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Direct observations of shining cuckoos (Chrysococcyx lucidus) parasitising and depredating grey warbler (Gerygone igata) nests

Notornis, 54 (1), 15-19

J.V. Briskie (2007)

Article Type: Paper

The grey warbler (Gerygone igata) is the main host of the shining cuckoo (Chrysoccocyx lucidus) in New Zealand. I describe 4 observations of egg-laying by shining cuckoos in the nests of grey warblers, and 2 observations of adult cuckoos evicting, or attempting to evict, nestling warblers from non-parasitised nests. Nest were parasitised from 0658 to 1731 h NZDT, and the cuckoos took 5–18 s to lay their egg. In 3 nests in which it could be determined, the cuckoo left the nest with an egg in its bill. Warblers were present at 2 nests during parasitism and responded by attacking the cuckoo. Cuckoos evicted nestlings by pulling them out through the nest entrance and throwing them on the ground. Head- wounds on evicted chicks suggest they were pecked. Nestling eviction by adult shining cuckoos has not been previously reported and it may be a strategy to increase nest availability by inducing hosts to relay.

The habitat, food and feeding ecology of kakapo in Fiordland: a synopsis from the unpublished MSc thesis of Richard Gray

Notornis, 53 (1), 55-79

D.J. Butler (2006)

Article Type: Paper

Gray studied the last natural mainland population of kakapo in Fiordland in the 1970s. Between 1974 and 1977 all 15 male birds located occupied home ranges high on the sides of valleys in areas of diverse vegetation associated with the tree line or avalanche and alluvial fans. Track-and-bowl systems were frequently positioned on the crests of ridges and knolls on well-drained sunny slopes. Studies of feeding sign and of faecal content using cuticle analysis provided detail of kakapo diet, confirming the bird to be an herbivore. About 80 species of plants were eaten in Fiordland. The kakapo bill is adapted to crushing and extracting nutrients and retaining fibre which is expelled as distinctive ‘chews’. A preliminary study of the nutrients in kakapo food suggested that the birds selected the most nutritious plant parts and species.

A simulation of the future of kakapo

Notornis, 53 (1), 164-172

G.P. Elliott (2006)

Article Type: Paper

The recent productivity and survival of the critically endangered kakapo (Strigops habroptilus) is summarised and its population trajectory in a variety of circumstances is modelled by simulation. Simulated kakapo population growth rates decline with decreasing intensity of management, and unmanaged kakapo on Codfish Island increase only slowly and have a significant risk of declining. Kakapo on islands where more than one fruiting species triggers their breeding have much higher growth rates than kakapo on islands where only rimu (Dacrydium cupressinum) triggers their breeding. The models predict that kakapo will reach a predetermined population milestone of 53 females in 2 – 6 years depending on the number of fruiting species that trigger breeding. At this milestone the intensity of conservation management will be reduced. Conservation management will be further reduced at a second predetermined milestone of 150 females in 19 – 37 years.

Diet of kakapo in breeding and non-breeding years on Codfish Island (Whenua Hou) and Stewart Island

Notornis, 53 (1), 80-89

D.J. Wilson; A.D. Grant; N. Parker (2006)

Article Type: Paper

Results from an analysis of plant remains found in faecal droppings of kakapo (Strigops habroptilus) collected from 1981 to 1998 on Codfish Island (Whenua Hou) and Stewart Island, were analysed statistically to identify patterns in the birds’ diet related to breeding. Females were more likely to have eaten podocarp fruit or leaves of trees or shrubs; males to have eaten fern and Lycopodium rhizomes, monocots (in breeding years), and manuka fruit (in non-breeding years). Podocarp fruits were much more prevalent in kakapo diets in breeding than in non-breeding years. When podocarp fruits were available in breeding years, kakapo were less likely to have eaten several other foods. Conversely, Blechnum fern fronds appeared more frequently in the droppings of females in breeding than in non-breeding years. As podocarp fruits increased in prevalence in the diets of both males and females during the summers of breeding years, the incidence of many other foods declined. The incidence of Hall’s totara leaf in the diet of females increased during summer in non-breeding years, but decreased in breeding years.

At what age should brown kiwi (Apteryx mantelli) eggs be collected for artificial incubation?

Notornis, 53 (2), 231-234

H.A. Robertson; R.M. Colbourne; A. Nelson; I.M. Westbrooke (2006)

Article Type: Paper

We recorded the fate of brown kiwi (Apteryx mantelli) eggs collected from Northland forests for artificial incubation at Auckland Zoo. The hatchability of eggs of different ages were combined with known rates of egg losses in the wild to derive models which predicted that optimal hatching success (>64%) was when the oldest egg in a brown kiwi nest was 41-57 days old at the time the eggs were collected. Collection before this interval risked egg failure resulting from unknown developmental problems associated with artificial incubation of freshly-laid eggs, whereas later collection of clutches risked failures in the wild before the eggs were collected.

Breeding ecology of three subantarctic snipes (genus Coenocorypha)

Notornis, 53 (4), 361-374

C.M. Miskelly; K.J. Walker; G.P. Elliott (2006)

Article Type: Paper

Information on the breeding ecology of Auckland Is snipe (Coenocorypha aucklandica aucklandica), Antipodes Is snipe (C. aucklandica meinertzhagenae), and Campbell Is snipe (Coenocorypha undescribed sp.) is summarised. Auckland Is snipe laid between Sep and Jan (peak late Nov), whereas Antipodes Is snipe laid from Aug to early Nov, with a 2nd pulse of breeding from late Jan to Mar. The 5 breeding events recorded for Campbell Is snipe were from clutches estimated to have been commenced between 11 Nov and 8 Jan. All 3 taxa laid 2 large eggs (each 19-22% of female body weight) in nests that were well concealed amid dense vegetation. Chicks left the nest soon after hatching, with each chick cared for by a single adult. Exceptions to this were adult Auckland Is snipe seen with 2 or 3 young chicks on 3 occasions. Chicks remained with adults until down-free and capable of flight. The only notable differences from the more thoroughly-studied Snares Is snipe (C.aucklandica huegeli) and Chatham Is snipe (C. pusilla) were the earlier breeding by Antipodes Is snipe, and its bimodal breeding season. Snipe were encountered more frequently on the Auckland Is (0.6 person–h-1 of walking on Adams I) than on Antipodes I (0.2 person–h-1) and this was also reflected in the frequency with which breeding events were recorded. We suggest that the impact of house mice (Mus musculus) on the invertebrate food supply available for snipe is the most plausible explanation for the much lower abundance of snipe on Antipodes I.
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