9781422279199

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A N TA R C T I C W I L D L I F E

Penguins are a key prey species for some types of killer whales. The huge number of the birds in the Antarctic draws one of the world’s largest orca gatherings.

Like many other whales, orcas communicate using sounds. Clicks, pulses, and whistling noises can be heard underwater as the killer whales move together. Scientists theorize that the sounds are directions on working together. Because they were never hunted for food or oil, killer whales have not faced any significant level of danger fromhumans.They also have no natural enemies in the water. However, human impact on the oceans—from pollution to rising temperatures due to climate change—will have a long-term negative effect on these mighty beasts.