| Home: Special status species: Humpback whale: Natural history |
SPECIAL STATUS SPECIES: HUMPBACK WHALE (Megaptera novaeangliae)
NATURAL HISTORY |
| |
| General |
| Taxonomy: |
Suborder
Mysticeti (Baleen Whales); Family Balaenopteridae
(Rorquals); there is only one species in the genus
Megaptera.
|
| Appearance: |
Adults
average 14 m (45 ft) long and can reach a weight of
40,000 kg (90,000 lbs).1
Their body is black above and mottled with white below.
They have a small dorsal fin and extremely long pectoral
fins (up to 1/3 of the body length). The top of the
head and lower jaw have rounded, bump-like knobs,
called tubercles. The leading edge of the pectoral
fins and trailing edge of the caudal fin is serrated,
which may help reduce turbulence. |
|
| Feeding Behavior |
| Overview: |
This species feeds
alone in California (cooperative feeding has been
observed off Alaska). Most foraging dives last 3-5
minutes, though longer dives do occur. Humpback whales
feed extensively on both krill and schooling fish;
there is some evidence that their distribution changes
in response to relative abundance of krill vs. schooling
fish.5 |
| Prey Items: |
Krill and small schooling
fish (e.g., anchovy, cod, sardines, mackerel, capelin,
herring, sandlance) |
| Method of
Capture: |
Feeds by lunging
into swarms of krill or schools of fish and gulping
large quantities of water and prey. Large volumes
of water and food can be taken into the mouth because
the pleated grooves in the throat expand. As the mouth
closes water is expelled through the baleen plates,
which trap the food on the inside near the tongue
to be swallowed. |
Photo: http://swfsc.nmfs.noaa.gov/PRD/ |
|
| Reproduction |
| Overview: |
During the breeding season, male
whales sing long complex songs. The purpose of the
songs is not known, but they are probably used to
attract females and/or to establish territories or
dominance hierarchies with other males. Males appear
to compete to become an “escort” to an
adult female. The length of time that an escort stays
with the female and the exact time of mating are not
well understood. |
| Time to Maturity: |
Probably 4-6 years;13
males at 11.6 m (35 ft); females at 12 m (40 ft) |
| Longevity: |
Probably at least 50
years;14
may live to 80 years |
| Breeding
Season: |
Calving and nursing
occurs from December-March; mating most likely occurs
at the end of the breeding season |
| Frequency
of Breeding: |
Females can calve in successive
years, but usually every 2-3 years |
| Gestation
Period: |
Approximately 12 months |
| Number of
Offspring per Pregnancy: |
One |
| Parental
Care: |
Maternal; mother nurses the calf
for approximately 10-12 months |
| Mating
System: |
Monogamy or polygamy;
it is unclear whether males can successfully gain
mating opportunities with multiple females in a season. |
|
|
| [ Top of page ] |
| |
and Twitter 
