Current and predicted trends of taxa under management

Kākāpō (Strigops habroptilus)

Context

The kākāpō (night parrot) is one of New Zealand’s unique endemic treasures with fewer than 150 known surviving birds. It is listed internationally as a critically endangered species. Its New Zealand threat status is listed as Threatened-Nationally Critical. Kākāpō are found on Whenua Hou (Codfish Island) near Stewart Island, Anchor Island and Te Kakahu (Chalky Island) in Fiordland, and Little Barrier Island (Hauturu-o-Toi) near Auckland. Its major threats are infertility, disease and low genetic diversity.

Key findings

The population demographics are continuing to improve for the Critically Endangered kākāpō thanks to intensive management and recent successful breeding seasons resulting in an improved population sex ratio, age structure and survival. However, low fertility and disease remain problems, and genetic management is in place to minimise the loss of genetic variation.

020406080Adult: Known ageAdult: Unknown ageJuvenile
MaleFemaleNumber of kakapo

Figure 1: Population composition of kākāpō by sex and age class.

01234519952000200520102015
JuvenileAdultNumber of deaths/yearYear

Figure 2: Number of kākāpō deaths by age class since 1990.

05010015019801985199019952000200520102015
Transferred to offshore islandStewart Island/RakiuraHatched on offshore islandsFiordlandNumber of kakapoYear

Figure 3: Total population of kākāpō since 1976.

Definition and methodology

Between 1974 and 1990, the key demographic parameters of kākāpō were simply estimated. However, since 1990, the entire kākāpō population has carried radio transmitters and been closely monitored so that the number of known living birds is likely to be equivalent in size to the entire population. kākāpō research and management is now focussed on tools to help improve the fertility of the population which has been subject to a severe genetic bottleneck. Artificial insemination techniques have been developed to manage copulations for enhanced genetic diversity and a plan to survey the complete genome of the species is now well underway.

Data quality

This measure is classified as a case study.

Relevance

This measure relates to indicator 1.4.2 - Security of threatened and at risk taxa.

Accuracy

Intensive management and low numbers of individuals allow for regular and complete censuses of the entire population, making the resultant assessment of key demographic parameters extremely accurate.

This measure complies with the data quality guidelines used in New Zealand’s Environmental Reporting framework.

Outcomes Monitoring Framework

The Department of Conservation’s (DOC’s) Outcomes Monitoring Framework provides a platform on which DOC and others can assess outcomes in a clear, structured and transparent way (Lee et al., 2005). It has been developed as a logical hierarchy that is based on broad, overarching Outcomes, beneath which are nested Outcome Objectives, Indicators, Measures and Data Elements to provide ever increasing levels of detail. The framework is scalable, as the indicators and measures remain compatible and consistent whether applied locally, regionally or nationally. The recently updated framework provides a roadmap for gathering information to meet the specific objectives of DOC and other agencies (McGlone and Dalley, 2015). The provision of a national framework with agreed outcomes, indicators and measures supports collaboration with land management and regulatory agencies, allowing for more integrated environmental policy and ‘State of the Environment’ reporting. DOC has partially implemented a national monitoring and reporting system, whereby priority indicators and measures are routinely used to report on progress against the objectives and outcomes. This factsheet reports on a measure for the 2017/2018 year.

Glossary of terms

Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically.

A population bottleneck (or genetic bottleneck) is a sharp reduction in the size of a population due to environmental events (such as disease, habitat loss or predation). Such events can reduce the variation in the gene pool of a population; thereafter, a smaller population, with a correspondingly smaller genetic diversity, remains to pass on genes to future generations of offspring through sexual reproduction.

References

Lee, W., McGlone, M., Wright, E., 2005. Biodiversity inventory and monitoring: A review of national and international systems and a proposed framework for future biodiversity monitoring by the Department of Conservation. Landcare Research Contract Report LC0405/122 (unpublished) for the Department of Conservation, Wellington.

McGlone, M., Dalley, J., 2015. A framework for Department of Conservation inventory and monitoring: Intermediate outcomes 1-5. Landcare Research Contract Report LC2427 (unpublished) for the Department of Conservation, Wellington.