Wonders and Curiosities 6

News from the Animal Kingdom

Interesting animal stuff. Part Six.

As usual for these posts, something for everyone, then a bit more for paying subscribers: chimps and yawning robots, the amazing variety of ribbon worms, how to cut rhino poaching, the cunning tricks of assassin bugs and more …

1. Dozens and Dozens of Undescribed Ribbon Worm Species

Nemerteans - ribbon worms - are whacky animals with a lot of remarkable stuff going on. Mostly (but not entirely) marine. I’ve only managed two podcast episodes about Nemerteans so far, which is a pretty poor performance. In my (slight) defence, they’re not that well studied, as evidence for which we’ve got this (I think) fun and cool study:

Some enterprising researchers thought to themselves ‘Nobody’s ever reported any Nemerteans from Oman. Why don’t we see what we can find?’. Result? They found over 100 species of ribbon worms in the coastal waters of Oman, almost all of which have never been scientifically described. They reckon there might still be another couple of hundred species waiting to be found in the area.

A sample there of the many species they found, from the original paper: Maslakova S, Cherneva I, Kahn E, Wong A, Paulay G. 2025. A hundred species, mostly new—first assessment of ribbon worm diversity and distribution in Oman. PeerJ 13:e19438. CC BY 4.0

Bottom line is, the sheer variety of species out there in the world is vastly bigger than most people realize. And most parts of the world and most types of animals remain terribly under-studied. Go somewhere new, look for something folks haven’t looked for before, and you will discover a treasure trove.

2. Contagious Yawning Again: Chimps and Robots.

I mentioned some research on contagious yawning the last time I did one of these news posts. Now, things get a bit weirder.

Researchers confronted chimpanzees with a realistic (but very uncanny-valley-style) android human head. Which yawned at them. If the chimps had seen more sf movies, they probably would have just destroyed the thing. But instead, they … yawned. And sometimes even lay down to rest.

Yes, chimpanzees can catch contagious yawning from a human-head android. A bit creepy. Also, kind of interesting: does confirm yawning is a pretty potent behavioural signal for them, inducing not just a copycat response but also perhaps actual rest/sleep.

3. Dehorning rhinos massively reduces poaching pressure. Nothing else does, really.

I guess this isn’t that surprising, but it’s important to have these things properly assessed.

Dehorning rhinos - literally sawing off their horns - is a somewhat desperate tactic to try to make them less appealing targets for poachers.

And boy, does it ever: Dehorning Rhinos Cuts Poaching by 78% – Saving Thousands of Animals' Lives.

A review of anti-poaching measures across a bunch of protected areas in South Africa, where there are loads of rhinos, found that dehorning was the only anti-poaching measure that had a really significant effect. Every other (much more expensive) measure tried - including heavy policing, patrolling, arrests, all sorts - none of it made a dramatic difference.

Cut off the rhinos’ horns, though, and poaching more or less immediately fell to a fraction of its previous level.

So that is how you stop rhino poaching. The catch is, it looks like you can never let the rhinos regrow their horns. If you do, the poachers’ll come and get them. Humans are just a very disappointing species sometimes.

And over to the paying subscribers for a bit more: agricultural sea spiders, sneaky assassin bugs and an amazing study of collective cultural memory loss in fish …