More baby whales are expected to migrate down Australia's east coast than have been seen in 50 years after indications of a bumper birthing season, wildlife experts said Friday.
The National Parks and Wildlife Service in New South Wales state said a large number of whales with newborn calves were set to swim past Sydney towards the cooler waters of Antarctica between September and November.
More than 1,000 whales were spotted passing Sydney's Cape Solander in June alone as the creatures made their way up to the warmer northern waters of Queensland state to breed.
Ross said volunteer whale spotters at Sydney's Botany Bay logged a 17 percent increase in whales migrating north, while whale-watching vessels were noting more calves making the trip back south.
"Certainly the indications are that we saw more whales at Cape Solander this year than in previous years. And that certainly augurs well for a good reproductive season," the service's Geoff Ross said.
"And we are getting a lot of anecdotal reports from skippers and our own staff in the field that there are lots of baby whales out there."
Ross said the numbers of humpback and southern right whales visiting waters off Australia's east coast were gradually growing back to levels not seen since the end of commercial whaling in New South Wales in the 1960s.
"What we are seeing is the result of a growing population of humpbacks and southern right whales," Ross said.
"So it's taken a long time for the humpbacks on the east coast to recover. The east coast humpbacks were heavily hunted. Humpbacks were hunted to very, very low levels, southern rights almost to the point of extinction.
"Gradually, over the years, those numbers are starting to claw back."
Ross, who praised state and federal government conservation work in protecting the massive creatures, said the baby humpbacks would typically be five to six metres (16 to 20 feet) long and weigh 20 to 30 tonnes.