ORCID Profile
0000-0002-1543-7139
Current Organisation
University of Canterbury
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Wiley
Date: 18-01-2021
DOI: 10.1002/ECM.1439
Abstract: Invasions by alien pest species contribute heavily to global bio ersity decline, with invasive mammals having some of the greatest impacts on endemic biota. Pest management within ecological restorations is therefore critical for conserving threatened biota. Coordinating restoration efforts at global scale requires evidence of the relative efficacy of different pest‐managed restoration approaches (“regimes”) for enhancing bio ersity. Our national meta‐analysis of 447 bio ersity responses across 16 ecological restorations quantifies significant benefits for bio ersity over two decades and multiple trophic levels, and across a spectrum of invasive mammal suppression‐to‐eradication regimes. Deeply endemic species had the strongest responses to pest control compared with recent native or introduced biota. Using this information, we predict levels of pest suppression required to confer bio ersity benefits, to guide future management strategies. Our findings provide new evidence that invasive pest control is an effective approach to ecological restoration, to aid decision‐makers in setting objectives and making targeted investments.
Publisher: Public Library of Science (PLoS)
Date: 18-03-2015
Publisher: Springer Science and Business Media LLC
Date: 02-2008
DOI: 10.1038/NATURE06518
Abstract: Many free-ranging predators have to make foraging decisions with little, if any, knowledge of present resource distribution and availability. The optimal search strategy they should use to maximize encounter rates with prey in heterogeneous natural environments remains a largely unresolved issue in ecology. Lévy walks are specialized random walks giving rise to fractal movement trajectories that may represent an optimal solution for searching complex landscapes. However, the adaptive significance of this putative strategy in response to natural prey distributions remains untested. Here we analyse over a million movement displacements recorded from animal-attached electronic tags to show that erse marine predators-sharks, bony fishes, sea turtles and penguins-exhibit Lévy-walk-like behaviour close to a theoretical optimum. Prey density distributions also display Lévy-like fractal patterns, suggesting response movements by predators to prey distributions. Simulations show that predators have higher encounter rates when adopting Lévy-type foraging in natural-like prey fields compared with purely random landscapes. This is consistent with the hypothesis that observed search patterns are adapted to observed statistical patterns of the landscape. This may explain why Lévy-like behaviour seems to be widespread among erse organisms, from microbes to humans, as a 'rule' that evolved in response to patchy resource distributions.
Publisher: Wiley
Date: 17-08-2021
DOI: 10.1002/EAP.2412
Abstract: As part of national biosecurity programs, cargo imports, passenger baggage, and international mail are inspected at ports of entry to verify compliance with phytosanitary regulations and to intercept potentially damaging nonnative species to prevent their introduction. Detection of organisms during inspections may also provide crucial information about the species composition and relative arrival rates in invasion pathways that can inform the implementation of other biosecurity practices such as quarantines and surveillance. In most regions, insects are the main taxonomic group encountered during inspections. We gathered insect interception data from nine world regions collected from 1995 to 2019 to compare the composition of species arriving at ports in these regions. Collectively, 8,716 insect species were intercepted in these regions over the last 25 yr, with the combined international data set comprising 1,899,573 interception events, of which 863,972 were identified to species level. Rarefaction analysis indicated that interceptions comprise only a small fraction of species present in invasion pathways. Despite differences in inspection methodologies, as well as differences in the composition of import source regions and imported commodities, we found strong positive correlations in species interception frequencies between regions, particularly within the Hemiptera and Thysanoptera. There were also significant differences in species frequencies among insects intercepted in different regions. Nevertheless, integrating interception data among multiple regions would be valuable for estimating invasion risks for insect species with high likelihoods of introduction as well as for identifying rare but potentially damaging species.
No related grants have been discovered for Alex James.