Publications Archive

Conservation and management of kakapo (Strigops habroptilus) has spanned more than a century and has cost many millions of dollars. Government policy goals have supported these efforts throughout this long period but decisions made have not always reflected an optimal approach to achieving them. Decisions made have influenced not only whether kakapo will recover, but also the time span to recovery and its cost, which have impacted on the ability to meet broader biodiversity goals. The establishment, in 1987, of a single conservation agency, administering both the land and the species contained thereon, significantly changed the way biodiversity management was delivered in New Zealand and created enormous potential for integrated conservation outcomes. Despite this, decision-making for managers of threatened species conservation programmes has become more complex as an increasing number of endangered species compete for limited resources. Using kakapo as an example, historic and recent recovery decisions are evaluated and the need for a decision-making framework to improve threatened species recovery and overall biodiversity maintenance is discussed.

Foraging deficiencies and supplementary feeding play critical roles in kakapo (Strigops habroptilus) breeding biology and conservation. We present a framework for the analysis of complex nutritional data (called the geometric framework – GF) which may contribute further understanding of the relationships between natural foods, supplementary feeding and kakapo reproduction. We outline the basic concepts of the approach, and illustrate its application using data for the protein, lipid and calcium content of a natural food (green fruits of rimu Dacrydium cupressinum) and a supplementary feed (“muesli”). We provide some pointers for the broader application of GF to the problem of kakapo supplementary feeding, and close with a brief review of a literature which suggests that calcium might be a key limiting factor in kakapo reproduction. We hypothesise that supplementary foods with low macronutrient:calcium ratios are likely to be most effective in supporting increased reproduction.

A growing literature indicates that genetic factors have a significant impact on the persistence of populations and hence play an important role in species recovery. Here, I review the role of genetic research in the recovery program of the critically endangered kakapo (Strigops habroptilus). By using three examples of how genetics has guided kakapo managers (molecular sexing, quantification of genetic diversity and confirmation of paternity from known matings), I highlight the important contribution genetics has made to kakapo recovery. I also explore three new avenues of research (genetic diversity at genes for disease resistance, molecular ageing, and genetic similarity and hatching success), all of which may have important implications for future conservation management of kakapo. As such, this review demonstrates that genetic research is an integral part of kakapo recovery.

The natural diet of the kakapo (Strigops habroptilus) is exclusively herbivorous. The bird breeds synchronously with the heavy fruiting or “masting” of certain plant species, including rimu (Dacrydium cupressinum), at intervals of 2 – 5 years, and did so in 2002 on Codfish Island (Whenua Hou) in southern New Zealand. Crop contents of kakapo chicks of 10 – 30 and 31 – 43 days of age, and samples of rimu fruit (entire fruit, red aril, green aril and seed) were collected and chemically analysed for dry matter, organic matter, crude protein, fatty acids, amino acids, fibre, simple sugars and minerals. The crop content samples contained predominantly carbohydrates (76 – 81 % by dry wt.), crude protein (7 – 13 %) and fatty acids (6 – 7 %). Entire rimu fruit contained 7.2 % crude protein, 10.9 % fatty acids, and 78 % carbohydrate predominantly of cellulose, hemicellulose and lignin. The red aril, green aril and seed nutrient composition were similar with the exception of the seed fatty acid profile. There was a large degree of similarity in the nutritional composition of the entire rimu fruit and the crop contents, supporting field observations of the time that female kakapo were feeding almost exclusively entire rimu fruit to their chicks. The nutrient profiles provide the first detailed descriptions of the diet of growing kakapo chicks which can guide the development of supplements and artificial rearing diets for this species. The diet of kakapo chicks up to 60 days of age appears to have a low concentration of essential nutrients and high indigestible matter content when compared with other species, consistent with specialised anatomical features and foraging behaviour of this parrot.

We studied the distribution along the Pacific coast of South and Central America of three large petrels species that nest on New Zealand and subantarctic islands: white-chinned petrel (Procellaria aequinoctialis), Parkinson’s petrel (P. parkinsoni) and Westland petrel (P. westlandica). During 15 cruises from 1980 to 1995, we conducted 1,020 hrs of surveys over 14,277 km² of ocean from the shoreline to 1500 km off the coast from Chile north to Panama, and recorded 2114, 179, and 20 individuals, respectively, of the three species. White-chinned petrels occurred throughout the study area, but were most abundant off Chile, Parkinson’s petrels were most abundant along the coasts of Ecuador and Peru, and Westland petrels off southern Chile. All three species preferred waters over the continental slope, although Parkinson’s petrel was abundant also over the continental shelf during the austral winter. Densities of each species were positively related to oceanographic properties that are associated with up-welling features. Abundance estimates, analyzed using generalized additive models, peaked during the non-breeding season of each species. Estimates were 722,000 White-chinned petrels during austral autumn (95% confidence interval “CI” = 349,000 – 907,000); 38,000 Parkinson’s petrels during austral autumn (95% CI = 28,000 – 50,000); and 3,500 Westland petrels during the austral spring (95% CI = 2,000 – 6,400). Scavenging appeared to be the primary feeding method of Procellaria, a habit that would make them susceptible to mortality as a result of their regular association with commercial fishing operations, particularly the recently developed long-line fishery on the continental slope of Chile.

A census of Chatham Island shag (Leucocarbo onslowi) and Pitt Island shag (Strictocarbo featherstoni), both endemic to the Chatham Islands, New Zealand, was conducted during their 2003/04 breeding season. Totals of 271 pairs of Chatham Island shags and 547 pairs of Pitt Island shags were recorded. Compared with the only previous survey (in 1997/98), numbers of both species were significantly lower. This decline most likely reflects broad scale marine changes affecting the birds’ food supply. Alternatively, it may suggest variability in the timing of breeding between seasons.

Corrections to figures and legends in McAllan, I.A.W.; Hobcroft, D. 2005. The further spread of introduced birds in Samoa. 52(1): 16-20

Foraging of female rockhopper penguins (Eudyptes chrysocome filholi) during the chick stage was investigated at Antipodes Islands during December 2002 – January 2003. During the guard stage eight birds were tracked to foraging areas 22 – 54 km NNE or E from their nests. Birds foraging NNE did so over waters 500-1500 m deep, while those that travelled E foraged in water > 1500 m deep. The mean duration of these foraging trips was 1.37 days, significantly (p 1500 m deep. Male parents guarded the chicks more or less continuously, with most females returning to feed the chicks from mid afternoon. In the post-guard stage, most male parents returned to the nest each evening, but fewer females attended the nest at this time. Weight increases indicated that chicks were fed, on average, about once per day during both the guard and early post-guard stages. The foraging trips of female rockhopper penguins at Antipodes Islands were usually of longer duration and extended farther from the nest than birds breeding at Amsterdam, Kerguelen and Crozet Islands, but occupied a similar time and covered a greater distance than birds breeding at Staten Island. However, they were of considerably shorter duration and distance than birds breeding at Macquarie Island. This may be related to the differing marine environments around each of these breeding locations.