In conservation, we talk a lot about the importance of creating and preserving habitat for species survival — if you don’t have the habitat then you won’t have the species. But that theory is so much better illustrated with an example. And the relationship between the northern brown argus butterfly and the common rockrose is a perfect one.

The northern brown argus is extremely rare and a Priority species under the UK Post-2010 Biodiversity Framework. This means it's one of our most threatened wildlife species and requires urgent conservation action to avoid becoming extinct. 

Conservation action is exactly what we’re doing at Wild Ingleborough! 

Found only in the north of England and Scotland, the northern brown argus is a close relative of the brown argus butterfly. It has the same striking white wing margins, but its overall colour is a deeper chocolate brown. It prefers warmth and shelter, and favours south-facing sites with hollows and scrub.

More precisely, the northern brown argus’ habitat of choice is wherever common rockrose is found. This is because common rockrose is its most important source of food and the only plant on which it chooses to lay its eggs.

Did you know? The female northern brown argus will lay a single egg on the upper surface of a rockrose leaf, which she locates by flying low to the ground and tasting the plants with her feet.

Golden banks of common rockrose make for a spectacular sight on Ingleborough’s limestone grasslands in the summer. A creeping shrub, it can grow in large, dense clusters — painting the grey-green landscape a beautiful bright yellow.

It attracts bees, moths and butterflies, and flowers between June and September. 

Because of the presence of common rockrose, Ingleborough is a stronghold for the northern brown argus, and its population numbers will increase as we protect and restore its preferred habitat. As it provides plenty of nectar, common rockrose is also the favoured food plant of other butterflies like green hairstreak and the rare silver-studded blue, so it’s not just the northern brown that will benefit. 

The unique habitats of Ingleborough already support diverse populations of invertebrates, and we are propagating common rockrose so that the numbers of northern brown argus not only increase here, but thrive.

It’s simple maths really: a bigger and more joined-up landscape at Ingleborough will have more common rockrose flowers to encourage and support more northern argus butterflies. 

Effectively, we’re creating Yorkshire’s very own Field of Dreams. Because if we grow them, they will come!

Where to see the northern brown argus:

Southerscales and Brae Pasture nature reserves, and on some of Natural England’s land like Scar Close, from June onwards.