Abstract

The Humboldt Penguin (Spheniscus humboldti) has been reported as declining along its distributional range and has recently been classified as vulnerable. The actual size of the Humboldt Penguin population is still unknown, and a complete population assessment, is required. Here we present a study combining both counts of molting birds on land and counts of birds at sea during the molting period. We conducted our study in me Coquimbo Region, Northern Chile, and round 7,619 birds on land and 2,700 at sea. adding up to a total of about 10,300 Humboldt Penguins during the molting season (February 1999). Since these numbers are much higher than all other recent estimates, we emphasize that assessment on land and at sea need to be combined to provide more reliable estimates.