Antarctic Minke Whale

Balaenoptera bonaerensis
Southern minke whale
Antarctic minke whales are among the smallest and most common of the rorqual whales, the largest number of baleen whales. These whales are noticeably more streamlined than other types of whales, being long and slender. An Antarctic minke whale has a pointed snout which is distinctively narrow, triangular, and pointed (thus the nicknames "little piked whale" and "sharp-headed finner") and a pair of blowholes; the upper part of its head is flat and broad). The upperparts of the whale are dark gray, while its underbelly is white, the flippers are pale and there are pale streaks on its sides.
515,000

population size

50 yrs

Life span

40 km/h

Top Speed

5.8-9 t

Weight

9.8-10.7 m

Length

Disrtibution

The Antarctic minke whale is found in all seas in the southern hemisphere and sometimes ranges into the northern hemisphere. In summer, these animals congregate in large numbers in Antarctic waters in order to feed; during winter most of them move north to more temperate or tropical waters to mate. Antarctic minke whales do not all migrate, with some overwintering in the Antarctic. They inhabit offshore and coastal waters. During the summer, many of them are found near the ice edge, amongst pack ice or in open water surrounded by ice.

Habits and lifestyle

Minke whales are usually seen on their own or in pairs or threes. Bigger groups can be found in both hemispheres in high latitudes of up to 10 to 15 animals. Minke whales are known for their curiosity and so are among the most frequently observed of the rorquals (of the baleen whale family) due to their habit of approaching boats that are stationary. Their usual dive lasts 2 to 6 minutes, then they spend 1 minute up at the surface, when they blow 5 to 8 times. A minke whale breaches more frequently than other baleens, lifting at least 40% of its body out of the water and then slamming back down into the sea, making a large splash and a thudding sound. Antarctic minke whales will sometimes use their beaks to break ice that is several centimeters thick, in order to create breathing holes. Holes are usually 200 - 300 m apart.

group name

pod, gam, herd, school, mod

Diet and nutrition

Like all baleens, minkes are carnivorous, and are seasonal feeders. They filter out krill, small plankton, and small fish, and sometimes chase schools of sardines, cod, anchovies, herring, and capelin.

Diet

Mating habits

Antarctic minke whales have a polygynous mating system, one male mating with multiple females. The mating and calving usually occurs during the winter. After a gestation lasting 10-11 months, a single calf is born. Like all mammals, minke calves drink their mother's milk until they are weaned, at about 4-6 months. They remain with their mothers for up to two years. Antarctic minke whales are sexually mature at about 7-8 years old.

Mating behavior

Reproduction season

during the winter

Pregnancy duration

10-11 months

Independent age

2 years
cow

female name

bull

male name

calf

baby name

1 calf

baby carrying

Population

Population status

ne
dd
lc
nt
vu
en
cr
ew
ex

Population threats

Scientific and commercial whaling are major threats for the Antarctic minke whale, and it is now a main target of the whaling industry in Japan, especially as larger species of whale have been depleted through hunting. Antarctic minke whales, like all cetaceans, are also vulnerable to noise and chemical pollution. Climate change is another possible major threat. With rising temperatures, the reduction of sea ice suggests a loss of 5 - 30 percent over the next 40 years of ice-associated habitat, which may also affect Antarctic krill abundance. There will be increased competition for food and space as the extent of prey populations and suitable habitat reduces, with the result that this whale population will decrease.

Population number

According to the International Whaling Commission's most recent estimate in 2003-2004, the population size of Antarctic minke whales is around 515,000 individuals. Currently this species is classified as Data Deficient (DD) on the IUCN Red List.

Fun facts for kids

  1. The vocalizations of minke whales can be up to 152 decibels, as loud as the noise of jet planes taking off.
  2. Minke whales are sometimes called “Stinky Minkes” due to the unpleasant smell of their spouting.
  3. The pleats on the throat of a minke whale (and those of similar whales) allows them to expand when they're feeding, to take in lots of water.
  4. These whales are often seen in the same places that sea birds congregate, and scientists deduce they may use the birds' location as an indication of a source of food.
  5. During deep dives the minke whale can hold its breath for as long as 20 minutes before coming to the surface to breathe fresh air.

References

  1. Antarctic Minke Whale Wikipedia article
    https://en.wikipedia.org/wiki/Antarctic_minke_whale
  2. Antarctic Minke Whale on The IUCN Red List site
    http://www.iucnredlist.org/details/2480/0