Sheep on the remote Scottish island of North Ronaldsay have a unique diet consisting mainly of seaweed and it has climate scientists excited.
A part of Scotland's far-flung Orkneys, the island is just over 5 kilometres long. So-called sheep dykes, a large system of stone walls, keep the animals away from fields and roads.
In the early 19th century the island's farmers wanted to use every available space to grow crops. Now, during the summer months, there is enough grass to keep the sheep happy. But when the weather gets colder they have to eat the island's plentiful supply of seaweed to survive.
While some other mammals such as Shetland ponies are known to snack on seaweed, scientists say that the North Ronaldsay sheep are unique for spending months eating only the marine plants.
Scientists at the James Hutton Institute in Dundee in eastern Scotland have been studying the sheep's diet for two decades. Inspired by their unusual habit, they have discovered a way to reduce methane emissions produced by livestock.
How would a seaweed diet help?
Farm animals belch and fart methane gas which is about 30 times more powerful than carbon dioxide when it comes to trapping heat in the atmosphere. With the world facing a deepening climate emergency, the issue has become a major focus for climate scientists.
The seaweed diet of the Orkney sheep may hold some answers. Scientists say it appears to have an effect on their digestive system resulting in reduced amounts of methane being produced.
"There's different components in the seaweed that actually interfere with the process (of) how methane is made," says a member of the team at The James Hutton Institute Gordon McDougall.
Researchers at the University of California, Davis also published results in March showing that a "bit of seaweed in cattle feed could reduce methane emissions from beef cattle as much as 82 per cent".
They have been exploring the theory more by adding seaweed to animal feed and monitoring the results. It would not necessarily mean a diet entirely comprised of seaweed, but it could supplement the usual feed of animals such as sheep and cattle to keep emissions down.
The marine plants - a good source of minerals, vitamins and omega-3 fatty acids - could partly replace soy, which is heavily used in animal feed. It is transported for thousands of miles and linked to deforestation.
Watch the video above to learn about Scotland's seaweed-eating sheep.