Is it actually lasing or is it just fluorescence filtered by the microstructure? Definition of lasing entails nonlinear processes, the article seems to only indicate monochromaticity which can be achieved via linear filtering alone?

Additionally, nonlinear processes don’t immediately imply lasing either. It could be anharmonicity causing high order harmonics, which many biological materials will exhibit in response to intense laser sources[0]. In order to actually qualify as lasing you need to have evidence of coherent amplification.

[0] https://en.wikipedia.org/wiki/Two-photon_excitation_microsco...

I agree, the question if something is a laser is actually quite complex and a lot of things that were claimed to be lasers turned out to only be amplified emission. Nature photonics made a checklist for this very reason (note I did not read the actual article so they might have ticked of that list) https://www.nature.com/articles/nphoton.2017.28

Yesterday was Pigeons As Hard Drives, today is Peacocks As Lasers.

I look forward to what tomorrow brings.

Combine them with a phalarope to make a fully functioning CD player?

I think I have a story idea for Austin Powers 4

Could someone update the Evil Overlord List? Peacocks are for-sure cheaper to keep than sharks, and we all know about prioritizing useful expenditures over intimidating decor.

Peacocks are intimidating regardless of the coherence of their light emissions. I would think twice before crossing someone who had roaming peacocks defending their Evil Lair.

Turns out it wasn't a mating display, it was a heat ray

"You may have noticed my garden contains many... intoxicating flowers, Mr. Bond. However your downfall—which you cannot smell—comes from the Peacock Aggression Pheromones, which are being released as we speak."

There was a cool scene in William Gibsons the peripheral involving bees.

The greenhouse scene in Minority Report is also good.