I spy with my orca eye

Despite a combined weight of as much as 30 tonnes, a synchronised swimming display by four orca proved one of the most graceful - and most rare - sights in New Zealand waters.

Orca researcher Ingrid Visser caught the unusual image as she tracked a pod of the animals in the Hauraki Gulf.

The orca were performing "spy hopping" - a practice they use to have a look around above sea level, using a similar technique a human would to tread water.

"In New Zealand waters in 15 years I've never seen so many spy hopping like this together," said Dr Visser. " I've occasionally seen it overseas, but never here in 1000 hours of whale-watching."

Dr Visser received a call that a pod of 10 had been seen at Cowes Bay on Wednesday morning. By lunchtime she had found them and was able to spend five hours observing the giant mammals.

They were at Thumb Pt, off the northwestern point of Waiheke Island, when another two orca arrived, and four of the curious creatures popped their heads up to watch the newcomers.

"It was a pretty amazing sight," said Dr Visser.

Estimates of the orca population in New Zealand waters range from 65 to 167. They are most frequently seen in the Bay of Plenty/East Cape/Hawkes Bay region in June, between October and December.

Dr Visser, who has been studying the animals since 1992, said "killer whale" was misleading.

"It's because they kill other whales, not humans, that they have that name. Orca are like any wild animal. As long as you are sensible you should not have a problem."

* If you spot an orca call 0800SEEORCA.