PATERNAL INVESTMENT IN THE BLACKSPOTTED STICKLEBACK GASTEROSTEUS-WHEATLANDI

We conducted a field experiment to evaluate die response of paternal m ale blackspotted stickleback (Gasterosteus wheatlandi) to risk of pred ation on themselves. We chased males away from their nests to simulate die arrival of a bird predator, and then recorded the time until retu rn, an index of risk-taking. Contrary to parental investment theory, r isk-taking was unrelated to brood size or age and did not change seaso nally. An environmental factor, nest depth was die only significant pr edictor of risk-taking. Males with nests in deep water returned sooner than ones with nests in shallow water. Our results differ from other studies of parental investment in sticklebacks.