Exotic Reptiles in the Pet Trade: Are They a Threat to New Zealand?

Mapping Intimacies ◽

10.26686/wgtn.16973740.v1 ◽

2021 ◽

Author(s):

◽

Kristina Heidy Kikillus

Keyword(s):

Invasive Species ◽

New Zealand ◽

Propagule Pressure ◽

False Negative ◽

Local Environment ◽

Physiological Models ◽

Thermal Requirements ◽

Survival Sex ◽

In Captivity ◽

Soil Measurements

Worldwide, invasive species are associated with severe ecological and economic impacts. As a group, reptiles are very successful invaders and in some areas where they have established they are responsible for the decline of native fauna and economic disruptions, whilst also posing a threat to human health. Due to its biogeographical isolation and unique evolutionary history, New Zealand is highly susceptible to invasive species. Importation of reptiles into New Zealand is illegal, however over a dozen species of exotic reptile are legally present in captivity and their risk of establishment is unknown. This study investigates their establishment potential and possible impacts by considering 1) the amount of trade and propagule pressure of species, 2) the degree of climate match between their native range and New Zealand, 3) areas that may be suitable for establishment based on physiological models of incubation and development, 4) their ability to transfer pathogens to native fauna and humans, and 5) overall establishment risk. The red-eared slider (Trachemys scripta elegans; RES) is the most common and easily obtained exotic reptile pet in New Zealand, with over 800 sales per annum. The RES is also the species most regularly released into the wild. Climate matching models in this study were developed to minimise false-negative predictions, to generate a suitability score irrespective of the prevalence of species records (allowing species to be easily compared to one another), and incorporated a weighted multimodel average prediction based on the relative importance of climatic variables to each species. These correlative models indicated that the blotched blue-tongue skink (Tiliqua nigrolutea) had the highest degree of climate match with parts of New Zealand, while the common blue-tongue skink (T. scincoides) had the highest proportion of land area predicted to be suitable for establishment. The other 10 species generally had both low climate match scores and limited areas within New Zealand predicted to be suitable. Mechanistic models focus upon environmental influences on physiological processes of a species, such as development and growth. Degree-day models, combined with soil measurements in potential reptile nesting sites in New Zealand, were utilised to determine if environmental conditions were suitable for the successful reproduction of oviparous exotic reptiles. These models predicted that the New Zealand environment meets the minimum thermal requirements for the incubation of eggs of RES, snake-neck turtles (Chelodina longicollis), and Reeves turtles (Chinemys reevesii). While prevalence of Salmonella in exotic reptiles is higher than that of native reptiles, it is considerably lower than that of exotic reptiles overseas. All serovars identified in this study had been previously reported both in humans and reptiles in New Zealand. The overall risk assessment for 12 species of exotic reptile kept in captivity in New Zealand indicates that blotched blue-tongue skinks and RES pose the highest establishment risk. Blotched blue-tongue skinks are allegedly only present in zoos. Therefore, based on propagule pressure, RES pose the highest establishment risk and efforts should focus on minimising release events and removing feral individuals from the New Zealand environment. In summary, at least eight species of exotic reptile legally traded within New Zealand are predicted to be capable of surviving in a portion of the New Zealand environment and at least three species have the potential to successfully breed in warmer microclimates. However, further research involving climatic tolerances and breeding potential (i.e., soil moisture content, juvenile survival, sex ratio, and predicted climate change) is recommended. Public education and possible regulations imposed on the New Zealand exotic reptile trade may prevent introductions of these species into the local environment and still allow selected species to be enjoyed by the New Zealand public. The methods developed in this study may be easily applied to other species and other geographic regions, allowing investigation into the establishment risk of alien species. This may help guide control and management efforts and help stem the tide of the growing problem of invasive species.

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Exotic Reptiles in the Pet Trade: Are They a Threat to New Zealand?

10.26686/wgtn.16973740 ◽

2021 ◽

Author(s):

◽

Kristina Heidy Kikillus

Keyword(s):

Invasive Species ◽

New Zealand ◽

Propagule Pressure ◽

False Negative ◽

Local Environment ◽

Physiological Models ◽

Thermal Requirements ◽

Survival Sex ◽

In Captivity ◽

Soil Measurements

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Faculty Opinions recommendation of The risk of establishment of aquatic invasive species: joining invasibility and propagule pressure.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1089738.544031 ◽

2007 ◽

Author(s):

Kai Chan

Keyword(s):

Invasive Species ◽

Propagule Pressure ◽

Aquatic Invasive Species

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The widespread collapse of an invasive species: Argentine ants ( Linepithema humile ) in New Zealand

Biology Letters ◽

10.1098/rsbl.2011.1014 ◽

2011 ◽

Vol 8 (3) ◽

pp. 430-433 ◽

Cited By ~ 34

Author(s):

Meghan Cooling ◽

Stephen Hartley ◽

Dalice A. Sim ◽

Philip J. Lester

Keyword(s):

Climate Change ◽

Invasive Species ◽

New Zealand ◽

Argentine Ant ◽

Environmental Costs ◽

Argentine Ants ◽

Ant Communities ◽

Mean Survival Time ◽

Colony Collapse ◽

Increasing Temperature

Synergies between invasive species and climate change are widely considered to be a major biodiversity threat. However, invasive species are also hypothesized to be susceptible to population collapse, as we demonstrate for a globally important invasive species in New Zealand. We observed Argentine ant populations to have collapsed in 40 per cent of surveyed sites. Populations had a mean survival time of 14.1 years (95% CI = 12.9–15.3 years). Resident ant communities had recovered or partly recovered after their collapse. Our models suggest that climate change will delay colony collapse, as increasing temperature and decreasing rainfall significantly increased their longevity, but only by a few years. Economic and environmental costs of invasive species may be small if populations collapse on their own accord.

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New Zealand’s Assistance with Invasive Species Management in the Pacific

10.26686/wgtn.16992301 ◽

2021 ◽

Author(s):

◽

Simon Lovatt

Keyword(s):

Invasive Species ◽

New Zealand ◽

International Development ◽

Biodiversity Loss ◽

Well Being ◽

Leadership Role ◽

Invasive Species Management ◽

The Pacific ◽

Species Management ◽

Critical Leadership

Invasive species are one of the biggest threats to development and well-being in the Pacific. They have wide-ranging impacts on economies, the environment, and societies; in addition to causing USD $1.4 trillion of losses each year. Invasive species are also the primary cause of biodiversity loss on islands which could significantly affect the ecosystem services which Pacific Islanders depend on. Every year New Zealand spends NZD $500 million on biosecurity, and Australia has spent AUD $175 million on a single eradication project. In comparison, in the Pacific there are only six people working fulltime on invasive species issues at a regional level and there is limited funding available. This thesis assesses the role of four New Zealand agencies that assist with invasive species management in the Pacific: the International Development Group of the Ministry of Foreign Affairs, the Biosecurity New Zealand division of the Ministry of Agriculture and Forestry, the Department of Conservation, and Landcare Research. Together these agencies provide funding, build capacity, offer technical advice, and occasionally implement projects. While there are important gains to New Zealand in assisting the Pacific with invasive species management, such as a reduced biosecurity threat and learning opportunities for staff, the desire to help the region for its own sake is a major driver. Suggestions for future improvement include having more information on the economic impacts of invasive species in the Pacific, increased coordination between donors, and including invasive species measures in regional trade agreements. It is hoped that New Zealand will continue to play its critical leadership role in invasive species management in the region.

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Interactions Between the Invasive New Zealand Mudsnail (Potamopyrgus Antipodarum) and a Native Snail (Fossaria Bakerilymnaea Bulimoides Group) in the Greater Yeelowstone

The UW National Parks Service Research Station Annual Reports ◽

10.13001/uwnpsrc.2011.3815 ◽

2011 ◽

Vol 33 ◽

pp. 161-170

Author(s):

Heather Thon ◽

Amy Krist

Keyword(s):

Invasive Species ◽

New Zealand ◽

American West ◽

Biological Diversity ◽

Potamopyrgus Antipodarum ◽

The Past ◽

Conservation Concern ◽

And Function ◽

New Zealand Mud Snail ◽

The Impact

Understanding invasive species impacts is critical to determining how an ecosystem may function after an introduction. Invasive species can alter the structure and function of ecosystems, reduce biological diversity, and alter communities through predation, facilitation and competition. In the past 30 years, the invasive New Zealand mud snail (Potamopyrgus antipodarum) has established in areas of conservation concern in the American West including Yellowstone National Park. To develop a greater understanding of the impact of P. antipodarum on the native co-occurring snail, Fossaria (Bakerilymnaea) bulimoides group, we conducted two experiments to assess the interactions occurring between these snails. We found that F. bulimoides growth was reduced by all interactors, but especially by P. antipodarum. In addition, growth of F. bulimoides was much more affected by high biomass of snails than P. antipodarum. P. antipodarum grew more in the presence of interactors and their growth was facilitated by the presence of the native snail F. bulimoides.

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The interface between invasive species science and legal regulation, using Hymenopteran species and their pathogens as a model system

10.26686/wgtn.17131952.v1 ◽

2021 ◽

Author(s):

◽

Evan Brenton-Rule

Keyword(s):

Invasive Species ◽

New Zealand ◽

Biological Invasions ◽

Honey Bee ◽

Legal Regulation ◽

Argentine Ants ◽

Deformed Wing Virus ◽

Introduced Range ◽

The Impact ◽

Bee Virus

Biological invasions are one of the major causes of biodiversity decline on the planet. The key driver of the global movement of invasive species is international trade. As a response to trade driven invasive species risk, international and domestic regulations have been promulgated with the goal of managing the spread and impact of non-native species. My aims in this thesis were twofold. First, my goal was to review a subset of international and domestic regulations with a view to commenting on their fitness for purpose and suggesting potential improvements. Second, I used the example of non-native and invasive Hymenoptera, as well as their pathogens, to illustrate the risks posed by invasive species and gaps in their management. In order to assess international and domestic regulations, I reviewed the World Trade Organization’s (WTO) Agreement on Sanitary and Phytosanitary Measures, as well as associated disputes. I argue that the WTO’s regulatory system does, for the most part, allow domestic regulators to manage invasive species risk as they see fit. Subsequently, the focus of the thesis narrows to investigate New Zealand’s pre- and post-border regime managing invasive species. I argue that New Zealand’s pre-border approach represents international best practice, but the post-border management of species is fragmented. The power to manage invasive species has been delegated to sub-national and regional bodies, which typically approach invasive species management in different ways. This variation has led to regulatory inconsistencies in pests managed and funding allocated. There appears to be a substantial lack of planning in some spaces, such as the risk of aquatic invasions. I make recommendations to ameliorate these inconsistencies. My second aim involved the study of non-native and invasive Hymenoptera in New Zealand, as well as the pathogens they carry, in order to illustrate the risks posed by invasive species and gaps in their management. I show that the globally widespread invasive Argentine ant (Linepithema humile) may play a role in the pathogen dynamics and mortality of honey bee hives where the species occur sympatrically. Hives in the presence of Argentine ants suffered significantly higher mortality rates relative to hives without ants and always had higher levels of a honey bee pathogen Deformed wing virus. I demonstrate that honey bee pathogens are found in a range of invasive Hymenoptera in New Zealand. I amplify entire genomes of the honey bee virus Kashmir bee virus (KBV) from three species of non-native or invasive Hymenoptera (Argentine ants, common wasps and honey bees). I show that there is KBV strain variability within and between regions, but more between regions. Further, I demonstrate the result that as sampled KBV sequence length increases, so too does sampled diversity. These results highlight how ‘an’ invasive species is typically not alone: they carry a range of diseases that are almost always not considered in international and regional management plans. Patterns of non-native Hymenoptera carrying honey bee diseases were not restricted to New Zealand. I used mitochondrial DNA to find the likely origin of invasive populations of the globally distributed invasive German wasp. I demonstrate that German wasps show reduced genetic diversity in the invaded range compared to the native range. Populations in the introduced range are likely to have arrived from different source populations. In some regions there were likely multiple introductions. Other regions are genetically homogenous and represent potential areas for use of gene drive technologies. All four different honey bee pathogens assayed for were found in German wasp populations worldwide. These results highlight how the introduction of one exotic species likely brings a range of pathogens. This example of pathogens in Hymenoptera is likely to be true for nearly all non-native introductions. Many of the impacts of biological invasions, such as predation and competition, are relatively obvious and are frequently studied. However some, such as the impact of pathogens, are unseen and poorly understood. Legal regulation is often a post-hoc response implemented once a problem has already arisen. At a global level regulatory regimes operate relatively effectively. As the focus becomes more granular, such as the case of pathogens of Hymenoptera, fewer controls exists. This thesis helps to reduce uncertainty in this area as well as makes recommendations as to how these risks may be managed.

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Ecological impact and spread of an invasive paper wasp in New Zealand (Hymenoptera: Vespidae)

10.26686/wgtn.14670114 ◽

2021 ◽

Author(s):

Matthew Howse

Keyword(s):

At Risk ◽

Invasive Species ◽

New Zealand ◽

Ecological Impact ◽

Diet Analysis ◽

Paper Wasp ◽

Gut Contents ◽

Suitable Habitat ◽

The South ◽

The North

Social wasps are considered among the most successful and impactful invasive species in the world. One species, Polistes dominula has spread from its native Mediterranean range to every continent except Antarctica. This wasp reached New Zealand in the last decade where it has established in the north of the South Island, however, reports of its presence are increasing throughout the country. Due to its recent arrival in New Zealand, little is known about where this species is likely to establish or what impacts it may have on local insect communities. In this thesis, I conducted two studies to investigate these questions, providing valuable information that may inform future management of this invasive species. In chapter 2, I used two bioclimatic modelling methods to predict areas of suitable habitat across four regions in the southern hemisphere. These models were informed by global temperature and precipitation data as well as global distribution occurrence data of P. dominula. These data were used to estimate conditions most highly correlated with the presence of this wasp. The models identified large areas across the target regions that were climatically suitable for the establishment of P. dominula. Many of these areas are not known to currently contain populations of this species, representing habitat potentially vulnerable to further invasion by P. dominula. Areas across South America, South Africa and Australia were predicted to be climatically suitable. In New Zealand, much of the North Island and eastern parts of the South Island were predicted to be suitable habitat for this wasp. These results suggest that P. dominula could potentially establish across more of the country and expand its invaded range. Information provided by these models may guide conservation and biosecurity management by highlighting key areas where prevention and mitigation should be prioritized. In chapter 3, I used molecular diet analysis to investigate the range of prey being utilised by P. dominula in New Zealand. Using DNA barcoding, larval gut contents of P. dominula and another closely related species, Polistes chinensis, were analysed to identify what species were present in the diet of both wasps. Butterflies and moths (Lepidoptera) were found to be the most highly represented order in both species’ diets. True bugs (Hemiptera) and flies (Diptera) were also abundant. Both wasps were shown to consume a range of native and introduced species including a number of agricultural pests. P. dominula was found to utilise a wider range of prey than P. chinensis. This more diverse prey range, combined with known differences in nesting behaviour, suggest that P. dominula may represent a more significant threat to invertebrate diversity than the already well-established P. chinensis. These results may inform conservation and biosecurity managers on which species are most at risk where this new invasive wasp becomes established. This thesis provides insights into the potential impacts of a new invasive species to New Zealand. Both chapters represent the first time that these methods have been used to study P. dominula. This work highlights the need for continued monitoring of wasp populations throughout New Zealand, especially in regions highlighted as vulnerable to P. dominula establishment. We also suggest the need to prioritise the conservation of ‘at-risk’ species in coastal and human-altered habitats. Increased public engagement through the citizen-science initiatives should be encouraged while more research into management and control methods is recommended.

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