© ABC, AustraliaBiologists say a number of whales did not migrate north over winter as usual.
Marine biologists are baffled by a change in the behaviour of whales visiting Victorian bays this year. The Dolphin Research Institute says a number of humpback whales remained in Western Port and Port Phillip bays throughout the migration season instead of travelling north.
Institute spokesman Jeff Weir says scientists are unsure what has caused the change in their migration pattern. He says they also saw the animals competing for the first time off Mount Martha and Mornington.
"These are big animals, the size of tourist buses, playing demolition derby under the water and then sometimes reaching the surface banging into each other jostling for position in the pod," he said.
Mr Weir says it is the kind of behaviour normally seen when the animals are mating in northern Australia.
"I mean, it possibly is simply numbers of whales are picking up again and the populations are increasing," he said.
"Maybe they're just spreading themselves more evenly around our coast. The critical thing will be to monitor it in the years to come."
Maybe a sign the Northern Hemisphere is in for a cold winter!