Wily Fathers Assess Paternity
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.”
