THE whales might have left but the shearwaters are back!
The south-west continues to be a focal point for some great annual animal migrations with tens of thousands of shearwaters, or mutton birds as they are often called, recently returning to their Port Fairy breeding ground after completing their long migration south from wintering grounds in the northern Pacific.
Department of Environment and Primary Industries (DEPI) senior biodiversity officer Mandy Watson said the short-tailed shearwaters, with their instinctive timing, reach the Port Fairy breeding ground on or close to September 22 each year.
“Shearwaters come in their thousands from the northern hemisphere summer feeding grounds off Alaska and Siberia.
“For more than 35 years they have arrived at the same time within a few days, returning to the same burrow each time,” Ms Watson said.
“They feed on fish and other seafood, tend to be more active at night, and generally mate with the same partner for life.
“After arriving, they clean out the burrows and mate, then the entire population flies off to sea for about two weeks before returning to lay eggs. They lay one white egg that generally hatches in seven weeks.
“The journey here may not be successful for all the birds.
“Depending on available feed during the northern summer, birds may arrive underweight and exhausted.
“This can result in dead or dying birds washing ashore in large numbers right along Victoria’s coastline.”
“Bad weather during their long flight can also increase the risk.
“After the seven-month breeding season the adult shearwaters leave the Port Fairy colony in mid-April to begin their long flight northwards, followed by the chicks in early May.”
Ms Watson said it appeared the last of the southern right whales to raise calves at Logans Beach this year had headed south. She said the most recent sighting had been on October 5 when a cow with calf were sighted.
The whales head south to their summer feeding grounds in the sub-Antarctic waters of the Southern Ocean.
Ms Watson said this year had been a very good breeding season with four cow and calf pairs taking up residence at Logans Beach and another two cow and calf pairs in the region.
“We had a maximum of 16 whales at Logans Beach in one day.”