The humpback Whales of Vava'u, Tonga
The humpback whales migrate each year from their feeding grounds in the Antarctic to the warm, sheltered waters of Vava’u to mate and calf. A journey of some 5000+ miles.
The longest migration of any mammal.
The humpbacks are baleen whales which means they have no teeth but baleen, which is like big toothbrush bristles, which they use to sieve the krill they feed on. However, the time they spend in Vava’u they do not eat as there is no krill to feed on. The females, known as cows, weigh up to 45 tonnes and are 16 meters in length. The calf when born weighs 1-2 tonnes and measures 1.5 meters. They rapidly grow in size from their mother’s milk which is like double cream and very fatty. The mother expresses 100 litres a day from either of her two breasts.
Usually mothers and calves are the best encounters with the mother lying at about 30 feet often sleeping with one eye closed for up to 20 minutes with the calf surfacing every 3 to 5 minutes and playing on the surface. The calves are very inquisitive and will approach swimmers so you are able to eyeball each other. Usually visibility is in excess of 100 feet and watching the calf feeding or playing around Mum is a magical experience.
Often the whales will approach the boat and swim around checking us out. Sometimes close enough that you could lean over the side and touch them – which we do not permit.
Often there is an escort with the mother and calf who is male. The female has come back into season even though she is lactating and it is possible for her to mate.
Some of the behaviour you will see displayed:
Heat Runs: The bulls behave quite aggressively when competing for the cows attention with a lot of pushing and lunging. It is usually a dominant bull attempting to keep the young bucks at bay. We do not attempt to swim in a heat run as the whales are traveling quite fast and there is a lot of white water created which restricts visibility.
Breaching: Humpbacks are the most playsome of all the whales and will throw their bodies completely out of the water and come down with a thundering crash – an awesome sight up close. Nobody really knows why they do this.
Pectoral Slap: The pectoral fins are 5 meters long, the longest appendage of any mammal, and the whales will lie on their side slapping the pectoral on the water. Sounds like a cannon going off. At the end of the pectoral is the same bone structure as your hand so way back in time it was an arm with a hand.
Logging: This is when a whale lies on the surface, probably sleeping, for periods up to 30 minutes. Perfect for encounters.
Tail Slapping: The whales will lie vertically in the water head down and slap their tails on the surface. We have seen them do this continually for 15 minutes.
Spyhop: The whales are vertical in the water with their heads rising up 3 meters. Usually the eyes are not out of the water so they are not looking around as such.
Our Motto: Maximum encounter – Minimal impact.