A female rock wren at Homer Saddle in Fiordland. Photo by
Rock wren numbers appear to be declining and trampers,
climbers and hunters are all being called upon to report any
sightings they might make of the diminutive threatened native
The rock wren, or tuke, is classed as nationally vulnerable,
and the results of a study have shown numbers appeared to be
declining in Mount Aspiring National Park, in the Murchison
Mountains and in the Henderson Range in the Kahurangi
University of Otago teaching fellow Sue Michelsen-Heath, of
the zoology department, studied more than 2000 sightings of
the rock wren recorded between 1912 and 2005.
The results of analysing the sightings showed areas the tiny
alpine bird inhabited had declined by 24% since 1984.
Predation by mice and stoats was a major factor in population
decline, she said.
Anecdotal evidence of population declines, evidence of
predation, unsuccessful searches in previous strongholds and
the extinction of five other New Zealand wren species in the
past 100 years did not bode well for the bird's future.
Department of Conservation technical support officer Peter
Gaze said climate change could also affect the rock wren, as
rats could start to colonise alpine areas as they became
The wren is the only true New Zealand alpine bird which
breeds and lives in the alpine zones all year round.
It was difficult to quantify changes in population size as
the bird was hard to detect because it was small and well
The rock wren is smaller than a silvereye, but has similar
colouring. Males are olive-green while females are more
The birds have a very short tail, long legs and distinctive
They are found in alpine basins of the Southern Alps among
rock falls, scree slopes and subalpine scrub. They can be
identified by their high-pitched, simple three-note call.
Sightings, with a GPS or map reference, can be reported to
Doc or entered on to the Ornithological Society of New
Zealand's website www.eBird.com/nz.
The findings of the study were published in the society's
scientific journal Notornis.