Conservation ecology of kea - Kea Conservation Trust website

Methods
Study Area
Kea occur throughout Nelson Lakes National Park and the neighbouring Upper Wairau
catchment (172°52′E, 41°53′S). Kea from Travers Valley, Wairau Valley and Six Mile
Valley regularly visit Rainbow Ski Area (hereafter referred to as ‘the skifield’) in the
head basin of Six Mile Creek and these valleys comprise our study area. These glaciated
valleys are U-shaped in cross section, often with grassy flats on the valley floor (c. 600-
700 m a.s.l.). The steep valley sides support continuous evergreen forest up to treeline at
about 1400 m. Red Beech (Nothofagus fusca) and Silver Beech (N. menziesii) dominate
the canopy from the valley floors up to about 950m, above which mountain beech (N.
solandri var. cliffortioides) forms the canopy, up to treeline. Above treeline are mountain
peaks reaching 1600-2100 m and snow-tussock grasslands (Chionochloa spp.) in which
grow various alpine and subalpine shrubs and herbs such as Celmisia spp., Podocarpus
nivalis and Hebe spp.. Lake Rotoiti and the skifield road allowed access to the valleys
within the study area.
Radio-telemetry
Radio-telemetry was the primary tool with which we found nests and followed the fates
of individuals. We used two-stage radio-transmitters each weighing 35 g (3.8% and 4.2%
of male and female body-weight, respectively) and with battery life of 24 months.
Transmitters were purchased from Sirtrack Limited, Private Bag 1403, Havelock North,
New Zealand. We captured kea in the skifield carpark and fitted them with transmitters
using backpack type harnesses made of braided nylon. A cotton weak-link was
incorporated into each harness so that the transmitter would eventually fall off if we
failed to recapture the bird (Karl & Clout 1987). Using hand-held Telonics TM TR-4
receivers with yagi aerials, we were almost certain to detect a signal if we were in the
same valley as the bird and within one-two km upstream or downstream.
33