This study will examine the relationship between polyandry and paternity in the Red-necked Phalarope (Phalaropus lobatus): an arctic-nesting, gender role-reversed, non-territorial shorebird with uniparental male care. Some females can produce up to 16 eggs in one breeding season;in contrast, males are able to produce one brood of four chicks, unless they are able to fertilize eggs that will be incubated by another male. Because sperm storage occurs in many bird species and because the time between clutches can be very brief in phalaropes (3-4 days), there is great potential for first males to fertilize eggs in subsequent polyandrous clutches. Such extra-pair fertilizations (EPFs) should be most likely in the first egg of a subsequent polyandrous clutch, according to the passive sperm loss model. EPFs will be determined by DNA fingerprinting (using multilocus probes) of sequential clutches by the same female, using blood and tissue samples from both parents and from embryos. The project dovetails well with behavioral observations of these birds that will document timing of copulation attempts and successful copulations. This study extends work on sexual conflict / sperm competition by Oring et al. (1992) to a non-territorial polyandrous species.
