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Wily Fathers Assess Paternity

April 16 2003

Males are more likely to devote time to their offspring when they are certain that they really are the father. A paper in the April 17 Nature finds that male bluegill sunfish (Lepomis macrochirus) adjust their level of parental care to their certainty of paternity. Male bluegill sunfish follow two types of life history: ‘parentals’ and ‘cuckolders.’ Parentals defend the nest, guard the eggs and help bring up the hatchlings, whilst some cuckolders sneak into the nest at the critical moment of spawning to fertilize the would-be eggs of another. Bryan D. Neff of the University of Western Ontario, London, Canada, finds that if sneakers are spotted nearby, parentals subsequently spend less time guarding their eggs. Parentals also use olfactory cues from hatchlings to assess their likelihood of being dad. “Although this expectation fits with the widespread use of DNA tests in messy divorce cases, it has proved extremely difficult to determine whether males in other species play by similar rules,” say John D. Reynolds of the University of East Anglia, Norwich, UK, and Ben C. Sheldon of the University of Oxford, UK, in an accompanying News and Views article. “These findings advance our understanding of the evolution of parental care and raise new questions about the conditions under which offspring should reveal their identity to parents, or conceal it.”

“Decisions about parental care in response to perceived paternity” by Michael H. Goldstein, Andrew P. King, and Meredith J. West, Nature April 17, 2003

Abstract © 2003 Nature

Bryan D. Neff, Department of Biology, University of Western Ontario

In the figure at left, a male bluegill swims above its nest, waiting for a female to arrive. Another male is on station in the middle background.
Photo © 2003 Bryan D. Neff