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Sea otters and polar bears are carnivorous marine mammals that
still resemble their terrestrial ancestors. Compared with Cetacea
(whales and dolphins), Sirenia (dugongs and manatees), and
Pinnipedia (seals, sea lions, and walrus), they are less adapted
for an aquatic life and the most recently evolved among marine
mammals. Sea otters are amphibious but seldom come ashore, and
polar bears primarily occur on sea ice or along the shore. When at
sea, both species spend most of their time swimming at the surface
or making short, shallow dives when foraging or pursuing prey.
Indeed, polar bears rarely pursue seals in water. Nevertheless,
polar bears are powerful swimmers and will stalk seals from the
water. As with many other large carnivores, they are solitary
hunters. Although sea otters are gregarious and form aggregations
at sea called rafts, they are primarily asocial. Except during
mating, the principal interaction among sea otters occurs between a
female and offspring during the six-month dependency period. In
large carnivores (e.g., wolves and lions) that feed on ungulates,
sociality and cooperation are favored because of the need to
capture large prey and defend carcasses. Polar bears, which are the
largest terrestrial carnivore, are solitary hunters of seals and
are neither gregarious nor social. Males and females briefly
associate during courtship and mating. During this time, males
aggressively compete for females. At other times, males generally
avoid each other except for aggregations of males that form while
summering on land, and females with cubs avoid males, which are
known for infanticide. As with sea otters, the interaction of polar
bears outside of mating occurs between a female and her offspring
during the 2-3 year dependency period. This interaction is
critically important when altricial cubs are born in the winter
den. This book provides new insight into the ethology and
behavioral ecology of sea otters and polar bears. Each chapter
reviews the discoveries of previous studies and integrates recent
research using new techniques and technology. The authors also
address historic and current anthropogenic challenges for their
survival as climate change alters entire marine ecosystems.
The Bureau of Ocean Energy Management (BOEM) is a agency within the
U.S. Department of Interior. BOEM has four sections that cover the
United States' waters: Alaska OCS Region, Pacific OCS Region, Gulf
of Mexico OCS Region and the Atlantic OCS Region. The Gulf of
Mexico OCS Region is responsible for almost 160 million acres of
lands off the coast of Texas, Louisiana, Mississippi, Alabama, and
Florida. Currently, more than 31 million acres are leased for gas
and oil development, and six million are actually producing oil and
natural gas. The Gulf of Mexico Region is in charge of addressing
the Environment, Leasing and Plans, and Resource Evaluation. The
publish a variety of documents with topics such as: Marine Biology,
Natural Gas, Oil Spills, Transportation, Chemical Products, etc.
This is one of those publications.
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