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Post by theropod on Jul 23, 2018 3:14:31 GMT 5
Actually, let me refine that a bit:
In the video, the seal takes 50 (±2) frames from the point were it disengages the tail of the orca to the apex of its trajectory, so that’s a t=2s (frame rate being 24fps). Since gt=v, vertical velocity at takeoff is 20ms⁻¹, and height at the top of its trajectory is 20m above the point it left the tail. So the height that was assumed was really good for a guess. Going frame by frame the preiod of accelleration is much more discernible, and it doesn’t look like more than 4 to 5 frames in the video, i.e .17-.21s, or an accelleration of 96-120ms⁻². Going with the 59kg seal, the necessary force to accellerate it would be 5673N or 567kg, but that’s probably slightly conservative, since the seal did not fly straight upwards (i.e. the total speed would have been higher still).
I don’t know what kind of g-forces seals can handle, but typical human tolerance is apparently ~5g, with up to ~9g in a special suit. So assuming seals are similar to humans in that regard, that tail catapulting move is definitely an efficient incapacitating technique on small prey (and seems much more fun than biting).
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Post by elosha11 on Jul 23, 2018 3:30:19 GMT 5
The speed of these Giant Trevally (and for that matter the sardines' comparative speed at their smaller body size) seem almost unreal. That poor unsuspecting shark, it was just chilling and hoping for a quick bite, and it got the equivalent of a water avalanche.
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Post by sam1 on Jul 23, 2018 12:25:13 GMT 5
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Post by Infinity Blade on Jul 23, 2018 18:26:41 GMT 5
Do (probable) fossil interactions count?
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Post by sam1 on Jul 23, 2018 19:47:41 GMT 5
Do (probable) fossil interactions count? sure, why not
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Post by Infinity Blade on Jul 23, 2018 22:50:55 GMT 5
I personally consider this to be quite fascinating. That's just me, though. Tooth puncture marks on a 30 million year old Dinictis skullJohn W. Hoganson & Jeff J. Person (2011) " We suggest that Hyaenodon killed this Dinictis because the geometry of the tooth punctures is similar to the slightly labially/lingually compressed shape of the upper canines of Hyaenodon (fig. 8). Also, the distance between punctures is consistent with the spacing between the upper canines of Hyaenodon. This is particularly true if multiple bites occurred, as we suggest. The punctures were not made by the lower canines of Hyaenodon because they are splayed out labially and would have produced a different shaped puncture. Both Hyaenodon horridus and Hyaenodon crucians have been recovered from the Brule Formation in North Dakota, but because the range of spacing between the upper canines (table 2) is more consistent with Hyaenodon horridus, we suggest that H. horridus is the more likely predator." " We envision that Hyaenodon horridus attacked this Dinictis felina from the rear on its left side (figs. 9 and 10). It dispatched the Dinictis by multiple bites to the skull. After at least two bites, its upper front canines created two incipient bite marks on the parietal near the sagittal crest and two crushing and deep penetrating punctures on the right parietal. During the attack, the lower jaw of Hyaenodon crushed the left zygomatic arch and its lower premolars created scratches on the left maxilla and another bite mark on the left parietal." www.dmr.nd.gov/ndgs/documents/newsletter/2011Summer/Toothpuncturemarks.pdf
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Post by sam1 on Jul 23, 2018 23:49:43 GMT 5
Yeah, I looked up about the two species involved and it seems that this was a battle of similarly sized animals. Kind of analoguos to wolf killing a puma with a skull bite? Damn. It's definitely not just you, that piece is indeed fascinating.
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Post by neogeneseamonster on Jul 24, 2018 12:39:27 GMT 5
Very interesting indeed. The footage clearly shows just how potential the "tail slap" is especially to smaller animals. And... is this the first recorded footage of orcas attacking a pelagic stingray (looks like this species judging from the appearance)? If so, it's even more interesting.
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Post by sam1 on Jul 24, 2018 20:21:39 GMT 5
Very interesting indeed. The footage clearly shows just how potential the "tail slap" is especially to smaller animals. And... is this the first recorded footage of orcas attacking a pelagic stingray (looks like this species judging from the appearance)? If so, it's even more interesting. Well, I dont know if this fits your criteria, but I guess the broad answer is, they attack and prey on all kinds of rays.
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Post by neogeneseamonster on Jul 25, 2018 9:57:34 GMT 5
Of course, all rays and frankly almost all marine animal sharing habitat with orcas are their potential prey. So it is not an unexpected situation. What I meant was that it is interesting to see the actual underwater footage rather than vaguely "understanding" they are the potential prey
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Post by sam1 on Jul 27, 2018 20:08:47 GMT 5
I take that most of you have seen this footage already. The video title really doesn't do it justice.
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Post by sam1 on Aug 4, 2018 20:49:28 GMT 5
This one actually has a great artistic value on top of everything else. Incredible.
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Post by sam1 on Nov 18, 2018 21:39:27 GMT 5
The eagle's tenacity and durability really surprised me..pretty sure he would've let the goat go if he got injured.
Also the second goat's behavior was interesting..as if he wanted to help his fellow out.
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Post by sam1 on Feb 8, 2019 13:52:13 GMT 5
I'm aware that Ratels aren't normally a prey for Leopards, but young ones do get taken out whenever the chance comes.
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Post by sam1 on Apr 13, 2019 22:33:34 GMT 5
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