Last week on #WhaleWednesday you read about the Antarctic Minke whale this week you’ll learn about the Common (or Northern) Minke Whale
Minke whales are the smallest and most abundant of the rorqual whales. They have a sharply pointed snout, straight mouth line and a long ridge along the head with two blowholes. They have hundreds of baleen plates 20 to 30cm long growing from their upper jaws and between 50 and 70 pleats running from their throat and ending just past their flippers. These pleats stretch, allowing the whale to take in huge volumes of water when feeding. Minke whales have a streamlined shape and smooth skin with no callosities or barnacles. They are black, dark brown, or grey on their upper side with a lighter belly and a dorsal fin positioned far behind the centre of their back. Minke whales in the northern hemisphere have a white band on each flipper, though many in the southern hemisphere do not. The fluke of a minke whale is rarely seen above the surface.
You are more likely to see minke whales at close quarters than other baleen whales because they are notoriously inquisitive and often approach boats.
The minke whale is the smallest of the rorqual whales. Females reach an average length of 8.5m and males grow to about 8m. Like other baleen whales, those found in the northern hemisphere tend to be smaller than those from the southern hemisphere. Minke whales weigh between five to 10 tonnes.
The minke is widespread and seasonally abundant in the North Atlantic Ocean. In the winter, they migrate southwards, although it is unclear where their breeding grounds are located. In summer, concentrations shift northward to Spitsbergen and the Barents Sea, the coast of Norway and the waters off Iceland, Greenland and Newfoundland. In the northern Pacific, minkes are found in the Bering and Okhotsk Seas, and Gulf of Alaska in the spring and summer.
Like other great whales, minkes migrate to temperate and tropical waters in winter and polar waters in summer. Minke whales are often solitary, although they often travel in pairs or groups of three. In higher latitudes they are sometimes found in larger groups.
Common minke whales are generally solo marine mammals and prefer to travel alone, however in some cases they may be accompanied by one or two other whales. During small gatherings groups may expand to 4-10 minke whales but these occurrences are rare.
In the eastern North Pacific and North Atlantic, breeding may occur throughout the year, but there appears to be a calving peak in winter. The gestation period is believed to be around ten months. Females give birth to a calf every 12 to 14 months. Killer whales prey on minkes, as do other natural predators. They are believed to live to 40 to 50-years-old.
Minke whales tend to feed on the food source that is most abundant in a given area, primarily krill and small schooling fish, but occasionally larger fish such as mature arctic cod and haddock. In the North Pacific, minke whales reportedly feed on euphausiids, copepods and sand eel, and those in the Okhotsk Sea feed on krill, and sometimes fish. In the North Atlantic, minke whales feed on a wide variety of prey, including sand eel, euphausiids, copepods, salmon, capelin, mackerel, and cod.
Northern minke whales are caught in the North East Atlantic by Norway pursuant to an objection to the International Whaling Commission’s (IWC) whaling moratorium, and by Greenlanders as “aboriginal subsistence” whaling. Japan hunts 150 whales a year in the North Pacific under their “scientific” reasearch permit. Japan also hunts up to 440 southern minkes a year in the Antarctic under their “scientific” research permit.
Minke whales are know to face attacks from groups of killer whales in areas where these predators are know to hunt other marine mammals. Numerous cases of minke whale meat being found in a killer whales stomach have been confirmed along with injuries and scares being observed on minke whales that have successfully escaped being killed. There are also a number of cases where dead minke whales have been spotted eaten by groups of sharks which my indicate that they are either hunted by sharks or the sharks wait for the whale to die and then consume the carcass.
The common minke whale global population however is currently under review by the IWC whilst little information is available for the dwarf minke whale. The species is listed as of Least Concern by IUCN (2008).
Video: Bait Ball – Common Minke Whale lunge feeding