Impacts of introduced mammalian predators on New Zealand’s alpine fauna

O’Donnell, C. F., Weston, K. A., & Monks, J. M. (2017). Impacts of introduced mammalian predators on New Zealand’s alpine fauna. New Zealand Journal of Ecology, 41(1), 01-22.

Alpine zones are threatened globally by invasive species, hunting, and habitat loss caused by fire, anthropogenic development and climate change. These global threats are pertinent in New Zealand, with the least understood pressure being the potential impacts of introduced mammalian predators, the focus of this review. In New Zealand, alpine zones include an extensive suite of cold climate ecosystems covering c. 11% of the land mass. They support rich communities of indigenous invertebrates, lizards, fish, and birds. Many taxa are obligate alpine dwellers, though there is uncertainty about the extent to which distributions of some species are relicts of wider historical ranges. The impacts of introduced mammalian predators are well described in many New Zealand ecosystems, though little is known about the impacts of these predators on alpine fauna. Here we review the importance of alpine habitats for indigenous fauna and the impacts of introduced mammalian predators; and develop a conceptual model explaining threat interactions. Most evidence for predation is anecdotal or comes from studies of species with wider ranges and at lower altitudes. Nevertheless, at least ten introduced predator species have been confirmed as frequent predators of native alpine species, particularly among birds and invertebrates. In the case of the endangered takahe (Porphyrio hochstetteri) and rock wren (Xenicus gilviventris), stoats (Mustela erminea) are primary predators, which are likely to be impacting significantly on population viability. We also document records of mammalian predation on alpine lizards and freshwater fish. While the precise impacts on the long-term viability of threatened species have not been evaluated, anecdotal evidence suggests that predation by mammals is a serious threat, warranting predator control. Future research should focus on predicting when and where mammalian predators impact on populations of indigenous fauna, furthering our understanding of the alpine predator guild particularly through adaptive management experiments, and exploring interactions with other threats.

Research, conservation and urban cat management in NZ

Kikillus, K. H., Chambers, G. K., Farnworth, M. J., & Hare, K. M. 2106. Research challenges and conservation implications for urban cat management in New Zealand. Pacific Conservation Biology.

Over the past 20 years, conservation efforts in New Zealand have moved from being concentrated in rural and isolated island locations, where exotic mammalian predators are often controlled, to begin to bring native fauna back to major cities. However, human–wildlife conflicts arise when conservation occurs in close proximity to cities. These are particularly intense when companion animals are involved either as potential predators or prey of high-value conservation animals. Within New Zealand, this conflict is particularly fraught around domestic cats (Felis catus) in the urban environment. Cats in New Zealand are recognised as major introduced predators of native fauna, but they also prey on small introduced predatory mammals. This dynamic causes much conflict between people with different attitudes towards animals; however, as yet, few studies have explored the role(s), either negative or positive, of urban cats in New Zealand. Here, we review current knowledge on domestic cats in urban New Zealand, identify gaps in knowledge and make suggestions for future research, which includes further social science research, citizen science-based research programs, market research, investigation into cat-management legislation, and more in-depth studies of cat diseases and zoonoses. These data are vital for informing the public and improving the management of urban cat populations, including mitigating conservation impacts. Urban ecologists will need to be versatile in the way they design and conduct experiments, exploiting multiple disciplines to both ensure scientific robustness, but also community and government support for uptake of results into management and legislation.

Spatial ecology and population genetics of cats living in or near conservation-sensitive areas

Cross, C. (2016). Spatial ecology and population genetics of cats (Felis catus) living in or near conservation-sensitive areas (Doctoral dissertation, University of Otago).


Human-mediated dispersal of organisms across the world has resulted in species introductions into many vulnerable ecosystems. Invasive mammalian predators have had detrimental impacts on native island biota, leading to declines and extinctions of many endemic prey species. Humans have transported cats (Felis catus) across the world as mousers on ships and as companion animals. The role cats (especially feral) have played in the decline and extinction of several island species is clear; however, different types of cats classified by their associations with humans has an influence on the public perception of cat impacts on wildlife and acceptance of appropriate management strategies.
I studied the spatial ecology of two different types of cats in two different conservation-sensitive areas (Te Anau Basin and Canterbury/North Otago) in the South Island of New Zealand. I conducted this research to gain an insight into companion cat spatial ecology and feral cat population genetics. Specifically, to investigate individual cat movement patterns and population level movements to discover putative geographic barriers to movement. Additionally, I intended to aid formulation and reinforcement of appropriate and current management strategies with respect to conservation-sensitive areas that support high levels of native biodiversity.

Cat capture rates in the Tasman Valley from March 2005 toFebruary 2013 (included as 2012).

In the Te Anau Basin, the township of Te Anau lies on the edge of Lake Te Anau, directly adjacent to Fiordland National Park. The Kepler Mire conservation area, also situated in the Te Anau Basin, is a nearby wetland that supports a diverse range of fauna. I GPS tracked 32 local companion cats (11F:21M) for a maximum of 10 to 14 days over the austral spring/summer. I recorded a total of 19,157 locations prior to filtering data for erroneous locations. Home range and habitat analysis were performed on a filtered dataset of 13,241 locations using 100% minimum convex polygons (MCP) and Objective-Restricted-Edge Polygons (OREP). Dispersal barriers might be acting to prevent movement of tracked cats into Fiordland National Park, but not the Kepler Mire conservation area. I found males (mean MCP: 22.13 ha, OREP: 1.05 ha) exhibited larger movements (home range and distance travelled from home) than females (mean MCP: 8.83 ha, OREP: 0.45 ha) and rural-living cats (mean MCP: 32.54 ha, OREP 1.33 ha) exhibited larger movements than urban-living cats (mean MCP: 5.90 ha, OREP: 0.46 ha).  Cats showed a tendency to preferentially select Built, Cover and Sealed habitat features.  Although there was great individual variation in the ranging behaviour, there was no sex or age-related difference observed in the cats’ resource selection.
To infer population movements, I used 10 microsatellite loci and a sexidentification marker, in a multiplex framework, to infer population structure of 157 feral cats in the upper Waitaki Basin (Tasman Valley, Ohau River and Ahuriri Valley) and Macraes Flat. I found some evidence of population connectivity between the sites based on migration rates and low FST values, indicating features in the landscape that act to facilitate dispersal. Bayesian clustering analysis noted the presence of three separate clusters; however, assignment rates were low for the Ohau River, Tasman Valley and Macraes Flat sites. Spatial autocorrelation and Mantel tests indicated rough terrain (i.e. mountain ranges) might limit dispersal. Macraes Flat and Ohau River might function as man-made sinks due to lower relatedness scores. Lower relatedness, genetic differentiation scores, and proximity to human habituation suggested there might be genetic input from nearby stray and companion cat populations. Due to large movements exhibited by feral cats in these areas, reinvasion into trapped areas seems likely; however, the Tasman Valley might be able to be managed as an eradication unit, if movement out of the Ohau River and surrounding area is reduced. Continued genetic monitoring of
these sites and sampling of local stray and companion cats might help to identify if there is connectivity between different types of cats (i.e. companion, stray and feral). Additionally, continued genetic monitoring might be able to determine if genetic differentiation increases between each site in response to trapping operations.
Tighter regulations regarding companion cat management might aid New Zealand conservation efforts by reducing and restricting movement and cat interactions with native wildlife. Stricter companion and stray cat regulations might also benefit feral cat control efforts; however, this aspect requires further analysis. 

Dogs vs camera traps: a comparison of techniques for detecting feral cats

Glen, A. S., Anderson, D., Veltman, C. J., Garvey, P. M., & Nichols, M. (2016). Wildlife detector dogs and camera traps: a comparison of techniques for detecting feral cats. New Zealand Journal of Zoology, 1-11.

A major challenge in controlling overabundant wildlife is monitoring their populations, particularly as they decline to very low density. Camera traps and wildlife detector dogs are increasingly being used for this purpose. We compared the costeffectiveness of these two approaches for detecting feral cats (Felis catus) on two pastoral properties in Hawke’s Bay, North Island, New Zealand. One property was subject to intensive pest removal, while the other had no recent history of pest control. Camera traps and wildlife detector dogs detected cats at similar rates at both sites. The operating costs of each method were also comparable. We identify a number of advantages and disadvantages of each technique, and suggest priorities for further research.

Toxoplasmosis in sea lions in NZ

Michael, S. A., Howe, L., Chilvers, B. L., Morel, P. C. H., & Roe, W. D. (2016). Seroprevalence of Toxoplasma gondii in mainland and sub-Antarctic New Zealand sea lion (Phocarctos hookeri) populations. New Zealand Veterinary Journal, (just-accepted), 1-14.

AIMS: To investigate the seroprevalence to Toxoplasma gondii in New Zealand sea lions (Phocarctos hookeri), as a potential contributor to reproductive failure.
METHODS: Archived sera were sourced from New Zealand sea lions from two recolonising mainland populations in the Otago Peninsula (n=15) and Stewart Island (n=12), as well as a declining population at Enderby Island (n=28) in the New Zealand sub-Antarctic. Sera were tested for antibodies to T. gondii using a commercially available ELISA (with samples considered positive if the sample to positive ratio was >30%), and latex agglutination test (LAT; with titres ≥1:32 considered positive). Western blot analysis was used to validate the results of a subset of 14 samples.
RESULTS: Five samples from sea lions in mainland locations were confirmed positive for antibodies to T. gondii. Two adult females exhibited high LAT antibody titres (min 1:2048, max 1:4096) on both occasions when sampled 1 and 2 years apart, respectively. No animals from Enderby Island were seropositive.
CONCLUSIONS: Toxoplasma gondii infection is unlikely to be a major contributor to poor reproductive success in New Zealand sea lions. However, continued surveillance is pertinent to assess subclinical and clinical impacts of the parasite on these threatened populations. The commercial tests evaluated here, with further species-specific threshold refinement could provide a fast, inexpensive and reliable indicator of T. gondii exposure in New Zealand sea lions.

An international comparison of the attitudes of urban people regarding predation by pet cats

Hall, C. M., Adams, N. A., Bradley, J. S., Bryant, K. A., Davis, A. A., Dickman, C. R., ... & Pollock, K. H. (2016). Community Attitudes and Practices of Urban Residents Regarding Predation by Pet Cats on Wildlife: An International Comparison. PLoS One, 11(4), e0151962.

International differences in practices and attitudes regarding pet cats' interactions with wildlife were assessed by surveying citizens from at least two cities in Australia, New Zealand, the UK, the USA, China and Japan. Predictions tested were: (i) cat owners would agree less than non-cat owners that cats might threaten wildlife, (ii) cat owners value wildlife less than non-cat owners, (iii) cat owners are less accepting of cat legislation/restrictions than non-owners, and (iv) respondents from regions with high endemic biodiversity (Australia, New Zealand, China and the USA state of Hawaii) would be most concerned about pet cats threatening wildlife. Everywhere non-owners were more likely than owners to agree that pet cats killing wildlife were a problem in cities, towns and rural areas.

Cat husbandry practices in different countries. (a) Percentage of households that own one, two or more than two cats (b) Percentage of cats kept in different conditions of confinement (c) Percentage of desexed cats. (d) Percentage of cats that have ever caught vertebrate prey.

Agreement amongst non-owners was highest in Australia (95%) and New Zealand (78%) and lowest in the UK (38%). Irrespective of ownership, over 85% of respondents from all countries except China (65%) valued wildlife in cities, towns and rural areas. Non-owners advocated cat legislation more strongly than owners except in Japan. Australian non-owners were the most supportive (88%), followed by Chinese non-owners (80%) and Japanese owners (79.5%). The UK was least supportive (non-owners 43%, owners 25%). Many Australian (62%), New Zealand (51%) and Chinese owners (42%) agreed that pet cats killing wildlife in cities, towns and rural areas was a problem, while Hawaiian owners were similar to the mainland USA (20%).

Percentage agreement of cat owners (dark blue) and non-owners (light blue) in each country to eight survey items: (a) There is a need for cat legislation (b) All cats should be kept in at night time (c) Cats should be kept on their owner's property at all times (d) It is important to have wildlife in cities, towns and rural areas (e) Pet cats killing wildlife in cities, towns and rural areas is a serious problem (f) Pet cats on farms are harmful to wildlife (g) Pet cats in nature reserves are harmful to wildlife (h) Except for a cat owned by a breeder, all cats should be desexed.

Thus high endemic biodiversity might contribute to attitudes in some, but not all, countries. Husbandry practices varied internationally, with predation highest where fewer cats were confined. Although the risk of wildlife population declines caused by pet cats justifies precautionary action, campaigns based on wildlife protection are unlikely to succeed outside Australia or New Zealand. Restrictions on roaming protect wildlife and benefit cat welfare, so welfare is a better rationale.

Use and perception of collars for companion cats in NZ

Harrod, M., Keown, A. J., & Farnworth, M. J. (2015). Use and perception of collars for companion cats in New Zealand. New Zealand veterinary journal, 1-4.


AIMS: To investigate the use and utility of collars for companion cats in New Zealand, and to explore public perception of collar use.

METHODS: An online questionnaire was distributed using emails and social media to members of the general public in New Zealand. The questionnaire collected details of respondents, cat ownership status, and responses to a number of questions regarding collar use in cats.

RESULTS: A total of 511 responses were collected. Of these, 393/511 (76.9%) reported owning ≥1 cat at the time of the survey, and 141/393 (35.9%) stated that ≥1 of their cats wore collars and 211/393 (53.7%) had ≥1 of their cats micro-chipped. Of the respondents with a pet cat, 351/393 (89.3%) allowed their cats some outdoor access. Respondents mainly used collars for identification and to reduce predation. Reasons for not using collars included cat intolerance of collars, repeated collar loss and concern over collar safety. Differences were found between cat owners and non-owners regarding whether they agreed that cats were important for pest control (43 vs. 25%, p<0.001); that not all cats will tolerate collars (81 vs. 64%, p<0.001); that cats should be kept indoors at night (37 vs. 58%, p<0.001); or disagreed that well fed cats will not catch birds (60 vs. 70%, p=0.04); and disagreed that a cat without a collar was likely to be a stray (85 vs. 76%, p<0.001). Respondents most trusted veterinarians and the Society for the Prevention of Cruelty to Animals as sources of pet care information.

CONCLUSIONS: Collar use within this sample of cat owners in New Zealand appeared to be low, with more using microchips for identification. The majority of cat owners in this study indicated their cats had some outdoor access, with collars being used for cat identification and to reduce hunting behaviour. Significant differences existed in opinions on cat management between cat owners and non-owners in this study. It should be noted that this preliminary exploration was based on a self-selected group of respondents and so results and conclusions cannot be extrapolated to the wider population.

RELEVANCE: As the most trusted source of information about pet care, an enhanced understanding of cat ownership and management may be of use to veterinarians to promote responsible pet ownership and to develop national policies and practices to improve cat welfare.

Corridors of introduced feral cats infringing ecologically sensitive areas in NZ

Recio, M. R., Seddon, P. J., & Moore, A. B. (2015). Niche and movement models identify corridors of introduced feral cats infringing ecologically sensitive areas in New Zealand. Biological Conservation, 192, 48-56.

The mitigation of the impact caused by introduced mammalian predators is a priority for conservation managers. Reducing predator population numbers is the most realistic strategy in mainland areas or large islands, and could be a feasible alternative to pest eradication. However, the success of control campaigns depends not only on removal of resident individuals, but also on managing reinvasions facilitated by connectivity with surrounding source populations. We combined niche analysis and fine-scale movement analyses of feral cats (Felis silvestris catus) to identify least-cost corridors from sources surrounding controlled areas of the ecologically sensitive area of Tasman Valley and Aoraki/Mt. Cook National Park, New Zealand. Intensive control of exotic predators has been executed during the last ten years in this area, where they pose a threat to native species such as endangered ground-nesting birds. Species distribution models revealed that cat distribution in the region was limited by its main prey, the European rabbit, and to mid-elevation (~ 1600 m) areas. Using GPS-tracking data and step-selection functions, we found that cats moved in an optimized fashion suggesting a maximum energy gain associated with high rabbit presence, while avoiding landscape obstacles such as rugged terrain. Connectivity between the high probability of cat presence in source and destination locations (in the control area) was facilitated by 1–3 corridors between valleys and multiple paths within valleys. Identification of least-cost paths, rooted in ecological and behavioral mechanisms underlying space use, can identify realistic putative corridors for focused implementation of control measures for introduced species in ecologically sensitive areas.

A call for predator profiling in wildlife protection programs

Moseby, K. E., Peacock, D. E., & Read, J. L. (2015). Catastrophic cat predation: A call for predator profiling in wildlife protection programs. Biological Conservation, 191, 331-340.

Introduced predators have been implicated in the decline of many fauna populations around the world and are the main factor responsible for the failure of numerous fauna reintroduction programs. As a result, control of introduced predators is a significant management action implemented in wildlife protection programs, particularly in Australia, New Zealand and on islands. Individual predators are seldom targeted in conservation programs, which usually conduct broad-scale, non-specific predator control based on the assumption that the removal of each individual predator is equally important. In contrast, predator management programs initiated by human–wildlife conflict typically use profiling or specific control techniques to target ‘problem’ predators.


We investigated whether individual domestic cats vary in the magnitude of their predation threat to wildlife by first reviewing published and anecdotal information on incidences where feral cats have had significant impacts on wildlife protection or translocation programs. We concentrated on prey species that were likely to be more challenging to cats based on their size, novelty or behavior. We then used the results from this review to create a profile of cats that were most likely to cause significant problems for challenging prey, and tested this during a translocation of a threatened mammal species. Both the review and translocation suggested that large male cats 3.5 kg or heavier were disproportionally responsible for predation events on challenging prey and possibly implicated in the failure of many protection or reintroduction programs of mammals greater than 1 kg. Some cats within this demographic profile were responsible for multiple prey deaths suggesting that both demography and prior experience may define predators capable of ‘catastrophic predation’ that threatens prey populations.

Current control programs for feral cats and foxes that do not target particular predator profiles may inadvertently avoid controlling individuals most likely to specialize on threatened prey. We call for the application of crime-fighting forensic and aggregate profiling techniques in wildlife protection programs to determine the profile of predators likely to prey on focal wildlife species and to guide the development of control methods that specifically target these individuals.

7 (more) kiwis dead by dogs

Dog attacks kill 7 kiwi in Kerikeri

Fatal Northland dog attacks on kiwi have left seven birds dead over the last two months. (continue reading on http://www.stuff.co.nz/)

Modelling future distribution of feral cats in NZ under Climate change

Aguilar, G.D., M.J. Farnwortha & L. Winder. 2015. Mapping the stray domestic cat (Felis catus) population in New Zealand: Species distribution modelling with a climate change scenario and implications for protected areas. Applied Geography, 63: 146–154

Species distribution models of stray cats were developed using two types of occurrence data: (i) a combined dataset of stray cats and cat colonies in Auckland and projected to the wider New Zealand area; and (ii) population density as an analogue for country-wide stray cat occurrence. These occurrence data, together with sets of environmental variables were used as input to the Maxent modelling tool to produce maps of suitability for the species. Environmental variables used in the models consist of current bioclimatic conditions, and a future climate scenario (RCP8.5 for year 2070 CCSM model). Commonly occurring bias in the modelling process due to latitude, the area for selecting background points in model evaluation, inherent spatial autocorrelation of occurrence points, and correlated bioclimatic variables were explicitly addressed. Results show that the North Island consistently provide more suitable areas for stray cats with increased suitability in a high emission climate change condition. Key protected areas at risk from the increased suitability to stray cats are also presented.

Watch: When the cat met the kiwi

Successful eradication of invasive vertebrates on Rangitoto and Motutapu Islands, NZ

Griffiths, R., Buchanan, F., Broome, K., Neilsen, J., Brown, D., & Weakley, M. (2014). Successful eradication of invasive vertebrates on Rangitoto and Motutapu Islands, New Zealand. Biological Invasions, 1-15.

An eradication program conducted on Rangitoto and Motutapu islands in New Zealand successfully removed stoats (Mustela erminea), cats (Felis catus), hedgehogs (Erinaceus europaeus occidentalis), rabbits (Oryctolagus cuniculus), mice (Mus musculus) and three species of rat (Rattus rattus, R. exulans and R. norvegicus) from an area of 3,842 ha. The project was significant because it was completed so close to Auckland, New Zealand’s largest city, but also, in contrast to many eradication projects, it targeted a suite of invasive mammals in a single operation. To achieve success and avoid conflict in the allocation of resources, target species were prioritized by likelihood of eradication success with resources allocated preferentially to species posing the greatest risk of failure and methods applied in a sequence that allowed each technique to capitalize on its predecessor. Consequences of applying this approach were increased operational efficiency, a shorter operation than planned and reduced project cost. When compared to other projects that targeted the same species but individually, we estimate the Rangitoto and Motutapu project to have cost less than 50 % of the total potential cost if each species had been removed in a discrete operation. Logistical efficiencies created by condensing several operations into one and the use of eradication and detection techniques that targeted multiple species are credited as having the greatest influence on the increased efficiencies observed.

Feral cat behaviour influence monitoring techniques and control methods

Fisher, P., Algar, D., Murphy, E., Johnston, M., & Eason, C. (2014). How does cat behaviour influence the development and implementation of monitoring techniques and lethal control methods for feral cats?. Applied Animal Behaviour Science.

Highlights
•Feral cats utilise the ‘wild’ end of the predatory and social behavioural spectrum of Felis catus.
•Efficacy in lethal control of feral cats is strongly influenced by prey resources.
•Cryptic habits and low densities in large remote areas make feral cat behaviour difficult to study.

Abstract
The need for lethal control of feral cats will remain in some contexts and potentially increase in others, alongside an obligation to develop and apply methods that are as cost-effective, humane and target-specific as possible. Drawing on practices particularly used in Australia, New Zealand and on offshore islands we review current lethal techniques applied for feral cat removal, such as shooting, trapping and poison baiting, and how our understanding of feral cat behaviour has influenced their development and application.

Tibble and the wren

One of the most frequently told stories about invasive species on islands or on the effect of cats on biodiversity is the tale of Tibble and Stephens Island Wren.

Extinct bird Xenicus lyalli (Xenicidae), male (lower) & female (upper).
From Buller, Walter Lawry, A History of the Birds of New Zealand.
Supplementary Notes to the 'Birds of New Zealand'. Vol. II.. 1905.

In a few words and following a common version, Tibble was the cat and only companion of the light-house keeper on Stephens Island and it's supposed to be the sole responsible of the extinction of the one flightless passerine, the local endemic Xenicus (Traversia) lyalli in 1894.
The story is easy to tell and remember: a villain, a victim and a moral (no hero, this time), but, in fact, as usual, reality is a bit more complex.

First, this is not the only known flightless passerine, but they were few of them, maybe just four (all of them extinct and all except one were New Zealand's wrens). This is the only that was still extant when known for science.

Second, the species was not endemic from Stephens Island, as the English name suggests, but relict to the island where it survives in recent times, although it is common in fossil deposits from both of the main islands before the arrival of maoris with kiores  (Worthy and Holdaway 1994).

Third, Lyall was not the light only human inhabitant of the island, neither the lighthouse keeper. He was the assistant and there were other people living there.

Fourth, and most important: how many "tibbles" where there? The first record of a single cat being responsible of the extinction is due, apparently, to Rothschild (1905). 

Image from
http://www.terranature.org/wren.htm

After Galbreath and Brown (2004), the Stephens Island wren Xenicus (Traversia) lyalli is widely quoted as having been discovered and promptly exterminated from its only locality, Stephens Island, New Zealand, by a single lighthouse keeper’s cat. Examination of archival and museum records indicates that this account is oversimplified, and throws more light on the roles of the lighthouse keeper David Lyall, the dealer Henry Travers, and the ornithologists Sir Walter Buller and Walter Rothschild. Cat predation probably was the main factor in the wren’s extinction, but not necessarily by a single cat: cats became established on Stephens Island in 1894, increased rapidly and exterminated several other species before they were eliminated. We are not sure if  "Tibble" was the name of any of them.

Fifth, the species didn't disappeared in 1884. following the same authors, extinction of the wren was more extended than generally stated: 10 specimens were evidently brought in by a cat in 1894, but another two-four were obtained in 1895, and two-three more after that and possibly as late as 1899. Fifteen of these specimens are still held in museums. 

Last, but not least, the simplified story forgets some other victims because cats were responsible for several more extinctions on Stephens island. Medway (2004) explains how Stephens Island provides the classic example in the New Zealand region of the effect that predation by feral cats (Felis catus) can have on an island land bird fauna. Twenty-five species of native New Zealand land birds were recorded on the island in the early 1890s when it was still forested and free of mammalian predators. It is probable that Stephens Island still had its original land bird fauna at that time. The land bird species included large populations of the extinct Stephens Island piopio (Turnagra capensis minor), and the endangered South Island saddleback (Philesturnus c. carunculatus).
Cats were introduced to Stephens Island probably in 1894. They soon became feral and multiplied rapidly. The evidence indicates that cats were responsible for the rapid demise of the native land bird fauna of the island.

References

• Galbreath, R. & Brown, D. (2004): The tale of the lighthouse-keeper's cat: Discovery and extinction of the Stephens Island wren (Traversia lyalli). Notornis 51(4): 193–200.
• Medway, D.G. (2004): The land bird fauna of Stephens Island, New Zealand in the early 1890s, and the cause of its demise. Notornis 51(4): 201–211.
• Rothschild, W. (1905): On extinct and vanishing birds. Proceedings of the 4th International Ornithological Congress, London: 191-217.

How to control the cats that are eating our wildlife

A feral cat in the bush. Credit: Tim Doherty

Feral domestic cats are a global threat to biodiversity and were recently named as the biggest threat to endangered Australian mammals.

But what about your pet cat, or the local stray? While any kind of domestic cat can kill wildlife, there's no "one size fits all" way to manage their impact

Continue reading.

Fatal toxoplasmosis in endemic NZ birds

Howe, L., Hunter, S., Burrows, E., & Roe, W. (2013). Four cases of fatal toxoplasmosis in three species of endemic New Zealand birds. Avian Diseases.  58(1): 171-175

Four cases of fatal toxoplasmosis in three endemic avian species are reported. Between 2009 and 2012, two kereru, one North Island brown kiwi, and one North Island kaka were submitted for necropsy examination. On gross post mortem the kiwi had marked hepatosplenomegaly while the kaka and two kereru had swollen, slightly firm deep red lungs. Histologically, there was extensive hepatocellular necrosis in the liver of the kiwi while the kaka and kereru showed severe fibrinous bronchointerstitial pneumonia. In the kiwi, protozoal organisms were present within both hepatocytes and Kupffer cells of the liver and within the epithelial cells and macrophages of the interstitium of the lung in the kaka and two kereru. The diagnosis of toxoplasmosis was confirmed with immunohistochemistry and PCR on the liver and/or lung of paraffin embedded formalin-fixed tissue. Genotyping of up to seven markers revealed an atypical Type II isolate of T. gondii was present in at least three of the cases. This study provides evidence that T. gondii can cause mortality in these endemic species and suggests further research is needed to determine that full extent of morbidity and mortality caused by this parasite in New Zealand's unique avifauna.

Dog predation on kiwis

Taborsky, M. (1988). Kiwis and dog predation: observations in Waitangi State Forest. Notornis, 35(3), 197-202.

A wild dog was found to kill 13 out of 23 kiwis marked with transmitters. 

The whole population may have lost 500 out of 900 birds, although this estimate may be conservative. The population will probably need 10-20 years and a rigorous protection scheme to recover to previous densities

Dogs among the main causes of death of blue penguins

Hocken, A.G. (2000) Cause of death in blue penguins (Eudyptula m.minor) in North Otago, New Zealand. New Zealand Journal of Zoology, 27:4, 305-309, DOI: 10.1080/03014223.2000.9518239

I necropsied 213 blue penguins (Eudyptula m. minor) collected during 1994 to 1998, mainly from Oamaru Harbour and urban areas, the remainder from sites south to Otago Peninsula. The dominant categories were malnutrition (16%), and cause of death (15%). Where malnutrition was involved, it was usually unclear whether it was the direct cause of death or the consequence of undiagnosed natural disease or infestation. Twenty five per cent of birds died from animal attacks. Aspergillosis was the commonest natural disease (3.3%). Endoparasitism was uncommon (1.3%). This study provides significant evidence of geographic variation in infestation of blue penguins.

Little blue penguins killed by dogs

From http://www.stuff.co.nz
03/09/2014

At least eight little blue penguins were killed by dogs near Little Kaiteriteri Beach over the weekend, prompting a call for public help to keep the birds safe.Department of Conservation staff were devastated to find the dead birds, and are urging dog owners to be more vigilant.