The Monarch is the largest butterfly seen in the British Isles and is also one of our rarest migrants. Known for its ability to travel large distances, the migrations in North America are one of the greatest natural phenomena in the world - where the adult butterflies can migrate from as far north as Canada to the overwintering grounds in Mexico, the west coast of California and Florida.

Millions of the butterflies make a 2,000-mile (3,220km) journey each year from Canada to pass the winter in central Mexico’s warmer weather. But climate change, pesticides and the incursion of illegal loggers have seen the forests dwindle and with them, the number of monarchs.

First recorded in the UK in 1876.

Size and Family

  • Family: Nymphalids
  • Size: Large
  • Wing Span Range (male to female): 95-100mm

Conservation Status                  

  • Butterfly Conservation priority: Low     
  • European status: Not assessed

Caterpillar Foodplants

Caterpillars feed on various Milkweeds (Asclepias species), a plant which is not native to the British Isles, and this explains why the butterfly has not been recorded to have bred here.


A rare migrant to the UK but in North America, the butterfly can be found almost anywhere that their foodplant grows, including farmland, gardens and even roadsides. The Monarch overwinters in sheltered forests made up of Eucalyptus trees, Monterey pines and Monterey cypresses.


  • Countries: England, Scotland, Ireland and Wales
  • Recorded throughout Britain and Ireland as a very rare immigrant with a concentration of sightings in the south-west, notably from Cornwall and Scilly Isles.
Monarch (male/underwing) - Pete Withers

Monarch (male/underwing)

Monarch (male/upperwing) - Iain Leach

Monarch (male/upperwing)

Monarch (female/underwing) - Adam Gor

Monarch (female/underwing)

Monarch (underwing) - Adam Gor

Monarch (underwing)

Monarch (female/upperwing) - Pete Withers

Monarch (female/upperwing)

Monarch (Male/On Milkweed) - Paul Davies

Monarch (Male/On Milkweed)

Monarch Migration Study - Dave Wendelken

Monarch Migration Study

Monarch - Dean Morley


Monarch (egg) - Peter Eeles

Monarch (egg)

Monarch (caterpillar) - David Morris

Monarch (caterpillar)

Monarch (caterpillar) - Paul Davies

Monarch (caterpillar)

Monarch (pupa) - Dean Morley

Monarch (pupa)