The fact that penguins can’t fly has been a mystery to scientists for decades. However, a new study on ravens – a species that closely resembles penguins in its ability to swim and dive, but can still fly – has helped provide the ultimate answer.
Scientists from the University of Aberdeen (UK) found that no bird is good at both flying and swimming/diving. Although I don’t know by, penguins are excellent swimmers. They can dive to a depth of 564 meters to catch fish, squid and small crustaceans to eat.
The team found that Urias use essentially less energy than most other birds when diving. However, the energy they require in the air is the highest of any level ever recorded for a bird in flight, and 31 times more when they are at rest.
Professor John Spookman, a member of the research team, said.” Our findings on the energy expenditure of swimming and diving in Uriah birds are entirely consistent with the predictions of biomechanical models.
The fact that penguins cannot fly used to be a mystery because it led to behaviors that seemed to indicate maladaptation. Emperor penguins, for example, often walk up to 60 kilometers between their nests on the beach and the ocean-a journey that takes several days but can be reduced to a few hours if they can fly.
Food preferences and resources
Penguins eat krill (a shrimp-like crustacean of the family Euphausiidae), squid and fish. Different species of penguins have slightly different food preferences, which reduces competition between species. (See the Appendix for information on the diet of each species).
Smaller penguin species in the Antarctic and Subantarctic feed primarily on krill and squid. Species found further north tend to eat fish.
Adelie penguins feed primarily on small krill, while chinstrap penguins feed on large krill.
Emperor and king penguins eat mainly fish and squid.
Intake varies with the amount and type of food available in different areas at different times of the year.
The entire breeding colony of Adélie penguins may consume up to 1,500,000,000 kg (1,500,000 metric tons) of krill, 115,000,000 (115,000 metric tons) of fish and 3,500,000 (3,500 metric tons) of squid per year.