Intractable: species in New Zealand that continue to decline despite conservation efforts

Figures & data

Table 1. Summary table of actions, outcomes and prospects for the New Zealand taxa used in case studies of conservation issues in this paper.

Case study	Primary conservation issues	Conservation actions	Conservation outcomes	Conservation prospects in next 30 years	Potential positive factors
Māui dolphin (Cephalorhynchus hectori maui)	Economic conflict (fisheries) Stakeholder conflict Low genetic diversity Disease	Habitat protection	Marine mammal sanctuary in core range	Likely extinction	Novel technologies may help Highly charismatic
Toanui (Ardenna carneipes)	Economic conflict (fisheries) Multiple jurisdictions Ecosystem change Pollution	Halt cultural harvest Predator control	Some breeding populations rebound	Continued serious decline	Cultural importance International conservation agreements
Pīngao (Ficinia spiralis, Cyperaceae)	Extreme change to ecosystem Economic conflict (agriculture/urbanisation) Private land Climate change	Coast care groups restore and protect small populations Development of propagation techniques and restoration methods	Scattered small populations Few large populations (larger populations are more resilient to disturbance)	Continued serious decline	Cultural importance Dedicated restoration groups
Kākahi (Echyridella species)	Non-charismatic and inconspicuous Complex life cycle	Laboratory propagation methods under development for E. menziesii	Incidental protection through catchment protection, riparian and water quality management, and fish barrier remediation	Stable in some places for E. menziesii Low for E. aucklandica in northern streams Unknown for E. onekaka	Long-lived Fish passage guidelines^a may lead to improvements in fish host populations
Forest ringlet butterfly (Dodonidia helmsii)	Limited knowledge on range and biology Demes	Surveys of some populations	Decline in most surveyed populations and reduced distribution	Localised extinctions likely without conservation action	Some new populations found
Hihi (Notiomystis cincta)	Ecosystem change/Habitat loss Conservation dependence Low genetic diversity/inbreeding Disease	Predator control & exclusion Monitoring Supplementary feeding Translocation	Five reintroduced populations; all require nest boxes and supplementary feeding	Additional populations may increase numbers	Charismatic
Grand and Otago skinks (Oligosoma grande and O. otaganse)	Conservation dependence Economic conflict (agriculture/mining) Limited resources Demes	Captive management Community/Māori involvement Land purchase/habitat protection Monitoring Predator control & exclusion Translocations	Managed eastern populations are stable (but small) Western populations in decline	Managed eastern populations remain stable; others go extinct Western populations extinct in wild, unknown outcome for managed areas	The past 30+ years of effort has stopped extinction, developed methods for mainland lizard conservation and benefited five other lizard species

Taxa are ordered in the same manner as in the text, from marine to onshore to subalpine. See main text and Table 2 for more details. Note: All species have cultural importance, but we indicate those with particular importance as a source of cultural harvest.

^a https://www.niwa.co.nz/static/web/freshwater-and-estuaries/NZ-FishPassageGuidelines-upto4m-NIWA-DOC-NZFPAG.pdf.

Figure 1. Pīngao (Pīkao; F. spiralis) are of cultural and ecological significance, and are morphologically variable across different parts of New Zealand. A, Woven tukutuku panel – the yellow fibre is pīngao and the white fibre is kiekie (Freycinetia banksia). B, Pīngao in many Te Ika-a-Māui/North Island locations have long spreading rhizomes, such as those pictured from Matakana Island, Bay of Plenty. C, Pīngao from many Te Waipounamu/South Island populations have short rhizomes, such as those pictured from Kaitorete Spit, Canterbury. (Photos: Stacey Bryan©).

Table 2. Summary of stressors and threats affecting seven case study taxa from New Zealand described in this paper.

Threats	Description	Case study taxon
		MD	Toanui	Pīngao	Kākahi	FRB	Hihi	GAOS
Ecosystem change	Change or complete loss of ecosystem structure, function integrity or composition		●	●	●	◌	●	●
Pollution*	Mortality, developmental or reproductive impacts (e.g. nutrient and sediment loads, toxins, light)		●		●
Invasive species*	Mortality, developmental or reproductive impacts (e.g. consumption, competition, hybridisation)		●	●	●	◌	●	●
Exploitation and harassment	Mortality or decreased fitness (e.g. harvesting, hunting, bycatch, road kills, persecution, disease)	●	●	●		◌	●	●
Accelerated climate change*	Further ecosystem change (e.g. change in weather, extreme weather, temperature change)		●	◌	◌			◌
Natural causes	Stochastic events (e.g. geologic events, wildfire, natural irruptions)	●	◌	●	◌	◌	◌	◌
Fragmentation/connectivity	Isolation of small habitats and/or loss of migratory pathways				●	●		●
Limited data on habitat or biology	Insufficient information to adequately classify or provide conservation action				●	●
Other threats*	Conservation dependent; perceived value; clash with economic or developmental priorities	●	●	●	●	●	●	●
Lack of direction	No obvious solution, causing debate and indecision	●				●

Threats are based on Wong (2011), with additional information from Anon (2000). Taxa discussed include: MD (Māui dolphin; C. hectori maui); toanui (flesh-footed shearwater, Ardenna carneipes); pīngao (pīkao, golden sand sedge, F. spiralis); kākahi (three species within genus Echyridella); FRB (forest ringlet butterfly; D. helmsii); hihi (stichbird; N. cincta); GAOS (grand [O. grande] and Otago [O. otagense] skinks). ● = known factors; ◌ = possible factors. *May also modify ecosystems.

Wong C. 2011. Guidance for the preparation of ESTR products – classifying threats to biodiversity. Canadian Biodiversity: Ecosystem Status and Trends 2010. Technical Thematic Report No. 2. Canadian Councils of Resource Ministers, Ottawa, ON. iii + 30 p. http://www.biodivcanada.ca/default.asp?lang = En&n = 137E1147-1.

 Google Scholar

Anon. 2000. New Zealand Biodiversity Strategy 2000-2020. New Zealand Department of Conservation. ISBN O-478-21919-9.

 Google Scholar