Egg 'Signatures' Allow Drongos to Identify Cuckoo 'Forgeries' Almost Every Time, Study Finds
upstart writes:
Egg 'signatures' allow drongos to identify cuckoo 'forgeries' almost every time, study finds:
African cuckoos may have met their match with the fork-tailed drongo, which scientists predict can detect and reject cuckoo eggs from their nest on almost every occasion, despite them on average looking almost identical to drongo eggs.
Fork-tailed drongos, belligerent birds from sub-Saharan Africa, lay eggs with a staggering diversity of colors and patterns. All these colors and patterns are forged by the African cuckoo.
African cuckoos lay their eggs in drongos' nests to avoid rearing their chick themselves (an example of so-called brood parasitism). By forging drongo egg colors and patterns, cuckoos trick drongos into thinking the cuckoo egg is one of their own.
But drongos use knowledge of their own personal egg "signatures"-their eggs' color and pattern -to identify cuckoo egg "forgeries" and reject them from their nests, say scientists. These "signatures" are like the signatures we use in our daily lives: unique to each individual and highly repeatable by the same individual.
Through natural selection, the African cuckoo's eggs have evolved to look almost-identical to drongo eggs-a rare example of high-fidelity mimicry in nature.
A team led by researchers at the University of Cambridge and the University of Cape Town, working in collaboration with a community in Zambia, set out to explore the effectiveness of "signatures" as a defense against highly accurate mimicry. The findings are published today in the journal, Proceedings of the Royal Society B.
They found that despite near-perfect mimicry of fork-tailed drongo eggs, African cuckoo eggs still have a high probability of being rejected.
Journal Reference:
Lund et al. When perfection isn't enough: host egg signatures are an effective defence against high-fidelity African cuckoo mimicry, Proceedings of the Royal Society B: Biological Sciences (2023). DOI: 10.1098/rspb.2023.1125
Read more of this story at SoylentNews.