Foraging areas of Magellanic penguins Spheniscus magellanicus breeding at San Lorenzo, Argentina, during the incubation period

During October 1994, 10 miniature global location sensors were attached to Magellanic penguins before they departed to sea to forage while their mates remained at the nest incubating. The devices indicated that birds swam a mean distance of 70.4 km (SD 42.1) on the first and last days of the foraging trips, thus distancing themselves rapidly from the colony. On other days the mean distance swum was 50.2 km (SD 31.4, mode 35), Maximum distance from the colony during the foraging trip by any bird was 303 km, but highest bird densities occurred at a point 120 km east of the colony and coincided with the presence of a front.