A new study from Lund University shows that moonlight is crucial for the migratory bird, the red-necked nightjar. The bird's feeding, migration, and breeding are entirely governed by the moon's cycle. Researchers highlight the vulnerability of nocturnal animals to changes in light environments.
Moonlight governs when the red-necked nightjar feeds, migrates, and breeds, according to the study from Lund University. The migratory bird breeds in southern Europe and overwinters in West Africa, following the moon's cycle.
During full moon, the bird can hunt insects almost all night. Breeding is timed to the moon's rhythm – eggs are laid so chicks hatch when nocturnal insects are most abundant.
On dark nights, hunting is limited to short periods at dusk and dawn. The bird then conserves energy by slowing down and lowering its body temperature.
“Unlike bats, the nightjar lacks the ability to navigate effectively in total darkness. This is an animal living on the margin. Without moonlight, the energy budget simply doesn't add up,” says Anders Hedenström, biology professor at Lund, in a press release.
The study is based on ten years of fieldwork in Doñana National Park in Spain and has been published in the journal Science Advances. The birds were tracked using multisensor data loggers developed in Lund.