Rapid eradication assessment (REA): a tool for pest absence confirmation

2020 ◽  
Vol 47 (2) ◽  
pp. 128 ◽  
Author(s):  
Juliana H. K. Kim ◽  
Peter Corson ◽  
Nick Mulgan ◽  
James C. Russell

Abstract ContextEradication of invasive species is necessary to protect and assist the recovery of native species and ecosystems. Knowing when to declare an eradication has been successful after ongoing non-detections is a challenge. AimsThe rapid eradication assessment (REA) model is a powerful simulation framework to determine, given model parameters and a fixed level of monitoring effort, the level of confidence in declaring the success of pest eradication. The aim of the present study was to extend the current functionality of the REA model for broader applicability. MethodsThe REA model was advanced so that it was able to account for (1) usage of multiple static device types with different probabilities of detection, (2) incursion detection at a known location and (3) usage of mobile detection devices, which are increasingly being used in conservation. Key resultsAn invasive rat incursion response on Great Mercury Island in New Zealand is used as a comprehensive example to demonstrate the distribution of estimated probability of pest absence among the cases using the current REA model and the extensions presented here. ConclusionsAlthough Great Mercury Island already had a sparse but extensive island-wide network of static biosecurity surveillance devices, and deployed additional static devices around the area of incursion, the greatest improvement in the estimated probability of pest absence following a rat incursion was from additionally using a trained rodent-detection dog. ImplicationsThe added functionality in the REA model and demonstration of its use on a real-world scenario will allow more realistic application by wildlife managers.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yang Liu ◽  
Penghao Wang ◽  
Melissa L. Thomas ◽  
Dan Zheng ◽  
Simon J. McKirdy

AbstractInvasive species can lead to community-level damage to the invaded ecosystem and extinction of native species. Most surveillance systems for the detection of invasive species are developed based on expert assessment, inherently coming with a level of uncertainty. In this research, info-gap decision theory (IGDT) is applied to model and manage such uncertainty. Surveillance of the Asian House Gecko, Hemidactylus frenatus Duméril and Bibron, 1836 on Barrow Island, is used as a case study. Our research provides a novel method for applying IGDT to determine the population threshold ($$K$$ K ) so that the decision can be robust to the deep uncertainty present in model parameters. We further robust-optimize surveillance costs rather than minimize surveillance costs. We demonstrate that increasing the population threshold for detection increases both robustness to the errors in the model parameter estimates, and opportuneness to lower surveillance costs than the accepted maximum budget. This paper provides guidance for decision makers to balance robustness and required surveillance expenditure. IGDT offers a novel method to model and manage the uncertainty prevalent in biodiversity conservation practices and modelling. The method outlined here can be used to design robust surveillance systems for invasive species in a wider context, and to better tackle uncertainty in protection of biodiversity and native species in a cost-effective manner.


2012 ◽  
Vol 18 (2) ◽  
pp. 77 ◽  
Author(s):  
Heather Parks ◽  
Kyle Clifton ◽  
Lauren Best ◽  
Bridget Johnson

PEST-PROOF (exclusion) fences are designed to prevent non-native, predatory and pest species from repopulating an area set aside to protect vulnerable native plant and animal species. Pest-proof fencing provides security from invasive species, but can isolate the native species enclosed within. On one hand, some rare native species exist on the mainland due to the pest-free status achieved through the use of exclusion fences. On the other hand, these reintroduced populations are now isolated a situation where they would not be found naturally (Jamieson et al. 2006). Exclusion fences must be constantly maintained or the sanctuary risks reinvasion. An important question for conservation biologists and managers to answer is therefore — when is exclusion fencing the best option for protecting native species from introduced pests? We have drawn our examples from New Zealand and Australia where progress has been made with regard to the design and utilization of exclusion fences.


Author(s):  
Amy Krist ◽  
Mark Dybdahl

Invasive species are one of the greatest threats to global biodiversity. Hence, understanding the role of invasive species is of grave importance to managing and minimizing the impact of biological invasions. To date, the ecological impacts of biological invasions have received significant attention, but little effort has been made to address the evolutionary impact (Sakai et al. 2001, Cox 2004). This is despite the fact that evolutionary impacts are likely to be widespread; invasive species have been shown to alter patterns of natural selection or gene flow within native populations (Parker et al. 1999), and many of the best examples of rapid evolution involve invasive species interacting with native species (Reznick and Ghalambor 2001, Strauss et al. 2006). We have begun to address some of the evolutionary consequences of the invasion of the New Zealand mud snail, (Potamopyrgus antipodarum) on a species of native snail in the Greater Yellowstone Area (GYA).


2013 ◽  
Vol 9 (6) ◽  
pp. 20130746 ◽  
Author(s):  
Murray P. Fea ◽  
Margaret C. Stanley ◽  
Gregory I. Holwell

Overlap in the form of sexual signals such as pheromones raises the possibility of reproductive interference by invasive species on similar, yet naive native species. Here, we test the potential for reproductive interference through heterospecific mate attraction and subsequent predation of males by females of a sexually cannibalistic invasive praying mantis. Miomantis caffra is invasive in New Zealand, where it is widely considered to be displacing the only native mantis species, Orthodera novaezealandiae , and yet mechanisms behind this displacement are unknown. We demonstrate that native males are more attracted to the chemical cues of introduced females than those of conspecific females. Heterospecific pairings also resulted in a high degree of mortality for native males. This provides evidence for a mechanism behind displacement that has until now been undetected and highlights the potential for reproductive interference to greatly influence the impact of an invasive species.


Author(s):  
Amy Krist ◽  
Caroline Charles

To understand the impacts of an herbivorous invasive species on native herbivores, it is critical to quantify the relative impact of the invasive and the native species on shared resources. In a field experiment, we compared grazing efficacy of periphyton by the invasive New Zealand mudsnail, Potamopyrgus antipidarum, and 3 native macroinvertebrate grazers. Depending on the measure of periphyton biomass, P. antipodarum removed as much or more periphyton than any of the native grazers. When we examined diatom genera individually, P. antipodarum also suppressed the relative abundance of the greatest number of diatom genera and suppressed those diatoms more than the native grazers. As a result, P. antipodarum should compete strongly for periphyton with native grazers. In particular, because Ephemerella mayflies were the second most effective grazers and grazed many diatom genera similarly to the invasive snails, these mayflies may be competing with P. antipodarum in the introduced range. Overall, grazing ability may contribute to the invasion success of P. antipodarum.


2020 ◽  
Vol 26 (1) ◽  
pp. 35 ◽  
Author(s):  
Nick Kirk ◽  
Robyn Kannemeyer ◽  
Alison Greenaway ◽  
Edy MacDonald ◽  
Dean Stronge

Invasive animal species threaten global biodiversity. In New Zealand invasive species threaten iconic native species, and scientists are seeking approval to research new technologies that might be capable of eradicating these invasive species. The aim of this research was to understand what New Zealanders with an interest in pest control consider to be the main risks and benefits of introducing new technologies to manage invasive species. We invited key informants to participate in the focus groups, selecting people with knowledge and experience of pest control issues in New Zealand. Data were collected from seven focus groups held in three locations across New Zealand. A thematic analysis of the data was then conducted in which three key themes emerged: concern about the risk of unintended consequences, the benefits of landscape-scale technologies, and New Zealand being an early adopter of new technologies. The focus groups articulated a variety of benefits from introducing new technologies – such as replacing dangerous poisons with non-toxic alternatives – but it was the risks of the new technologies that dominated the discussions. Given these results, we recommend an education and communication strategy focussed on social learning, in conjunction with a codesigned decision-making process, to help establish social licence for the application of potentially controversial technologies.


2020 ◽  
Vol 637 ◽  
pp. 195-208 ◽  
Author(s):  
EM DeRoy ◽  
R Scott ◽  
NE Hussey ◽  
HJ MacIsaac

The ecological impacts of invasive species are highly variable and mediated by many factors, including both habitat and population abundance. Lionfish Pterois volitans are an invasive marine species which have high reported detrimental effects on prey populations, but whose effects relative to native predators are currently unknown for the recently colonized eastern Gulf of Mexico. We used functional response (FR) methodology to assess the ecological impact of lionfish relative to 2 functionally similar native species (red grouper Epinephelus morio and graysby grouper Cephalopholis cruentata) foraging in a heterogeneous environment. We then combined the per capita impact of each species with their field abundance to obtain a Relative Impact Potential (RIP). RIP assesses the broader ecological impact of invasive relative to native predators, the magnitude of which predicts community-level negative effects of invasive species. Lionfish FR and overall consumption rate was intermediate to that of red grouper (higher) and graysby grouper (lower). However, lionfish had the highest capture efficiency of all species, which was invariant of habitat. Much higher field abundance of lionfish resulted in high RIPs relative to both grouper species, demonstrating that the ecological impact of lionfish in this region will be driven mainly by high abundance and high predator efficiency rather than per capita effect. Our comparative study is the first empirical assessment of lionfish per capita impact and RIP in this region and is one of few such studies to quantify the FR of a marine predator.


2019 ◽  
Vol 147 (5) ◽  
pp. 1429-1445 ◽  
Author(s):  
Yuchu Zhao ◽  
Zhengyu Liu ◽  
Fei Zheng ◽  
Yishuai Jin

Abstract We performed parameter estimation in the Zebiak–Cane model for the real-world scenario using the approach of ensemble Kalman filter (EnKF) data assimilation and the observational data of sea surface temperature and wind stress analyses. With real-world data assimilation in the coupled model, our study shows that model parameters converge toward stable values. Furthermore, the new parameters improve the real-world ENSO prediction skill, with the skill improved most by the parameter of the highest climate sensitivity (gam2), which controls the strength of anomalous upwelling advection term in the SST equation. The improved prediction skill is found to be contributed mainly by the improvement in the model dynamics, and second by the improvement in the initial field. Finally, geographic-dependent parameter optimization further improves the prediction skill across all the regions. Our study suggests that parameter optimization using ensemble data assimilation may provide an effective strategy to improve climate models and their real-world climate predictions in the future.


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