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Post by Gorilla king on Sept 26, 2021 21:41:27 GMT -5
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Post by tyrannosaurs on Sept 27, 2021 9:28:24 GMT -5
Tooth damage in captive orcas (Orcinus orca):
Abstract Objectives: Tooth damage as a result of oral stereotypies is evident in captive orca, yet little research on the topic exists. This study examines the associations between dental pathology, sex, facility, duration of captivity and other factors in captive orca.
Design: We evaluated mandibular and maxillary teeth from dental images of 29 captive orca owned by a US-based theme park. Each tooth was scored for coronal wear, wear at or below gum line and bore holes. Fractured and missing teeth were also noted. Summary statistics described the distribution and severity of pathologies; inferential statistics examined how pathologies differed between sexes, between wild-captured and captive-born orcas and between captive orca at four facilities. We also evaluated how dental pathology and duration of captivity were related.
Results: Approximately 24% of whales exhibited "major" to "extreme" mandibular coronal tooth wear, with coronal wear and wear at or below gum line highly correlated. More than 60% of mandibular teeth 2 and 3 exhibited fractures. Bore holes were observed primarily among anterior mandibular teeth, with more than 61% of teeth 2 and 3 bearing evidence of having been drilled. Four of five orca with the highest age-adjusted tooth pathology indices were captive-born.
Conclusions: Various dental pathologies were observed across all whales, with pathologies beginning at a young age. Oral stereotypies exhibited by captive orca contributed to the observed dental damage. By making dental and health records of captive whales publicly available, the theme park industry is uniquely positioned to provide further insight into dental pathology and resultant health consequences in captive orca.
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Post by Gorilla king on Sept 27, 2021 22:49:32 GMT -5
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Post by Gorilla king on Oct 12, 2021 9:19:25 GMT -5
Killer whale vs. great white? No contest — the shark always flees
Both the great white shark and the killer whale or orca are fearsome top predators. But of the two massive animals, the killer whale may be the more formidable one, a new study has found.Researchers monitoring white sharks, lion seals and orcas around California’s Southeast Farallon Island have found that every time orcas pass through the area, the great white sharks vanish and don’t return to their hunting grounds until the next season.The researchers aren’t sure why the sharks move away as soon as orcas arrive. It could be because orcas may be targeting white sharks as prey, or the killer whales could be bullying their competition out of the way to gain access to the island’s elephant seals.
In the ocean, both the great white shark (Carcharodon carcharias) and the killer whale or orca (Orcinus orca) are fearsome top predators. But of the two massive animals, the killer whale may be the more formidable one, a new study has found.
Salvador Jorgensen, a marine ecologist at the Monterey Bay Aquarium in California, and his colleagues first noticed this while studying white sharks around California’s Southeast Farallon Island (SEFI). They had lured the sharks to their research boat using a seal decoy made of carpet fabric, then inserted electronic tags into the sharks to keep track of their movements along the California coast.
In 2009, they noticed something odd: 17 of their tagged white sharks had been regularly feeding on elephant seals around SEFI for months. But on Nov. 2 that year, when orcas from two different pods arrived at SEFI, not staying for too long, all 17 sharks disappeared within the next eight hours. Most of them didn’t return until the next season several months later. Jorgensen and his colleagues observed this same fleeing behavior among white sharks on three more occasions in the following years.
In fact, when the researchers combined information on 165 great white sharks they’d tagged between 2006 and 2013 with data collected on lion seals and orcas as part of a long-term wildlife monitoring program at Farallon Islands National Wildlife Refuge, they found that the sharks’ fleeing behavior had a consistent pattern.
Great white sharks gather around SEFI each fall between September and December to hunt for young elephant seals. Orcas also hunt elephant seals, but they only come by occasionally. And when they do, the sharks withdraw from the area.
“When confronted by orcas, white sharks will immediately vacate their preferred hunting ground and will not return for up to a year, even though the orcas are only passing through,” Jorgensen, lead author of the study published in Scientific Reports, said in a statement.
The elephant seals seem to benefit from the arrival of the orcas. Whenever killer whales were sighted in the region, fewer seals were hunted that season.
“On average we document around 40 elephant seal predation events by white sharks at Southeast Farallon Island each season,” said Scot Anderson, a scientist at Monterey Bay Aquarium and co-author of the study. “After orcas show up, we don’t see a single shark and there are no more kills.”
The researchers aren’t sure why the sharks move away as soon as orcas arrive. It could be because orcas may be targeting white sharks as prey: in 1997, a pair of orcas killed a white shark that had interrupted their meal, consuming only its liver. In 2017, five white sharks that had washed ashore on a South African beach had their livers missing from their otherwise intact bodies. Orcas had been spotted nearby, and the bite marks on the sharks’ bodies suggested that the whales had punctured their bodies to feast on their calorie-rich livers. The orcas could also be bullying the sharks, their competition on the food chain, out of the way to gain access to the elephant seals.
“I think this demonstrates how food chains are not always linear,” Jorgensen said. “So-called lateral interactions between top predators are fairly well known on land but are much harder to document in the ocean. And because this one happens so infrequently, it may take us a while longer to fully understand the dynamics.”
www.google.com/amp/s/news.mongabay.com/2019/04/killer-whale-vs-great-white-no-contest-the-shark-always-flees/amp/
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Post by Gorilla king on Dec 17, 2021 11:44:06 GMT -5
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Post by arctozilla on Dec 28, 2021 11:11:10 GMT -5
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Post by Gorilla king on Feb 6, 2022 15:17:14 GMT -5
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Post by fluffyfatbear on Feb 6, 2022 19:18:26 GMT -5
We need more accounts of killer whales killing great white sharks
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Post by Gorilla king on Feb 6, 2022 21:15:12 GMT -5
Prey of killer whales (Orcinus orca) in Iceland
Abstract and Figures
Killer whales have a cosmopolitan distribution and as a species are generalists, feeding on a variety of prey. However, local populations tend to specialise on specific prey types. In Ice-landic waters, killer whales are generally associated with herring and, thus, have been presumed to be herring specialists. However, recent studies suggest a more complex foraging ecology, possibly including a mosaic of strategies. With increased observational effort in recent years due to research and whale-watching activities, there have been several reports of interactions with different prey, including confirmed predation events. In this study we aimed to summarise the range of potential prey of killer whales observed in Icelandic waters. We report on 12 previously unpublished accounts and review 15 accounts published in the scientific literature or local newspapers, making a total of 27 events where killer whales were observed interacting with actual or potential prey. Thirteen different species, including birds (n = 1), cephalopods (n = 1), fish (n = 5) and marine mammals (n = 6), are reported, although herring is by far the species that killer whales are most often observed interacting with. This study provides the first summary of actual and suspected killer whale prey in Ice-landic waters, and contributes towards our understanding of this population's prey preferences. However, describing the diet of individuals/groups was not possible and this study points to a need for continued monitoring to understand the intricacies of killer whale foraging behaviour in this area.
Killer whale with a lumpfish in its mouth. Observed in Kolgrafafjörður (W Iceland) on 3 March 2014 (photograph by W. Jan Strietman).
Killer whale tossing a salmon in the air. Observed in Vestmannaeyjar (S Iceland) on 15 July 2015 (photograph by F. Samarra).
Killer whale predation on a minke whale. Observed in Skjálfandi bay (NE Iceland) on 22 July 2008 (photograph by M. Rasmussen).
Killer whale predation on a harbour porpoise. Observed in Eyjafjörður (N Iceland) on 23 September 2017 (photograph by M. O ´. Elíasdóttir).
www.researchgate.net/publication/329591657_Prey_of_killer_whales_Orcinus_orca_in_Iceland
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Post by Gorilla king on Feb 7, 2022 10:48:25 GMT -5
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Post by Gorilla king on Jun 2, 2022 20:58:34 GMT -5
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Post by oldindigosilverback on Jul 1, 2022 4:57:43 GMT -5
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Post by Gorilla king on Jul 1, 2022 6:02:31 GMT -5
Sure does mate. Orcas completely dominate great white sharks.
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Post by arctozilla on Jul 14, 2022 6:01:45 GMT -5
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Post by arctozilla on Jul 14, 2022 6:04:16 GMT -5
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Post by oldindigosilverback on Jul 30, 2022 6:53:48 GMT -5
"An interviewee from Repulse Bay indicated that killer whales normally do not go after tusked narwhal, and another indicated that narwhal with tusks are never found floating dead. A Pond Inlet interviewee had observed killer whales going after female narwhal, but not males. He recounted a story that tusked narwhal had killed killer whales in the past; the narwhal pierced the killer whale with its tusk, and become stuck, with both animals dying as a result. Tusked narwhal may therefore represent a danger to killer whales; however, a Pangnirtung interviewee stated that they will attack narwhal with and without tusks, and two interviewees had observed killer whales kill tusked narwhal. An Arctic Bay hunter found a dead tusked narwhal covered with killer whale bite marks." ... "However, there is disagreement among opinions and/or observations of different behavior. Several Repulse Bay interviewees suggested that killer whale do not normally attack tusked narwhal and that only females are found dead. The same information has been reported previously [26], possibly from the same local experts. These observations are contrasted by those of other interviewees who indicate that tusked narwhal are killed on occasion. In northwest Greenland (Avanersuaq District), hunters have also observed killer whales attacking and killing both male and female narwhal [45]. A Pond Inlet interviewee reported a story of a narwhal piercing a killer whale with its tusk, suggesting that male narwhal are dangerous to attack. Rosing [77] described an observation from Greenland in December 1924 where killer whales were observed killing narwhal and one was seen jumping out of the water with a narwhal stuck to its side, with its tusk penetrating to the root straight through the killer whale. During interviews for the Igloolik Oral History project [78], an elder provided a story [79] of a dead killer whale that was found in the waters of qaqqalik (possibly near Kimmirut) that had a narwhal tusk pierced through its mouth." www.researchgate.net/publication/224809500_Prey_items_and_predation_behavior_of_killer_whales_Orcinus_orca_in_Nunavut_Canada_based_on_Inuit_hunter_interviewsFrom Rorqual on Carnivora. This is an article I have never seen before. Polar bears are known to kill narwhales, therefore, this arcticle saying a narwhale as a dangerous opponent is shocking.
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Post by Gorilla king on Jul 30, 2022 7:26:41 GMT -5
Males are damn sure a dangerous opponent:
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Post by oldindigosilverback on Jul 30, 2022 8:43:20 GMT -5
/\ How would a narwhale do against a great white shark?
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Post by arctozilla on Jul 30, 2022 9:00:57 GMT -5
/\ It would do a spit of shark.
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Post by Gorilla king on Jul 30, 2022 9:30:50 GMT -5
/\ How would a narwhale do against a great white shark? If the great white can evade that tusk, it would probably win like 6/7 out of 10 times.
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