Simon Mustoe.

INTRODUCTION

Just came back from a fantastic weekend whale-watching off New South Wales, Australia.

I went out with SOSSA (the Southern Ocean Seabird Study Association) off Wollongong. Although SOSSA are mainly concerned with seabirds, they have been recording cetaceans off the coast for a number of years. The team consider this to be one of Australia’s best whale and dolphin locations. They have recorded Pygmy Killer Whale regularly over the past few years and this was the species I was mainly interested in seeing.

The trip was excellent and the variety of species exceeded all expectations. Ten encounters were had with a total of six species, including False Killer Whales and Pygmy Killer Whales. Pygmy Killers are particularly exciting as they have not normally been encountered until later in the year. This species is also very poorly known in Australia. Elsewhere in the world they remain difficult to pin down and this may represent one of the only reliable sites to see them.

A detailed description and link to photographs of the animals is below.

The vessel was the ‘Sandra K’ operated by Captain Carl Loves out of Wollongong harbour. There were 24 observers on board the Sandra K although only about half a dozen were actively searching for cetaceans from an eye height of about 6m. The rest were pre-occupied with the seabird research. Wind speed was mainly Beaufort 2, occasionally dropping to Beaufort 1 and a swell not exceeding about 0.5m. The sky was overcast near the coast but cleared offshore to blue sky with some cirrus cloud forming in the afternoon so glare was not a big problem. Maximum water depth was about 1000 metres.

COMMON DOLPHINS

We left Wollongong at 7:15 am and headed to sea. The first encounters were with Common Dolphins a little over an hour after leaving. Common Dolphins were seen several times during the day, including an odd encounter with a single animal. This individual bow-rode for a while before racing off in pursuit of a fish which breached in front of the boat.

HUMPBACK WHALE

A little further out and we encountered a Humpback Whale. This was sighted three times in all. It first dived and fluked about 3km ahead of the boat and was then refound diving again a few hundred metres behind the boat. Forty minutes later it was seen to breach clear of the water several times.

PYGMY KILLER WHALES

One of the highlights of the day was coming across a group of about 30 Pygmy Killer Whales at about 10:15am in water about 200m deep. These animals were simply logging at the surface. Pygmy Killers are known to be somewhat lethargic and they hardly moved for twenty minutes or so as we bobbed nearby. The group was tightly packed and contained at least one Bottlenose Dolphin, identified by its obvious beak, higher more falcate dorsal fin and larger size. The Pygmy Killer Whales were about 2.5m in length with a characteristic pale grey cape running back from below the blowhole along the flanks (a very obvious surface feature). The dorsal fins were somewhat variable but generally triangular and only slightly falcate. The snouts were blunt, rather than pointed as they would be on Melon-headed Whales. The lips were distinctly white (see photo). One of the animals obligingly rolled on its back and exposed extensive white on the belly. This is another clinching feature that differentiates the species from the similar Melon-headed Whale which, instead has a grey belly. When the pod eventually moved off, they did so slowly. At the surface, Pygmy Killer Whales are very inconspicuous. The blows are virtually invisible and, at least when travelling slowly, they do not create much of a wake. Owing to both its enigmatic behaviour and small size, I would imagine that this species is extremely easy to overlook, even in low sea states.

For a series of photos showing the main features of these animals, follow this link. The images are quite poor owing to the bad quality of my scanner!:

http://www.ecology-solutions.com.au/pygmy_killers.html

SPERM WHALES

No other cetaceans were seen for an hour until the vessel was in water about 1000m deep at 12:30. Several Sperm Whales were found at the surface initially in an area that appeared to be subject to some upwelling, as indicated by patches of calmer water at the surface. During the following hour the vessel drifted about 0.5Nm and several Sperm Whales were seen to fluke up and dive while others appeared on the surface. Up to 14 animals were estimated. At one point a particularly small animal was observed and it is considered likely that this pod was a group of females and calves. According to the regular seabird team members, groups of Sperm Whales are often seen in abundance off Wollongong and this may represent a significant feeding / calfing area.

FALSE KILLER WHALES

Quite close to the coast on the return to Wollongong, a very active group of False Killer Whales were encountered. The species seems behaviourally very distinct compared to Pilot Whales and is certainly quite simple to identify. The animals were observed to lunge / half-breach out of the water putting on massive bursts of speed followed by periods of slow swimming. The dorsal fins were characteristically short and blunt and the snout was tapered. A calf also breached several times revealing the lack of any white patterning that would be expected on the other ‘blackfish’. The pod which was initially quite tightly packed dispersed into several small groups about 1Nm apart. Twice animals passed beneath the bow of the vessel to within literally several metres of observers.

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This was a fitting end to a wonderful day at sea and I was thrilled to encounter Pygmy Killer Whale, a species that I thought it may take me much more effort to see.

Weather conditions off the east coast of Australia are not often as favourable as they were on this trip, which would in part explain the large number and variety of cetaceans encountered. Last year, large numbers of cetaceans were seen off Wollongong, many of which are usually thought to inhabit the warmer tropical waters of the Coral Sea. This included monthly encounters with Pygmy Killer Whales. The East Australian Current is a warm water current that annually runs down the east coast of Australia and forms fronts and warm-core eddies that transport food and nutrients southward, often as far as the east coast of Tasmania in summer. If last year is anything to go by, this year could be even better as this is an El Nino year. Later in the year you can expect to see Striped Dolphins, Pan-tropical Spotted Dolphins and Spinner Dolphins. SOSSA have also recorded occasional beaked whales including Cuvier’s, Blainville’s and Strap-toothed.