Orca shark interactions

[Grey]

Oct 10, 2014 19:09:28 GMT 5 theropod said:

A selection from Appendix I in Jefferson et al. 1991:

Date	Location	Description	Cooperation?	Kill?	Source
Pre-1886	Tigalda Island, AKm U.S.S	2 KWs attack a large Fin Whale	Y	?	Turner (1886)
6 July 1908	Sukkertoppen, W. Greenland	Whaler record of 2 KWs killing a Fin Whale	?	Y	Reeves & Mitchell (1988)
1983-87	Greenland	8 observations of chases or attacks involving 4-5, 8-10, 2,2,2,2,2-4 KWs)	?	?	Heide-Jorgensen (1988)
7 July 1984	Faroe Islands	2 KWs attack a Fin Whale (report from fishermen)	?	?	Bloch & Lockyer (1988)
1800s	Sea of Okhotsk	3 KWs attack and mortally-wound a large Bowhead	Y	Y	Bullen (1898)
11 September 1984	Baffin Island, eastern Canada	2 KWs presumably attack single Bowhead, while 12 other Bowheads socialize nearby	?	?	Finley (1990)
November 1961	Southern CA, U.S.A.	Second-hand report of single KW attacking and Killing single Grey [whale]	N	Y	W.F. Samaras and S. Leatherwood (unpubl.)
February 1966	Southern CA, U.S.S.	Second-hand report of 2-3 KWs attacking 3 Greys, killing 1	?	Y	W.F. Samaras (in litt.)

I think that should lend a little more credibility to the account I already posted. It’s rare on the whole, but there is still a fairly good record of small groups or single Killer Whales killing large baleen whales, sometimes attacking groups of them.

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Reference:
Jefferson, T. A.; Stacey, P. J.; Baird, R. W.: A review of Killer Whale interactions with other marine mammals: predation to co-existence. Mammal Review, Vol. 21 (1991); 4; pp. 151-180

That's definitely more interesting that your first account you use since pages. Orcas are no doubts very impressive predators and I believe such interactions can be seen as equivalents of giants theropods hunting giants sauropods (size wise).

Now :

Pre-1886
Tigalda Island, AKm U.S.S
2 KWs attack a large Fin Whale

No report of an eventual killing, so as much it is impressive to see how two orcas can engage a much larger opponent, it is not conclusive about their killing capabilities. The account is itself old so no wonder quite vague about the outcome.

6 July 1908
Sukkertoppen, W. Greenland
Whaler record of 2 KWs killing a Fin Whale


Impressive though beware about whalers claims. The size of the whale isn't specified either, but that remains interesting.

7 July 1984
Faroe Islands
2 KWs attack a Fin Whale (report from fishermen)

Same comment than before, no information regarding the outcome, the size of the prey (young, juvenile, adult) its health (sick, wounded or healthy ?) and since the report is from fishermen, it is not as reliable as a scientific observation.

1800s
Sea of Okhotsk
3 KWs attack and mortally-wound a large Bowhead

The problem is that one is once again it is very old, the case like the report. But still interesting.

11 September 1984
Baffin Island, eastern Canada
2 KWs presumably attack single Bowhead, while 12 other Bowheads socialize nearby


"Presumably". That's not demonstrated either.

November 1961
Southern CA, U.S.A.
Second-hand report of single KW attacking and Killing single Grey [whale]


As you may expect I have the problem with the fact the case is from a second hand report. No information about the size and situation of the prey. But that's possibly believable if you ask me.

February 1966
Southern CA, U.S.S.
Second-hand report of 2-3 KWs attacking 3 Greys, killing 1

Same comment but here we have at least the outcome.


All these accounts are interesting but not actual scientific observations. That's quite valuable though.


Regarding the large group of 29 orcas having trouble to kill a 18 m blue whale, there's some contradiction when you say that they had trouble because of the speed of the prey, not because of its size.

Fin whales like those in these accounts are very fast, athletic mysticetes too, still apparently in some of these cases, few orcas succeeded to kill one individual.

If one, two or three orcas only can subdue a large, fast whale, why almost 30 of them couldn't ?

No, the difficulties for this group of orcas were a combination of the great speed of the blue whale and its great size, not its speed alone. Plus, greater speed is directly related to larger size (but less maneuvrability), just like greater resilience is due to larger size. Any larger prey item is a more difficult prey item for predators and orcas are no exception to this.

[theropod]

Yes and so ?

Well, I don’t believe seagulls are a real threat to a multiton aquatic animal. At best infections would be, but strangely whales seem to be quite resilient to those, as shown by their high rate of healed wounds.

And you say that I'm the one personnally attaking you here ? My adequate response here : "because perhaps you do, genius ?".

As a matter of fact, you were, you were the one calling me biased. I was stating the obvious, that you cannot look into the head of a false killer whale. Are you saying you can? If not, why are you pretending to feel insulted? If you can’t stand people challenging your arguments, don’t argue.
I’m not the one making up hypotheses about their intentions that are not backed up by their behaviour. The truth is, none of us know their intentions, but you were the one using your hypothesis about their intentions as an argument. Obviously, that leads me to call your knowledge of those into question.

And that has nothing to do with it being a deliberate attack, it obviously was. What attacks in the animal kingdom are not deliberate? Maybe those by sharks on humans, because they mistake them for different prey, but apart from such cases I can't think of much.
Do you think the fkws mistook the sperm whales that they engaged in an open, aggressive confrontation for "small fish and squid"

As long it is stated to be flesh-grazing and no deliberate attempt to kill that's fine to me.

And where is it stated to be flesh-grazing, and where do you take your definition of flesh-grazing as not involving a deliberate attack from? More importantly though, what exactly is "fine to you"?

There are proportionately fewer animals in its ecosystem that are bigger than an orca than there are animals bigger than a lion for example, so by inference it is less likely to encounter prey larger than itself. In part because an orca is in a different size class, in part ebcause giant whales are rare.

And if FKW were mainly made to kill big games they would move in waters where big games preys live. But they actually live in the waters where their main preys items consisting of fishes and squids actually live.

What you were replying to had nothing to do with that, but with the relative likelyhood of any large predator to kill a prey larger than itself. and FKW are made to "kill big games" to a similar degree. It’s not the whale’s fault that you think a pinniped is the definition of "big game".

Absolutely, that's why we rely on what is documented, studied and reliably supported, not on over-speculations.

And what over-speculations would that be?

So you're suggesting that beside sea turtles, modern aquatic and marine reptiles are just as fast, active, reactive and agil than seals ?

There are no modern marine reptiles besides sea turtles, unless you are counting marine iguanas (which are herbivores) and not particularly adapted for aquatic locomotion either, and salties (which I don’t think have been recorded being preyed upon by any other predator).

Are you suggesting fish aren’t as "fast, active, reactive and agil than seals", and if you do, do you have evidence of that? Because False Killer Whales have not been recorded preying on reptiles to begin with, making an argument involving reptiles beyond pointless. The only reptile I know any marine mammal to prey on are penguins, and these definitely are very fast, active and reactive, just like seals. False killer whales prey on sailfish and tuna, which are respectively the fastest and among the fastest marine animals in existence.

Tunas and salmons are exceptionnal cases among fishes.

They are? And sailfish too I presume? False killer whales prey on those. They don’t prey on marine iguanas or crocodiles tough.

I claim that a GWS has less problem to catch and kill a 50 kg turtle than a 50 kg seal.

Your claim is your opinion, not a fact. And it is not important, because it would not be dependant on their metabolism but their locomotory apparatus. What I have seen doesn’t make me think turtles are easy prey tough.

I claim that a large GWS is individually a more formidable predator than a FKW.

I agree if you are talking about a larger great white shark. I still and again don’t see the relevance though. We were discussing what would happen between similar-sized individuals, and we were discussing their trophic niches and whether one preys on the other. imo the outcome of a confrontation between a 3.3t Great white and a false killer whale does not have a lot to add to the debate, while a false killer whale is both a similarly formidable animal at size parity, and can operate on the same trophic levels on the whole due to pod-hunting.

As long as there's no modern reliably documented cases, my examples are reliable. But the further data you've brought could revise this a bit.

But I don't rely too much on very old observations not widely reported and supported since.

You’ll have noticed I also don’t rely too much on documentaries, they are terribly unreliable. But that doesn’t mean I don’t believe them if they show footage of a specific behaviour.
And neither do I dismiss multiple reports from various sources, especially if all of them are reported in scientific papers (not ominous blogs or newspapers).

Mainly smaller-sized than adults GWS preys items. The abstract I've posted about the stomach contends of a sample of FKW does not show large-sized preys items. The squids species found in great number in them are small-sized.

And who said they were all adults? They probably were not. Or are juveniles immune to stranding?

I’ve also posted stomach contents of 9 GWS of various size classes that consisted entirely of fish (Tricas & McCosker 1984). That’s not the same sample size, but you should get the picture of how much that tells us about the global diet of the species.
Yes, in a sample of 27 FKWs all that had stomach contents had fish and/or squid in there, with mid-sized squid-species being predominant, but in case you forgot, all but one were poorly nourished to begin with and what you posted did not say anything about their maturity.

I think it's pretty easy to distinct deliberate attempts to kill and flesh-grazing and I don't see why you insist in that case of FKW when flesh-grazing on large whales bodies is reported from others species. If you want to demonstrate that these FKW were actually trying to kill one of the whales, then bring some evidence.

Well, if that is so easy to distinguish, the interaction between FKW and sperm whales cannot have been flesh grazing, parasitism was not even one of the three proposed scenarios in the paper…

Flesh grazing by a large predator on a prey item that involves a full-on attack obviously is not easily discernable from predation, and neither does it have to derive from different intentions.

Pre-1886
Tigalda Island, AKm U.S.S
2 KWs attack a large Fin Whale

No report of an eventual killing, so as much it is impressive to see how two orcas can engage a much larger opponent, it is not conclusive about their killing capabilities. The account is itself old so no wonder quite vague about the outcome.

7 July 1984
Faroe Islands
2 KWs attack a Fin Whale (report from fishermen)

Same comment than before, no information regarding the outcome, the size of the prey (young, juvenile, adult) its health (sick, wounded or healthy ?) and since the report is from fishermen, it is not as reliable as a scientific observation.

No, no report on the outcome. Evidence that pairs of killer whales in fact attack fin whales.
But I remind you that you considered a stranded False Killer Whale reported in a blog post that’s 286 words long, of which a single sentence reports the presence of bite marks that may or may not be the result of an attack, and that may or may not have been the cause of death, and that was also not written by scientists, to be clear indication that great white sharks occasionally prey on false killer whales. You’ll have to admit that’s not better at all.

All these accounts are interesting but not actual scientific observations. That's quite valuable though.

That would perhaps be a valid point of not accepting a single account, but I posted 8, and there might be more. Also note that it seems to get reported where there are juveniles involved, in the table and also in the literature dealing with orca predation that I read so far. Whale calves and adults are exceedingly easy to tell apart by sheer size, at least if you can identify the species (which was the case in all these reports).
And on the whole, these are far better accounts than, for example, that alledged predation attempt by a great white on a false killer whale.

Regarding the large group of 29 orcas having trouble to kill a 18 m blue whale, there's some contradiction when you say that they had trouble because of the speed of the prey, not because of its size.

Fin whales like those in these accounts are very fast, athletic mysticetes too, still apparently in some of these cases, few orcas succeeded to kill one individual.

That’s no contradiction of mine, it is a peculiarity of the data. An adult fin whale or bowhead whale is can be as large or larger than an 18m bue whale, and yet they have been recorded to be brought down by smaller groups of orcas.
But seeing as Orcas also have a high rate of failure with Minke whales, I think the speed and stamina of rorquals is the most important problem they face.

And this is what I wrote, not more:
I think their struggle was due to the whale’s sustained speed rather
than their inability to kill it. They also have a considerable rate of
failure with minke whales, and there can hardly be any doubt that a
group of orcas could easily kill one (and they do actually, unless the
minke whale can outdistance them), after all they don”t even fight back
when cornered.

Plus, greater speed is directly related to larger size (but less maneuvrability), just like greater resilience is due to larger size. Any larger prey item is a more difficult prey item for predators and orcas are no exception to this.

Greater speed is not automatically related to larger size. The opposite, in fact, is the case in many animals and over a wide range of sizes, but that doesn’t seem to apply to marine animals to the same degree (although just as with terrestrial animals the fastest marine animals seem to fall into a certain size range, between sailfish and marlin), as there is no need for specific-weight-support adaptions in the larger taxa. 
And orcas can reach higher top speeds than rorquals (Ford et al. 2005), they just seem to have inferior stamina, and that’s independent of size–at least this situation is the same with minke whales which are only slightly larger than orcas. So their shape seems to be the most important factor.
Of course the size and durability are important too, but seemingly less so, as eventually these aren’t what makes rorquals escape from orcas in most cases.

No, the difficulties for this group of orcas were a combination of the great speed of the blue whale and its great size, not its speed alone.

I do think so. But I also think that the speed is the main problem, because great size does not explain their success rates with smaller, less resilient and positively defenseless whales.
Also I think the case of about 30 Killer Whales struggling to kill a Blue Whale is likely not representative.

If one, two or three orcas only can subdue a large, fast whale, why almost 30 of them couldn't ?

I’m not sure what you want to imply with that. Do you think the single account involving the 30 orcas to be unreliable? I doubt that, I think it just isn’t what would normally happen (just like I wouldn’t necessarily think a single peccary could deter two jaguars, each twice its own size for extended periods of time, no matter how feisty it is). Exceptional confrontations happen in nature, that doesn’t mean they ALWAYS happen.

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References:
Ford, J. K. B.; Ellis, G. M.; Matkin, D. R.; Balcomb, K. C.; Briggs, D.; Morton, A. B. : Killer Whale Attacks on Minke Whales: Prey Capture and antipredator Tactics. Marine Mammal Science, 21 (2005); 4; pp. 603–618
Palacios, D.M.; Mate, B.R.: Attack by false killer whales (Pseudorca crassidens) on sperm whales (Physeter macrocephalus) in the Galapagos Islands. Marine Mammal Science, Vol. 12 (1996); 4; pp. 582-587
Tricas, T. C.; McCosker, J. E.: Predatory Behaviour of the White Shark (Carcharodon carcharias) with notes on its biology. Proceedings of the California Academy of Sciences, Vol. 43 (1984); 14; pp.221-234

[Grey]

DAMN DAMN DAMN, I had posted a long response and my connexion just crashed, incredibly irritating. I'll post later. F*ckin' internet.

[creature386]

I know that too well…
In fact, I sometimes even type longer texts (not forum comments, but profiles or blog entries) in another program and then copy & paste it.

[theropod]

It hasn’t happened to me in quite some time, but it used to be quite common on proboards.
Now there is that autosave feature (which is actually sort of annoying if you often look up something on another page of the thread or board while writing a comment, but I suppose it’s worth it), which informs you that you have an unsaved draft the next time you open something on the forum. Don’t you have that?

Also you should be able to "go back one page" once you see that the connection has failed and recover what you’ve typed, but obviously that’s of no use if one doesn’t do it immediately (and i don’t know whether it works with all browsers).

[Grey]

Given that the ‘frontal’ (read on) was over a metre long, and given the discrepancy in size between a metriorhynchid and an adult Leedsichthys, this interaction might imply that metriorhynchids acted in a similar fashion to cookie-cutter sharks: that they swam up to giant animals and took chunks out of them. As mentioned earlier, interactions of this sort have been observed in cetaceans, as False killer whales Pseudorca crassidens have been filmed biting chunks out of Sperm whales Physeter macrocephalus (Paul 1998).

scienceblogs.com/tetrapodzoology/2009/07/02/biggest-ever-fish-has-been-revised/


Relative to jaw size, the teeth of the false-killer whale Pseudorca are perhaps the largest of any odontocete (with the exception of the enlarged tusk of the narwhal Monodon), but marine mammals seem to form a minor part of its diet and most prey are fish and squid (Stacey et al. 1994).

McHenry 2009.

Old discussion but it's clear that C. carcharias operates at a higher trophic level than Pseudorca.