1573
|
p < 0.25
|
Accept
|
N25
|
3.93
|
7.71
|
0.6281
|
p > 0.25
|
Accept
|
The
N1 call type was used significantly more on average at the rubbing
beach versus while foraging (p < 0.05). The I15s emitted the N23
call significantly more while beach rubbing activity than during forging
behaviour (p < 0.05). The N4 and N16 call types were used more
while foraging with marginal insignificance (p < 0.10). There was no
significant difference found for the N2, N3, N5, N7, N9, N24, and N25
call types.
DISCUSSION
This
study analyzed Northern Resident killer whale call use between
beach-rubbing and foraging areas. A significant difference was found
for the N1 and N23 discrete calls being used more on average at Main
Beach than at the Cracroft Point foraging site. The N4 and N16 call
types were used with a higher rate while foraging with marginal
insignificance difference. The information from this study increases
knowledge of call types used during certain Northern Resident
behaviours. Further information from different years is needed to
conclude a higher rate of specific calls may indicate beach-rubbing or
foraging behaviour.
REFERENCES
Deecke,
V. B., Barrett-Lennard, L. G., Spong, P., Ford, J. K. B. (2010) The
structure of stereotyped calls reflects kinship and social affiliation
in resident killer whales (Orcinus orca) Naturwissenschaften. Vol. 97 (5), 513-518.
Foote,
A. D., Morin, P. A., Pitman, R. L., Ávila-Arcos, M. C., Durban, J. W.,
van Helden, A., Sinding, M.S., Gilbert, M. T. P. (2013) Mitogenomic
insights into a recently described and rarely observed killer whale
morphotype. Polar Biology, in press.
Ford, J. K. B. (1987) A Catalogue of Underwater Calls Produced by Killer Whales (Orcinus orca) in British Columbia. Canadian Data Report of Fisheries and Aquatic Sciences. No. 633.
Ford, J. K. B. (1989) Acoustic behaviour of resident killer whales (Orcinus orca) off Vancouver Island, British Columbia. Canadian Journal of Zoology. 67: 727 – 745.
Ford, J. K. B. (1991) Vocal traditions among resident killer whales (Orcinus orca) in coastal waters of British Columbia. Canadian Journal of Zoology. 69:1454–1483.
Morin, P., Archer, F., Foote, A., Vilstrup, J., Allen, E., Wade, P., Durban, J., Parsons, K.,
Pitman, R., Li, L. (2010) Complete mitochondrial genome phylogeographic analysis of killer whales (Orcinus orca) indicates multiple species. Genome Research. 20: 908.
Ness, S., Symonds, H., Spong, P., and Tzanetakis, G. (2013) The Orchive: Data mining a massive bioacoustic archive. International Conference on Machine Learning 2013 Workshop on Machine Learning for Bioacoustics (WBIOAC).
