Fourth International Orca Symposium and Workshop - CEBC - CNRS

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Bigg, M. A. (1982). "An assessment of killer whale (Orcinus orca) stocks off Vancouver Island, British Columbia." Report of the International Whaling Commission 32: 625- 666. FOURTH INTERNATIONAL ORCA SYMPOSIUM AND WORKSHOPS SEPTEMBER 23-28 2002, CEBC-CNRS, France 34
KILLER WHALES AT MARION ISLAND, SOUTHERN OCEAN M.N. Bester, M. Keith & P.A. Pistorius Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, 0002, South Africa. Marion Island (46°54’S, 37°45’E), the larger of the two islands within the Prince Edward Island group, is situated in the Southern Indian Ocean north of the Antarctic Polar Front. The island has an area of 296 km 2 and a circumference of approximately 72 km (Condy et al. 1978). Data on killer whales were collected on an opportunistic basis between 1973 and 2000 by researchers operating within the South African National Antarctic Programme (SANAP) as described in Condy et al. (1978), Keith et al. (2001) and Pistorius et al. (2002). Spatial distribution - distance nearshore - Most killer whales sighted off Marion Island were predominantly in the nearshore area (Condy et al. 1978, Keith et al. 2001, Pistorius et al. 2002). As southern elephant seal pups (Mirounga leonina) remain in near shore waters during play and local post-weaning dispersion (Lenglart & Bester 1982; Wilkinson & Bester 1990), and elephant seal females and penguins enter and exit the water here at the land-sea boundary, it is likely to be the most rewarding hunting area for killer whales (Keith et al. 2001; Pistorius et al. 2002). Especially newly weaned southern elephant seal pups would be prone to predation near the shore since Guinet et al. (1992) found a high predation rate of killer whales on weaned elephant seal pups at the Îles Crozet. Swimming speeds of killer whales patrolling the beaches varied between 11.9 km h -1 and 14.44 km h -1 (Pistorius et al. 2002). Distribution around Marion Island - The most sightings of killer whales were recorded around the base station (Keith et al. 2001) possibly due to the high number of potential observers present there. Observer activity also possibly led to an increase in sightings at some sites in the vicinity of eight to ten field huts, focal points of human activity, situated along the coast of Marion Island. However, prey distribution and availability may also play a definite role in the frequency of occurrence of observations around the island. The areas with high percentage frequencies of sightings away from the base area support colonies of penguins and elephant seals. By far the majority of breeding (and moulting) elephant seals occupy the eastern coasts (Wilkinson & Bester 1990). The consequent higher seal movement could explain the predominance of killer whales on the east coast. In addition, on 13 December 2000, all of the 260 sightings of individuals which were recorded right around the island (Pistorius et al. 2002) were made from the four observation sites along the northeast coast, except one killer whale that was seen at Kildalkey on the southeast coast (Fig. 1). Despite the large number of fur seals (Arctocephalus tropicalis) residing on the west and north coasts of Marion Island (Hofmeyr et al. 1997), relatively few sightings of killer whales were recorded there. This might be related to the behaviour, distribution and difference in the seasonal haulout cycle of these two (of three) seal species found at Marion Island. Seasonal occurrence - The seasonal occurrence of killer whales at Marion Island (Keith et al. 2001) follows that recorded by Condy et al. (1978) and Guinet et al. (1992) where the maximum frequency of observations occurred in October, November and December, on Marion Island (Fig. 2) and Îles Crozet respectively. Condy et al. (1978) and Keith et al. (2001) further found a steep decline in number of sightings during January and February, with another, less pronounced, increase in sightings occurring during March to May. Roux (1986), on the other hand, found a clear seasonal cycle of occurrence at the temperate Amsterdam Island with killer whales being rare in July to August and more common in February to March FOURTH INTERNATIONAL ORCA SYMPOSIUM AND WORKSHOPS SEPTEMBER 23-28 2002, CEBC-CNRS, France 35
Page 1 and 2: Fourth International Orca Symposium
Page 3 and 4: Anatomy of a Long-term Study: Popul
Page 5 and 6: KILLER WHALE WORKSHOP - FORAGING EC
Page 7 and 8: (including crittercams) and high-fr
Page 9 and 10: The way prey avoids killer whale pr
Page 11 and 12: KILLER WHALE WORKSHOP - CONSERVATIO
Page 13 and 14: • Are killer whales opportunistic
Page 15 and 16: 6. Lack of Governance The wise appl
Page 17 and 18: Appendix 1 Top 3 threats to killer
Page 19 and 20: KILLER WHALE WORKSHOP - ACOUSTIC Pa
Page 21 and 22: lowest band, and burst-pulsing can
Page 23 and 24: the presence of killer whales throu
Page 25 and 26: KILLER WHALE WORKSHOP - POPULATION
Page 27 and 28: that resident killer whales have bo
Page 29 and 30: Bigg also used the alphanumeric sys
Page 31 and 32: Stevens, T.A., D.A. Duffield, E.D.
Page 33: population but that have markedly d
Page 37 and 38: watching from shore based vantage p
Page 39 and 40: Frequency of occurrence (%) 5 4,5 4
Page 41 and 42: Great White Shark (north of Montere
Page 43 and 44: white shark attack 1997 40° 30° 8
Page 45 and 46: KILLER WHALES (ORCINUS ORCA) OF ALA
Page 47 and 48: sightings for RJ were obtained from
Page 49 and 50: Figure 1. Sightings (o) and strandi
Page 51 and 52: RESULTS AND DISCUSSION Sightings Ov
Page 53 and 54: Fig. 2 - The overall gray pigmentat
Page 55 and 56: average click sounds with 51 clicks
Page 57 and 58: THE BC CETACEAN SIGHTINGS NETWORK:
Page 59 and 60: VOCAL BEHAVIOUR OF TRANSIENT KILLER
Page 61 and 62: Call rate (calls per individual per
Page 63 and 64: MIRROR IMAGE PROCESSING IN KILLER W
Page 65 and 66: ANALYSIS OF THE DISCRETE CALLS OF K
Page 67 and 68: REFERENCES Ford J.K.B. Call traditi
Page 69 and 70: IS KILLER WHALE (ORCINUS ORCA) BEHA
Page 71 and 72: localize the vocalizations of indiv
Page 73 and 74: A total of 16 pods were described f
Page 75 and 76: BEHAVIOURAL AND ACOUSTIC DIFFERENCE
Page 77 and 78: ANALYSIS OF PHOTO-IDENTIFICATION DA
Page 79 and 80: Overall, there is some evidence for
Page 81 and 82: ASSESSING THE IMPACTS OF KILLER WHA
Page 83 and 84: WORLD-WIDE GENETIC DIVERSITY IN THE
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COOPERATIVE HUNTING AND PREY HANDLI
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Using this method established by Bi
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SURFACE INTERVALS OF AN ADULT MALE
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VARIABILITIES IN SURFACE INTERVALS
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The lack of understanding of transi
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ANATOMY OF A LONG-TERM STUDY: POPUL
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Blubber from biopsy samples were an
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km from southeastern Alaska, south
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Most large whale kills from Mexico
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Figure 1 FOURTH INTERNATIONAL ORCA
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UNRAVELING THE INFLUENCE OF SOCIAL
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On the basis of these reported sigh
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KILLER WHALES (ORCINUS ORCA) IN AUS
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Southern Oceans Orca Database The S
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evidence that it had ingested piece
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Figure 1. Distribution of killer wh
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LIFE HISTORY AND POPULATION DYNAMIC
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The population model predicted that
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LIFE HISTORY AND DECLINE OF KILLER
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and Otto’s and Generalised Remova
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killer whale concentrations in Prin
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TOXICOLOGICAL EFFECTS OF TOXIC CHEM
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3. Barrett-Lennard,L.G. 2000. Popul
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THE BIOLOGY AND STATUS OF AN ENDANG
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MATCHED VOCAL EXCHANGES OF SHARED S
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The total number of good quality lo
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AERIAL VOCALISATIONS OF KILLER WHAL
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Pilot Whales (Globicephala melas),
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FIG.1: Research Area FIG.2: Aleator
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THEODOLITE STUDY OF THE EFFECTS OF
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FOURTH INTERNATIONAL ORCA SYMPOSIUM
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Southeaster n Alaska Study Figure 1
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ENCOUNTERS 5 4 3 2 1 0 SEP OCT NOV
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WHAT IS THE FAVOURITE PREY ? FORAGI
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1998, Hoelzel et al. 1998, Matkin e
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LITERATURE CITIED Bain, D.E. 1989.
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een an observed attack on Northern
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percent number of sightings 16 14 1
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also analyse earlier recordings obt
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Thomsen, F., Franck, D. and Ford, J
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A REVIEW OF SHORT- AND LONG-TERM EF
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question of whether whale watching
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values of all possible pairs of wha
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Bigg, M.A, Ellis, G.M., Ford J.K.B.
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Figure 2. Cluster tree of associati
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RESULTS: A total of 55 echo-sounder
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Figure texts for the summary of: "N
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The Orca Survey staff has accentuat
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Travel formation in relation to num
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NEW ZEALAND ORCA Visser I.N. Orca R
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Visser, I. N. (2000). Orca (Orcinus
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~ Some Antarctic killer whales have
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FIRST PHOTO-IDENTIFICATION MATCHES
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variable calls was significantly hi
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whales, rather than providing infor
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Figure 1. Predicted density of kill
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Probability Randomly choose paramet
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WHY DO SOME KILLER WHALES TALK SO M
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Figure2: Spectrographic examples of
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Deecke, V. B., J. K. B. Ford, et al
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Secchi, 47 Shapiro, 136 Sigurjonsso
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Fourth International Orca Symposium and Workshop - CEBC - CNRS

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