Whale tail IDs – in the middle of a heat run.

Posted on August 3, 2012 by annabelle 1 Comment

The Kimberley is big tide country – this remarkable marine environment governed largely by the moon and the massive tidal circulations that sweep around the Kimberley coast.   These tidal differences are caused by the varying gravitational forces exerted by the sun and the moon.  The new moons and full moons herald the start of the spring tides, with up to a 14m difference between high and low tide in a six hour period*.   After a period of relative calm during the neap tides,  the first day of the spring tides brings the marine environment to life with an increase in water movement up and down the coast.  Humpback  whales tend to rest over the neap tides and become more active on the springs as they travel with the tides.

Water gushes off a Humpback whale's tail just north of Broome off Willie Creek. (Annabelle Sandes/© Annabelle Sandes | Kimberley Media 2012)

Broome's Cable Beach

Turquoise waters off Broome’s Cable Beach

We spent the first day of these springs in the beautiful turquoise waters off the Dampier Peninsula, filming and photographing whales, dolphins and turtles between Broome and Willie Creek.  Amongst other wildlife we counted three turtles surfacing near the boat, Bottlenose dolphins and approximately 30 pods of Humpbacks (Megaptera novaeangliae), concentrated around the sandbanks off Willie Creek.  Humpback whales are identified by the unique patterns of black and white and on the ventral surface (underside) of their tail flukes, and by the scalloping along the trailing edge.  Databases of whale fluke photos are used to identify individual whales and to determine their migration patterns and paths.

 (Annabelle Sandes)

A Flatback turtle (Natator depressus) near Willie Creek, showing evidence of damage by shark, crocodile or propeller. (Annabelle Sandes/© Annabelle Sandes | Kimberley Media 2012)Shortly after leaving Gantheume Point at the southern end of Broome’s 22km long Cable Beach, this magnificent old Flatback turtle (Natator depressus) surfaced near the dinghy in obvious distress.  Deep grooves in the shell and a missing flipper indicated damage from a crocodile, propeller or shark attack.  The turtle had trouble navigating with the stumpy flipper, which was not a fresh wound and showed evidence of healing.  A milky covering on its shell seemed to indicate that the turtle was suffering from some sort of disease.

An injured Flatback turtle surfaces near Willie Creek, north of Broome (Annabelle Sandes/© Annabelle Sandes | Kimberley Media 2012)

Flatbacks are oceanic turtles measuring an average length of 90cm, with a low domed shell  upturned at the edge.  The turtles feed on a variety of invertibrates, soft corals, sea cucumbers and seagrass, and although the turtles are found thoroughout the Indonesian archipelago, Irian Jaya and Papua New Guinea, they nest only on Australian beaches, including the Kimberley’s Wailgwin Islands in Camden Sound and the Lacepede Islands to the northwest of Broome.  Males never make landfall after hatching, and the turtles are considered vulnerable to extinction in Western Australia.

These spring tides brought an abundance of bait activity, with seabirds, dolphins and whales observed feeding together.  We were fortunate to witness wildlife feeding behaviour,  as a small flock of Brown boobies (Sula leucograster)  dived into schools of fish near a pod of Humpbacks as they blew bubble nets to the surface, schooling the baitfish and then skim feeding.  A small pod of Bottlenose dolphins  (Tursiops truncatus) feeding in the same area were chased off by one of the whales.

A humpback whale bull blows as he engages with competing bulls of Willie Creek, north of Broome. (Annabelle Sandes/© Annabelle Sandes | Kimberley Media 2012)

Sitting off Willie Creek in the 18ft aluminium zodiac we found ourselves in the middle of a bull fight or “heat run” around the dinghy as four males charged  each other and tail slapped only metres from the boat, competing for mating rights with the females.  Pushing and shoving each other, the whales slap tails and pectoral fins, creating bow waves as they surge forward.  Most of the activity takes place underwater, but as they break the surface it’s a thrilling sight to witness four forty tonne testosterone charged whales on the move.

A male humpback whale surges forward creating a bow wave as it competes in a heat run off Willie Creek north of Broome. (Annabelle Sandes/© Annabelle Sandes | Kimberley Media 2012)

Two humpback whale bulls fight just off Willie Creek to the north of Broome. (Annabelle Sandes/© Annabelle Sandes | Kimberley Media 2012)

A humpback whale tail slashes just off Willie Creek to the north of Broome. (Annabelle Sandes/© Annabelle Sandes | Kimberley Media 2012)

* At the Yule Entrance in Collier Bay.

Watch a c lip from the BBC’s Life series, as males battle in a heat run.

 

One comment

  • Kerry Firkin says:

    We love seeing the whales when they go down the coast each year I am lucky enough to live in Port Stephens each year there is nothing more I love doing is going whale watching
    So when I found out what the State and Federal Government have planned for the James Price Point it made my blood boil I have been luck enough to have holidays in the Kimberley and I know how beautiful this place is we just cannot stand by and let them destroy this beautiful place
    We have to protect it for the whales and all that call James Price Point home

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