Could T-rex have been an endurance/persistence hunter?

[Sight Reader]

Hello everyone!

I’m relatively new to reading about dinosaurs, so please forgive me if this a really stupid idea or gets asked way too much. Anyway, it sounds like T-rex really wasn’t really faster than most of its prey, so now I’m trying to picture how something like a T-rex might hunt.

Could a T-rex have hunted by OUTLASTING its prey instead of out-sprinting it? I’ve heard this idea of “persistence hunting” proposed for early hominids, where your advantage is the ability to sustain an elevated pace of pursuit for long periods of time without needing long recovery periods. Might T-rex have simply been in “better shape” than its prey, using its tracking skills to relentlessly close on hiding prey who were still trying to cool down after burning too much energy sprinting away?

Thanks for any ideas... and for not laughing at me, if possible!

[John Harshman]

It's sure hard to tell this sort of detail from the fossil record, so
your answer will probably always be "maybe". Even estimates of its top
speed are iffy. Now if I had to guess, I'd guess not, as analogous
persistence hunters in the modern world tend to hunt in groups, and such
evidence as there is suggests that tyrannosaurs were solitary.

It's been suggested that they made a living by hijacking the kills of
other, faster predators. But then again, tyrannosaur teeth have been
found broken off and embedded in hadrosaur skeletons, which suggests
active predation (but doesn't quite rule out the alternative).

So, to sum up: we don't know.

[jillery]

You might find interesting this article:
<https://en.wikipedia.org/wiki/Feeding_behaviour_of_Tyrannosaurus>

It's possible that individuals' hunting behavior changed as they aged
and grew in size, with the younger individuals going for more active
predatory strategies.

I vaguely recall reading of a trackway that showed what might have
been a tyrannosaur synchronizing its pace with what might have been a
brontosaur. This is a practice observed in modern predators just
before their final lunge upon their prey.

As an aside, posters to sbp generally don't laugh at others. Instead
they merely condescend, perhaps because it uses less energy.

[jillery]

On Thu, 15 Apr 2021 03:04:50 -0400, jillery <69jp...@gmail.com>
wrote:

This isn't the article I read, but it does match my recollection:

<https://www.smithsonianmag.com/science-nature/in-the-steps-of-a-hungry-acrocanthosaurus-33988/>

<https://tinyurl.com/ph25ymcm>

[Oxyaena]

Many modern day predators alternate between active predation and simple
scavenging of other predator's kills. I don't see any reason why late
Cretaceous ecology would've been different in this regard.

[John Harshman]

We can agree that there's a continuum between pure predation and pure
hijacking (a term I prefer to scavenging, as it implies aggressive
takeover). Where T. rex might fall on that continuum I don't know. Nor
do I know whether they ever hunted in packs, which is itself a continuum.

[jillery]

And to bring it back to the question raised by the OP, extant
predators display a range of hunting strategies, from the solitary
ambusher and stalker ex. leopard, polar bear, to the gregarious
disorganized communal hunters ex. grizzly bear, crocodile, to the
highly structured persistence hunters, ex. wild dogs, wolves.

WRT scavenging, my understanding is there are few hungry predators
which will turn away from a carcass.

WRT T.rex specifically, there are several fossils of prey species with
partially healed wounds from what appear to be T.rex bite marks. If
so, then T.rex hunted live prey, and in at least some cases the prey
got away.

[John Harshman]

That last bit is certainly true.

[nyik...@gmail.com]

Also, The Virginia Museum of Natural HIstory, tucked away in the little city
of Martinsville, has a fossil of a Triceratops with the tooth mark of a
Tyrannosaurus. It's not on display there, but I was in a group which were taken
behind the scenes that most museum visitors are confined to.

> > Many modern day predators alternate between active predation and simple
> > scavenging of other predator's kills. I don't see any reason why late
> > Cretaceous ecology would've been different in this regard.

> We can agree that there's a continuum between pure predation and pure
> hijacking (a term I prefer to scavenging, as it implies aggressive
> takeover).

Interesting. For decades now I've been under the impression that
some vultures, and certain large storks (adjutant, malibou) would
scavenge carcasses that were too spoiled to interest the predator
that killed them any longer.

Besides, animals often die of natural causes (disease, starvation,
old age,...) that have nothing to do with predators. A carnivore could
just be a beneficiary of a lucky find. And vultures seek out these
targets of opportunity from a vantage point and lifestyle ideally
adapted to the task. Big storks too, I would suspect.

> Where T. rex might fall on that continuum I don't know.

Reflexive answer: predator or top dog hijacker. Do you disagree?

> Nor do I know whether they ever hunted in packs, which is itself a continuum.

It would be nice to know.


Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos

[nyik...@gmail.com]

On Wednesday, April 28, 2021 at 6:47:02 PM UTC-4, nyik...@gmail.com wrote:
>
> Interesting. For decades now I've been under the impression that
> some vultures, and certain large storks (adjutant, malibou)

Correction: marabou.

[John Harshman]

Certainly. But we aren't talking about scavengers of that sort, but
about predators that chase other predators away from their fresh kills.
Both lions and hyenas do that. Not sure who else.

> Besides, animals often die of natural causes (disease, starvation,
> old age,...) that have nothing to do with predators. A carnivore could
> just be a beneficiary of a lucky find. And vultures seek out these
> targets of opportunity from a vantage point and lifestyle ideally
> adapted to the task. Big storks too, I would suspect.
>
>
>> Where T. rex might fall on that continuum I don't know.
>
> Reflexive answer: predator or top dog hijacker. Do you disagree?

No.

>> Nor do I know whether they ever hunted in packs, which is itself a continuum.
>
> It would be nice to know.

Have you seen the paper cited here in support of that pack behavior? I'm
a little wary of the conclusion, but you should look.

[John Harshman]

On 4/28/21 3:52 PM, nyik...@gmail.com wrote:
> On Wednesday, April 28, 2021 at 6:47:02 PM UTC-4, nyik...@gmail.com wrote:
>>
>> Interesting. For decades now I've been under the impression that
>> some vultures, and certain large storks (adjutant, malibou)
>
> Correction: marabou.

Yes, the Malibu stork doesn't scavenge. It just lives in a fun house
with its boyfriend Ken.

[Oxyaena]

Turkey vultures almost exclusively eat carrion, whereas black vultures
are a bit more versatile in how they get their meals. More evidence of
the continuum John mentions.

>
>
>> Where T. rex might fall on that continuum I don't know.
>
> Reflexive answer: predator or top dog hijacker. Do you disagree?

Again, I see no reason why T. rex couldn't've been both.

[jillery]

On Sun, 11 Apr 2021 12:20:14 -0700 (PDT), Sight Reader
<thesigh...@gmail.com> wrote:

I recall a time when I was young and dumb and full of... dinosaurs.
The consensus was dinos were cold-blooded, overweight behemoths which
had trouble enough getting out of their own way. If T.rex actively
hunted, it was only because their prey were equally lumps of scaly
flesh, living on metabolic Valium, lazing in swampy jacuzzis, as
illustrated in museum panoramas.

Also, dinos were dumb, small-brained dumb, Baby Huey dumb, perhaps not
quite as dumb as rocks, but only just. Dinos were so dumb they
couldn't help but succumb to us smarty-pants mammals.

So if you had suggested back then that T.rex might have persistence
hunted, which requires not only great energy and stamina, but also
inelligence and teamwork, I have no doubt you would have inspired a
few smirks and chuckles, if not outright guffaws and hoots.

And then I read about John Ostrom's hyper Deinonychus and Jack
Horner's nest-building Maiasaurus. And then I read Robert Bakker's
Scientific American article, that dinosaurs were warm-blooded, fast
growing, and built for speed. And then I read about dinosaurs with
feathers and that birds are dinosaurs.

After the paradigm shift of this Dinosaur Renaissance, nobody is going
to laugh at your idea.

[Daud Deden]

Built for speed? No, built for balance during bipedal walking, parallel to giant ground sloths and giant short-faced kangaroos.
https://royalsocietypublishing.org/doi/10.1098/rsos.201441
Finally they are questioning the running T rex motif.

[jillery]

Dinosaurs, with their vertical legs, hips strongly attached to their
spine, close to their center of gravity, and pneumatized bones, had
greater speed and endurance than other animals of the Triassic.

WRT T.rex specifically, their range in size, from hatchling to mature
adult, may have required an adjustment in lifestyle and locomotion.
Although there are no land animals today even close to the mass of an
adult T.rex, multi-ton extant species like hippo, rhinoceros, and
elephant still approach 25-30 mph in a sprint when sufficiently
motivated. My understanding is young T.rex did at least as well.