Monday, July 30, 2007

Humpback whale fact sheet


Humpback are distinguished by their long pectoral fins (which can reach up to 5 m in length), and by their knobbly head (these “tubbercles” are actually hair follicles). They are also well known for their aerial behaviours, as these whales are often seen breaching, lobtailing, pectoral fin slapping, and spyhopping, especially in the breeding grounds. In the tropical breeding grounds male humpback whales can also be heard ‘singing’ very complex haunting melodies which are thought to be to show their suitability to the females. The whales spend the winter months in the warmer breeding grounds and carry out long migrations to spend the winter months feeding on plankton in the cooler waters. The scientific name means 'big wing new englander' and refers to the pectoral fins and the species was first described in New England.

The Azores is along the northern hemisphere migration route, from Cape Verde and on their way to Norway (as we have ID matches from these places). They might also be migrating from Costa Rica. So these whales can occasionally be seen here, but not as regularly as the other baleen whales. 

Humpback whales are colour blind. Most of the colours in the ocean appear blue or green, because blue and green light waves penetrate deeperinto the ocean, leaving those of us with colour vision at a loss. Humpback whales don't need to worry about colours, all they care about is contrast. They see contrasts very well which helps them see their prey of schooling fish or krill. These big schools appear as dark masses while the background (water) is lighter, so their food stands from the rest. Sined they likely feed at night or in very deep waters at times, eyesight is probably not the only way they find food. But the shining lining behind their retina (tapetum lucidum) makes the most of whatever light is underwater.

Length: 
• Male: 17 m
• Female: 19 m
• Calf: 4 – 5 m

Weight: 
• Female: 40,000 kg
• Calf: 1,000 – 2,000 kg

Global population: c.63,000 (population trend increasing)

Status: Least Concern

Diet: Krill, small schooling fish

Baleen: 270 – 400 pairs (grey)

Longevity: Up to 48 years

Breeding age: Unknown

Gestation: 1 year

Nursing: 1 year

In other languages
Portuguese: Baleia-de-bossas
Spanish: Ballena jorobada
French: Baleine à bosse
Italian: Megattera
German: Buckelwal
Dutch: Bultrug

Swedish: Knölval
Norwegian: Knølhval
Danish: Pukkelhval
Finnish: Ryhävalas
Polish: Pletwal
Russian: Dlinnorukyi polosatik, gorbach









No comments:

Related Posts Plugin for WordPress, Blogger...