Scientists baffled as orcas start wearing salmon as 'hats' again for the first time in 40 years

Orcas are wearing dead fish on their heads (again).

Apparently the large mammals were first seen sporting the unusual headgear back in the 80s - a time when many people's fashion choices were rather questionable.

Now, like fashion trends to do, the bizarre 'hat' has made a comeback after scientists and whale watchers in Washington State recently saw some orcas with dead salmon on their heads.

In a Facebook post shared to the Orca Network Community Group last month, one whale watcher shared a snap of an orca with the outlandish headwear.

"A few more long distance shots from Point No Point," they penned alongside the snaps.

"And the salmon hat again. Sound Watch kept the few boats out in line. I wish they could be out with them every day."

As to what started the bizarre movement in the first place, it's still unknown. With this is mind, it's also unknown why its made an apparent comeback.

A whale was recently spotted wearing a dead salmon on its head (Jim Pasola/Facebook)

It's been suggested that orcas might put salmons on their head for storage space, rather than a fashion statement, having caught the fish in abundance and wanting to save some for later.

Apparently this kind of thing has been done before.

"We've seen mammal-eating killer whales carry large chunks of food under their pectoral fin, kind of tucked in next to their body," Deborah Giles, an orca researcher at the University of Washington, told New Scientist.

Elsewhere, some researchers have previously proposed that orcas develop 'fads', which is what the salmon-wearing could be.

As per a 2024 study published by the International Whaling Commission, it was said that: "Some populations may also develop unusual and temporary behavioral ‘fads’ and other idiosyncrasies that do not appear to serve any obvious adaptive purpose.

"Understanding the recent boat interactions by Iberian killer whales may benefit from an examination of such ephemeral traditions in other well-studied killer whale populations."

Apparently killer whales are known to follow 'fads' (Getty Stock Images)

Backing this, director of Bay Cetology, Jared Towers, previously told Discover: "Killer whales do have fads that come and go, and they're often most prevalent among certain sex and age classes in the population. Then, over time, they tend to disappear."

Noting another apparent 'fad' where some orcas have been ramming into boats for no reason, Towers went on: "I'm certainly hoping that's what happens with this behavior. But it's been going on for a few years now. So, we're not quite sure what to expect."

Long story short, orcas are unusal animals.