Short-tailed shearwater or Tasmanian mutton bird
Short-tailed shearwater or Tasmanian mutton bird

What has happened to Tassie’s mutton birds?

TASMANIA'S mutton bird colonies are a month late returning from their annual migration to Alaska and bird experts and the Aboriginal community fear the hold up might signal a problem.

The birds usually arrive with precision from September 21 but only small numbers have so far returned to burrow on Tasmania's islands.

What has caused the delay and if large numbers have died in their northern hunting grounds or on their 15,000km return journey will not be known until the yearly egg count is conducted in December.

Dead mutton birds washing up on the beach in Alaska provided the first indication things might not be well.

"Concerns started being raised at the end of last month that the normal number of birds were not seen coming into burrow," Tasmanian Aboriginal leader Michael Mansell said today.

"1 went out to Babel Island - Tasmania's largest shearwater colony - in early October and was surprised at the low numbers of scratchings around burrows.

"I thought 'there appears to be a problem". We will go back out in December to see if they have laid eggs in the burrows then we will have a better idea.

There are concerns about the late arrival of mutton birds in Tasmania.
There are concerns about the late arrival of mutton birds in Tasmania.

"We are hoping the low return rate does not signal a repeat of the dire conditions of 2014."

The breeding season in 2014 was so bad harvesting on Babel Island was called off.

In that year, there were fewer than 40 chicks in the island's 523 burrows.

In Victoria, the Environmental Department reported very low returning bird numbers at Port Fairy's Griffiths Island and that some birds were in bad condition,

Eric Woehler from BirdLife Tasmania said the mutton birds were certainly late returning this year.

Dr Woehler also reported that "not insignificant numbers" had been found washed up on beaches in Alaska over the last two months.

"I've been out to a couple of islands and while some birds are back we don't know yet if this is the full return," he said.

"Every season there are a couple of benchmarks used to track the health of the mutton bird population - the laying of eggs, the hatching of those eggs and the number of chicks in burrows. We will know more when it is time to count the eggs."

There are 43 colonies where recreational harvesters can operate in Tasmania including islands in the King Island Group, the Hunter Group, the Furneaux Group and Cape Sorell.

The harvesting season is from March 17 to April 30.