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Post by elosha11 on Apr 15, 2019 0:45:46 GMT 5
^Yes, there was a follow up article in which some researchers stated it was almost certainly a mako because great whites only rarely frequent these waters, and the bite mark size more closely aligns with a mako shark than with the larger great white, which would have likely left a significantly larger bite mark. Still, I think it does show that if a sizeable shark does bite even a much larger male orca, it's going to do significant damage. Just to follow up, here's the article I reference in the above post re the mako shark's probable bite on the orca's tail. Found at www.deadlinenews.co.uk/2015/01/28/mako-inflicted-orca-bite-says-expert/.
Mako shark may have inflicted orca bite says expertBy Jenny Kane -January 28, 2015 A DEADLY mako shark could have inflicted the huge bite discovered on the fin of a Scottish killer whale, according to a marine expert. A remarkable photo taken off the West Coast of Scotland has been release showing a large male killer whale with a chunk of his tail fluke missing. After consultations with experts the Hebridean Whale and Dolphin Trust said the damage was “almost certainly the result of a shark attack”. Now a Marine Biologist from the University of St Andrews has said while it is impossible to be certain it could have been a mako that took the bite. Dr Yannis Papastamatiou said while it was extremely unlikely, an attack by a Great White could not be ruled out. Mako sharks, which are known to attack humans, are a close relation to the great white and have been spotted in British waters. They can grow to up to four meters, are the world’s fastest shark, and are known to have attacked 42 people over 30 years. The sharks attack by lunging from deep water and rip chunks of flesh from their target. Dr Papastamatiou, a research fellow at the university’s Scottish Oceans Institute, said: “I can’t recall having seen evidence of a shark bite on a free swimming orca.” After examining the image, he said it was “very surprising” for a shark to attack an orca that big. Asked to comment on the most likely shark suspect, he replied: “Mako sharks, a close relation of the white shark, are in Scottish waters.” Commenting on the possibility it was a great white that bit the killer whale he said: “It’s not impossible. “There has never been a recognised record of a great white in British waters. That doesn’t mean they’re not there. “It’s unlikely but not impossible.” In December, a 10ft Mako was washed up on the Barmouth beach on the north coast of Wales. Ali Hood, Director of Conservation for the Shark Trust, said: “Sharks generally avoid encounters with cetaceans and certainly a healthy mature Orca would not be the likely target prey for a shark.” |
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Post by sam1 on Apr 18, 2019 11:46:55 GMT 5
The new study is quite telling, to say the least. Unlike previous theory that suggested sharks fleeing after sensing the scent of their own species being killed by orcas, it is now clear that Great white sharks are simply TERRIFIED of orcas regardless of the background. I don't think any dolphin species goes to such lengths of avoiding any shark species. |
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Post by elosha11 on Apr 19, 2019 7:15:45 GMT 5
Actually, I think it's rather impressive that large predatory sharks more than hold their own (speaking strictly as to predatory encounters) with the vast majority of dolphins, despite those animals being in large pods and being somewhat comparable in size to the sharks. There is literally only one species of dolphin that seems to have any real predatory advantage over sharks and that is the absolutely enormous orca. Orcas are, no doubt, extremely impressive and the undisputed number one apex predator in the ocean. But it makes sense that great whites would flee such an animal, which outweighs it by 3 or 4 times and almost would always attack a great white shark in a team approach. There's simply no hope for the solitary shark. So yes, even the largest great whites will readily flee from a pod of orcas. However, put a predatory shark and a cetacean at parity size and it seems to be a whole different story.
In any event, the recent research is certainly helpful and makes me again wonder if orcas are being forced by man's activities to turn to other prey sources, such as great whites, which may historically been less frequently targeted.
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Post by theropod on Apr 19, 2019 16:57:28 GMT 5
Ok, what "study" are you talking about? I’ve looked through the last pages but could find nothing of the sort.
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Post by theropod on Apr 19, 2019 17:33:06 GMT 5
Actually, I think it's rather impressive that large predatory sharks more than hold their own (speaking strictly as to predatory encounters) with the vast majority of dolphins, despite those animals being in large pods and being somewhat comparable in size to the sharks. By the same standards, it is also impressive that lions hold their own against zebras or wildebeest in predatory encounters (except that those are actually larger than lions, unlike the dophins sharks prey on). One is simply a predator evolved to incorporate prey that size of the other into its diet, the other is not. |
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Post by elosha11 on Apr 19, 2019 19:37:21 GMT 5
Actually, I think it's rather impressive that large predatory sharks more than hold their own (speaking strictly as to predatory encounters) with the vast majority of dolphins, despite those animals being in large pods and being somewhat comparable in size to the sharks. By the same standards, it is also impressive that lions hold their own against zebras or wildebeest in predatory encounters (except that those are actually larger than lions, unlike the dophins sharks prey on). One is simply a predator evolved to incorporate prey that size of the other into its diet, the other is not. Big cats may be the most versatile individual predators on the planet, combining strength, intelligence, agility, grappling ability and a powerful bite. Even individually, a lion is a great predator that can take down animals larger than itself, as can tigers, jaguars, leopards, and cougars. That said, it's a little bit of apples to oranges comparing land based predators to ocean predators. For one, big cats have the ability to grapple, an advantage over virtually any prey animal and an advantage no ocean predator has. Of course ocean prey items can't kick like a zebra or wildebeest either, so an ocean based predator doesn't need to worry about a hoof to the face, or a horn to the stomach (although a ram attack/defense may be just as deadly) As to the question of what prey size large predatory sharks take, I would agree that most interactions involve prey items substantially smaller than themselves, but that by no means establishes that they, as solitary hunters, are incapable of predating on animals their own size. For instance, large great whites have been recorded as preying on adult bull elephant seals, which reach comparable weights to very large great whites. Bull sharks and mako sharks prey on dolphins fairly routinely and those dolphins are sometimes the same size as the shark. And we've gone over (ad nauseum) in other threads some evidence of shark bite marks on FKWs and pilot whales, which generally share the same size range as large great whites. Are such animals attacked by sharks often? Almost certainly not. But I tend think it's the pod numbers combined with their larger size (compared to say a bottlenose dolphin) that offers these larger dolphins such overall protection. As for orcas, they are undisputedly the greatest current ocean predator. Even if they were solitary predators, they would be virtually immune from attack/aggressive interactions except from perhaps very large whales. On the other hand, I'm not sure they would have ever grown as large as they are today without their pod behavior (along with whales' recent increase in size in the last couple million years). Whether orcas would be the top apex predator in other other eras is a different, but very interesting question. EDIT - when I speak of "orcas" this is necessarily an extremely loose term. In general, although they exhibit a huge size range between subspecies, most orca subspecies are still individually far larger than the largest predatory sharks. However, there's an interesting, if a bit sloppy, discussion on carnvira in an individual match up between a much smaller orca subspecies, the Ross Sea orca, and a great white shark. I may make this match up soon on WoA, especially if I can find more detailed info on this orca. |
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Post by theropod on Apr 19, 2019 20:16:13 GMT 5
I stand corrected, I was forgetting about bull sharks. Any evidence for other shark species preying on a delphinid larger than itself though? I think we’ve sufficiently reviewed the past accounts, unless there are any I am forgetting there is still no record of any shark other than bull sharks killing an odontocete its own size or larger.
I simply don’t think a macrophagous predator coming out on top of its prey, even at similar sizes, is something particularly remarkable. Predators that regularly prey on animals their own size are not that common (and neither are they common among sharks), but if they do it, that is just something they evolved to do, and should be expected to be conpetent in.
For years now I’ve seen this misconstrued into an argument about who would be the more powerful predator "at parity", a macrophagous shark or an orca, usually ignoring that none of those delphinids sharks have been recorded preying on are themselves adapted to handle large prey. A bottlenose dolphin being killed by a shark is far more comparable to a zebra being killed by a lion than to an orca alledgedly being outmatched by a similar-sized shark, for instance.
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Post by prehistorican on Apr 20, 2019 6:38:18 GMT 5
Ross Sea Orca is about 6m max. So maybe about 3-4 tonnes as wikipedia puts for a 5-7m long individual killer whale. Still much larger than the largest white sharks of 2-3 tonnes, although at parity MASS I might favor the shark.
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Post by dinosauria101 on Apr 20, 2019 7:03:55 GMT 5
prehistorican do you think a matchup between a female Ross Sea killer whale and a large subspecies of great white would be fair?
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Post by prehistorican on Apr 20, 2019 7:18:42 GMT 5
I guess so though I wonder what a large white shark subspecies would be (if there is one).
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Post by dinosauria101 on Apr 20, 2019 7:23:20 GMT 5
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Post by elosha11 on Apr 20, 2019 19:43:22 GMT 5
Ross Sea Orca is about 6m max. So maybe about 3-4 tonnes as wikipedia puts for a 5-7m long individual killer whale. Still much larger than the largest white sharks of 2-3 tonnes, although at parity MASS I might favor the shark. That's really the the question for me, how heavy is the Ross Sea orca. I don't know if it is the same overall robustness of the larger orcas, or is comparatively lighter at equal lengths. Orcas seem to be exceptionally robust dolphins in general. They are more robust and heavier than FKW at equal lengths, and I would assume would be heavier at equal lengths than other large dolphins such as the bottlenose. The only dolphin that I can think of that approaches its robusticity might be the pilot whale, but even then I think the orca is heavier. The pictures I've seen of Ross Sea orcas seems to indicate a relatively typical orca shape, so I might presume it could weigh 3-4 tons, based on weights of other 5-7 meter orca subspecies. I'd still like to know if any Ross Sea orca has actually ever been weighed to verify. Modern great whites are giants at 2.5 tons, so there still seems to be a great size disparity even at max sizes. Great whites are no slouches in the robustness category, so it's incredible how much even more robust a comparably sized orca will be. |
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Post by elosha11 on Apr 20, 2019 19:48:12 GMT 5
prehistorican do you think a matchup between a female Ross Sea killer whale and a large subspecies of great white would be fair? That's an interesting question as we don't know how large female Ross Sea orcas are compared to males (at least nothing that I've seen yet documents it). Presume they are shorter and more lightly built than the males, however, female orcas in other subspecies are also noted to be more agile and active (although certainly less powerful) than the males, so perhaps being smaller has its advantages. |
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Post by dinosauria101 on Apr 20, 2019 19:50:36 GMT 5
I think I'll make the match and see what others think (and scale down the killer whale based on the closest other population)
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Post by dinosauria101 on Apr 20, 2019 19:58:57 GMT 5
prehistorican do you think a matchup between a female Ross Sea killer whale and a large subspecies of great white would be fair? That's an interesting question as we don't know how large female Ross Sea orcas are compared to males (at least nothing that I've seen yet documents it). Presume they are shorter and more lightly built than the males, however, female orcas in other subspecies are also noted to be more agile and active (although certainly less powerful) than the males, so perhaps being smaller has its advantages. I went to Wikipedia for the scaling down, and the female Ross C whale would be about 2.4 tons. The average great white, by contrast, weighs about 1 ton. However, I've heard many people say they'd strongly favor a great white over a killer whale at parity, so maybe the matchup would be fairer than size alone suggests. |
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