Bid to see if penguins show same ‘urgency’
SATELLITE tracking could show whether rehabilitating ‘‘the world’s leastknown, most enigmatic penguin species’’ while they are moulting has an effect on their behaviour when they return to sea.
Otago University department of zoology researcher Dr Thomas Mattern, of the Tawaki
Project, is tracking 16 Fiordland crested penguins, or tawaki, as they return to sea after moulting — but two of those birds will not be starting from Milford Sound, Codfish Island/Whenua Hou, or Jackson Head on the West Coast, where the majority of the birds in the study moulted.
Two rehabilitated birds were released from the Oamaru Blue Penguin Colony after this year’s moult and satellite tracking could help to establish whether the birds show the same ‘‘urgency’’ to find food as those that were not handfed during the weeks they spent ashore losing then replacing their feathers, Dr Mattern said.
‘‘The birds in rehab, they get fed and that’s a luxury the other birds don’t have,’’ Dr Mattern said.
‘‘Once they [unrehabilitated birds] are through with the moult — they’ve been on land three to four weeks not having eaten anything and they’ve expended lots of energy on growing new feathers, so they must be hungry as hell.’’
A couple of years ago, 17 birds tracked during their premoult journey from the West Coast travelled ‘‘insane distances’’ in a short time, leading to the species being dubbed ‘‘marathon penguins’’.
The results at the time were surprising, as premoult birds were expected to waste as little energy as possible ‘‘so they can get as fat as possible’’ to survive the moult.
In the premoult study, the birds travelled up to nearly 8000km over the course of seven to 10 weeks. Five birds were tracked back to their moulting destinations on the West Coast — no tracking devices were recovered.
Already this year, one of the newer satellite tracking devices had been lost.
Yesterday, a 2.9kg young adult male, which had just moulted into its adult plumage for the first time, was released from a beach on Cape Wanbrow after being picked up by Oamaru Blue Penguin Colony staff in Waterfront Rd, at Oamaru Harbour, on February 11.
And a week earlier a 2.3kg female was released from the same beach after being picked up earlier from a beach at Kakanui.
The Oamaru female had proven ‘‘stroppy as hell’’ when he attached the tracker and after travelling 100km from the Oamaru coast, the bird spent nearly an hour and ahalf on the sea surface, during which it probably preened the device off, Dr Mattern said.
The tracker soon stopped sending frequent ‘‘pings’’ and about 170km into her journey it stopped sending signals, making it highly likely the tracker was now at the bottom of the ocean.
All the other birds were heading southwest, whereas the Oamaru female was heading southeast.
Tawaki this year had already passed the Auckland Islands in search of food and krill swarms at the subantarctic front were a possible food source. A female from Milford Sound had already been tracked 861km this year.
While the birds were listed by the Department of Conservation as ‘‘one of the rarest of New Zealand’s mainland penguins’’, very little was known about the species and it was possible the counts were low because of the birds’ secretive nature and the original counts ‘‘missed a considerable amount of the birds just because they were out of sight’’, Dr Mattern said.