Sperm Whales
Physeter macrocephalus
Sperm whales (Physeter macrocephalus) are the largest of the
odontocetes and are also the deepest diving and longest diving of the
vertebrates (138 minutes and 3000m). Sperm whales feed almost
exclusively on squid but will take fish on occasion.
The best estimate of sperm whale population size in the Northwestern
Atlantic ocean waters of the US is 3500
As in other toothed whales, sperm whales are sexually dimorphic in size;
males (36-66 ft.) are larger than females (27-56ft.). Also, as in all
toothed whales, the head is asymmetrical, with a single blowhole. Sperm
whales exhibit matrilineal social groups, in which most females spend
their lives with close female relatives. Sperm whale males attain sexual
maturity at an average of 12 years of age; females at 9 years. Sperm
whale females and young remain in lower latitudes throughout much of the
year. Males, generally move to higher latitudes for feeding, and will
return for breeding. The matrilineal groups are quite stable, while
males can interact and mate with females of other groups (i.e., other
than their natal group). Old "bull" males rarely leave higher latitude
and probably no longer mate.
Sperm whales are found in the waters of New York in the autumn, winter,
and late spring, and occasionally during early summer. Sperm
whales are listed by the IUCN (International Union for the Conservation
of Nature and Natural Resources) as "Vulnerable." This means that
the species (or population) is not Critically Endangered or
Endangered but is facing a high risk of extinction in the wild in the
medium-term future. To see the most recent (2000 edition)
IUCN Red List of Threatened Species
click here. To see information about the Red List categories,
click here.
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