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Designed based on perching birds like ravens and crows that frequently switch between air and land, the multifunctional robotic legs allow it to take off autonomously in environments previously inaccessible to winged drones.

The study focused on birds that move at night, as most migrators do, particularly perching birds such as warblers, thrushes and sparrows.

Ms McRobert said the warbler, one of the passerine order, or perching birds, was only able to make the journey from west to east, not in the other direction.

In 2012, evolutionary biologist Catherine Sheard started an ambitious Ph.D. project: measuring the shape of every kind of passerine, or perching bird, in the world.

For perching birds, a shutter speed of 1/500th-second will usually yield sharp results when using a tripod.