| Home: Special status species: North Pacific right whale : Natural history |
| SPECIAL STATUS SPECIES: NORTH PACIFIC RIGHT WHALE (Eubalaena japonica) NATURAL HISTORY |
| |
| General |
| Taxonomy: |
Suborder
Mysticeti (baleen whales); Family Balaenidae (right
whales). This species was formerly known as Eubalaena
glacialis or Eubalaena glacialis japonica. |
| Appearance: |
Robust, medium-sized
baleen whale. Adults reach a length of 17-18.3 m (56-60
ft) and up to 90,000 kg (200,000 lb); females are
larger than males. The body is black with varying
amounts of white on the underside. They have a broad
back that lacks a dorsal fin. The head is large (more
than 1/4 of body length) and covered in places with
cream-colored callosities. The upper jaw is down-curved,
the lower jaw is very strongly arched and the mouth
contains baleen plates that are very long (may exceed
3 m (9 ft)). |
|
| Feeding Behavior |
| Overview: |
This species feeds
alone or in unstable, small groups. Often found at
or near the surface. Feeding dives below the surface
can last for 10-20 minutes.14 |
| Prey Items: |
Large calanoid
copepods (e.g., Calanus spp. and Neocalanus spp.)
appear to be the preferred prey of this species.6 |
| Method of
Capture: |
Feed by “skimming”
– swimming with their mouths open through patches
of plankton continuously filtering the water as they
swim |
.
|
|
| Reproduction |
| Overview: |
Courtship groups of 3 to 30 whales
have been observed in North Atlantic right whales,
a closely related species. Usually many males jostling
for position surround a single female. Sperm competition
is likely to occur because females may mate with more
than one male, and males have very large testes. |
| Time to Maturity: |
9-10 years estimated for females; based on North Atlantic species15 |
| Longevity: |
Known to exceed 70
years16
|
| Breeding
Season: |
Calving (and probably
also breeding) occurs in winter |
| Frequency
of Breeding: |
Usually give birth every 3-5
years |
| Gestation
Period: |
~12 months |
| Offspring per Pregnancy: |
One calf |
| Parental
Care: |
Maternal; female nurses calf
for 6-12 months |
| Mating
System: |
Promiscuous, sperm
competition; males compete for access to females and
fertilization success; females may mate with multiple
males |
|
|
|
| [ Top of page ] |
| |
and Twitter 
