What do whales specifically eat and how do they expel water after
digesting their food?
That's a little like asking, What do birds eat? There are somewhere between
75 and 90 species of cetaceans (whales, dolphins and porpoises) and they
eat a vast array of animal life from the oceans. Perhaps the only
similarity in their diets are that they all eat marine animals of some kind.
This question offers an opportunity to elaborate a bit on the eating habits
of cetaceans. When the earliest cetaceans began to eat animals, rather than
plants, perhaps 40-50 million years ago, they probably all ate about the
same types of fish, amphibians, reptiles and birds. When they began to
radiate into the varieties we see today - the baleen whales, the toothed
whales, large whales, small whales, nearshore whales, pelagic whales, etc,
they moved into new ecological niches to find food, adapting their bodies
and eating habits rather than competing with one another for limited
resources.
For example, 50-ton right whales eat huge swarms of tiny copepods, each
about one-eighth of an inch across. Other baleen whales eat small fish such
as sand lance and immature herring, or krill. Dolphins eat a wide variety
of small fish and squid, while orcas may eat larger fish or even mammals,
depending on their cultural traditions. Sperm whales and beaked whales dive
to great depths to catch larger squid. These are but a few examples, so you
see, there are many answers to your question.
The answer to your second question (how do they expel water?) is much
simpler. They urinate.
Howard Garrett
Orca Network
Greenbank WA
(360) 678-3451
www.orcanetwork.org
howard@orcanetwork.org
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