Humpback Whales Annual Migration
Humpback whales hunt and feed during the summer months in the colder waters like Antarctica and then migrate to warmer tropical waters during the winter months for mating. It is around this time of the year that we are able to start to see the annual migration take place with humpback whales passing by the Kaikoura Coastline between May / June / July and August – heading up towards Australia and Tonga for the mating season. Over the last few weeks we have been able to sight quite a few humpback whales as they pass by Kaikoura heading further north. One day last week we actually were able to see throughout the day 8 individual humpback whales passing through.
The humpback whale is one of the most easily recognised whale species. Known for their large flippers (which can be up to one-third of their body size), and the hump on their backs. Their colouring is anywhere from a grey to black colour and have white markings on their underbelly. These markings are differing in every whale, being like fingerprints, allowing researchers to identify individuals.
The humpback whales diet is made up of fish and krill. They are baleen whales, meaning they are filter feeders. These whales have two parallel rows of baleen plates attached to their jaws, allowing them to filter water for the fish and krill.
During the mating season humpback whales will fast, living off body fat reserves and completely forgo eating.
Humpback whales breathe voluntarily, unlike human beings. Since they have to remember to breathe, researchers believe humpback whales sleep by shutting off half of their brain at a time.
These whales are known for their complex mating songs. Researchers have studied the whale songs for years, and the complexity of these songs suggests the whales are extremely intelligent creatures. Only the males are responsible for the whale songs, however, since they are primarily a mating signal. These sounds can be heard many miles away and are heard as a combination of moans, howls and cries among other noises which can go on for hours.
Not only famous for the haunting love songs these whales are also well known for their acrobatics. They can be frequently seen leaping out of the water and sometimes can use their flukes to propel themselves completely out of the ocean – known as a breach.
In the Southern hemisphere, commercial whaling in the 20th century brought humpbacks close to extinction. NZ ceased whaling in 1964, with the closure of the Perano whaling station in Tory channel. The stocks had diminished such that humpbacks were no longer migrating through Cook Strait and commercial whaling was no longer viable. Since then NZ has become a vocal advocate for whale protection and conservation – annually for the last 10 years there has been a whale count of humpbacks passing through the Cook Strait – volunteers such as old time whalers turned conservationists and staff from DOC for a 6-12 week period spend the days watching through binoculars for signs of humpback activity and note down details, last week was the biggest count yet for a single day with 27 humpback whales being counted. This year’s Whale Survey ends on the 11th July – here is hoping for a greater tally than last year’s count.