Answers about visitor still to surface
The mysteries swimming around Wellington’s whale will remain unanswered for the time being.
The National Institute of Water and Atmospheric Research (Niwa) has little to show from initial research into the whale, answering few questions about the visitor which arrived in Wellington Harbour on July 2.
In publishing their latest findings, researchers have sought to quash speculation the southern right whale may be male, saying results of a dart gun biopsy are possibly weeks away.
And a possible recording of the whale’s call brings us no closer to understanding its motives.
Wellingtonians have scrambled to see the whale. Yesterday there were sightings reported near the Interislander ferry terminal and across the harbour near Te Papa.
On Sunday, a steady stream of onlookers keen to glimpse the playful whale caused traffic jams around Evans Bay.
There is hope the visit is a sign of improving fortunes for the hunted species.
University of Auckland PhD student Victoria Warren, who has analysed data recorded in the harbour last week, said speculation that the whale’s regular breaching indicated it was male was premature.
‘‘There is no real need for male southern right whales to show off to females, because a female mates with multiple males, and the male that produces the most sperm is usually the one that fertilises the egg.’’
Listening to 70 minutes of underwater audio taken within 100m of the whale, Warren said there were five possible whale calls captured but no maleindicative ‘‘gunshot sounds’’ recorded.
‘‘However, it is difficult to tell whether these sounds were produced by the whale because of vessel noise in the harbour. No gunshot sounds were recorded so we have no more clues about the animal’s gender.’’
Warren said southern right whales make an annual migration north from Antarctica, and a Wellington Harbour visit was not unprecedented.
‘‘It may be a sign of a recovering population follow the decimating impacts of commercial and illegal whaling.’’
An estimated 2200 whales commonly winter off the subAntarctic Auckland Islands in the south, a population thought to recover by 7 per cent per year, according to a 2016 paper published by the Royal Society.
This is estimated to be only 12 per cent of the population in New Zealand waters prior to whaling.
DNA evidence indicated fewer than 40 mature females survived the 19th century whaling eraand no whales were seen in mainland waters for the 35 years between 1928 and 1963.
But a slow recolonisation of mainland bays might be taking place.
A 2003 Department of Conservation paper on southern right sightings noted 11 possible cow and calf southern right whale pairs had been seen around the mainland in 25 years.
Whales without calves were reported to rarely stay longer than a week at a location, with some cow and calf pairs staying longer than two weeks.
It was impossible to tell how long a whale might stay in the harbour, and the whale’s behaviour showed no cause for concern, Warren said.
‘‘There is no real need for male southern right whales to show off to females.’’ PhD student Victoria Warren