ArticlePDF Available

No Danger in Sight? An Observation of Sperm Whales (Physeter macrocephalus) in Marguerite Formation off Muscat, Sultanate of Oman

Authors:
  • The MareCet Research Organization
Aquatic Mammals 2016, 42(2), 162-167, DOI 10.1578/AM.42.2.2016.162
Short Note
No Danger in Sight? An Observation of Sperm Whales
(Physeter macrocephalus) in Marguerite Formation
off Muscat, Sultanate of Oman
Louisa S. Ponnampalam1, 2, 3
1Environment Society of Oman, Suite 22, 1st Floor, Building 1197, Ajit Khimji Building, 2519 Darsait, Oman
2Institute of Ocean and Earth Sciences, University Malaya, 50603 Kuala Lumpur, Malaysia
3The MareCet Research Organization, 40460 Shah Alam, Malaysia
E-mail: louisa.ponnampalam@gmail.com
Whales have developed anti-predator strategies of Isla San Pedro Martir in the Gulf of California,
varying sophistication (Lima & Dill, 1990; Ford & Mexico, was made in April 2013. This was sup-
Reeves, 2008). An aspect of the complex behav-ported by photographs and also was reported
ioural ecology of sperm whales (Physeter macro-online (see https://www.expeditions.com/daily-
cephalus) includes the “marguerite” formation, expedition-reports/155632/baja-california).
first described by Nishiwaki (1962) and observed Herein, I report on the first confirmed sighting of
by whalers off Peru (Caldwell et al., 1966). The sperm whales from Oman engaging in marguerite
marguerite formation involves a group of whales and parallel formations, one that is in the absence
positioning themselves in a circle at the surface in of any visible predators.
a manner akin to the spokes of a wheel, with their
The sperm whale is one of 18 species of ceta-
heads together on the inside of the formation and
ceans known to occur in the deeper waters of
their tails radiating outwards (Nishiwaki, 1962;
the Sultanate of Oman (Alling, 1986; Gallagher,
Whitehead, 2002) or in reverse with their heads
1991; Baldwin, 1998; Ballance & Pitman, 1998;
facing outwards (Arnbom et al., 1987). A litera-
Ponnampalam, 2009; Minton et al., 2010). In the
ture review of this behaviour revealed that almost
Arabian Sea, the species was a target of Yankee
every documented observation of sperm whales
whaling fleets between 1850 and 1870 (Wray &
in marguerite and parallel flank-to-flank forma-
Martin, 1983; Smith et al., 2012) and illegal Soviet
tions was associated with the presence of cetacean
whaling fleets between 1963 and 1967 (Mikhalev,
predators, such as killer whales (Orcinus orca),
2000). Sperm whales were the most frequently
short-finned pilot whales (Globicephala macro-
sighted cetacean species during a survey in the
rhynchus), and false killer whales (Pseudorca
western tropical Indian Ocean in 1995, which
crassidens) (Smultea et al., 2008), and/or attacks
included the coast of Muscat, Oman (Ballance &
by these predatory species (Arnbom et al., 1987;
Pitman 1998). Boat-based surveys of cetaceans
Palacios & Mate, 1996; Weller et al., 1996; Pitman
along various parts of Oman’s coastline between
et al., 2001; Hucke-Gaete et al., 2004; Dunn &
2000 and 2006 yielded much lower encounter rates
Claridge, 2013).
of sperm whales (< 10 sightings) (Ponnampalam,
Sironi et al. (2008) reported two incidents of
2009; Minton et al., 2010).
southern right whales (Eubalaena australis) in On 31 May 2006, during line transect boat sur-
Argentina gathering in marguerite formation when veys for cetaceans south of Muscat, my team and
the groups came under attack by killer whales in I were contacted (0944 h) by a dolphin-watching
1972 and 1975. A video posted online showed a tour operator who had encountered a large group
group of sperm whales off southern Sri Lanka of sperm whales offshore (23° 39.725' N, 58°
clustering together in marguerite formation as they 41.574' E) of the village of Sidab, approximately
came under attack by a pod of killer whales in April 11.0 km east of Muscat and 5.7 km northeast of
2013 (Heinrichs, 2013; Gemmell et al., 2015) in where our research team was located. Our team
what appears to be the first documented account immediately proceeded towards the sighting loca-
of such for the Northern Indian Ocean region tion and, upon arrival (0957 h), found the group of
(Gemmell et al., 2015). A similar observation of sperm whales (possibly females and young adults,
an unsuccessful orca attack on sperm whales near judging from body sizes) mixed with bottlenose
163Muscat Sperm Whales
(Tursiops sp.) and Risso’s dolphins (Grampus We did not observe any agonistic behaviour
griseus), along with two dolphin-watching tour or startled reactions from the sperm whales. A
boats. Water depth was 499 m, weather conditions mother-calf sperm whale pair was seen during the
were calm and sunny, and the Beaufort sea state first hour of the sighting, surfacing several times
was 1 to 2. The estimated group sizes of the sperm at the periphery of the main group, with the calf
whales, bottlenose dolphins, and Risso’s dolphins remaining close to its mother (< 1 m distance) at
were 35, 75, and 200, respectively. The bottlenose all times. Approximately 25 min into the sighting,
and Risso’s dolphins were dispersed over approxi-the sperm whales dived, only to resurface 250 m
mately 0.25 km2, an area larger than the area the away less than 10 min later. Seventeen individ-
sperm whales were occupying. Approximately ual sperm whales formed a marguerite formation
10% of the Risso’s dolphins and 20% of the bot-upon surfacing, with the remainder of the group
tlenose dolphins appeared to be swimming near loosely scattered around them nearby. Two indi-
and among the sperm whales, with the remainder viduals were in the center of the formation, ori-
of both species 400 to 500 m away. No other ceta-ented vertically in the water column with their
cean species were observed. melons protruding from the surface (Figure 1).
At the start of the encounter, the sperm whales As our 10-m research vessel moved slowly
appeared to be logging; approximately 12 indi-towards the sperm whales, we saw a large cepha-
viduals were in a haphazard marguerite formation lopod tentacle sinking in the water that was not
with their heads facing inwards and tails radiating chased after by any of the dolphins or sperm
outwards. The other sperm whales were distrib-whales. By this time (1042 h), the tour boats had
uted singly, in pairs, or trios around the subgroup left the scene. The sperm whales did not appear
of 12 whales in formation. During this time, the to react to the presence of our vessel, which fol-
Risso’s and bottlenose dolphin groups as a whole lowed at idle speed. At one point while the sperm
did not appear to be traveling in any specific direc-whales were still in marguerite formation, the
tion, and those near the sperm whales appeared to engines of the vessel were turned off, and the
be milling. A small number of Risso’s dolphins vessel slowly drifted to within 30 m of the sub-
were observed engaging in tail-up/head-standing group in formation. I entered the water briefly
behaviour (see Minton et al., 2010; Bearzi et al., (~5 min) to observe the sperm whales under
2011) and waving their flukes in a slow side-to- water, staying approximately 7 m away. I heard
side motion above the sea surface. Individual clicks (coda) that I attributed to the sperm whales.
bottlenose dolphins that were swimming further Ten minutes later, the sperm whales dived again,
away from the sperm whales were observed to resurfacing 16 min later approximately 400 m
occasionally leap. away in a marguerite formation but without
Figure 1. The sperm whales (Physeter macrocephalus) in marguerite formation, where two individuals in the center are
oriented vertically in the water with their bulbous heads protruding from the surface
164 Ponnampalam
any vertically oriented individuals in the center
(Figure 2). The research vessel moved towards
the sperm whales and stopped approximately
250 m away from the group. At this time, only
a few Risso’s and bottlenose dolphins remained
near the sperm whales and appeared to be mill-
ing, while the remainder of both species’ groups
were highly dispersed (> 0.25 km2) in the general
vicinity and became difficult to track. The tail-up/
head-standing behaviour seen previously in some
Risso’s dolphins had ceased.
The sperm whales logged in marguerite for-
mation for approximately 28 min after their last
surfacing before the formation started changing
shape. The sperm whales then sank below the
water’s surface for 1 min before resurfacing in
two haphazard rows, their bodies parallel to each
other (< 2 m apart) and facing in the same direc-
tion. In slow motion, the sperm whales aligned
themselves in a straight row parallel to each other
within 90 s and logged at the surface for another
3 min (Figure 3). Subsequently, the sperm whales
dove with their flukes up, one by one in a “domino
effect” manner—that is, the animal on the farthest
left of the parallel formation dove first, followed
by the next animal to the right, and then the next,
and so on, until all the whales had dived at 1307 h.
The last dive was completed 4 km northeast from
where the animals were first sighted over 3 h ear-
lier. The Risso’s and bottlenose dolphins that were
still present in the area appeared to cluster and con-
tinued milling. Our team remained in the vicinity
(23° 41.376' N, 58° 43.096' E) for another 45 min,
but the sperm whales were not sighted again.
Most observations of marguerite and paral-
lel formations in sperm whales were linked to
predator presence or attacks (Caldwell et al., 1966;
Arnbom et al., 1987; Visser, 1999; Pitman et al.,
2001; Hucke-Gaete et al., 2004; Dunn & Claridge,
2013) and whaling (Nishiwaki, 1962; Caldwell
et al., 1966). However, during this encounter, these
defense-oriented formations did not appear to be
in response to a particular threat. Surveys of ceta-
cean distribution in Omani waters since 2000 have
yielded many more sightings of sperm whales
than killer whales (Ponnampalam, 2009; Minton
et al., 2010), consistent with the general notion
that killer whales are less common in lower lati-
tudes (Dahlheim & Heyning, 1999). Additionally,
surveys in Oman have not yielded any records of
false killer whale groups mixed with sperm whales
(Baldwin, 1998; Ponnampalam, 2009; Minton
et al., 2010).
Previous surveys in Oman have recorded several
mixed species groups of bottlenose and Risso’s
dolphins (Minton et al., 2010) and bottlenose dol-
phins and sperm whales (Ponnampalam, 2009).
Still, the sighting reported herein represents only
the second record of a mixed species group con-
taining bottlenose and Risso’s dolphins with sperm
whales, the first of which was observed in 1996
(Baldwin, 1998). While there are reports of ago-
nistic behaviours towards sperm whales by Risso’s
dolphins (Pereira, 2008; Smultea et al., 2014) in
which the latter species is possibly displaying
kleptoparasitism (i.e., forcing the sperm whales
to regurgitate their food so that the dolphins can
feed on it [Palacios & Mate, 1996]), the Risso’s
dolphins seen with the sperm whales reported
herein did not display any aggression towards the
sperm whales at the surface. However, it is pos-
sible that such aggression might have occurred and
Figure 2. Sperm whales in marguerite formation, with their heads pointing inwards towards the center and tails radiating
outwards
165
then subsided prior to the arrival of our research
team (see Bacon & Johnson, 2012). Other signs
of distress or excitement associated with observa-
tions of the marguerite formation, such as defeca-
tion (Clarke, 1956; Caldwell et al., 1966; Palacios
& Mate, 1996; Pereira, 2008; Hooper, 2015) and
agitated behaviour (Nishiwaki, 1962; Palacios &
Mate, 1996; Pitman et al., 2001; Pereira, 2008;
Dunn & Claridge, 2013; Smultea et al., 2014;
Gemmell et al., 2015), were not seen during this
encounter.
Sperm whales observed in marguerite forma-
tion off Sri Lanka prior to the incident reported
by Gemmell et al. (2015) seemed to be socialis-
ing (Gordon, 1987). Similarly, there have been
frequent reports and observations of sperm
whales off northwestern and eastern Sri Lanka
logging in parallel formation in the absence of
other species and threats, leading the observers
to believe that the sperm whales were engag-
ing in social behaviour (A. D. Ilangakoon, pers.
comm., 9 September 2014). Sperm whales stud-
ied around the Galápagos Islands were reported
to have “social times” in which the whales spent
1 to 8 h clustering in a compact mass at the sur-
face and were less active (Whitehead, 1987).
Figure 3. The sperm whale group (a) closing ranks and (b) in parallel formation towards the end of the sighting
Muscat Sperm Whales
166 Ponnampalam
A sighting of parallel logging sperm whales off
Muscat in 2012 captured on video and posted
online (https://vimeo.com/61702468) showed that
the animals could have been engaging in similar
behaviour after a bout of feeding. Sperm whales
also have been reported to be skittish (Whitehead,
2003) and may display mild reactions to aircraft
and vessel presence (Pitman et al., 2001; Smultea
et al., 2008). The presence of other species such
as bottlenose dolphins might also cause sperm
whales to dive when approached (R. L. Pitman,
pers. comm., 12 December 2013). While there
appeared to be no obvious threat detected during
the encounter off Muscat, diving and congregat-
ing in marguerite and parallel formations may
have been responses to the presence of the boats
or the underwater behaviour of the Risso’s and
bottlenose dolphins not visible to our research
team. Separately, in southern Sri Lanka, there was
an account of a large group of false killer whales
that were hunting when first encountered. Twenty-
five minutes into observing the false killer whales,
a subgroup of 13 animals suddenly went into a
marguerite formation for a few minutes before
synchronously diving with their flukes up. The
animals repeated this behaviour once, resurfaced
minutes later, and resumed hunting. The observers
who witnessed this sighting reported no apparent
predator threat or other danger at the time, and the
observed behaviour remains unexplained (A. D.
Ilangakoon, pers. comm., 9 September 2014).
Much remains unknown about sperm whales in
Omani waters, although the observations reported
herein provide an insight into the species’ behav-
iour in the Sea of Oman region and could form the
basis of future efforts in sperm whale ethological
research. The behaviours reported herein appear
to be a rarity for Oman and even for the northern
Indian Ocean region (except in Sri Lanka where
parallel formations are reportedly seen regularly).
The apparent scarcity in such observations, how-
ever, may also be due to less survey effort in off-
shore areas where sperm whales are found more
frequently (see Ballance & Pitman, 1998) or to
less killer whale presence in the lower latitudes
(Dahlheim & Heyning, 1999; Forney & Wade,
2006).
Acknowledgments
We would like to thank the Oman Ministry of
Environment and Climate Affairs for relevant
permits to conduct cetacean research and the
Environment Society of Oman (www.eso.org.om)
for its support of cetacean research in Oman. Thank
you to Shell Marketing Oman for its in-kind sup-
port that made surveys possible. Thank you also
to Rebecca Lovegrove, Victoria Hill, and Rebekah
Oxley who volunteered their time and efforts on
the boat during the survey. Appreciation goes to
Dr. Robert Pitman, Anoukchika Ilangakoon, and
Tim Collins for reviewing and improving an ear-
lier version of this manuscript.
Literature Cited
Alling, A. (1986). Records of odontocetes in the northern
Indian Ocean (1981-1982) and off the coast of Sri Lanka
(1982-1984). Journal of the Bombay Natural History
Society, 83, 376-394.
Arnbom, T., Papastavrou, V., Weilgart, L. S., & Whitehead,
H. (1987). Sperm whales react to an attack by killer
whales. Journal of Mammalogy, 68(2), 450-453. http://
dx.doi.org/10.2307/1381497
Bacon, C., & Johnson, C. (2012). Rare Southern California
sperm whale sighting. Currents (Navy’s Environmental
Magazine), 44-47.
Baldwin, R. (1998, May). A note on sightings of sperm
whales off the coasts of the Sultanate of Oman and the
United Arab Emirates, October 1994 to October 1997
(Unpublished document SC/50/CAWS22). Presented
at the 50th Meeting of the International Whaling Com-
mission, Muscat, Oman.
Ballance, L. T., & Pitman, R. L. (1998). Cetaceans of
the western tropical Indian Ocean: Distribution, rela-
tive abundance, and comparisons with cetacean com-
munities of two other tropical ecosystems. Marine
Mammal Science, 14(3), 429-459. http://dx.doi.
org/10.1111/j.1748-7692.1998.tb00736.x
Bearzi, G., Reeves, R. R., Remonato, E., Pierantonio, N., &
Airoldi, S. (2011). Risso’s dolphin Grampus griseus in
the Mediterranean Sea. Mammalian Biology, 76(4), 385-
400. http://dx.doi.org/10.1016/j.mambio.2010.06.003
Caldwell, D. K., Caldwell, M. C., & Rice, D. W.
(1966). Behavior of the sperm whale. In K. S. Norris
(Ed.), Whales, dolphins, and porpoises (pp. 667-
717). Berkeley: University of California Press.
Clarke, R. (1956). Marking whales from a helicopter. Norsk
Hvalfangst-Tidende, 45, 311-318.
Dahlheim, E., & Heyning, J. E. (1999). Killer whale
Orcinus orca (Linnaeus, 1758). In S. H. Ridgway & R.
Harrison (Eds.), Handbook of marine mammals (Vol. 6,
pp. 281-322). London: Academic Press.
Dunn, C., & Claridge, D. (2013). Killer whale (Orcinus
orca) occurrence and predation in the Bahamas. Journal
of the Marine Biological Association of the United
Kingdom, 94(6), 1305-1309. http://dx.doi.org/10.1017/
S0025315413000908
Ford, J. K. B., & Reeves, R. R. (2008). Fight or flight:
Antipredator strategies of baleen whales. Mammal
Review, 38(1), 50-86. http://dx.doi.org/10.1111/j.1365-
2907.2008.00118.x
Forney, K. A., & Wade, P. R. (2006). Worldwide distri-
bution and abundance of killer whales. In J. A. Estes,
D. P. DeMaster, D. F. Doak, T. M. Williams, & R. L.
Brownell, Jr. (Eds.), Whales, whaling and ocean
167
ecosystems (pp. 145-162). Berkeley: University of Ponnampalam, L. S. (2009). Ecological studies and
California Press. conservation of small dolphins in the Sultanate of
Gallagher, M. D. (1991). Strandings of sperm whales Oman, with special reference to spinner dolphins,
(Physeter macrocephalus) on the shores of Oman, Stenella longirostris (Gray, 1828) (Doctoral disserta-
Eastern Arabia (UNEP Marine Mammal Technical tion). University (London) Marine Biological Station
Report, 3, 241-245). Millport, Scotland.
Gemmell, G. L., McInnes, J. D., Heinrichs, S. J., & Sironi, M., López, J. C., Bubas, R., Carribero, A., Garcia,
Wijeyeratne, G. D. S. (2015). Killer whale (Orcinus C., Harris, G., . . . Payne, R. (2008, June). Predation by
orca) predation on whales in Sri Lankan waters. Aquatic killer whales (Orcinus orca) on southern right whales
Mammals, 41(3), 265-271. http://dx.doi.org/10.1578/ (Eubalaena australis) off Patagonia, Argentina: Effects
AM.41.3.2015.265 on behavior and habitat choice (Unpublished document
Gordon, J. C. D. (1987). The behaviour and ecology of SC/60/BRG29). Presented at the 60th International
sperm whales off Sri Lanka (Doctoral dissertation). Whaling Commission Meeting, Santiago, Chile.
University of Cambridge, Cambridge, UK.
Smith, T. D., Reeves, R. R., Josephson, E. A., & Lund, J. N.
Heinrichs, B. (2013, April 21). Killer whales (Orca) attack
(2012). Spatial and seasonal distribution of American
sperm whales pod [Video file]. Available from https://
whaling and whales in the Age of Sail. PLOS ONE, 7,
www.youtube.com/watch?v=tielUPfyzaY
e34905. http://dx.doi.org/10.1371/journal.pone.0034905
Hooper, R. (2015, January 28). Sperm whale’s emer-Smultea, M. A., Mobley, J. R., Jr., Fertl, D., & Fulling,
gency evacuation . . . of its bowels. New Scientist, G. L. (2008). An unusual reaction and other observa-
3006, 22-23. Retrieved from www.newscientist.com/ tions of sperm whales near fixed-wing aircraft. Gulf and
article/mg22530064.700-sperm-whales-emergency- Caribbean Research, 20(1), 75-80.
evacuation-of-its-bowels.html Smultea, M. A., Bacon, C. E., Lomac-MacNair, K., Visser,
Hucke-Gaete, R., Moreno, C. A., & Arata, J. (2004). F., & Bredvik, J. (2014). Rare mixed-species associa-
Operational interactions of sperm whales and killer tions between sperm whales and Risso’s and northern
whales with the Patagonian toothfish industrial fishery right whale dolphins off the Southern California Bight:
off southern Chile. CCAMLR Science, 11, 127-140. Kleptoparasitism and social parasitism? Northwestern
Lima, S. L., & Dill, L. M. (1990). Behavioral decisions Naturalist, 95(1), 43-49. http://dx.doi.org/10.1898/NW
made under the risk of predation: A review and pro- N13-11.1
spectus. Canadian Journal of Zoology, 68(4), 619-640. Visser, I. N. (1999). A summary of interactions between
http://dx.doi.org/10.1139/z90-092 orca (Orcinus orca) and other cetaceans in New Zealand
Mikhalev, Y. A. (2000). Whaling in the Arabian Sea by waters. New Zealand Natural Sciences, 24, 101-112.
the whaling fleets Slava and Sovetskaya Ukraina. In Weller, D. W., Würsig, B., Whitehead, H., Norris, J. C.,
A. V. Yablokov, V. A. Zemsky, & D. D. Tormosov Lynn, S. K., Davis, R. W., . . . Brown, P. (1996).
(Eds.), Soviet whaling data (1949-1979) (pp. 141-181). Observations of an interaction between sperm whales
Moscow: Centre for Russian Environmental Policy. and short-finned pilot whales in the Gulf of Mexico.
Minton, G., Collins, T., Findlay, K. P., & Baldwin, R. Marine Mammal Science, 12(4), 588-594. http://dx.doi.
(2010). Cetacean distribution in the coastal waters of the org/10.1111/j.1748-7692.1996.tb00071.x
Sultanate of Oman. The Journal of Cetacean Research Whitehead, H. (1987). Sperm whale behavior on the
and Management, 11, 301-313. Galápagos grounds. Oceanus, 30, 49-53.
Nishiwaki, M. (1962). Aerial photographs show sperm Whitehead, H. (2002). The sperm whale Physeter mac-
whales’ interesting habits. Norsk Hvalfangst-Tidende, rocephalus. In W. F. Perrin, B. Würsig, & J. G. M.
51, 395-398. Thewissen (Eds.), Encyclopedia of marine mammals
Palacios, D. M., & Mate, B. R. (1996). Attack by false (pp. 1165-1172). San Diego: Academic Press.
killer whales (Pseudorca crassidens) on sperm whales Whitehead, H. (2003). Sperm whales: Social evolution in
(Physeter macrocephalus) in the Galápagos Islands. the ocean. Chicago: University of Chicago Press.
Marine Mammal Science, 12(4), 582-587. http://dx.doi. Wray, P., & Martin, K. R. (1983). Historical whaling
org/10.1111/j.1748-7692.1996.tb00070.x records from the western Indian Ocean. Reports of the
Pereira, J. N. D. S. G. (2008). Field notes on Risso’s International Whaling Commission, Special Issue 15,
dolphin (Grampus griseus) distribution, social ecol- 213-231.
ogy, behavior, and occurrence in the Azores. Aquatic
Mammals, 34(4), 426-435. http://dx.doi.org/10.1578/
AM.34.4.2008.426
Pitman, R. L., Ballance, L. T., Mesnick, S. I., & Chivers,
S. J. (2001). Killer whale predation on sperm
whales: Observations and implications. Marine
Mammal Science, 17(3), 494-507. http://dx.doi.
org/10.1111/j.1748-7692.2001.tb01000.x
Muscat Sperm Whales
Article
Full-text available
On Saturday 07.10,2017, two Arabian Humpback Whales(Megaptera novaeangliae indica Gervais, 1883) mother and juvenile were live-sighted in the Sea of Dubai-Jumeirah, near-shore off the Dubai Offshore Sailing Club, between 13.35 – 13.45 hours. The video-recorded sighting was recorded in the Facebook page of the UAE Dolphin Project. This was the First Live-Sighting Record of the Arabian Humpback Whale in the Sea of Dubai. Reference: Khalaf-Prinz Sakerfalke von Jaffa, Prof. Dr. Sc. Norman Ali Bassam Ali Taher Mohammad Ahmad Mostafa (November 2017). First Sighting Record of the Arabian Humpback Whale (Megaptera novaeangliae indica Gervais, 1883) in the Sea of Dubai, United Arab Emirates, Arabian Gulf. Gazelle: The Palestinian Biological Bulletin. ISSN 0178 – 6288. Volume 35, Number 155, November 2017, pp. 16-50. Published by Prof. Dr. Norman Ali Khalaf Department for Environmental Research and Media, National Research Center, University of Palestine, Gaza, State of Palestine.http://marine-life-uae-2.webs.com/arabian-humpback-whale
Article
Full-text available
On Saturday 23.09.2017, I visited the Natural History Museum in Muscat, Sultanate of Oman. The museum falls under the Omani Ministry of Heritage and Culture. During my visit, I visited the Whale Hall, which contains skeletons of various cetacean species which had stranded on Omani beaches. The Cetacean skeletons belonged to: Sperm Whale (Physeter macrocephalus), Dwarf Sperm Whale (Kogia simus), Killer Whale (Orcinus orca), False Killer Whale (Pseudorca crassidens), Bryde’s Whale (Balaenoptera edeni), and Common Dolphin (Delphinus delphis). The huge skeleton which was displayed in the middle of the Whale Hall was of a male Sperm Whale (Physeter macrocephalus Linnaeus, 1758), which stranded at Barka, Al Batinah, 60 kilometers northwest of Muscat, in September 1986. It was about 25 years old and 14 meters long, but could have grown to 18 meters. The bones weigh 3.5 tonnes and the live animal would have weighed about 35 tonnes. All the skeleton bones are original, except the teeth and digits (replaced by wood), and the cartilage (replaced by plaster). The ear-bones are missing. The skeleton has been painted to preserve it and to reduce the oily smell. Reference : Khalaf-Prinz Sakerfalke von Jaffa, Prof. Dr. Sc. Norman Ali Bassam Ali Taher Mohammad Ahmad Mostafa (2018). Sperm Whale (Physeter macrocephalus Linnaeus, 1758) Skeleton at the Natural History Museum in Muscat, Sultanate of Oman. Gazelle: The Palestinian Biological Bulletin. ISSN 0178 – 6288. Volume 36, Number 165, September 2018, pp. 1-31. Published by Prof. Dr. Norman Ali Khalaf Department for Environmental Research and Media, National Research Center, University of Palestine, Gaza, State of Palestine. http://cetacea.webs.com/
Article
Full-text available
This study reports new information on Grampus griseus (G. Cuvier, 1812) distribution with depth and slope, group size, general and interspecific behaviour, and calving intervals for the Azorean archipelago. Observations are in agreement with scarce previous work and most other regions in the North Atlantic and Mediterranean. Data were collected on 107 sightings south of Pico Island that took place between 17 May and 29 August 2003 from opportunistic research platforms. Information on occurrence, provided by an observer with 50 y of land-based cetacean experience, was included for comparison. Risso's dolphins preferred areas between 497 and 1,233 m depth (modal class 600 to 650 m; N = 69), with slopes between 27 and 35%, although these data require validation. The majority of groups were composed of up to 20 individuals (modal 6 to 10), averaging 12.3 (1 to 55; N = 74). Large socializing aggregations observed during July and August (55 to ~175 individuals) were similar to land-based observations between 1992 and 2005. G. griseus's diurnal activities in this study were mostly traveling (77%) and socializing (13%), with feeding (5%) and resting (3.7%) occurring less frequently. The first newborn calves are reported. Twospecies groups and interactions with six cetacean species are described. Harassment behaviours with Globicephala spp. and Physeter macrocephalus suggest competitive interference. Year-round observations between 1992 and 2005 near Pico Island, together with birth reports and recent data on site fidelity, suggest population residency.
Article
Full-text available
Killer whales ( Orcinus orca) have a cosmopolitan distribution, yet little is known about populations that inhabit tropical waters. We compiled 34 sightings of killer whales in the Bahamas, recorded from 1913 to 2011. Group sizes were generally small (mean = 4.2, range = 1-12, SD = 2.6). Thirteen sightings were documented with photographs and/or video of sufficient quality to allow individual photo-identification analysis. Of the 45 whales photographed, 14 unique individual killer whales were identified, eight of which were re-sighted between two and nine times. An adult female (Oo6) and a now-adult male (Oo4), were first seen together in 1995, and have been re-sighted together eight times over a 16-yr period. To date, killer whales in the Bahamas have only been observed preying on marine mammals, including Atlantic spotted dolphin (Stenella frontalis), Fraser's dolphin (Lagenodelphis hosei), pygmy sperm whale (Kogia breviceps) and dwarf sperm whale (Kogia sima), all of which are previously unrecorded prey species for Orcinus orca.
Article
Full-text available
This chapter provides a review of the published literature on worldwide killer whale population structure, abundance, distribution, and known prey. It discusses differences in the methods that have been used to identify and assess killer whale populations, including sighting and whaling records, photo-identification methods, mark-recapture estimates, and distance sampling methods from shipboard and aerial platforms. Each method has limitations and strengths and provides somewhat different information on population size, structure, and distribution. When combined within a single region, these sources can complement one another to provide a clearer picture of killer whale biology; however, taken individually, they make comparisons between regions difficult.
Article
Full-text available
The significance of killer whale Orcinus orca predation on baleen whales (Mysticeti) has been a topic of considerable discussion and debate in recent years. Discourse has been constrained by poor understanding of predator-prey dynamics, including the relative vulner- ability of different mysticete species and age classes to killer whales and how these prey animals avoid predation. Here we provide an overview and analysis of predatory interactions between killer whales and mysticetes, with an emphasis on patterns of antipredator responses. 2. Responses of baleen whales to predatory advances and attacks by killer whales appear to fall into two distinct categories, which we term the fight and flight strategies. The fight strategy consists of active physical defence, including self-defence by single individuals, defence of calves by their mothers and coordinated defence by groups of whales. It is documented for five mysticetes: southern right whale Eubalaena australis, North Atlantic right whale Eubal- aena glacialis, bowhead whale Balaena mysticetus, humpback whale Megaptera novaeangliae and grey whale Eschrichtius robustus. The flight strategy consists of rapid (20-40 km/h) directional swimming away from killer whales and, if overtaken and attacked, individuals do little to defend themselves. This strategy is documented for six species in the genus Balaenoptera. 3. Many aspects of the life history, behaviour and morphology of mysticetes are consistent with their antipredator strategy, and we propose that evolution of these traits has been shaped by selection for reduced predation. Fight species tend to have robust body shapes and are slow but relatively manoeuvrable swimmers. They often calve or migrate in coastal areas where proximity to shallow water provides refuge and an advantage in defence. Most fight species have either callosities (rough and hardened patches of skin) or encrustations of barnacles on their bodies, which may serve (either primarily or secondarily) as weapons or armour for defence. Flight species have streamlined body shapes for high-speed swimming and they can sustain speeds necessary to outrun pursuing killer whales (>15-20 km/h). These species tend to favour pelagic habitats and calving grounds where prolonged escape sprints from killer whales are possible. 4. The rarity of observed successful attacks by killer whales on baleen whales, especially adults, may be an indication of the effectiveness of these antipredator strategies. Baleen whales likely offer low profitability to killer whales, relative to some other marine mammal prey. High-speed pursuit of flight species has a high energetic cost and a low probability of success while attacks on fight species can involve prolonged handling times and a risk of serious injury.
Article
Small boat surveys were conducted between 2000 and 2003 in three main regions of Oman's coastal waters: Muscat, the Gulf of Masirah and Dhofar. Survey data were analysed to calculate relative abundances of the seven most frequently encountered species in these areas. These include (in order of frequency) bottlenose dolphins (Tursiops sp.), long-beaked common dolphins (Delphinus capensis), humpback whales (Megaptera novaeangliae), spinner dolphins (Stenella longirostris), Indo-Pacific humpback dolphins (Sousa chinensis), Bryde's whales (Balaenoptera sp.) and Risso's dolphins (Grampus griseus). Other species observed include false killer whales (Pseudorca crassidens), blue whales (Balaenoptera musculus), rough-toothed dolphins (Steno bredanensis) and unidentified beaked whales. Encounterrates per distance searched were plotted by 0.1 × 0.1 degree grid cell, giving an indication of relative abundances and key areas of habitat used by each of the seven most frequently encountered species. These plots demonstrate that the nearshore areas of the Gulf of Masirah, as well as the coastal waters of Dhofar, are areas of concentration for the Arabian Sea's recently designated Endangered subpopulation of humpback whales, as wellas Indo-Pacific humpback dolphins, which are considered Near Threatened on the IUCN Red List of Threatened Species. 1 The results presented here provide valuable baseline data for future research and help to inform conservation management efforts that are required to address the highly vulnerable status of the humpback whale and Indo-Pacific humpback dolphin populations in question.
Book
This thorough revision of the classic first edition brings this authoritative book right up-to-date. Articles describe every species in detail, based on the very latest taxonomy, and a host of biological, ecological and sociological aspects relating to marine mammals. The latest information on the biology, ecology, anatomy, behavior and interactions with man is provided by a cast of expert authors - all presented in such detail and clarity to support both marine mammal specialists and the serious naturalist. Fully referenced throughout and with a fresh selection of the best color photographs available, the long-awaited 2nd edition remains at the forefront as the go-to reference on marine mammals. * More than 20% NEW MATERIAL includes articles on Climate Change, Pacific White-sided Dolphins, Sociobiology, Habitat Use, Feeding Morphology and more * Over 260 articles on the individual species with topics ranging from anatomy and behavior, to conservation, exploitation and the impact of global climate change on marine mammals * New color illustrations show every species and document topical articles FROM THE FIRST EDITION "This book is so good... a bargain, full of riches...packed with fascinating up to date information. I recommend it unreservedly it to individuals, students, and researchers, as well as libraries". - Richard M. Laws, MARINE MAMMALS SCIENCE "...establishes a solid and satisfying foundation for current study and future exploration" - Ronald J. Shusterman, SCIENCE.