Korbinian Pacher

Schedule and Conference details here👉 asabwinter.github.io/2025/schedule/

Please reach out to @stacheljochen.bsky.social @maxlicht.bsky.social or myself for more Hublet details!

The largest shoals

Better and faster decisions by larger fish shoals in the wild When attacked by birds, wild shoals of fish make better decisions as shoals get larger.

So larger shoals really seem to become smarter by overcoming two major trade-offs in decision making: general accuracy and speed accuracy, and all this connected to predator protection and thus a direct functionality in the wild.

Great team effort with @igb-berlin.de and @scioi.bsky.social

The largest shoals were almost perfect in identifying real predator attacks. However, their false alarms towards flybys did not increase. This means their decisions really became more accurate! And suprisingly they also became faster!

But diving down into the hypoxic water is costly, so they need to decide if a situation is worth it. We looked at shoals of different sizes and if they are able to discriminate between harmless flybys by any bird and actual predator attacks. Turns out as shoals get larger they can!

Or they join a group! Shoals of sulphur mollies are bound to the surface due to their hypoxic environment. This attracts various predatory birds. But fish shoals are not defenceless: When attacked they dive collectively and repeatedly producing surface waves, that can scare away their predators.

Animals are constantly forced to make decisions. Most crucially if they are in danger of predation or not. Solitary animals can become more sensitive and react to almost everything, which does not increase decision accurcy. Or they take their time, make better decisions but at the cost of speed.

Better and faster decisions by larger fish shoals in the wild When attacked by birds, wild shoals of fish make better decisions as shoals get larger.

New paper out on collective cognition in wild sulphur molly shoals!
We show that larger shoals become better in discriminating between harmless and dangerous situations.
In addition they also become faster and seem to mitigate the classic speed accuracy trade-off!
www.science.org/doi/10.1126/...

A bit late to the party, but i would love to join as well!:)

To kick-off my Bluesky, I want to highlight a paper from earlier this year - the first one together with my best friend @stacheljochen.bsky.social 👬🏼
We report several #Natrixnatrix from #Berlin with untypical pattern.
Hopefully, we can find out what’s happening there genetically, next year.

Korbinian Pacher: Understanding the dynamics behind prey motion and the performance of non-kin related group hunting predators in the open ocean. In our latest post, Korbinian Pacher takes us out to hunt as they share insight behind their paper: “Evidence for a by-product mutualism in a group hunter depends on prey movement state”. Korbinian…

👀Blog post out now!👀

🐟Korbinian Pacher explains how striped marlin groups hunt schools of sardine and opens our eyes to the endless possibilities of studying behavioural ecology in the open ocean, using aerial vehicles!🎥

https://buff.ly/3Zx3Wfm

🧪🌍