Because penguins migrate entirely by swimming, their migration speeds are not strictly comparable with those of other birds. Magellanic Penguins Spheniscus mag-ellanicus were tracked northward up the coast of Argentina. Some reached more than 1800 km north of the nesting colony but, by following the coastline, they had travelled at least 2700 km. Average travelling speeds of 10 birds were in the range 1.1-1.9 km per hour, higher initially and slower later in the journey when the birds encountered better feeding areas. Maximum speeds recorded over short periods were up to 6.1 km per hour (Putz et al. 2000). Higher mean speeds were recorded for Adelie Penguins Pygoscelis adeliae on migration, at 1.8-3.4 km per hour (Davis et al. 1996). These mean rates translate to average daily distances of 26-46 km and 43-82 km in the two species, which are not dissimilar to the average daily distances recorded for many short-distance passerine migrants (including stopovers). Even higher travelling speeds have been reported for various penguins in the breeding season when they had chicks to feed, with King Penguins Aptenodytes patagonicus recorded at up to 10 km per hour on return journeys (Putz et al. 1998). Another mode of locomotion, related to swimming, is also employed by penguins. Using their short stiff wings, they can paddle on their bellies across snow fields. On well-used 'penguin highways' the birds achieve speeds between running and swimming.

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