New Zealand

Little penguin (Eudyptula minor) diet at three breeding colonies in New Zealand

At-sea shifts in food quality and availability can affect populations of marine birds; however, it is difficult to evaluate the impacts of changes in prey composition and availability without some baseline information on diet composition. The little penguin (Eudyptula minor) is a common inshore-feeding seabird in New Zealand and Australia. To date, only two dietary studies have been undertaken on the little penguin in New Zeaalnd, at two widely separated locations.

Assessment of protected area coverage of threatened ground beetles (Coleoptera: Carabidae): a new analysis for New Zealand

Gap analysis is a tool that allows conservationists to quantify the effectiveness of protected areas at representing species diversity, but the lack of distribution maps for invertebrates has precluded its application to the world’s most diverse animal groups. Here, we overcome this limitation and conduct a gap analysis, using niche modelling, on the Pterostichini (Coleoptera: Carabidae) of New Zealand, one of the most diverse and most threatened tribes of ground beetles in the nation.

Response of a reintroduced bird population to rat reinvasion and eradication

Many endemic species on islands are vulnerable to predation and local extinction by introduced rats (Rattus spp.). As a result, the reintroduction of species to predator-free sanctuaries is a successful conservation strategy, especially in New Zealand. Nevertheless, reintroduced populations, even those that reach high densities, are still vulnerable to predation in the event of a rat reinvasion, and may also be susceptible to non-target poisoning during a subsequent eradication operation.

Age-specific differences in settlement rates of saddlebacks (Philesturnus carunculatus) reintroduced to a fenced mainland sanctuary

Mortality and/or dispersal immediately after release can cause translocated populations to fail over both the short and long term, particularly at mainland sanctuaries. However, post-release mortality and dispersal can be limited by releasing individuals with an increased probability of survival and site attachment. We monitored a South Island saddleback (tieke; Philesturnus carunculatus carunculatus) population, translocated to a mainland sanctuary, for one year after release to understand the combined influence of post-release mortality and dispersal on initial establishment.

Cleared and uncleared pellet plots as indices of brown hare density

Faecal pellet counts are commonly used as indices of lagomorph abundance but uncertainty over variation in decay rates among sites has led to most researchers recommending the use of pellet accumulation rates in previously cleared plots rather than the simpler and quicker method of counting uncleared plots. We use data from cleared and uncleared 0.1-m2 brown hare pellet plots at six sites in the central North Island of New Zealand to test the reliability of the two methods.

Are introduced birds unimportant mutualists? A case study of frugivory in European blackbirds (Turdus merula)

Many types of birds regularly consume fleshy fruits and, as seed dispersers, perform important mutualistic services for plants. Some frugivorous birds have recently been introduced to geographic locales beyond their native range. Are non-native birds important frugivores in their introduced range? To answer this question, I observed native and introduced birds foraging for fruits in a New Zealand forest at approximately 5-day intervals for 5 years.

Effectiveness of cyanide pellets for control of dama wallabies (Macropus eugenii)

Dama wallabies (Macropus eugenii) are an introduced pest in New Zealand requiring control. Historically, sodium fluoroacetate (1080) has been used to control wallabies but there is increasing resistance to this method of pest control. Pen trials have shown that Feratox® cyanide pellets are an effective and humane toxin for use on dama wallabies. The aim of this study was to test the effectiveness of these cyanide pellets in field trials for controlling dama wallabies.

Exploring the concept of niche convergence in a land without rodents: the case of weta as small mammals

The distinctiveness of New Zealand’s large endemic orthopterans and lack of small mammals in our forest ecosystems led to the description of weta as ecologically equivalent to rodents in other countries. We review the use of this metaphor and the characteristics, such as diet and reproductive behaviour, given to support it. We note, however, that species are rarely specified when comparisons are made, thereby neglecting the ecological diversity of both weta and rodents.

Microclimate characteristics of alpine bluff ecosystems of New Zealand's South Island, and implications for plant growth

Descriptions of alpine climate in areas of high solar radiation are increasing, but there is a paucity of microclimate data for shaded alpine rock bluff ecosystems. These shaded systems are important because they represent plant habitats that are subject to unique climate drivers within the alpine ecosystem, but which are poorly characterised globally.

Testing the power of an experiment to measure predator control and habitat complexity impacts on farmland bird abundance

In this study I assess the statistical power to detect a significantly greater increase in bird population size on treatment farms than on control farms given that there is a substantial treatment effect. Computer simulations of bird populations on New Zealand sheep/beef farms were used to generate significant changes in bird abundance from (a) controlling predation by introduced small mammals, (b) habitat structural complexity, and (c) an interaction of both.