Humpback whale season in full swing
Whale season in the Tropical North is now in full swing with regular sightings of humpback whales offshore from Cairns.
Passengers and crew aboard dive and snorkel vessel Silverswift were treated to one of the first sightings of humpback whales in our region on the way to Flynn Reef on Friday 22 July.
Quicksilver Group Marine Biologist Phil Coulthard said, “There were a group of five male humpbacks, identified by their competing behaviour, displaying the range of spy-hopping, pectoral slapping, synchronised breaching and body rolls. This more aggressive display is seen vying for female attention.
Yesterday (26 July) a mother and calf were sighted with Great Adventures cruises while travelling to Green Island. The calf was very active breaching out of the water while mum, approximately 12 metres in length was close by.
“These sightings mark the beginning of the winter migration to our region of east coast humpback whales from the southern oceans of Australia to the Great Barrier Reef Marine Park.
Observations of all sightings are recorded for the GBRMPA’s Eye on the Reef monitoring program.
Humpbacks are generally seen on the Great Barrier Reef between the months of June to September with regular sightings near Green Island and at the Outer Reefs, bringing an added bonus for passengers at this time.
Humpback whales regularly migrate from Antarctic waters along the east coast of Australia every winter to the warmer waters of the Great Barrier Reef to breed and calve. They are easily identified by having extremely large pectoral fins (their scientific name is Megaptera, which literally means giant wing). They grow up to approximately 16 metres in length, weighing in at 30-40 tonnes. Male humpbacks produce “songs”, which are believed to attract females at mating times.
Humpbacks can display a wide range of behaviour, including:
- Tail slapping: This is where they slap their tail on the surface. It can be a form of communication, but more often than not it is an aggressive display.
- Spy Hop: Humpbacks will often surface vertically, and actually stick their head out of the water so that they can see above the waterline.
- The Blow: Often the first indication that a whale is in the area. The vapour cloud produced is caused when the whale empties its lungs, and can be quite pungent if you’re downwind!
- Breaching: The most spectacular display of all, where the animal leaps almost clear of the water, creating the kind of splash that only a 40 tonne animal can produce!
Pictured image of calf breaching near Green Island. Credit Indepth Video and Photography.