conservation

The Hochstetter’s frog (Leiopelma hochstetteri) is a nationally At Risk – Declining species, but management decisions for this species are limited by the lack of established monitoring protocols and analytical methods. We compared methods for inferring spatial and temporal patterns in abundance on Aotea (Great Barrier Island) using count data collected from fifteen 100 m stream transects in 2012, 2015 and 2021. Each transect was surveyed 2–3 times on the same day each year.

Little is known about the impacts of fire on New Zealand’s lizard fauna. Anecdotal evidence suggests that the direct impact of fire and subsequent loss of habitat are drastically negative for arboreal and grassland species. The impact of fire on saxicolous (ground-dwelling) species is less understood and difficult to presume given we understand little about the protective nature of rocky refugia and species’ reliance on fire-susceptible habitat.

Predator-free sanctuaries can assist the conservation of multiple endemic species, but quantitative evidence of these benefits is often lacking, especially for herpetofauna. We measured population responses of three common lizard species (schist geckos, Woodworthia ‘Central Otago’; McCann’s skinks, Oligosoma maccanni; and southern grass skinks, O. aff. polychroma Clade 5) 1 year before and 5 years after mammalian predators were removed inside a mammal-proof fence in a dry grass/shrubland habitat with abundant schist rock in Central Otago, New Zealand.

Translocations are becoming increasingly common although the effectiveness of this conservation tool for amphibians is highly variable. We reviewed ten translocations of Leiopelma frogs occurring between 1924 and 2016. Data were gathered on factors which may have influenced translocation outcomes. Results at each location were measured against an established four-step framework for stages of success: survival of individuals, reproduction, population growth, and population viability.

Amphibians are considered susceptible to a range of potential effects generated by climate change. We applied species distribution model (SDM) techniques to predict future areas of climatic suitability for Archey’s and Hochstetter’s frogs under two different climate change scenarios using climate variables derived from their existing geographic extent. For Hamilton’s frog their current range was too restricted to model future range, so we used past climate data from current strongholds to establish that these sites may not be suitable for this species in the long-term.

Control of introduced predators is part of the management strategy for many conservation programs. However, when such programs are designed to protect a single species, the benefits to sympatric native species are usually not assessed. We used site occupancy modelling to investigate whether predator control implemented to protect a native bird species (North Island kōkako) in the Hūnua Ranges, New Zealand also benefits the sympatric native Hochstetter’s frog population.

Habitat disturbance is a significant factor contributing to biodiversity decline worldwide. Amphibians are particularly vulnerable because of their specific microclimatic and microhabitat requirements. In Aotearoa New Zealand, Archey’s frogs (Leiopelma archeyi) have shown some degree of resilience to severe habitat disturbance historically. However, it is unknown how much L. archeyi populations are currently being impacted by historical and ongoing mining activities and development within their range.

Indigenous Knowledge (IK) provides effective solutions to environmental threats and pressures. Using approaches that fully include Indigenous concepts, ideas, worldviews, knowledge, process, and practice helps the recovery of threatened species and endangered ecosystems, but it is essential that such work engages with Indigenous Peoples and that engagement is respectful, reciprocal, and meaningful.

To test the long-term efficacy of mammalian pest control, annual distance sampling estimates of the density of North Island kākā (Nestor meridionalis septentrionalis) within the southern Waipapa Ecological Area (WEA), Pureora Forest Park from 2008–2020 are compared to previously published estimates made at the same sites and time of year (October) between 2000–2007. Kākā density increased approximately four-fold from an average of c. 0.5 (95% CI 0.5–0.6) birds ha⁻¹ between 2000 and 2007 to c. 2.3 (95% CI 1.9–2.8) birds ha⁻¹ in 2020.

Auckland Island, the fifth largest island in New Zealand, is the only island in New Zealand’s subantarctic region where introduced mammalian pests remain (pigs, Sus scrofa; mice, Mus musculus; cats, Felis catus). The island has unique biodiversity and is a key site for progressing New Zealand’s goal to be free of several introduced predators by 2050. Recent island eradication successes have rekindled interest in eradicating pests from Auckland Island, and for the first time considering all three pests in one project.