Babies of a bird species called the Eurasian Roller vomit a foul-smelling orange liquid as a defense mechanism.
- The baby Eurasian Roller's defense involves vomiting a noxious substance onto itself.
- When a bird is covered in vomit, it becomes less attractive as a snack, plus the parents smell the liquid and rush back to their nestlings.
Offspring of the bright-blue jackdaw-sized bird -- Latin name Coracias garrulus -- throw up the repugnant fluid when they are frightened in their nests, according to a paper appearing on Wednesday in the journal Biology Letters.
Covered in vomit, the nestlings not surprisingly become less attractive as a snack, the team says.
But the smell also alerts parents, returning to the nest, that a threatening incident has happened in their absence, they believe.
The scientists tested the "olfactory cue" theory by visiting nests with 10-day-old nestlings inside.
They used a small paintbrush to daub a tiny amount of either lemon juice or vomit on the inside of the nest. Parents returning to a vomit-treated nest reacted with great caution, delaying the time when they would settle in the home.