Some parrots in might be getting high off smelly trees.
Norfolk Island green parrots have been observed applying chewed pepper tree bark and shoots to their feathers and skin.
Researchers think this helps preen away parasites thanks to the tree’s strong source of piperine – pungent chemical that has insect repellent qualities.
But researchers noted in the journal Austral Ecology that the birds seem to be enjoying themselves too much by getting high in the process.
On two different occasions, the researchers observed the birds stripping leaves off plants and covering their features in the sap.
Some birds actually placed the leaves themselves between their features in what the researchers said is a form of self-medicating.
The researchers wrote: ‘During their grooming routine, several Norfolk Island green parrots Cyanoramphus cookii were observed and photographed, and a pair was videoed, biting off and chewing small pieces of lateral shoot and bark of pepper trees Piper excelsum and working the chewed material through their feathers.
‘This appears to be a rare example of a bird using plant material to anoint themselves, which we interpret as a way to repel blood-sucking insects and ectoparasites and, possibly, void endoparasites, thereby improving fitness.’
The birds would bite off a section off the lateral shoots and chewed a portion to preen their feathers, mixing in preen oil from its uropygial gland with the aromatics from the tree to mix through its feathers.
The study’s first author, Dr Penny Olson, suggests that the birds are doing a form of ‘anting’ where birds rub insects, usually ants, on their feathers, to release chemicals such as formic acid.
And by inhaling the strong fumes from the young pepper trees, the birds could be getting high.
In The Conversation, Dr Olson wrote: ‘Likening green parrots rubbing aromatic vegetation through their plumage to inebriated pigeons falling from trees may seem a stretch.
‘But nature rewards behaviour that offers evolutionary advantage, often, it seems by tapping into animals’ pleasure centres.
‘The pursuit of pleasure is an important, usually overlooked, aspect of animal behaviour, worthy of attention and further research.’
As well as getting high, birds have been known to get drunk through fermented berries and observed stumbling around and dropping from perches, as you may imagine what a drunk bird does.