Lundy’s core recording area covers a distance of approximately 5 km, sampling all habitats present within the southern quarter of the island. The route is walked daily during spring and autumn migration, and periodically during the summer and winter months. The defined recording area covers most sites south of Quarter Wall, encompassing the vegetated combes of Millcombe and St John's Valley, the rugged sea cliffs of Benjamin’s Chair, freshwater habitats around Rocket Pole, and the grazed, semi-improved grasslands and drystone walls bordering South West Field, Old Light, Ackland’s Moor and the Village.