Horn-like structures as antipredator weapons (or not)

[Infinity Blade]

So I think most of us are aware that herbivores with horns or horn-like structures (antlers, ossicones, tusks) don’t actually seem to use them to lethal effect against predators as often as people think. That’s not to say it’s impossible or that they never do, but recorded instances are harder to come by than one would imagine. Even species with weapons suited for goring (e.g. rhinos, mountain goats) don’t actually seem to typically shank their predators. In fact, rhinos seem to stab other megaherbivores more than predators (and even the former still seems comparatively rare).

The question is why do herbivores seem surprisingly inept at using their horns/similar weapons? I found someone on iNaturalist trying to explain/demonstrate this. He basically says that while ungulates have the “hardware”, they lack the “software” (i.e. mentally) to have a willingness/skill to use their horns to fight predators (as opposed to ritualistic combat between conspecifics).

www.inaturalist.org/posts/52018-most-ungulates-are-surprisingly-inept-at-using-their-horns-against-predators-part-1https://www.inaturalist.org/posts/52018-most-ungulates-are-surprisingly-inept-at-using-their-horns-against-predators-part-1

www.inaturalist.org/journal/milewski/86153-most-ungulates-are-surprisingly-inept-at-using-their-horns-against-predators-part-2https://www.inaturalist.org/journal/milewski/86153-most-ungulates-are-surprisingly-inept-at-using-their-horns-against-predators-part-2

I’d also like to add, maybe trying to aim and stab with a head/neck (with monocular vision and potentially questionable eyesight) isn’t as effective as say, a human trying to stab with their dexterous arms and clear binocular vision.

[Supercommunist]

Gemsbok/oryx seem to be a notable exception.

www.reddit.com/r/HardcoreNature/comments/186rpg6/victory_at_a_cost_a_lion_takes_down_a_gemsbok_but/



ewasolions.org/treating-a-lion-injured-by-an-oryx/

www.youtube.com/watch?v=BwXsUP61F1I



koedoe.co.za/index.php/koedoe/article/view/805/910

Researchers also seemed to have notice how deadly they are as they assigned them as rank 2 threat in a lion study, the highest threat level in that study.

ibs.bialowieza.pl/g2/pdf/1595.pdf

It's funny because at first glance, the gemsbok's horns seem impractically long but clearly its working for them.

I would guess the main reason they are so deadly is because the horns actually reach behind them and can catch ambushing predators.

In a frontal fight their horns might actually be less effective.

I also agree with you on the second point. Besides mentality, the fighting effectiveness of horned animals could be hampered by poor vision. Most animals need to lower their heads to use their horns effectively. That probably makes it a lot more difficult for them to actually keep the predators in their sights.

That's part of the reason why I think triceratops was so formidable compared to other herbivores. It looks like it could use its horns without needing to mess around without moving its head around so much.


I think a really good hypothetical defensive biplaun for a herbivore would incorporate gemsbok/sable-like horns for sneak attacks and boar/rhino like tusks for frontal engagements.

[Infinity Blade]

Regarding oryxes, I remember reading that their long straight horns are actually primarily for delivering stave (quarterstaff)-like blows (along with some wrestling) in intraspecific combat. Horn reach was positively correlated with fencing and negatively correlated with stabbing. It’s acknowledged that long horns can be effective stabbing weapons (as demonstrated by your accounts), but also that it may be difficult and dangerous to bring them into position for stabbing (something that may be consistent with the idea that oryx/gemsbok horns are less suited for a frontal engagement).

Lundrigan (1996)


Kingdon (1988)

[Infinity Blade]

That's part of the reason why I think triceratops was so formidable compared to other herbivores. It looks like it could use its horns without needing to mess around without moving its head around so much.

Agreed. I also think it’s the fact that ceratopsids in general were built like hell (putting even rhinos to shame) and aside from their horns, they always had their beaks as additional weapons. And those were powerful enough that even Thomas R. Holtz straight-up said it was inconceivable that a Triceratops would have an inferior bite force to a T. rex (which is really saying something).

And speaking of ceratopsids, the closest thing I can think of to your hypothetical combination ungulate is something like Styracosaurus. Long spikes on the frill that protect the nape from neck bites (similar to an oryx), extremely powerful and sharp beak (instead of rhino or pig-like tusks), and even a rhino-like nasal horn.

[Supercommunist]

It is worth noting that dehorned rhinos appear to be less effective at defending their young from predators and they themselves may be more susceptible to predation.

[Infinity Blade]

Is that really true? There was a recent study looking at dehorned black rhinos, and overall they found no significant differences in survival among adults and calves.

It might reduce intraspecific fight-related deaths, though.

The black rhinoceros (rhino) (Diceros bicornis) is critically endangered, with poaching being one of several threats to the species’ survival. Many reserves across several countries, including Namibia, South Africa, and Zimbabwe, now dehorn their rhinos in an attempt to reduce poaching. Historical data collected by the Namibian Ministry of Environment, Forestry, and Tourism and Save the Rhino Trust were used to investigate whether dehorning has an effect on age at first reproduction (AFR), inter-calving interval (ICI), birth sex ratios, calf survival, cause of death, and lifespan. These were assessed in four Namibian sub-populations (hereafter referred to as ‘populations’) of black rhino (denoted A, B, C, and D) which have undergone varying levels of dehorning. No significant difference was found in any of the variables between dehorned and horned individuals. Population was a significant predictor of AFR (LRT = 7.433, p = 0.024) and ICI (LRT = 13.281, p = 0.004), although pairwise comparisons only found populations A and B to be significantly different (AFR: z = −2.736, p = 0.017, ICI: z = −3.705, p = 0.001). Additionally, a significantly higher number of males than females were born in population D (p = 0.021, CI = 0.544, 0.960). The main cause of death across all individuals was poaching, although there was no significant difference in the proportion of rhinos poached between dehorned and horned individuals (X2 = 0.638, p = 0.424, n = 265). No evidence was found to suggest that dehorning has any effect on AFR, ICI, birth sex ratios, calf survival, or lifespan in the black rhino, which is reassuring in the continued use of dehorning as an anti-poaching technique in this species.

link.springer.com/article/10.1007/s10344-022-01607-5

[Supercommunist]

Mar 9, 2024 16:49:22 GMT 5 Infinity Blade said:

Is that really true? There was a recent study looking at dehorned black rhinos, and overall they found no significant differences in survival among adults and calves.

It might reduce intraspecific fight-related deaths, though.

The black rhinoceros (rhino) (Diceros bicornis) is critically endangered, with poaching being one of several threats to the species’ survival. Many reserves across several countries, including Namibia, South Africa, and Zimbabwe, now dehorn their rhinos in an attempt to reduce poaching. Historical data collected by the Namibian Ministry of Environment, Forestry, and Tourism and Save the Rhino Trust were used to investigate whether dehorning has an effect on age at first reproduction (AFR), inter-calving interval (ICI), birth sex ratios, calf survival, cause of death, and lifespan. These were assessed in four Namibian sub-populations (hereafter referred to as ‘populations’) of black rhino (denoted A, B, C, and D) which have undergone varying levels of dehorning. No significant difference was found in any of the variables between dehorned and horned individuals. Population was a significant predictor of AFR (LRT = 7.433, p = 0.024) and ICI (LRT = 13.281, p = 0.004), although pairwise comparisons only found populations A and B to be significantly different (AFR: z = −2.736, p = 0.017, ICI: z = −3.705, p = 0.001). Additionally, a significantly higher number of males than females were born in population D (p = 0.021, CI = 0.544, 0.960). The main cause of death across all individuals was poaching, although there was no significant difference in the proportion of rhinos poached between dehorned and horned individuals (X2 = 0.638, p = 0.424, n = 265). No evidence was found to suggest that dehorning has any effect on AFR, ICI, birth sex ratios, calf survival, or lifespan in the black rhino, which is reassuring in the continued use of dehorning as an anti-poaching technique in this species.

link.springer.com/article/10.1007/s10344-022-01607-5

Rhinos have been perceived as invulnerable targets for millions of years so I think there is an inherent intimidation factor, but hypothetically if a no horned and no tusked rhino popped into existence I think it would be more vunerable to attack.

There are videos of dehorned rhinos that appear to be have been put in bad situations that a horned rhino would have been less likely to experience.

www.reddit.com/r/HardcoreNature/comments/1apzs2d/2_male_lions_try_to_take_down_a_young_dehorned/

www.youtube.com/watch?v=1Fog6jeeAZk

[mechafire]

I remember back in the day Blaze speculating about why Asian rhinos and elephants seem to fall prey to big cats more readily than their African counterparts. From what I recall their idea was basically that the African rhinos had longer horns and both males and female African elephants have tusks while only bull Asian elephants do. It’s an intriguing idea though I don’t know about any science backing it.

Would Cape buffalo be another exception? There are plenty of examples of buffalo killing more wounding lions just on YouTube and wildlife documentaries.

[Infinity Blade]

Mar 10, 2024 2:52:09 GMT 5 Supercommunist said:

Mar 9, 2024 16:49:22 GMT 5 Infinity Blade said:

Is that really true? There was a recent study looking at dehorned black rhinos, and overall they found no significant differences in survival among adults and calves.

It might reduce intraspecific fight-related deaths, though.

link.springer.com/article/10.1007/s10344-022-01607-5

Rhinos have been perceived as invulnerable targets for millions of years so I think there is an inherent intimidation factor, but hypothetically if a no horned and no tusked rhino popped into existence I think it would be more vunerable to attack.

There are videos of dehorned rhinos that appear to be have been put in bad situations that a horned rhino would have been less likely to experience.

www.reddit.com/r/HardcoreNature/comments/1apzs2d/2_male_lions_try_to_take_down_a_young_dehorned/

www.youtube.com/watch?v=1Fog6jeeAZk

I think it would depend on the context. The fight against the hippo, yeah, the rhino would suffer massively without a horn, as there it's fighting another megaherbivore that itself is well armed. The study I posted also suspects that intraspecific fight deaths may also be reduced in dehorned rhinos, so for fighting other large animals, yeah, having a horn probably matters.

Against two lions, the size alone is probably already deterrent enough for lions to generally not hunt adult rhinos. But there is one instance where two inexperienced lions managed to kill an adult female rhino (which I presume was horned).

Two male lions with their rhino kill

We also spotted a male lion in the tall grass and as we approached, we realized that two brothers had managed to kill a fully grown female rhino. Our guide, Pule, was beside himself because he didn't think that a pair of relatively inexperienced lions (they know all the lions in the reserve by name) could take down a rhino, but as he said, "Miracles do happen".

razaman.blogspot.com/2009/08/south-africa-2009-part-4.html

[Supercommunist]

Herbivores in general seem to have a hard time fending off predators without hurting their own young.

I think a mother rhino instinctively try to attack a predator with their horn whilst they are attacking her young.

I think in most instances, her sheer size would scare off the predators but in the event the predator is determined she may really struggle to defend her half as she may have simply end up nudging the predator with her nose or end up trampling over her baby.

[Supercommunist]

Video of an elephant disemboweling a giraffe.



Also thoughts on deinotheriums?

The guy that created the kaimere setting thinks they are more practical weapons against hypothetical giant predators. Personally, I am not sure is the cases given that they evolved at a time where no predator could hunt a healthy adult so I am not sure if the tusks are positioned at an effective angle.

www.deviantart.com/illustratedmenagerie/art/Koga-928339975

[tyrannasorus]

tbf, the elephant is substantially larger and giraffes aren't the most durable megaherbivores

look at elephants fighting rhinos and hippos or even each other and you'll see that they mainly use their size to attack rather than their tusks 

[razor45dino]

Mar 22, 2024 11:34:44 GMT 5 Supercommunist said:

Video of an elephant disemboweling a giraffe.



Also thoughts on deinotheriums?

The guy that created the kaimere setting thinks they are more practical weapons against hypothetical giant predators. Personally, I am not sure is the cases given that they evolved at a time where no predator could hunt a healthy adult so I am not sure if the tusks are positioned at an effective angle.

www.deviantart.com/illustratedmenagerie/art/Koga-928339975

i'm not sure how Deinotherium's tusks would be so practical for fighting at at all, let alone how it would be better than a regular elephant tusk against giant predators. Deinotherium's tusks are awkwardly positioned relative to it's body, they face down on an animal that has pillar like legs with front legs taller than hind legs. I'm not sure how strong hurling your head repeatedly down like that would be but it looks extremely awkward in my eyes. Not only that but if those hypothetical giant predators are the height of theropods, they probably can't even do that unless the theropod willingly puts its head down because even in regular position they are about as tall as the elephant. Not only that but they are faced curved towards the deinotherium's body and relatively short, meaning it would have to stretch its neck even more to strike. 

[Infinity Blade]

Mar 22, 2024 11:34:44 GMT 5 Supercommunist said:

Video of an elephant disemboweling a giraffe.



Also thoughts on deinotheriums?

The guy that created the kaimere setting thinks they are more practical weapons against hypothetical giant predators. Personally, I am not sure is the cases given that they evolved at a time where no predator could hunt a healthy adult so I am not sure if the tusks are positioned at an effective angle.

www.deviantart.com/illustratedmenagerie/art/Koga-928339975

Okay first, awesome find!

Tbf for that art piece, it is a fictional descendant of deinotheres that the artist said this for. That said, I also think deinothere tusks were impractical weapons. For them to be deployed their opponent would need to be just short enough to be hit by a downward strike of the tusks, but also not short enough to be out of range (deinotheres were tall). Not many animals fit that description, and the tusks might as well have been useless as weapons. Their heads are proportionately smaller than those of modern elephants as well.

[Supercommunist]

I don't think the giraffe account was very impressive but it is one the goriest elephant kills I've seen.