Fledglings of a southern African bird species threaten suicide to blackmail their parents into bringing them more food, scientists said Wednesday.
When hungry, pied babbler fledglings flutter from the nest to the ground, where predators roam, and start screeching to highlight their plight, said a study published in the British journal Proceedings of the Royal Society B.
"This stimulates adults to increase their provisioning rates," the science team wrote. "Once satiated, fledglings return to the safety of cover."
The strategy is dangerous, as the birds are not good flyers at this tender age and at particular risk of predators on the ground.
But the short-term risk of being caught is probably lower than the long-term costs of being small and weak, said the paper.
Pied babblers have high reproductive rates and competition for mates is high.
Weaker birds are often kicked out of the nest by siblings, putting them at a huge disadvantage in the race for survival and procreation.
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More information: The influence of fledgling location on adult provisioning: a test of the blackmail hypothesis, rspb.royalsocietypublishing.org/lookup/doi/10.1098/rspb.2013.0558