Killer whale (Orcinus orca) occurrence and predation in the Bahamas

2013 ◽  
Vol 94 (6) ◽  
pp. 1305-1309 ◽  
Author(s):  
Charlotte Dunn ◽  
Diane Claridge
Keyword(s):  
Marine Mammals ◽  
Sperm Whale ◽  
Orcinus Orca ◽  
Killer Whales ◽  
The Bahamas ◽  
Stenella Frontalis ◽  
Photo Identification ◽  
Spotted Dolphin ◽  
Lagenodelphis Hosei ◽  
Identification Analysis

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.

scholarly journals Underwater Mirror Exposure to Free-Ranging Naïve Atlantic Spotted Dolphins (Stenella frontalis) in the Bahamas

2013 ◽  
Vol 26 (2) ◽  
Author(s):  
Fabienne Delfour ◽  
Denise Herzing
Keyword(s):  
Marine Mammals ◽  
Bottlenose Dolphins ◽  
Killer Whales ◽  
California Sea Lions ◽  
The Bahamas ◽  
Single Male ◽  
Stenella Frontalis ◽  
Self Recognition ◽  
In The Wild ◽  
Free Ranging

The “mirror state,” described for human self-recognition, has been found in captive or human-raised species. In marine mammals, bottlenose dolphins and killer whales have shown evidence of body examination, self-directed and contingency checking behaviors whereas false killer whales appeared ambiguous and California sea lions did not recognize themselves in a mirror. Self-recognition processes in wild cetaceans remain unknown. Since 1985, a resident community of Atlantic spotted dolphin (Stenella frontalis) has been studied underwater in the Bahamas. We describe the reaction of free-ranging dolphins during 14 exposures to the presence of a mirror from 1994/1995 and 2004/2005. Responses to the mirror were mixed. Initial reactions of mother/calf groups were to swim around mirror and stay in close physical proximity. Others ignored the mirror entirely, or swam around or underneath. A single male became stationary and postured in an aggressive stance in front of the mirror. The wild spotted dolphins showed a significant preference to exposing and/or orienting their right side to the mirror versus their left side. We suggest that the animals assign different meanings to a mirror in the wild versus the same object in captivity.

scholarly journals Middle/late Miocene hoplocetine sperm whale remains (Odontoceti: Physeteridae) of North Germany with an emended classification of the Hoplocetinae

Fossil Record ◽  
2006 ◽  
Vol 9 (1) ◽  
pp. 61-86 ◽  
Author(s):  
O. Hampe
Keyword(s):  
Late Miocene ◽  
Killer Whale ◽  
Sperm Whale ◽  
Tooth Wear ◽  
Orcinus Orca ◽  
Killer Whales ◽  
Functional Tooth ◽  
North Germany ◽  
Middle Pliocene

Abstract. Hoplocetus ritzi n. sp. is a new hoplocetine physeterid from the Bolboforma fragori /subfragoris Zone of the middle/late Miocene mica-clay of Groß Pampau in Schleswig-Holstein, North Germany. The Hoplocetinae are known from the early Miocene to the Pliocene. Comparative studies of cranial characters and tooth morphology allow an emended diagnosis of the Hoplocetinae Cabrera, 1926. Four genera, Diaphorocetus, Idiorophus, Scaldicetus, and Hoplocetus are included in this subfamily. The pattern of functional tooth wear deduced from the described Hoplocetus ritzi n. sp. remains is reminescent of that known from Orcinus orca. The hoplocetine physeterids possibly occupied the killer whale niche before the killer whales appeared during the middle Pliocene. Mit Hoplocetusritzi n. sp. wird ein neuer hoplocetiner Physeteride beschrieben. Der Fund stammt aus der Bolboformafragori /subfragoris Zone des mittel-/obermiozänen Glimmertons von Groß Pampau in Schleswig-Holstein, Norddeutschland. Die Hoplocetinae sind vom unteren Miozän bis ins Pliozän nachgewiesen. Anhand vergleichender Untersuchungen an wenigen Schädelmerkmalen und der Zahnmorphologie gelingt eine Neudiagnose der Hoplocetinae Cabrera, 1926 und eine vorläufige Abgrenzung zwischen den als valid angesehenen Gattungen dieser Unterfamilie, Diaphorocetus, Idiorophus, Scaldicetus und Hoplocetus. Das Abkauungsmuster der Zähne von Hoplocetusritzi n. sp. erinnert an das des heutigen Orcinusorca. Möglicherweise sind die hoplocetinen Pottwale habituell den Schwertwalen, die erdgeschichtlich erstmals im mittleren Pliozän auftreten, vergleichbar. doi:10.1002/mmng.200600002

Fireproof killer whales (Orcinus orca): flame-retardant chemicals and the conservation imperative in the charismatic icon of British Columbia, Canada

2006 ◽  
Vol 63 (1) ◽  
pp. 224-234 ◽  
Author(s):  
Peter S Ross
Keyword(s):  
British Columbia ◽  
Trophic Level ◽  
Polybrominated Diphenyl Ethers ◽  
Marine Mammals ◽  
Polychlorinated Biphenyl ◽  
High Trophic Level ◽  
Orcinus Orca ◽  
Weight Of Evidence ◽  
Older Individuals ◽  
Killer Whales

Long-lived and high trophic level marine mammals are vulnerable to accumulating often very high concentrations of persistent chemicals, including pesticides, industrial by-products, and flame retardants. In the case of killer whales (Orcinus orca), some of the older individuals currently frequenting the coastal waters of British Columbia (BC) were born during the First World War, well before the advent of widespread chemical manufacture and use. BC's killer whales are now among the most polychlorinated biphenyl (PCB) contaminated marine mammals in the world. While the "legacy" PCBs have largely been banned, polybrominated diphenyl ethers (PBDEs) have recently emerged as a major concern. The endocrine-disrupting nature of these two persistent fire retardants in biota spells trouble at the top of the food chain, with increasing evidence of effects on reproductive health, the immune system, and development in exposed mammals. The heavy contamination of BC's killer whales, coupled with their long life span and high trophic level, highlights the need for a "weight of evidence" approach in research, conservation planning, and regulatory decisions. Given the global nature of contaminant dispersion, such approaches can only be effective when carried out on both national and international scales.

Killer whales (Orcinus orca) in Angolan and Gulf of Guinea waters, tropical West Africa

2010 ◽  
Vol 90 (8) ◽  
pp. 1601-1611 ◽  
Author(s):  
Caroline R Weir ◽  
Tim Collins ◽  
Inês Carvalho ◽  
Howard C. Rosenbaum
Keyword(s):  
Group Size ◽  
Orcinus Orca ◽  
Humpback Whales ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Killer Whales ◽  
External Appearance ◽  
Tropical Waters ◽  
Photo Identification ◽  
Mola Mola

Killer whales Orcinus orca are considered to be relatively uncommon in tropical waters. Few sightings have been reported from the west coast of Africa due to a paucity of survey coverage. We present data on 32 killer sightings from tropical waters off Angola (N = 18), Gabon (N = 7), São Tomé (N = 6) and Cameroon (N = 1), comprising a combination of dedicated survey sightings (N = 21) and reliable anecdotal records (n = 11). Killer whales were reported from coastal waters, the shelf edge and deep, oceanic areas. Sightings indicate a probable year-round occurrence of killer whales within the region. Mean group size was 5.6 animals. There was no difference in group size between sightings in waters >200 m deep and those on the continental shelf. No photo-identification matches were found between Angola, Gabon and São Tomé. Re-sightings of two individuals occurred annually in São Tomé during 2002–2004. Killer whales had external appearance consistent with the Type A nominate species form. Antagonistic encounters were recorded between killer whales and humpback whales Megaptera novaeangliae off Angola, Gabon and Cameroon, and with sperm whales Physeter macrocephalus off Angola. Predation on ocean sunfish Mola mola was recorded in São Tomé, and possible predation on sharks was recorded twice in Gabon.

Population size, survival and reproductive rates of northern Norwegian killer whales (Orcinus orca) in 1986–2003

2013 ◽  
Vol 94 (6) ◽  
pp. 1277-1291 ◽  
Author(s):  
Sanna Kuningas ◽  
Tiu Similä ◽  
Philip S. Hammond
Keyword(s):  
Population Size ◽  
Killer Whale ◽  
Survival Rates ◽  
Clupea Harengus ◽  
Orcinus Orca ◽  
Adult Males ◽  
Killer Whales ◽  
Apparent Survival ◽  
Photo Identification ◽  
Reproductive Rates

A long-term photo-identification study of killer whales (Orcinus orca) in northern Norway was initiated in 1986, when their prey the Norwegian spring-spawning herring (Clupea harengus) started to winter in a complex fjord system. The aim of this work was to estimate population size and apparent survival rates in this killer whale population using photo-identification and mark–recapture techniques with data collected during October–December 1986–2003. Total population size was estimated to be highest in 2003: 731 individuals (SE = 139, 95% CI = 505–1059) using a model taking heterogeneity of capture probabilities into account. Apparent survival of adult males and adult females was estimated using the Cormack–Jolly–Seber model as 0.971 (SE = 0.008) and 0.977 (SE = 0.009), respectively. Calving intervals ranged from 3 to 14 years (mean = 5.06, SE = 0.722). These are the first estimates of northern Norwegian killer whale population parameters, allowing their dynamics to be investigated and comparisons to be made with killer whale populations globally.

The cetaceans of Aruba, southern Caribbean

2013 ◽  
Vol 94 (6) ◽  
pp. 1161-1174 ◽  
Author(s):  
Jolanda A. Luksenburg
Keyword(s):  
Killer Whale ◽  
Sperm Whale ◽  
Common Dolphin ◽  
Physeter Macrocephalus ◽  
Cetacean Species ◽  
Additional Species ◽  
Pilot Whale ◽  
Stenella Frontalis ◽  
Spotted Dolphin ◽  
Delphinus Capensis

Aruba is one of the most densely populated islands in the Caribbean. However, very little is known about its cetaceans. In 2010 and 2011, a total of 19721 km (1686 h) boat-based surveys over nearshore transects resulted in 117 positively-identified sightings comprising eight species. New records are also added for one of three previously-documented species. Five additional species were documented from strandings or reports by others. This brings the total number of cetacean species identified in Aruban waters to 16, of which nine are authenticated here for the first time. Atlantic spotted dolphin (Stenella frontalis (N = 59) and bottlenose dolphin (Tursiops truncatus) (N = 33) were the most frequently observed species, with sightings of both year-round, followed by spinner dolphin (S. longirostris) and false killer whale (Pseudorca crassidens). Additional species recorded are pantropical spotted dolphin (S. attenuata), striped dolphin (S. coeruleoalba), common dolphin (Delphinus capensis), rough-toothed dolphin (Steno bredanensis), short-finned pilot whale (Globicephala macrorhynchus), killer whale (Orcinus orca), Risso's dolphin (Grampus griseus), humpback whale (Megaptera novaeangliae), Bryde's/Eden's whale (Balaenoptera brydei/edeni), sperm whale (Physeter macrocephalus) and an unidentified beaked whale (Mesoplodon sp.). All cetaceans were sighted within 22 km of the coast in relatively shallow waters. Sighting rate was low (0.69 cetacean sightings per 100 km). Sightings of calves and neonates indicate that Aruba may be a nursing or breeding area for some species. The presence of several species of cetaceans in Aruba's coastal waters year-round indicates that status and threat assessments are needed to protect them.

scholarly journals Evidence of killer whale predation on a yearling bowhead whale in Cumberland Sound, Nunavut

2020 ◽  
Vol 6 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Brent G. Young ◽  
Sarah M.E. Fortune ◽  
William R. Koski ◽  
Stephen A. Raverty ◽  
Ricky Kilabuk ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Killer Whale ◽  
Canadian Arctic ◽  
Bowhead Whale ◽  
Orcinus Orca ◽  
The Arctic ◽  
Killer Whales ◽  
Eastern Canada ◽  
Cumberland Sound ◽  
Potential Impact

Accounts of killer whale (Orcinus orca) predation on marine mammals in the Canadian Arctic are relatively uncommon. Although second-hand reports of killer whale predation events in the Arctic are more common in recent years, these observations are generally poorly documented and the outcome of attacks are often unknown. On 12 August 2016, a floating bowhead whale (Balaena mysticetus) carcass was found off-shore in Cumberland Sound, Nunavut — presumably predated by killer whales that were sighted in the area. Inspection of the carcass revealed injuries consistent with published accounts of killer whale predation on large whales and observations of killer whale predation on bowheads described in Inuit traditional knowledge. The bowhead was male, 6.1 m long in good nutritional condition and estimated between 14 and 16 months old. As a recently weaned yearling, this whale would have been highly vulnerable to killer whale predation. With decreasing summer sea ice making some areas of the Arctic more accessible, the incursion and presence of killer whales in the Arctic is expected to increase. A better understanding of Arctic killer whale predation pressure is needed to predict the potential impact they will have on the eastern Canada–west Greenland bowhead population as well as on other marine mammal prey.

Cetacean distribution and relative abundance in offshore Gabonese waters

2010 ◽  
Vol 90 (8) ◽  
pp. 1613-1621 ◽  
Author(s):  
Marijke N. de Boer
Keyword(s):  
Species Composition ◽  
Sperm Whale ◽  
Sea Surface ◽  
Baleen Whale ◽  
Cetacean Species ◽  
Stenella Frontalis ◽  
Spotted Dolphin ◽  
Wide Range ◽  
Oceanographic Conditions ◽  
Cetacean Distribution

Information on cetaceans off Gabon in tropical West Africa is summarized from boat-based surveys carried out between 7 March and 7 August 2009. Thirteen cetacean species were positively identified comprising two baleen whale species, one sperm whale species and ten species of delphinid. Bryde's whale (Balaenoptera brydei) and humpback whale (Megaptera novaeangliae) were the most frequently encountered species. Cetaceans were found throughout a range of sea surface temperature between 20.5°C and 27.5°C and a wide range of depths with the majority of effort and sightings occurring seaward of the shelf break. Of particular interest from the study were the following: (1) Gabonese waters have a broad cetacean diversity, especially with a large and diversified delphinid community in the northern part of the study area; (2) the variations in oceanographic conditions within Gabonese waters are likely to result in a temporal variation in species composition; (3) the sightings of Atlantic spotted dolphin (Stenella frontalis) are the first at-sea sightings confirmed for these waters, although not unexpected given their distribution and abundant presence in surrounding waters; and (4) the poorly known Clymene dolphin (Stenella clymene) was sighted on four occasions in deep oceanic waters and was the most abundant cetacean. These are the first confirmed records of Clymene dolphins in Gabonese waters.

scholarly journals Directionality of Sexual Activities During Mixed-Species Encounters between Atlantic Spotted Dolphins (Stenella frontalis) and Bottlenose Dolphins (Tursiops truncatus)

2013 ◽  
Vol 26 (2) ◽  
Author(s):  
Denise L. Herzing ◽  
Cindy R. Elliser
Keyword(s):  
Social Interactions ◽  
Adult Male ◽  
Bottlenose Dolphin ◽  
Bottlenose Dolphins ◽  
Aggressive Behaviors ◽  
Mixed Species ◽  
The Bahamas ◽  
Stenella Frontalis ◽  
Spotted Dolphin ◽  
Atlantic Spotted Dolphins

In the Bahamas, interspecific groups of Atlantic spotted dolphins, Stenella frontalis, and bottlenose dolphins, Tursiops truncatus, have been observed underwater since 1985 on Little Bahama Bank. Mixed-species groups engage in associative behaviors and aggression on a regular basis. Because of their complex cognitive behaviors and large brain encephalization, dolphins are likely capable of complex social interactions, even between species.Between 1993-2003, 177 Mixed-Species Encounters (MSE) were categorized by the age class of male spotted dolphins, the ratio of spotted dolphins to bottlenose dolphins, behavior as Associative (traveling, babysitting, play) or Aggressive (chases, mounting, head to heads) and by directionality of sexual behavior. The majority (68%) of MSE involved adult spotted dolphin. Associative behaviors were observed more than aggressive behaviors in groups where no adult male spotted dolphin, only male calves, or male juvenile spotted dolphins were present. Aggressive behaviors were observed more frequently than associative behaviors in adult male spotted dolphin groups. When groups were unbalanced in favor of one species or the other, differences in social interactions occurred. Male spotted dolphins were never observed attempting to mount male bottlenose dolphin although they chased them. Despite the larger ratio of male spotted dolphins to bottlenose dolphins during MSE, directionality of male-to-male sexual contact was primarily one-way. Male bottlenose dolphin mounted and copulated with male spotted dolphins but not the reverse. Opportunities for cross-species mating and hybridization clearly occurred. Male bottlenose dolphins copulated with female spotted dolphins and male spotted dolphins copulated with female bottlenose dolphins. These sympatric dolphins in the Bahamas have a complex and dynamic relationship that varies with sex and age and revolves around potential reproductive isolation issues.

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