Friday, September 2, 2011

A penguin's peril


BARRY HARCOURT/The Southland Times
SHOULD I GO OR NOT?: This tawaki on one of the Shelter Islands pauses before leaving on a feeding trip. The birds may spend up to a week at sea before returning to take over nesting duties.
Photographer BARRY HARCOURT travelled to Breaksea and Shelter Islands with Conservation Department biodiversity rangers monitoring Fiordland crested penguins.

The Fiordland crested penguin, or tawaki, ranges on New Zealand's West Coast from South Westland to Whenua Hou, or Codfish Island, off Stewart Island.
They number fewer than 5000, which puts their official conservation status at "nationally vulnerable", but monitoring by Conservation Department staff has shown that their status should be elevated to endangered or even critical.

Hanna Edmonds, a biodiversity ranger with DOC Te Anau, says there is not enough recognition or funding for penguin conservation in New Zealand.
Where there is, the focus has been on hoiho, or yellow-eyed penguins, and more recently the emperor penguin Happy Feet, which is not even a New Zealand bird.

Several birds of lower conservation status receive more attention and funding than tawaki, in particular mohua (yellowhead), whio (blue duck) and the North Island kokako.
Conservation staff have been monitoring and counting nests in breeding colonies on Breaksea Island, Shelter Islands and Martins Bay, on the Fiordland mainland, since 1994, as well as at sites on Whenua Hou and South Westland, where observations suggest the species is in decline.

Tawaki monitoring is difficult: they nest in small colonies, often in small caves in tree roots where they are hard to find, and mostly in dark places. They are also flighty and easily disturbed.
In one cave on the Shelter Islands we found nine pairs of tawaki on eggs in very muddy conditions with no light whatsoever reaching the nests; it's possible penguins have been using this nesting site for 100 years.
Concern over the reliability of nest counts has prompted monitors to start double-counting to test accuracy, with a second team following the first team and looking for any nests missed. The GPS co-ordinates of all nests are recorded.

Data suggests a 95 per cent chance of detecting a 10 per cent change in population.
Breaksea Island is predator free but the tawaki population still seems to be in decline, so availability of food could be an issue.
Tawaki spend most of their life at sea, returning only to nest or, for a short period in February, to moult. They arrive back at their preferred site in July to set up nests. Up to two eggs are laid in August, hatching in September. Chicks are then kept in a creche with a few adults watching over them, before they depart to the sea in late November.


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