Scientists studying a colony of king penguins in Antarctica have reported getting so high on the nitrous oxide emitted by the animals' droppings that it made them ill.
The emissions of nitrous oxide given off by the colony's guano were about 100 times higher than those from a recently fertilised field, according to a recently-published 2019 study by researchers from the University of Copenhagen.
More commonly known as laughing gas, nitrous oxide slows down a person's brain and their body's responses and as a result, is often used in the medical profession as a sedative.
Professor Bo Elberling, one of the University of Copenhagen researchers, said the quantity of the gas produced by the penguins was overpowering.
"It is truly intense - not least because nitrous oxide is 300 times more polluting than CO2," he was quoted as saying by Science Daily.
"After nosing about in guano for several hours, one goes completely cuckoo ... One begins to feel ill and get a headache."
Nitrous oxide canisters are often taken recreationally through a balloon, with users frequently littering the small canisters behind.
Commenting on the environmental impact of the penguins' droppings, Professor Elberling added: "It is clear to us that the level of nitrous oxide is very high in places where there are penguins — and thereby guano — and vice versa, lower in places where there is none.
"While nitrous oxide emissions in this case are not enough to impact Earth’s overall energy budget, our findings contribute to new knowledge about how penguin colonies affect the environment around them, which is interesting because colonies are generally becoming more and more widespread."
The nitrogen in the nitrous oxide emitted by penguin poo comes from the seabird's diet of fish and krill, both of which contain large amounts of nitrogen absorbed from phytoplankton in the ocean.
Once released, the penguin guano is converted by soil bacteria into nitrous oxide, a greenhouse gas.
