Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Issue 2, February 2011

Invasive Mammal Impacts (IMI) is a collaborative research programme looking at invasive mammal impacts on biodiversity.

In this issue:

  • Update: Dryland Strand
  • Update: Global Change Strand


Welcome to Newsletter No. 2 of the FRST-funded programme on invasive mammal impacts on biodiversity (IMI). IMI is a collaborative programme of research involving Landcare Research, the New Zealand Department of Conservation (DOC), several New Zealand and Australian universities, regional councils, and community conservation groups throughout New Zealand. This second issue gives you an overview of how our work is progressing. In this issue we also highlight our students and postdocs.

What is the IMI programme about?

For a summary of the aims of the IMI programme, see Newsletter #1

The programme is divided into four research strands: Forests (leader: Wendy Ruscoe), Drylands (leader: Grant Norbury), Global Change (leader: Andrea Byrom), and Theory (leader: Roger Pech). The Forests, Drylands, and Global Change strands involve major field-based projects, while the Theory Strand provides the theoretical and conceptual ‘glue’ to ensure synthesis and overview of all the research projects in the programme.

Roger Pech
Programme Leader

Upcoming events

IMI Programme Meeting: 7 & 8 March 2011

In March we will hold a meeting involving all participants in the programme. It’s not too late to let us know you’d like to come along! The aim of the meeting will be to give you an overview of some of the exciting research projects spanning the breadth of the programme, and also to seek feedback from everyone about anything – design, methods, relevance to management of invasive mammals – whatever you like. There will be plenty of time for questions and discussion. The meeting will be held just outside of Christchurch near the earthquake epicentre. Call Andrea Airey (03 321 9618), Andrea Byrom (03 321 9629) or Roger Pech (03 321 9855) or email if you are keen to attend.

Biosecurity Bonanza

We are aiming to hold another one-day Biosecurity Bonanza, this time in Auckland in June. You will be able to choose between two concurrent sessions as this workshop includes talks on weeds as well as the latest research findings on mammal pests. There is no charge to attend this workshop. If you would like to be sent further information about the date, venue and programme please contact Andrea Airey (

Recent events

External Advisory Group (EAG)

What is the EAG? It’s a requirement of all our Foundation contracts that we have a group of stakeholders associated with the programme who can give us input, feedback and guidance on research directions. In November 2010, the inaugural EAG meeting was held at Lincoln for several of Landcare Research’s FRST-funded invasive species programmes (Beating Weeds, Invasive Mammal Impacts, Strategic Technologies for Managing Pests, Control of small mammal pests, Sustaining Tb Freedom, Species-selective Control and Tb and multi-pest suppression systems). Attendees were Susan Timmins (DOC), Campbell Leckie (HBRC), Richard Bowman (Environment Southland), Geoff Ridley (ERMA), Eric van Eyndhoven (MAFBNZ), Hazel Johnstone (MAF Policy), Denis Peters (Nga Whenua Rahui), Paul Livingstone (AHB), and Greg Blunden (NZ Kiwi Foundation). Others were Graeme Bôurdot (AgResearch), Roger Pech, Simon Fowler, Graham Nugent, Penny Fisher, Janine Duckworth, Brian Hopkins, Phil Cowan, and Andrea Byrom (Landcare Research). Steve Urlich (FRST) attended the meeting as an observer. We discussed the role of EAG and developed terms of reference for the group, but agreed that it will have a somewhat transitional role as the new Core Purpose funding model for Crown Research Institutes is developed. The EAG’s role will become pivotal as parts of Landcare Research’s invasive species programmes move towards core funding over the next few years, so the group will meet again in May 2011.

Visit to IMI programme by Chris Dickman, University of Sydney

Chris Dickman (Professor of Terrestrial Ecology, School of Biological Sciences) braved New Zealand in mid-winter 2010 to provide advice, input and ideas to the IMI programme. To ease the temperature transition from Sydney to New Zealand Wendy Ruscoe, Roger Pech and Andrea Byrom first took him to visit Greg Blunden (NZ Kiwi Foundation), Don McKenzie (Northland Regional Council) and Todd Hamilton (Whangarei Heads Landcare Forum: ) in Northland, to observe some of the inspirational community-driven work there and to discuss potential involvement of IMI researchers in community pest control and biodiversity conservation. Grant Norbury, Dean Anderson and others then hosted Chris down south, in Dunedin and at Macraes Flat, to discuss new IMI Drylands work at Macraes Flat (see pictures in the Dryland Strand Update below). Chris’s input at this early stage of the IMI programme was invaluable, and many of the ideas he suggested are now being put into place.

Update: Forest Strand

Project Kākā in the Tararua Ranges

Setting up a transect to measure seedfall and stick insect eggs in the Tararua RangesProject Kākā is a Department of Conservation initiative involving intensive pest control in a 22,000 ha zone in Tararua Forest Park where DOC intends to restore the forest and its native wildlife. A range of invasive mammals occur in the Tararua Ranges; including possums that damage the forest canopy, reduce populations of threatened plants such as mistletoe, and, along with rats and stoats, kill birds, reptiles and invertebrates. The Project Kākā zone was treated by the aerial application of 1080 (with prefeed) in November 2010 and this will be repeated every 3 years. Intensive monitoring of birds, weta and vegetation will occur across the boundary of the project zone to determine the extent of protection provided by pest control.

Aerial view of the Tararua Ranges, site of Project KākāWendy Ruscoe, Mandy Barron, and Pen Holland (Landcare Research) are working in conjunction with James Griffiths, Colin Miskelly and Ben Reddiex (DOC) to answer research questions about pest reinvasion (and therefore biodiversity protection) at the boundary of the control operation. Using the same monitoring methods as DOC (seedfall traps, weta houses), biodiversity benefits (native species) are being quantified along 5-km transects (2.5 km inside and 2.5 km outside) the operational zone. Transects were put in place in Spring 2010. Along the same transects, invasive mammal species are being monitored. In the first post-control monitoring session (November 2010) we observed reasonable reductions in abundance of possums, rats and stoats on our monitoring lines. Fieldwork will continue for the next four years.

Wide-scale predator control and biodiversity monitoring in Hawke’s Bay

In a joint initiative, Campbell Leckie, Rod Dickson, Allan Beer (Hawke’s Bay Regional Council), Jan Hania, Bryan Welsh, Ian Cooksley, Denise Fastier (DOC), Wendy Ruscoe (Landcare Research) and a number of community groups, including the Tutira-Maungaharuru Visionary Group, have launched a new environmental programme in the Hawke’s Bay with funding from the Robertson Foundation. This programme aims to restore native habitats and species within the Hawke’s Bay fragmented farming landscape. The first stream of work will be determining the feasibility and cost-effectiveness of extensive predator control over an 8000-ha area around the Boundary Stream Mainland Island, co-funded by HBRC and an Envirolink grant. This area was selected because of the enthusiasm of local community groups and because it has been identified as a priority area within the DOC Wellington/Hawke’s Bay Conservancy.

Intensive mustelid and rat control is undertaken in Boundary Stream Mainland Island. These pests as well as native biota have been monitored by DOC staff in forest reserves for 15 years, providing a good baseline dataset. Monitoring will be supplemented by Wendy and the team in the Forest Strand of the IMI programme to determine whether broad-scale control is sufficient to allow native bird and invertebrate populations to survive outside intensively managed areas and move through the fragmented landscape. Al Glen (Landcare Research) and Tom Etherington (University of Auckland) will use mathematical models developed in the IMI-Theory programme to simulate animal movement through these patchy landscapes and to test predictions based on meta-population theory.

Update: Dryland Strand

New research sites established at Macraes Flat

Chris Dickman (University of Sydney) and Grant Norbury preparing tracking tunnels for feral cats at Macraes Flat.One of New Zealand’s largest predator control programmes takes place at Macraes Flat in eastern Otago to protect critically endangered grand and Otago skinks. The Department of Conservation traps predators over 4000 ha, and has eradicated them within two pest-proof fences nearby. This is a huge and ongoing investment. Fortunately the skinks have responded very well, but the responses are space-dependent – populations towards the edge of the management area have not responded as well as those in the core because of immigrant predators at the edge. DOC is interested in how other species, both native and introduced, have responded to this management. Are fauna such as weta, geckos and other skink species responding in the same way? Are pests like mice and rabbits increasing in response to fewer predators? If this is the case, their impacts might offset recovery of other native species. An experiment has been designed by Grant Norbury and Deb Wilson to help DOC answer these questions. We have randomly chosen 130 monitoring sites at Macraes Flat, stratified by three habitat types, and completed a pilot study on a subset of these sites straddling high and low predator abundances. The preliminary data collected on fauna responses are currently being analysed and some results will be provided in the next newsletter. This will guide our thinking about how to proceed to the next stage of the research. The outcome for DOC will be a better understanding of the wider effects of their management on the broader ecosystem, including habitat-specific and spatially dependent patterns.

Analysis of DOC predator control data from Macraes Flat

As part of Landcare Research’s collaboration with the Department of Conservation’s skink recovery programme, Andy Hutcheon (DOC), Grant Norbury and Dean Anderson are analysing a huge kill-trap dataset to guide best practice on the minimum area over which trapping should be deployed to achieve meaningful benefits, and on optimum bait and trap combinations that achieve maximum kills. Grant is also helping DOC with a bio-economic analysis of the merits of protecting native lizards by kill-trapping versus pest-proof fencing. The cost structures of these two methods are very different, and the analysis is yielding useful results on scale-dependent benefits of one approach over the other that will help guide the next phase of DOC’s management.

DOC’s predator-proof fence at Macraes Flat to protect native lizards Andy Hutcheon (DOC) and Andrea Byrom inside the predator-proof fence at Macraes Flat
DOC’s predator-proof fence at Macraes Flat to protect native lizards Andy Hutcheon (DOC) and Andrea Byrom inside the predator-proof fence at Macraes Flat

Drylands Biodiversity Forum

In partnership with the Department of Conservation and Central Otago’s Sustainable Living Programme, Grant Norbury jointly organised a public Biodiversity Forum to increase awareness about dryland biodiversity and to debate its future conservation needs. The forum had five speakers, followed by an open panel discussion. Speakers were:

Geoff Rogers (DOC): Whence Central's relict biodiversity – misty notions of 700 years of landscape change
John Barkla (DOC): Down but not out – finding and repairing Central's biodiversity fabric
Grant Norbury (Landcare Research): The future of Central’s biodiversity in a landscape of weeds and pests
Russell Hamilton (high country farmer): Biodiversity enhancement: high-country farming for the future
David Parker (Labour Party MP): Utilising the levers of government – action not talk

The forum was attended by over 60 people, and included politicians, district councillors, high country farmers, and DOC. A spirited and lively debate ensued. A recording of the evening is available (contact ).

Did you know that Grant Norbury is also the chairperson of the Central Otago Ecological Trust? More information about COET can be found here.

Removal of grazing increases species richness in dryland ecosystems

Grazed pasture in South Canterbury. R: Site that has not been grazed for 30 yearsA medium-term goal of our researchers in the Dryland Strand is to determine the influence of invasive species on vegetation succession. Seral non-forest ecosystems in the eastern South Island are perfect ‘outdoor laboratories’ for understanding shrub succession because they are currently being retired from pastoral use through Tenure Review. This amounts to thousands of hectares of grassland/shrubland ecosystems that are often under-represented in legal protection. Yet former pastoral lease lands potentially have high conservation values and require management that takes into account future transition to shrub dominance. Andrea Byrom, Richard Clayton, Roger Pech and Amy Whitehead investigated the effects of livestock exclusion on native vegetation in dryland communities by comparing sites where grazing ceased 10–30 years ago with paired sites where grazing has continued. Ungrazed sites had significantly higher native vegetation richness and lower exotic richness than grazed sites. Ungrazed sites also had significantly more native shrubs than grazed sites and higher shrub cover. These differences were reflected in the invasive mammal community: grazed sites were typically associated with higher abundances of rabbits and hedgehogs whereas hares, possums and mice were dominant in ungrazed sites. The team have concluded that removal of livestock grazing can have profound effects on long-term successional trajectories of grassland/shrubland ecosystems, and on the potential impacts of invasive mammal pests. By quantifying ecological community responses to retirement of land to the conservation estate we can support evidence-based management of such ecosystems. The next steps will be to examine the role that invasive mammals play in the invasion and spread of non-native woody weeds.

Possum ecology in dryland ecosystems

Possum sheltering in a briar shrub on Molesworth StationMembers of the IMI team recently submitted a paper to the New Zealand Journal of Ecology describing the ecology of brushtail possums in a dryland environment on Molesworth Station in the north-east of the South Island. Although possums are a major environmental and agricultural pest in New Zealand, there is little information available on their ecology in drylands, which cover around 19% of the country. Al Glen and colleagues described a snapshot of possums’ diet, feeding preferences, movement patterns and survival rates. This basic ecological information will be useful in modelling and managing the impacts of possum populations in drylands. The summer diet, based on the stomach contents of 100 possums, was dominated by forbs and sweet briar, both of which were consumed in larger amounts than expected based on their availability. Possums also strongly preferred crack willow, which was uncommon in the study area and consumed only occasionally, but in large amounts. Radio-tracking suggested that possums on Molesworth may have unusually large home ranges. Whereas possums in New Zealand forests typically occupy home ranges of 1–2 ha, possums on Molesworth occupied areas averaging 5.1 ha. During the daytime, possums most commonly sheltered in sweet briar shrubs and rock outcrops. The results suggest that invasive willow and sweet briar may facilitate the existence of possums by providing abundant food and shelter. In turn, possums may facilitate the spread of weeds by acting as a seed vector. This work is being followed up with a more intensive study of possum movements and home ranges in dryland environments by Ivor Yockney, Graham Nugent, Carlos Rouco and Grant Norbury.

Update: Global Change

Interaction between climate change and invasive species impacts: alpine ecosystems in New Zealand

Alpine landscape on the Robert Ridge, Nelson Lakes National Park, where potential climate change effects on rat incursion will be studiedIn the last newsletter we reported on an initiative by Department of Conservation and Landcare Research scientists (Jenny Christie, Warren Chinn, Roger Pech, Mike Perry, Elaine Murphy, Derek Brown and Andrea Byrom). The team aims to understand how invasive species’ impacts on native biodiversity might be exacerbated by the effects of climate change, and our model system is to examine the interaction between climate change and predation impacts using incursions of ship rats (Rattus rattus) into alpine areas. The team have now selected research sites and will work with DOC staff from the Nelson Lakes Area Office, on the mainland island on the St Arnaud Range as well as nearby Robert Ridge. In the next newsletter we hope to report preliminary results of our initial surveys of vegetation, invertebrates, and invasive mammals that will be done in late February 2011.

Update: Theory Strand

Threat-defined functional groups: how will native biota respond to control of invasive species?

Tree weta (<em>Hemideina thoracica</em>): one of several native species often monitored as an index of biodiversity benefits from controlling invasive mammalsIn New Zealand many native species can be affected by invasive mammals. So, how do we decide what to measure if we want to quantify the potential impacts of invasive mammals, and the response of native species and natural ecosystems to pest control? Clare Veltman (DOC) and Roger Pech are working on a structured approach to this question. Some answers might come from published research relating extinctions of avian species on islands to the number, or functional diversity, of invasive mammals. Also, it is possible to classify the range of ways native species are impacted by invasive mammals, which is an approach being used in the project in alpine ecosystems described above. A third aspect of this work is to develop ecological criteria that can be used, in conjunction with practical considerations, for selecting which particular native species should be monitored to provide the most useful index of impacts of invasive mammals on vital ecosystem processes such as plant recruitment, seed dispersal, etc.

An integrated landscape approach to managing invasive species

Research recently presented at the Australasian Wildlife Management Society Conference by Al Glen, Andrea Byrom and Roger Pech is investigating how to manage invasive species so that biodiversity benefits are delivered at a landscape scale. Because of finite resources, invasive species management is rarely conducted across entire landscapes. Instead, pests are usually managed only in high-priority areas, with little or no management in the surrounding landscape. This may lead to persistence of some native species only in areas where pests are controlled. As long as there is some dispersal of organisms between patches, when a local population becomes dangerously small or disappears, immigrants from neighbouring patches can provide a ‘rescue effect’. The likelihood of extinction for a group of connected sub-populations is therefore much lower than that of a single, isolated population. In their presentation entitled Invasive species management: towards an integrated landscape approach, Al, Andrea and Roger explored ways in which integrated networks of pest management zones could be created to facilitate dispersal of native species through landscapes. The goal is to improve the timing and location of pest control to re-establish large-scale ecosystem processes such as migration and dispersal, and hence provide greater overall benefits for biodiversity.

Student and Postdoc profiles

Student profiles

Richard Clayton

We’re delighted to welcome Richard to the IMI research team as a student. Richard has until recently been working as a senior technician at Landcare Research, but his successful application for the Braided River PhD featured in the previous newsletter highlights his transition to student status. Richard’s PhD is co-funded by Environment Canterbury, Lincoln University and Landcare Research, and he will be supervised by Richard Duncan and Phil Hulme at Lincoln University and Andrea Byrom at Landcare Research. The working title of Richard’s PhD is ‘The ecology of invasive species in New Zealand’s braided rivers’, and the overall objectives of his research (subject to change!) will be to examine the ecological role that invasive weed species play in shaping the biodiversity of braided rivers. These could be direct (modifying structural processes and habitat) or indirect (providing more sites for invasive mammals). Richard begins his study in early February 2011, after finishing up his job at Landcare Research. His previous research interests have been around managing animal pests, understanding landscape changes associated with the cessation of grazing, and measuring biodiversity in wetlands.

Hannah Windley

Hannah’s PhD project is entitled ‘A nutritional analysis of NZ forest tree foliage to explain the browse choice of brushtail possums’. Hannah is jointly supervised by Bill Foley at Australian National University and Pen Holland and Wendy Ruscoe from Landcare Research. She will be looking at leaf chemistry (specifically the ‘available nitrogen’) of a large number of trees in the Tararua Ranges to investigate the common belief that foliage in New Zealand is more nutritious for possums than their native diet in Australia. This is based on the premise that trees in New Zealand did not co-evolve with mammalian folivores. She will also use nutrition to explain selective browsing by possums within and between tree species in the Tararua Ranges. Hannah will use near-infrared reflectance spectroscopy (NIRS) to develop calibration equations for several nutrients and secondary chemicals that will allow us to assess quickly the nutritional value of different trees, species and sites and how they vary over time. This may provide a method whereby longitudinal changes in possum browse can be monitored easily in the future.

Tom Etherington

Tom is a PhD student within the Centre for Biodiversity and Biosecurity, a joint research centre between Landcare Research and the University of Auckland. Supervised by George Perry and Mick Clout (University of Auckland) and with input from Pen Holland, Tom’s research looks at ways to model risk of pest invasion using spatially explicit landscape ecological concepts, with a view to producing risk maps that also visualise the associated uncertainties. The brushtail possum is being used as an example species. Recently completed work has focused on the potential to use graph theory as an underlying methodology to integrate landscape ecology and transport geography. The aim is to develop risk models that recognise the invasion process as a combination of both natural and human-mediated dispersal.

Eru Nathan

Eru has recently joined the IMI programme, having completed a Postgraduate Diploma in Biosecurity at the University of Auckland. Eru is now embarking on an MSc project entitled ‘Pest rat management: effectiveness and extent’. His researchwill focus on the spatial extent of the biodiversity and ecosystem outcomes of pest rat management. Rat populations are subject to control measures in many areas of high ecological significance in New Zealand, with the aim of reducing their predatory and competitive impacts on native flora and fauna. Eru’s study aims to (1) determine the effectiveness of pest rat management in terms of biodiversity and ecosystem outcomes by monitoring several ‘biodiversity and ecosystem indicators’ and (2) determine the spatial extent of these biodiversity and ecosystem outcomes, both within and potentially outside the actual pest management area. The study will take place at Whangarei Heads in Northland. Native bird, lizard and invertebrate abundance, seedling density, seed predation rates and pollination success rates will be measured within and outside areas subject to rat control. Measurement of these biodiversity indicators will use methods designed to be robust but cheap and easy to undertake for community group members. The research aims to enable more effective biodiversity monitoring by community groups and increase our understanding of the effective area of biodiversity benefits in relation to the actual area of pest control. Eru’s project will be supervised by Margaret Stanley (University of Auckland) and Al Glen (Landcare Research).

Maggie Triska

Maggie is a PhD student who recently joined the Ecosystem Restoration Laboratory at the University of Western Australia, after competing her MS in Wildlife and Fisheries Biology. Her current project is entitled ‘Modelling fauna populations in a production landscape’. Maggie is supervised by Mike Craig and Richard Hobbs at the University of Western Australia, Roger Pech at Landcare Research and Vicki Stokes at Alcoa. She will be researching how faunal populations (specifically reptiles and small mammals) respond to rehabilitation within an unmined/rehabilitated matrix landscape at a bauxite mine within the jarrah forest in south-west Western Australia. Occupancy and other modelling techniques will be used to evaluate species presence and recolonisation rates, using previously collected data. In addition, management techniques – including thinning and/or burning regenerating forest, and additional of log piles – will be evaluated through modelling. A field component of the project will use tracking tunnels to determine whether phascogales (carnivorous marsupials) that rely on tree hollows in mature forest also use regenerating forest on rehabilitated mine sites. Overall, she hopes to provide Alcoa with information on how to ensure the successful re-establishment of native fauna on former mine sites. From the perspective of the IMI programme, this project is an example of the importance of understanding how connectivity facilitates the persistence of native species in a fragmented landscape.

Recently completed student projects

Two student projects funded by our previous Foundation programmes ‘Spatial Ecology and Modelling’ and ‘Multiple Pest Dynamics’ have recently been completed.

Rebecca Lawrence

Rebecca has just completed her MSc at the University of Otago. She has been supervised by Kath Dickinson (University of Otago) and co-supervised by Roger Pech and Deb Wilson (Landcare Research). Her research looked at the foraging behaviour of ship rats in mixed podocarp–broadleaved forest, in particular whether different levels of perceived stoat predation risk differed between microhabitats. She found that although ship rats preferred to forage under dense ground cover provided by kiekie (Freycinetia banksii), it is likely their behaviour is also influenced by other factors, such as background food availability and ship rat densities. Her research indicates that ship rat control programmes may benefit by placing control devices in covered microhabitats, such as under kiekie.

Liz Rayner

Liz was recently awarded her MSc at the University of Otago, supervised by Phil Seddon (University of Otago) and Grant Norbury (Landcare Research), on the functional response of wild rabbits. A functional response describes the relationship between an animal’s consumption rate of food and the abundance of the food resource. Such responses illustrate how consumers cope with declining food resources and provide a greater understanding of plant–herbivore relationships. These play a central role in modelling the dynamics of ecosystems. Liz found that rabbits exhibited very different patterns of food intake between different pasture types. To help understand these differences, she measured the nutritional quality of the pastures and found that rabbits needed to consume greater amounts of low quality pasture to satisfy their energy needs. Few functional response studies have examined the effect of food quality on an animal’s daily food intake rate. Functional response experiments may therefore be far more informative by including a term for food quality for describing the shape of the response curve.

Postdoctoral Fellows

Al Glen

In addition to the study of possum ecology in drylands (described above), Al is working on a number of other projects in the IMI programme. In conjunction with Andrea Byrom and Roger Pech, he has been developing a conceptual framework that aims to enhance the benefits of invasive species management by restoring connectivity and ecological processes at a landscape scale (this is described in more detail in our report on the Theory Strand). This work was recently presented at the Australasian Wildlife Management Society Conference, and is the subject of a forthcoming journal article. Along with Wendy Ruscoe, Al has also been collaborating with Northland Regional Council, the New Zealand Kiwi Foundation and Whangarei Heads Landcare Forum to investigate the effectiveness of community-led pest control for the conservation of kiwi. Preliminary results indicate that trapping is effectively reducing numbers of stoats, weasels and ferrets, and that kiwi populations are responding favourably.

Pen Holland

Pen’s research is focused on models of herbivore impacts in New Zealand. Over the last two years she has developed a model of possum-browse-induced tree mortality in mixed forest sites. This uses the interaction between preferential browsing behaviour within and among tree canopies and tree foliage growth rates to make a context-dependent prediction of tree mortality rates, which can then be used to estimate the intensity of pest control required at a particular site to achieve management outcomes. Pen will be staying at Landcare Research for the foreseeable future, and hopes to be able to expand the tree mortality model using Hannah Windley’s chemical analyses to explicitly quantify possum browse preferences among individual trees and species. She is also integrating models of forest and pest dynamics with the economics of pest control, working towards a whole-forest simulation model that will be used for resource allocation problems, and to visualise the cost and effect of different management strategies.

Carlos Rouco

Carlos is a wildlife ecologist from Spain, where he researched the management and conservation of wild rabbit populations, and interactions of parasites and viral diseases of wild rabbits. As part of his European-funded postdoc, Carlos organised a reciprocal arrangement with New Zealand colleagues Grant Norbury, Roger Pech and Andrea Byrom studying the ecology of pest species and their impacts in Central Otago dryland ecosystems. Carlos is currently using GPS collars to establish habitat preferences by possums in such habitats. This work was recently presented at the New Zealand Ecological Society conference, and is the subject of a journal article that will reveal that possum home ranges are strongly related to landscape features. Also Carlos, in collaboration with Bill Lee, is studying the potential risk of possums as a disperser of introduced shrubs in drylands, using sweet briar as a model species. In collaboration with Dan Tompkins and Alex Bertó-Morán (Spanish PhD student), Carlos is also planning an experiment to begin in autumn to evaluate the effects on hare populations of intestinal parasite prevalence in wild rabbits in Central Otago. Carlos will also be working with Grant on an Animal Health Board contracted project evaluating the efficiency and effectiveness of ground-based possum control and monitoring in the southern South Island. So it seems we are going to have this Spaniard around for a while yet!

Kararehe Kino

This newsletter details in-house research undertaken by Landcare Research to produce timely, cost-effective and publicly acceptable vertebrate pest management. The newsletter is produced every 6 months and seeks to keep readers better informed on the progress and outcomes of research. You can always find contributions from IMI researchers in Kararehe Kino.

A selection of recent research publications

Anderson D, Sturtevant B 2011. Pattern analysis of eastern spruce budworm Choristoneura fumiferana dispersal. Ecography [online early].

Brown PR, Singleton GR, Pech RP, Hinds LA, Krebs CJ 2010. Rodent impacts in Australia: mouse plagues in cereal crops. In: Singleton GR, Belmain S, Brown P, Hardy B eds Rodent outbreaks: ecology and impacts. Pp. 225–238.

Byrom AE, Ruscoe WA, Nkwabi JA, Metzger K, Forrester GJ, Craft ME, Durant S, Makacha S, Bukombe J, Mchetto J, Mduma S, Reed DN, Sinclair ARE In press. Small mammal diversity and population dynamics in the greater Serengeti ecosystem. In: Sinclair ARE, Fryxell J eds Serengeti IV: Sustaining biodiversity in a coupled human-natural system. To be published in 2012.

Glen AS, Wayne A, Maxwell M, Cruz J 2010. Comparative diets of the chuditch, a threatened marsupial carnivore, in the northern and southern jarrah forests, Western Australia. Journal of Zoology (London).

Jones C, Pech R, Forrester G, King CM, Murphy EC 2011. Functional responses of an invasive top predator Mustela erminea to invasive meso-predators, Rattus rattus and Mus musculus, in New Zealand forests. Wildlife Research: in press.

Pech R, Byrom AE, Anderson D, Thomson C, Coleman M 2010. The effect of poisoned and notional vaccinated buffers on possum (Trichosurus vulpecula) movements: minimising the risk of Tb spread from forest to farmland. Wildlife Research 37: 283–292.

Ramsey D, Parkes JP, Will D., Hanson CD, Campbell KJ 2011. Quantifying the success of feral cat eradication, San Nicolas Island, California. New Zealand Journal of Ecology 35(2): online early.

Ruscoe W, Pech R 2010. Rodent outbreaks in New Zealand. In: Singleton G, Belmain S, Brown P, Hardy B eds Rodent outbreaks: Ecology and impacts. Pp. 239–251.

Smith DHV, Moller H, Wilson DJ, Murphy EC 2010. Prey switching by stoats (Mustela erminea): a supplemental food experiment. Wildlife Research 37: 604–611.