Reservations about the current MIBA evaluations

Concerns are raised about the current evaluations of MIBAs around South African penguin breeding colonies, specifically as regards the kernel smoother approach used and especially the value of 7 km selected for the smoothing parameter h. In principle arguments are put forward that the approach will result in MIBAs inflated to sizes appreciably in excess of the foraging ranges for penguins provisioning their chicks. A simple model using available penguin maximum foraging distance data indicates that this inflation could be a near doubling in terms of area. This suggests that the matter of the sensitivities to value chosen for h of the current MIBA proposals warrants detailed attention. This is of importance, for example, for the closure proposals made by the CAF which are heavily reliant on the existing MIBA calculations.