Jaime Rojo's Image

Jaime Rojo (Spain) reveals the epic migration undertaken by monarch butterflies and the efforts being made to save them.

These monarch butterflies, on the way to their overwintering grounds, have stopped to roost for the night next to a highway.

Much of the recording of such stopover sites is done by members of the public taking part in community science activities. This is helping to map their migration routes in greater detail.

Jaime found this site after reports of large numbers of dead monarchs at the side of the road. A study was done in 2020 to look at butterfly deaths caused by vehicle collisions. It showed that in a single autumn, nearly 200,000 butterflies died at just two road crossing points studied in Mexico.

Urban stopover sites also expose the butterflies to light pollution. This can disrupt their circadian rhythms, day cycles, which are part of the body’s internal clock. This leads to abnormal night-time flight activity when they should be resting.