KRAAAK!
Kraaak! Kraaak! They fly over our place almost every night in the summer
at around 7pm. Like a motorcycle gang, but dressed in olive brown rather
than black leather, they zoom up the valley from the seacoast straight
through the gap between us and Little Windy Hill. Then on down to
Tryphena I guess. We usually see about five at once, however other
residents up here have seen as many as eleven.
They look and sound tough with their screeching but are actually
increasingly vulnerable. Last year kaka were upgraded to Status 2 –
Nationally Endangered. That rating has put them up there with brown teal
and chevron skinks. There is only one higher score and that is
Critically Endangered, a status reserved for birds like the kakapo,
dangerously close to extinction for half a century.
So we are very lucky to have them here! I know it doesn’t feel like that
when they attack our fruit trees (but more on that later).
Kakas are practically extinct as a breeding bird on the mainland
existing only where there are ‘mainland islands’ with targeted predator
programmes (or fences) such as Mt Bruce, Pureora Forest and the Karori
Sanctuary. Indeed both Mt Bruce and Karori are captive breeding kaka in
their endeavours to re-establish a wild kaka population. It has taken
ten years of effort at Mt Bruce to get the kaka numbers up to around 75.
I found no research available focused on Great Barrier kaka and why they
remain viable here. But it appears that the absence of stoats (and
possibly Norway rats) allows nesting females and chicks to survive
better in their deep hollow-tree nest sites. Recent nationwide research
found that possums too feast on both eggs and chicks and will even kill
adult females. So the absence of possums on Great Barrier Island is also
a positive factor. Of course we still have the problem of feral cats and
rats.
Young kaka are practically flightless for several days after they leave
the nest though they can climb quite well. Kaka lay their eggs through
spring and early summer and these take 24 to 26 days to incubate. The
female does all the sitting on eggs and is fed every hour and a half by
the male (great room service!). The nestlings take about another 10
weeks before they fledge and these ‘babies’ are not fully independent
from the adults for a further 5 months. Quite a parenting effort!
If like us you have regular kaka visitors, then you are very likely
seeing the same birds over and over – adult kaka generally have a
relatively small home range. They do go on excursions however and
movements of over 30 km have been recorded for newly fledged birds which
take a while to settle. Recent bird counts carried out by the Trust on
Great Barrier found kaka distributed throughout the island – they were
seen in pasture, estuary, kanuka/manuka, lowland bush and montane bush
eco-systems.
So what can you do to help this highly endangered bird survive?
• keep your dogs
on a leash especially in any bush areas where there may be fledglings on
the ground or nests low down;
• net your fruit
trees – but this must be sturdy and may only work if made of
wire to
stop the birds eating their way through;
• some other
suggestions for your garden are to use bird scaring devices such as
raptor kites, hazing tape or streamers or playing recorded alarm calls –
so try these out – or simply accept that a portion of your fruit is
going to a good cause;
• get your pet
cat spayed or neutered to ensure there is no likelihood you unwittingly
add to the feral cat population;
• keep a diary
of your observations of these fascinating birds;
• leave your
pets at home if you are a holiday maker, or keep them very well managed
on the island;
• be very
careful if you are visiting or returning to the island not to bring any
unwanted ‘visitors’ (possums, stoats, ferrets, Norway rats) with you or
your luggage, car, freight or boat;
• Kaka breed
most successfully after a good season of kahikatea or rimu seed
production so if you are planting something new, consider one of these
native trees.
REFERENCES:
Birds of Aotearoa: A Natural and Cultural History. Margaret Orbell.
Reed 2003.;
Biodiversity Advice Fund
Report 1. John Ogden. 2006; Biodiversity Conservation DOC Fact
Sheet Feb 1997; Field Guide to the Birds of New Zealand,
Heather & Robertson, 1996 Viking; Great Barrier Island, Canterbury University Press, 2001;
New Zealand Birds, Geoff
Moar, Reed Field Guide 1992; Personal Communication, Halema
Jamieson; Personal Communication, Raelene Berry; Research
summary and options for conservation of kaka (Nestor meridionalis).
T.C. Greene et alia. DOC Internal Science series 178, 2004.
WEB SITES:
• www.terranature.org/parrots
• www.mtbruce.org.nz kaka_captive_more
• www.doc.govt.nz/Conservation/ 001~Plants-and-Animals/ 006~Threatened-species/Bird
• www.iucnredlist.org/search/ details.php/14728/summ