[Nasrudith]

Well I think the bigger issue for gazelles is energy density period - brains are calorie hogs and it doesn't take much cunning to track down grass. Grass eating is the opposite direction in a food strategy - going for abundant but low density food instead of chasing higher density.

A diverse diet is a bit of a hallmark of intelligence in itself in that they are able to use their brains to get more food to make it worth the investment - similarly to complex group behavior I guess.

Hermit crabs for instance are shockingly intelligent for crustaceans, especially for ones of their size. I know that improperly shut lids which while closed have enough play - they cold push from the inside causing them to rotate on their axis and let them escape. That isn't quite tool use but recognizing tools unlike anything in nature and how to manipulate them to get what they want.

Hermit crabs have both and live in large social groups and eat a diverse diet as well.

[erikig]

Speaking of Hermit Crabs, I was also blown away by their communal shell exchange process.

Many hermit crabs will come together and work as a team to change shells in hierarchy. If you've never seen it, you are in for a treat.

https://www.youtube.com/watch?v=f1dnocPQXDQ

[mcv]

I feel like there's something taboo, something indecent about seeing a hermit crab out of its shell.

That one crab was caught with its pants down for a moment.

[kwxza]

That was fascinating, thank you for sharing.

[singularity2001]

Also big herds probably discourage engaging in complex group behaviors: Just blindly follow the flock and you'll be ok most of the time.