de Lange P.J.,Science and Capability Group
PhytoKeys | Year: 2014
A revision of the New Zealand Kunzea ericoides complex is presented. This paper is the final of a series that has explored the systematics of the New Zealand Kunzea complex using cytological and molecular variation, as well as experimental hybridisations between postulated segregates. As a result of those studies ten species, all endemic to New Zealand, are recognised; seven of these are new. One species, K. triregensis sp. nov., is endemic to the Three Kings Islands and another species K. sinclairii, endemic to Aotea (Great Barrier Island). The North Island of New Zealand has seven species, K. amathicola sp. nov., K. salterae sp. nov., K. serotina sp. nov., K. robusta sp. nov., K. tenuicaulis sp. nov., K. toelkenii sp. nov., and K. linearis comb. nov. Of these, K. linearis, K. salterae, K. tenuicaulis and K. toelkenii are endemic to the North Island, and K. amathicola, K. robusta and K. serotina extend to the South Island which also supports one endemic, K. ericoides. Typifications are published for Leptospermum ericoides A.Rich., L. ericoides var. linearis Kirk, L. ericoides var. microflorum G.Simps., L. ericoides var. pubescens Kirk, and L. sinclairii Kirk, names here all referred to Kunzea. The ecology, conservation, extent of natural hybridisation and some aspects of the ethnobotany (vernacular names) of these Kunzea are also discussed. © Peter J. de Lange.
Grayson K.L.,Victoria University of Wellington |
Grayson K.L.,Virginia Commonwealth University |
Mitchell N.J.,University of Western Australia |
Monks J.M.,Science and Capability Group |
And 3 more authors.
PLoS ONE | Year: 2014
Understanding the mechanisms underlying population declines is critical for preventing the extinction of endangered populations. Positive feedbacks can hasten the process of collapse and create an 'extinction vortex,' particularly in small, isolated populations. We provide a case study of a male-biased sex ratio creating the conditions for extinction in a natural population of tuatara (Sphenodon punctatus ) on North Brother Island in the Cook Strait of New Zealand. We combine data from long term mark-recapture surveys, updated model estimates of hatchling sex ratio, and population viability modeling to measure the impacts of sex ratio skew. Results from the mark-recapture surveys show an increasing decline in the percentage of females in the adult tuatara population. Our monitoring reveals compounding impacts on female fitness through reductions in female body condition, fecundity, and survival as the male-bias in the population has increased. Additionally, we find that current nest temperatures are likely to result in more male than female hatchlings, owing to the pattern of temperature-dependent sex determination in tuatara where males hatch at warmer temperatures. Anthropogenic climate change worsens the situation for this isolated population, as projected temperature increases for New Zealand are expected to further skew the hatchling sex ratio towards males. Population viability models predict that without management intervention or an evolutionary response, the population will ultimately become entirely comprised of males and functionally extinct. Our study demonstrates that sex ratio bias can be an underappreciated threat to population viability, particularly in populations of long-lived organisms that appear numerically stable. © 2014 Grayson et al.
Chilvers B.L.,Science and Capability Group |
Dobbins M.L.,Southern Islands Area Office |
Edmonds H.K.,Te Anau Area Office
New Zealand Journal of Zoology | Year: 2015
Yellow-eyed penguins (hoiho, Megadyptes antipodes) are a Nationally Vulnerable species, restricted in distribution to the lower South Island, Stewart Island/Rakiura, and the New Zealand sub-Antarctic islands. The foraging behaviour of penguins is considered an indicator of marine ecosystems because when breeding they rely on the availability of prey close to their nests. Time-depth recorders were attached to eight nesting hoiho at Port Pegasus/Pikihatiti, Stewart Island. While at sea, hoiho spent 55% of their time diving in water > 3 m deep. Their mean dive depth was 61 ± 6.1 m with mean dive duration 2 ± 0.1 min. Based on bathymetric charts, hoiho could undertake these dives < 10 km from their nesting sites. There was significant variability in hoiho foraging behaviour within New Zealand depending on bathymetry and anthropogenic impacts. Understanding hoiho foraging behaviours could help to determine to what extent they impact on this species' life history and its role as an ecosystem indicator. © 2014 © 2014 The Royal Society of New Zealand.
Jarvie S.,University of Otago |
Jarvie S.,Science and Capability Group |
Monks J.M.,Science and Capability Group
New Zealand Journal of Zoology | Year: 2015
There are few effective or efficient established methods for monitoring cryptic herpetofauna. Footprint tracking tunnels are routinely used to index small mammal populations, but also have potential for monitoring herpetofauna. We evaluated the utility of tracking tunnels for identification of New Zealand lizards using captive- and wild-sourced animals (four skink and eight gecko species). All skink prints that we obtained were indistinct or obscure, but we obtained relatively clear, measurable prints for all gecko species. We found that identification to species level was possible for the two gecko species for which we had a large sample - Naultinus gemmeus and Woodworthia Otago large - using linear discriminant analysis (the best model correctly assigned 96.1% of individuals). Our findings suggest that footprints from tracking tunnels may be used to distinguish between species of geckos. Additional research is needed to assess the ability to further discriminate intra- and inter-genera lizard footprints from tracking tunnels, and the utility of the technique for surveying and monitoring lizard populations. © 2014 © 2014 The Royal Society of New Zealand.
Buxton R.T.,University of Otago |
Jones C.,Landcare Research |
Moller H.,Science and Capability Group |
Towns D.R.,University of Otago |
Towns D.R.,Auckland University of Technology
Conservation Biology | Year: 2014
Eradication of introduced mammalian predators from islands has become increasingly common, with over 800 successful projects around the world. Historically, introduced predators extirpated or reduced the size of many seabird populations, changing the dynamics of entire island ecosystems. Although the primary outcome of many eradication projects is the restoration of affected seabird populations, natural population responses are rarely documented and mechanisms are poorly understood. We used a generic model of seabird colony growth to identify key predictor variables relevant to recovery or recolonization. We used generalized linear mixed models to test the importance of these variables in driving seabird population responses after predator eradication on islands around New Zealand. The most influential variable affecting recolonization of seabirds around New Zealand was the distance to a source population, with few cases of recolonization without a source population ≤25 km away. Colony growth was most affected by metapopulation status; there was little colony growth in species with a declining status. These characteristics may facilitate the prioritization of newly predator-free islands for active management. Although we found some evidence documenting natural recovery, generally this topic was understudied. Our results suggest that in order to guide management strategies, more effort should be allocated to monitoring wildlife response after eradication. © 2014 Society for Conservation Biology.