Great Barrier Island Environment Trust, working with Okiwi School
and other community members has initiated a project to find out more
about the remnant kākāriki population of Okiwi.
The research is being funded by the
Trust, and initially includes two aspects—nest searching and
population counts. Nest searches in the study area were carried out
in December 2017 and February 2018. Locating potential and active
nests of kākāriki / red-crowned parakeet (Cyanoramphus
novaezelandiae novaezelandiae) was
identified as a key component of the research, as nest protection is
an important requirement for the management of a species,
particularly in areas where predators are present. This strategy has
been used successfully on Norfolk Island for the Tasman parakeet (Cyanoramphus
Why kakariki remain in Okiwi
The population of kākāriki persist in
the Okiwi Valley despite the presence of ship rats and feral cats.
These birds are sociable and vocal, especially when in small groups
and are well known to local residents.
The number of kākāriki resident in
Okiwi is unknown, with no formal count or monitoring known to have
been undertaken. Single birds and birds in groups of up to a dozen
have been sighted in the Okiwi River and adjacent forested areas.
The species is believed to nest in
mature puriri trees along the Okiwi River, most likely in the Okiwi
Reserve – where Okiwi School has carried out rat control for many
The yellow track shows areas of the Okiwi Valley where searching was
carried out for kākāriki nests in December 2017. A subsequent search
in February 2018, covered further areas with mature puriri trees.
Further searches are planned for later in 2018.
On predator free islands kākāriki can
be found nesting in flax, logs, burrows on the ground, and in
excelsa) and puriri (Vitex
The presence of rats and cats in the
Okiwi Valley mean that the Aotea Great Barrier Island kākāriki are
highly unlikely to be successfully using ground level nest sites.
Kākāriki prefer mature trees with
access to water. Sections of bush in the study area were identified
as potential nest sites where they had mature puriri trees and were
close to watercourses. Permission was sought from owners of each
property prior to the undertaking the searches.
Literature on this species informed
the identification of potential nest trees. The literature notes
that natural nests in puriri trees were found in alive and healthy
trees that were greater than 300 mm diameter at breast height,
indicating mature trees2,3.
Puriri tree search and cavity check
Each section of identified bush was
searched and suitable puriri trees were identified. Cavities in
puriri trees are formed when a tree limb drops off and the scar left
behind rots away and becomes hollow. For this reason, young trees
were not searched as they most often have all of their limbs
attached. Every tree that fits the criteria was searched for
cavities, and if a cavity was found, it was examined for bird
activity if accessible.
Bird activity included droppings,
feathers, complete eggs or shell fragments, chicks or adult birds.
If adults, chicks, or eggs were seen it was recorded as an active
nest. If only presence indicators (droppings and feathers) were
noted, it was recorded as unoccupied.
Any cavities with no bird activity,
but otherwise suitable (for example a dry hollow with a large enough
cavity), were recorded as potential nest sites. All active nest
sites, unoccupied or potential sites had their location recorded.
Unoccupied nest in mature puriri tree, Okiwi Valley. Photo: S
Nest search results
Four nests were found with signs of
bird activity: one active, two unoccupied, and one considered a
possible nest. The active nest was found in the Okiwi Reserve. The
entrance to the nest was formed by a fallen limb and is
approximately 5 m from the ground and is roughly 40 mm long and 20
mm wide. Two birds were observed near this nest and one was seen
entering the entrance.
The first unoccupied nest was found in
a medium size puriri tree near Mabey Road and was about 1.6 m from
the ground with a small entrance. This nest had a few feathers found
inside it but no sign of current bird activity.
The second unoccupied nest was found
on the short scenic walking track that crosses through the
Whangapoua Reserve off Aotea Road. This nest was in the base of a
large puriri tree, approximately 0.5 m from the ground. This nest
had a skeleton and feathers present but no signs of current
activity. A possible nest was also found on private property close
to the estuary in a large puriri by the stream. A bird was perched,
calling, approximately 6-7m
from the ground in this tree, near a hollow. The bird was gripping
on to the tree and proceeded to go upside down and stick its head
into the roots of a widow maker (Collospermum
hastatum), near the
A total of 49 potential [kākāriki] nests were
identified in puriri trees around the Okiwi Valley area.
Some of these (n=4) were found in the
bush area adjacent to the Department of Conservation offices, while
the majority were found in the Okiwi Reserve beside the school and
private properties bordering the Okiwi Stream. Some of the trees had
multiple hollows at varying heights. Some of the potential nests had
rat droppings present.
Interior of a potential nest site with rat droppings present, Okiwi.
Photo: J Scarlett
Kākāriki are vulnerable to rats
The results show
that there are kākāriki using the Okiwi Valley area as a nesting
site. While only one active nest was found, it can be assumed that
there are more nests in the area. Considerable bird activity occurs
in this area, such as perching around potential trees, calling and
Rats present the biggest threat to this species, as
rats can enter the cavity and destroy eggs and chicks on the nest,
while also attacking chicks that have recently fledged.
Some of the
potential nests that were found contained rat droppings which
confirm that rats are entering nests. One nest was found with
feathers and a skeleton of a kākāriki inside, suggesting that a bird
had been killed on the nest. The stage of the feathers indicate that
it was either a pre-fledged juvenile or an adult, and so likely
cause of death was either that it starved or was killed by a
predator, most likely a rat.
Conclusions and recommendations
The results of
the research to date are important as they show that there is a need
for nest protection in the Okiwi Valley. After talking with
residents of the area, it is clear that this population of kākāriki
are an important part of the environment, both culturally and
scientifically. Nest protection for this species should be provided,
as well as nest monitoring, around identified active and potential
nests. It is essential that the community continue to feel a sense
of ownership and engagement with this species and to be involved
with any protection initiatives. Traps placed near active nests will
reduce rat presence around the tree and importantly allow juveniles
to fledge and have a chance at survival.
Nests could also
be monitored with night vision cameras to provide insights into
chick development while allowing predators entering the nest to be
identified - particularly useful for nests that are difficult to
produce clutches of eggs throughout their breeding season and may
not have established a nest at the time of this study. Further nest
searching at different times of the breeding season will add to our
knowledge of this species in Okiwi.
of kākāriki are an important part of the story that involves the
translocation of kākāriki around the North Island, to areas such as
Tiri Tiri Matangi Island, Tawharanui Regional Park, Motuihe Island
and nearby Little Barrier Island (Te Hauturu-o-Toi)4,5.
The population could also be important for future translocations and
the mixing of genetic material in this species. Without nest
protection, this species may reduce so much in numbers that they
become functionally extinct, which would be a great loss.
Red crowned parakeet at nest hole in
Mature puriri trees are likely to be the
only trees with suitable nesting sites.
Photo: Department of Conservation
of National Parks. 2010. Norfolk Island Region Threatened Species
Recovery Plan. Dept. of the Environment, Water, Heritage and the
L., & Brunton, D. H. 2010. Success of translocations of red-fronted
Cyanoramphus novaezelandiae novaezelandiae from
Little Barrier Island (Hauturu) to Motuihe Island, Auckland, NZ.
Conservation Evidence, 7, 21-26.
T. C. 2003) Breeding biology of red-crowned parakeets (Cyanoramphus
novaezelandiae novaezelandiae) on Little Barrier Island, Hauraki
Gulf, New Zealand. Notornis, 50, 83-99.
C. M., & Powlesland, R. G. 2013. Conservation translocations of New
Zealand birds, 1863–2012. Notornis, 60, 3-28.
L., & Brunton, D. H. 2009. Nesting sites and nesting success of
reintroduced red‐crowned parakeets (Cyanoramphus
novaezelandiae) on Tiritiri Matangi Island, NZ. NZ Journal of
Zoology, 36(1), 1-10.