SATELLITE TRACKING OF MAGELLANIC PENGUIN MIGRATION

We tracked four male Magellanic Penguins (Spheniscus magellanicus) fro m the beginning of their winter migration for periods ranging from thr ee to six weeks. Upon leaving the colony at Punta Tombo, Argentina whe re they had bred and molted, all four birds traveled northeast along t he coast at speeds consistent with sighting and band-return data which suggest a round-trip winter migration in this species of up to severa l thousand kilometers. Three of the birds followed a similar route, mo ved at approximately the same rate, and were still moving northeastwar d at a distance of over 800 km from the colony when signals ceased. Th e fourth bird departed from the northeast route at approximately 300 k m into its trip and remained in a large bay for at least 29 days, when the last signal was received. Initially, the birds traveled rapidly a nd made few deep dives. Later, their rate of travel slowed, their path s became more erratic, and they made more deep dives, all indications of probable foraging. This suggests that location of the penguin migra tion route and rate of travel along it may be determined by seasonal m ovement of prey. As all birds were within 250 km of shore for the enti re period in which signals were received, our results underscore the i mportance of controlling pollution associated with petroleum transport along the coast of Argentina, currently a major source of Magellanic Penguin mortality.