Geology topics

Antoinette J. Piaggio

Publications and source records attributed to Antoinette J. Piaggio.

9 recordsLinked to original sources

USGS2026

An evaluation of next-generation biological control methods for the invasive brown treesnake in the Mariana Islands

The brown treesnake (BTS) invasion in Guam continues to cause extensive ecological and economic damage, yet existing control tools cannot achieve islandwide suppression or eradication, highlighting the need for new strategies. This review evaluates the feasibility of classical and genetic biocontrol approaches for BTS and identifies priority knowledge gaps. Classical biocontrol, which relies on pathogens or parasites from a pest’s native range, has had limited success in vertebrates, though certain viruses may hold potential. For BTS, prior work has identified candidate agents, including hemogregarines and paramyxoviruses, but major uncertainties remain in transmission, specificity, long term efficacy, and ecological risk. Theoretical models suggest that moderately virulent pathogens may offer the strongest potential for sustained suppression, with Ophidian paramyxoviruses emerging as a leading prospect, though substantial empirical research is still required. Genetic biocontrol offers additional possibilities, including gene drives that could bias inheritance, reduce fertility, or skew sex ratios. Self sustaining homing and shredding drives could theoretically produce long term reductions, while “enhanced” self limiting systems may provide geographically restricted alternatives. Approaches involving genetically modified prey and toxic males that shorten female lifespan through mating may have future relevance but require major development and validation. Risks across genetic strategies include unintended spread, ecological side effects, technical constraints such as producing engineered snakes, potential resistance, and regulatory complexity. Because feasibility depends on societal acceptance, the review emphasizes the need for early engagement with Guam’s local and Indigenous communities, whose perspectives will shape future development and implementation. Key research priorities include improved modeling, native range genomic characterization of BTS, expanded pathogen surveys, advances in BTS genetic tools and captive rearing methods, and further exploration of both classical pathogen candidates and genetically engineered prey systems. Collectively, the review concludes that classical and genetic biocontrol hold promise for long term, cost effective BTS suppression, but substantial scientific, ethical, ecological, and social groundwork remains before deployment.

Hawai’i Cooperative Fishery Research Unit Technica↗

USGS2026

A practical framework for identifying genetic subpopulations and ESUs: Insights for IUCN assessments and broader management

Species conservation assessments evaluate extinction risk, and recovery potential, advancing species persistence through guiding resource prioritization and planning. Assessment frameworks, including the International Union for Conservation of Nature Red List and Green Status of Species, typically focus on species as a whole. Importantly, they do not routinely account for genetically distinct units or do not have standardized methods of unit delineation. This limits the representation of genetically distinct components, including adaptive genetic diversity that underpins long-term resilience and recovery. Incorporating standardized within-species units like subpopulations and Evolutionarily Significant Units (ESUs) into species assessments could help address this oversight. However, identifying and delineating such units remain challenging, particularly when molecular data are limited. Here, we propose a flexible framework that integrates molecular and non-molecular evidence to identify both subpopulations and ESUs across taxa, providing a practical tool to incorporate within-species diversity into conservation assessments.

BioScience↗

USGS2025

A practical framework for identifying genetic subpopulations and ESUs: Insights for IUCN assessments and broader management

The International Union for Conservation of Nature (IUCN) sets global conservation standards, including the Red List of Threatened Species and the Green Status of Species. Recent analyses showed that genetic diversity has not been effectively considered by IUCN species assessments, despite being fundamental to species’ fitness and adaptive potential. Incorporation of genetic diversity into IUCN assessments can support its successful long-term conservation. To enhance the preservation of genetic diversity, assessments should include genetically meaningful within-species units. Subpopulations are recognized units by the IUCN for protecting natural connectivity, however infrequently evaluated. Evolutionarily Significant Units (ESUs) are currently not recognized as a formal unit by the IUCN. However, incorporating ESUs into conservation frameworks could significantly enhance our capacity to identify and protect adaptive genetic diversity. To facilitate inclusion of these units in IUCN assessments, we outline a widely applicable framework for their identification that uses non-molecular and molecular data for global accessibility.

EcoEvoRxiv↗

USGS2024

Analysis of mitochondrial DNA sequence data demonstrates that monophyly of myotis occultus is complicated by greater sampling of myotis lucifugus

The validity of Myotis occultus as a species unique from Myotis lucifugus has been a source of debate. Most recently, many authorities treat M. occultus as a distinct species, at least in part because a previous study showed that M. occultus and M. l. carissima (the subspecies that occurs in closest geographic proximity to M. occultus ) form separate monophyletic clades based on sequences of two mitochondrial genes (cytochrome- b [cytb] and cytochrome oxidase subunit II [COII]). We re-evaluated the phylogenetic relationship between M. occultus and M. lucifugus based on mitochondrial sequences using an expanded dataset of cytb and COII sequences that originated from more genetically diverse specimens of M. lucifugus collected across a broader geographic area. Based on a phylogenetic analysis, we found that M. occultus sublineages embedded within a well-supported clade that included some specimens of M. lucifugus . These results indicate that the previous genetic analysis demonstrating that M. occultus and M. lucifugus form distinct monophyletic groups is unsupported by our larger dataset. Future research will likely need to focus on genetic work involving whole-genome sequencing of nuclear DNA to better resolve the true taxonomic relationship between M. occultus and M. lucifugus . La valides de Myotis occultus como una especie distinta a Myotis lucifugus ha sido fuente de debate. Recientemente, muchas autoridades han considerado M. occultus como una especie diferente, en parte porque un estudio anterior mostró que M. occultus y M. l. carissima (la subespecie con la mayor proximidad geográfica a M. occultus) forman clados monofiléticos separados basados en secuencias de dos genes mitocondriales (el citocromo-b [cytb] y la subunidad II de citocromo oxidasa [COII]). Nosotros hemos reevaluado la relación filogenética entre M. occultus y M. lucifugus usando una ampliada colección de datos que contiene secuencias de los genes mitocondriales cytb y COII de especímenes de M. lucifugus genéticamente más diversos que fueron muestreados en un área geográfica más extensa. Nuestro análisis filogenético muestra que los sublinajes de M. occultus están incrustados dentro de un clado bien respaldado que incluye algunos especímenes de M. lucifugus. Estos resultados indican que el análisis genético anterior que demostró que M. occultus y M. lucifugus forman grupos monofiléticos distintos no está respaldado por nuestra más amplia colección de datos. Es probable que para resolver mejor la verdadera relación taxonómica entre M. occultus y M. lucifugus sea necesario el uso de secuenciación del genoma completo del ADN nuclear.

Southwestern Naturalist↗

USGS2021

Strategic considerations for invasive species managers in the utilization of environmental DNA (eDNA): Steps for incorporating this powerful surveillance tool

Invasive species surveillance programs can utilize environmental DNA sampling and analysis to provide information on the presence of invasive species. Wider utilization of eDNA techniques for invasive species surveillance may be warranted. This paper covers topics directed towards invasive species managers and eDNA practitioners working at the intersection of eDNA techniques and invasive species surveillance. It provides background information on the utility of eDNA for invasive species management and points to various examples of its use across federal and international programs. It provides information on 1) why an invasive species manager should consider using eDNA, 2) deciding if eDNA can help with the manager’s surveillance needs, 3) important components to operational implementation, and 4) a high-level overview of the technical steps necessary for eDNA analysis. The goal of this paper is to assist invasive species managers in deciding if, when, and how to use eDNA for surveillance. If eDNA use is elected, the paper provides guidance on steps to ensure a clear understanding of the strengths and limitation of the methods and how results can be best utilized in the context of invasive species surveillance.

Management of Biological Invasions↗

USGS2019

Reporting the limits of detection and quantification for environmental DNA assays

Background Environmental DNA (eDNA) analysis is increasingly being used to detect the presence and relative abundance of rare species, especially invasive or imperiled aquatic species. The rapid progress in the eDNA field has resulted in numerous studies impacting conservation and management actions. However, standardization of eDNA methods and reporting across the field is yet to be fully established, with one area being the calculation and interpretation of assay limit of detection (LOD) and limit of quantification (LOQ). Aims Here, we propose establishing consistent methods for determining and reporting of LOD and LOQ for single‐species quantitative PCR (qPCR) eDNA studies. Materials & Methods/ Results We utilize datasets from multiple cooperating laboratories to demonstrate both a discrete threshold approach and a curve‐fitting modeling approach for determining LODs and LOQs for eDNA qPCR assays. We also provide details of an R script developed and applied for the modeling method. Discussion/Conclusions Ultimately, standardization of how LOD and LOQ are determined, interpreted, and reported for eDNA assays will allow for more informed interpretation of assay results, more meaningful interlaboratory comparisons of experiments, and enhanced capacity for assessing the relative technical quality and performance of different eDNA qPCR assays.

Environmental DNA↗

USGS2019

Is there convergence of gut microbes in blood-feeding vertebrates?

Animal microbiomes play an important role in dietary adaptation, yet the extent to which microbiome changes exhibit parallel evolution is unclear. Of particular interest is an adaptation to extreme diets, such as blood, which poses special challenges in its content of proteins and lack of essential nutrients. In this study, we assessed taxonomic signatures (by 16S rRNA amplicon profiling) and potential functional signatures (inferred by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt)) of haematophagy in birds and bats. Our goal was to test three alternative hypotheses: no convergence of microbiomes, convergence in taxonomy and convergence in function. We find a statistically significant effect of haematophagy in terms of microbial taxonomic convergence across the blood-feeding bats and birds, although this effect is small compared to the differences found between haematophagous and non-haematophagous species within the two host clades. We also find some evidence of convergence at the predicted functional level, although it is possible that the lack of metagenomic data and the poor representation of microbial lineages adapted to haematophagy in genome databases limit the power of this approach. The results provide a paradigm for exploring convergent microbiome evolution replicated with independent contrasts in different host lineages.

Philosophical Transactions of the Royal Society B:↗

USGS2019

Development of microsatellite loci for two New World vultures (Cathartidae)

Objective Use next-generation sequencing to develop microsatellite loci that will provide the variability necessary for studies of genetic diversity and population connectivity of two New World vulture species. Results We characterized 11 microsatellite loci for black vultures ( Coragyps atratus ) and 14 loci for turkey vultures ( Cathartes aura ). These microsatellite loci were grouped into 3 multiplex panels for each species. The number of alleles among black vulture samples ranged from 2 to 11, and 3 to 48 among turkey vulture samples.

BMC Research Notes↗

USGS2016

Integrating early detection with DNA barcoding: species identification of a non-native monitor lizard (Squamata: Varanidae) carcass in Mississippi, U.S.A.

Early detection of invasive species is critical to increasing the probability of successful management. At the primary stage of an invasion, invasive species are easier to control as the population is likely represented by just a few individuals. Detection of these first few individuals can be challenging, particularly if they are cryptic or otherwise characterized by low detectability. The engagement of members of the public may be critical to early detection as there are far more citizen s on the landscape than trained biologists. However, it can be difficult to assess the credibility of public reporting, especially when a diagnostic digital image or a physical specimen in good condition are lacking. DNA barcoding can be used for verification when morphological identification of a specimen is not possible or uncertain (i.e., degraded or partial specimen). DNA barcoding relies on obtaining a DNA sequence from a relatively small fragment of mitochondrial DNA and comparing it to a database of sequences containing a variety of expertly identified species. He rein we report the successful identification of a degraded specimen of a non-native, potentially invasive reptile species ( Varanus niloticus ) via DNA barcoding, after discovery and reporting by a member of the public.

Mississippi↗