Behavioral ecology of killer whales (Orcinus orca) in the Pacific Northwest

1988 ◽  
Vol 66 (3) ◽  
pp. 565-578 ◽  
Author(s):  
James R. Heimlich-Boran
Keyword(s):  
Pacific Northwest ◽  
Behavioral Ecology ◽  
Prey Capture ◽  
Open Water ◽  
Orcinus Orca ◽  
Foraging Strategies ◽  
Killer Whales ◽  
The Pacific ◽  
Patterns Of Behavior ◽  
Physiographic Regions

Killer whales (Orcinus orca) were found to use different physiographic regions of their habitat in unique ways. Resident whales fed more in areas of high relief subsurface topography along salmon migratory routes, and may use these geographic features to increase feeding efficiency. Transient whales fed in shallow protected areas around concentrations of their prey, harbor seals (Phoca vitulina). Whales traveled across deep, featureless areas in moving from one feeding area to another. Whales rested depending on the previous sequence of behaviors and played in open water areas or adjacent to feeding areas. The location of food resources and habitats suitable for prey capture appears to be the prime determining factor in the behavioral ecology of these whales. These patterns of behavior most likely represent cultural mechanisms that have been learned through trial and error experiences leading to successful foraging strategies.

Sounds associated with foraging and prey capture in individual fish-eating killer whales, Orcinus orca

2019 ◽  
Vol 146 (5) ◽  
pp. 3475-3486 ◽  
Author(s):  
Marla M. Holt ◽  
M. Bradley Hanson ◽  
Candice K. Emmons ◽  
David K. Haas ◽  
Deborah A. Giles ◽  
...  
Keyword(s):  
Prey Capture ◽  
Orcinus Orca ◽  
Killer Whales ◽  
Individual Fish

Acoustic surveys of killer whales during winter along the Pacific Northwest Coast

2004 ◽  
Vol 116 (4) ◽  
pp. 2589-2589
Author(s):  
Thomas Norris ◽  
Brad Hanson ◽  
Dawn Noren ◽  
Linda Jones
Keyword(s):  
Pacific Northwest ◽  
Northwest Coast ◽  
Killer Whales ◽  
Pacific Northwest Coast ◽  
The Pacific ◽  
Acoustic Surveys

Dietary specialization in two sympatric populations of killer whales (Orcinus orca) in coastal British Columbia and adjacent waters

1998 ◽  
Vol 76 (8) ◽  
pp. 1456-1471 ◽  
Author(s):  
John KB Ford ◽  
Graeme M Ellis ◽  
Lance G Barrett-Lennard ◽  
Alexandra B Morton ◽  
Rod S Palm ◽  
...  
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Stomach Contents ◽  
Orcinus Orca ◽  
Foraging Strategies ◽  
Field Observations ◽  
Killer Whales ◽  
Sympatric Populations ◽  
Mammal Species ◽  
Dietary Specialization

Two forms of killer whale (Orcinus orca), resident and transient, occur sympatrically in coastal waters of British Columbia, Washington State, and southeastern Alaska. The two forms do not mix, and differ in seasonal distribution, social structure, and behaviour. These distinctions have been attributed to apparent differences in diet, although no comprehensive comparative analysis of the diets of the two forms had been undertaken. Here we present such an analysis, based on field observations of predation and on the stomach contents of stranded killer whales collected over a 20-year period. In total, 22 species of fish and 1 species of squid were documented in the diet of resident-type killer whales; 12 of these are previously unrecorded as prey of O. orca. Despite the diversity of fish species taken, resident whales have a clear preference for salmon prey. In field observations of feeding, 96% of fish taken were salmonids. Six species of salmonids were identified from prey fragments, with chinook salmon (Oncorhynchus tshawytscha) being the most common. The stomach contents of stranded residents also indicated a preference for chinook salmon. On rare occasions, resident whales were seen to harass marine mammals, but no kills were confirmed and no mammalian remains were found in the stomachs of stranded residents. Transient killer whales were observed to prey only on pinnipeds, cetaceans, and seabirds. Six mammal species were taken, with over half of observed attacks involving harbour seals (Phoca vitulina). Seabirds do not appear to represent a significant prey resource. This study thus reveals the existence of strikingly divergent prey preferences of resident and transient killer whales, which are reflected in distinctive foraging strategies and related sociobiological traits of these sympatric populations.

Killer whales (Orcinus orca) feeding on schooling herring (Clupea harengus) using underwater tail-slaps: kinematic analyses of field observations

2000 ◽  
Vol 203 (2) ◽  
pp. 283-294 ◽  
Author(s):  
P. Domenici ◽  
R.S. Batty ◽  
T. Simila ◽  
E. Ogam
Keyword(s):  
High Performance ◽  
Prey Capture ◽  
Clupea Harengus ◽  
Physical Contact ◽  
Orcinus Orca ◽  
Whole Body ◽  
Maximum Speed ◽  
Killer Whales ◽  
Maximum Acceleration ◽  
Maximum Angle

Killer whales (Orcinus orca) feeding on herring (Clupea harengus) in a fjord in northern Norway were observed using underwater video. The whales cooperatively herded herring into tight schools close to the surface. During herding and feeding, killer whales swam around and under a school of herring, periodically lunging at it and stunning the herring by slapping them with the underside of their flukes while completely submerged. The kinematics of tail-slapping were analysed in detail. Tail-slaps were made up of a biphasic behaviour consisting of two phases with opposite angles of attack, a preparatory phase (negative angles of attack) and a slap phase (positive angles of attack). During the slap phase, the mean maximum angle of attack of the flukes was 47 degrees. The maximum speed of the flukes, measured at the notch, increased with whale length (L(w)) and was 2.2 L(w)s(−)(1), while the maximum acceleration of the flukes was size-independent and was 48 m s(−)(2). When killer whales slapped the herring successfully, disoriented herring appeared on the video at approximately the time of maximum fluke velocity, in synchrony with a loud noise. This noise was not heard when the tail-slaps ‘missed’ the target, suggesting that the herring were stunned by physical contact. Killer whales then ate the stunned herring one by one. Of the tail-slaps observed, 61 % were preceded by lunges into the school. We suggest that lunging was aimed at directing the school rather than at capturing the herring, since it occurred at a relatively low speed and there were no observations of the killer whales attempting to capture the herring during lunging behaviour. Given the high performance of the tail-slaps in terms of speed and acceleration, we suggest that tail-slapping by killer whales is a more efficient strategy of prey capture than whole-body attacks, since acceleration and manoeuvrability are likely to be poor in such large vertebrates.

The Legacy of Capture

Orca ◽  
2018 ◽  
Author(s):  
Jason M. Colby
Keyword(s):  
Pacific Northwest ◽  
Gunshot Wounds ◽  
Environmental Values ◽  
Family Tree ◽  
Tourist Industry ◽  
Human Relationship ◽  
Killer Whales ◽  
Whale Watching ◽  
The Pacific ◽  
Quiet Day

It was a quiet day in the summer of 1983 when the shots rang out in Robson Bight. Just minutes earlier, researcher Dave Briggs had been watching A4 pod visiting the rubbing beaches. The orcas had then headed in the direction of nearby purse seine vessels, and something had clearly gone wrong. Rushing down to the water, Briggs signaled a nearby whale-watching boat, which picked him up and motored out to investigate. Soon after, two orcas approached the vessel. It was the pod’s matriarch, A10, and her young calf, A47, both of whom had been shot. The horrified passengers watched as the injured mother pushed her child toward the tour boat. “We could see the wound oozing blood,” Briggs recounted. “It really seemed that she was showing us: Look what you humans have done.” Jim Borrowman learned of the shooting within minutes. An environmental activist and whale-watching entrepreneur based in nearby Telegraph Cove, he jumped into his Zodiac—a small, inflatable boat—and raced to the area. “I saw A10 with a bullet hole in the side of her face,” he recalled. “I just couldn’t believe it.” Over the years, Borrowman had seen many gunshot wounds on orcas, but this seemed a senseless act of violence reminiscent of an earlier era. Appearances aside, the incident underscored how far the human relationship with the species had come. No longer the indistinguishable black masses of the past, each orca in the Pacific Northwest now had an alphanumeric label, a family tree, and even affectionate nicknames. Once considered menacing pests, killer whales had become symbols of the region’s new environmental values and prime attractions for its tourist industry. Writing in the early 1980s, naturalist Erich Hoyt had little doubt that the display of killer whales at oceanariums had caused this shift. “The most important result of the captiveorca era has been the almost overnight change in public opinion,” he observed. “People today no longer fear and hate the species; they have fallen in love with them.”

Orca

2018 ◽  
Author(s):  
Jason M. Colby
Keyword(s):  
Pacific Northwest ◽  
Killer Whales ◽  
The Public ◽  
Marine Predator ◽  
Us Military ◽  
The Pacific ◽  
The Us ◽  
The World ◽  
History Of ◽  
Official Records

Since the release of the documentary Blackfish in 2013, millions around the world have focused on the plight of the orca, the most profitable and controversial display animal in history. Yet, until now, no historical account has explained how we came to care about killer whales in the first place. Drawing on interviews, official records, private archives, and his own family history, Jason M. Colby tells the exhilarating and often heartbreaking story of how people came to love the ocean's greatest predator. Historically reviled as dangerous pests, killer whales were dying by the hundreds, even thousands, by the 1950s--the victims of whalers, fishermen, and even the US military. In the Pacific Northwest, fishermen shot them, scientists harpooned them, and the Canadian government mounted a machine gun to eliminate them. But that all changed in 1965, when Seattle entrepreneur Ted Griffin became the first person to swim and perform with a captive killer whale. The show proved wildly popular, and he began capturing and selling others, including Sea World's first Shamu. Over the following decade, live display transformed views of Orcinus orca. The public embraced killer whales as charismatic and friendly, while scientists enjoyed their first access to live orcas. In the Pacific Northwest, these captive encounters reshaped regional values and helped drive environmental activism, including Greenpeace's anti-whaling campaigns. Yet even as Northwesterners taught the world to love whales, they came to oppose their captivity and to fight for the freedom of a marine predator that had become a regional icon. This is the definitive history of how the feared and despised "killer" became the beloved "orca"--and what that has meant for our relationship with the ocean and its creatures.

scholarly journals The Whale and the Region: Orca Capture and Environmentalism in the New Pacific Northwest

2014 ◽  
Vol 24 (2) ◽  
pp. 425-454
Author(s):  
Jason Colby
Keyword(s):  
Pacific Northwest ◽  
Killer Whale ◽  
Human Relations ◽  
Killer Whales ◽  
Government Officials ◽  
Marine Predator ◽  
The Pacific ◽  
Principal Source ◽  
Human Perceptions ◽  
The Impact

Although the orca is today widely recognized as a cultural and ecological icon of the Pacific Northwest, historians have ignored the impact of killer whale capture on the development of the region’s environmental values and identity. Between 1964 and 1976, the waters in southern British Columbia and Washington State were the world’s principal source of captive killer whales. The display of orcas by the region’s aquariums transformed human perceptions of this marine predator, and soon aquariums around the world were placing orders for Pacific Northwest killer whales. Yet the expanding capture and export of orcas in the late 1960s and early 1970s raised troubling ecological and moral questions for the region’s human residents. In the context of shifting attitudes toward cetaceans and rising environmental awareness throughout North America, Pacific Northwesters on both sides of the border increasingly viewed orcas as symbols of their region’s shared ecological concerns. The transnational nature of the region’s killer whale pods helped spur not only ecological reflection but also transborder cooperation among activists, scientists, and government officials to study and eventually protect the species. In the process, the shifting human relations with orcas helped redefine the Pacific Northwest.

Relationships Between Stream and Intragravel Temperatures in Coastal Drainages, and Some Implications for Fisheries Workers

1986 ◽  
Vol 43 (9) ◽  
pp. 1818-1822 ◽  
Author(s):  
Bruce G. Shepherd ◽  
Gordon F. Hartman ◽  
William J. Wilson
Keyword(s):  
Pacific Northwest ◽  
Open Water ◽  
Benthic Invertebrate ◽  
Daily Maximum ◽  
Thermal Mass ◽  
Pacific Northwest Coast ◽  
Heating And Cooling ◽  
The Pacific ◽  
Specific Variation ◽  
Maximum Temperatures

By a depth of 10 cm into the streambed, water temperatures are likely to be different from those in the open water of the stream. Combined results from three independent studies on disparate streams on the Pacific Northwest coast indicated that there are widespread similarities in the thermal behavior of intragravel water. In general, the thermal mass of the substrate causes parallel but lagged and buffered heating and cooling trends in infiltration-source intragravel water compared with surface water. Intragravel mean daily temperatures were generally 0.5–1.0 °C warmer in winter and 0.5–1.5 °C cooler in summer, with cross-overs around March and October; intragravel daily maximum temperatures could be up to 6 °C different in summer (a difference of 4 °C was common). The degree of difference showed considerable site-specific variation, and potentially can be affected by several factors. Such intragravel temperature differences have implications for those involved in salmonid egg incubation and fry emergence studies, enhancement projects, benthic invertebrate research, and environmental impact assessments.

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