Female butterflies breed despite male shortage
Published:16 May2023 Source:University of Exeter
Female monarch butterflies have no trouble finding a mate -- even when a parasite kills most of the males, new research shows.
Some females carry a parasite called Spiroplasma that kills all their male offspring, meaning highly infected populations have very few males. But the new study -- by the universities of Exeter, Rwanda and Edinburgh, and the Dian Fossey Gorilla Fund -- found females mated about 1.5 times on average, regardless of how many males were around.
The male proportion dropped below 10% in some cases, but it appears the remaining hard-working males managed to breed with most of the available females. 10-20% of females remained unmated, only slightly higher than the expected average in a population with plenty of males (5-10%).