Biology subjects

McDevitt, A.

Publications and source records attributed to McDevitt, A..

17 recordsLinked to original sources

bioRxiv2025

Complementary assessment of fish biodiversity across the upper/lower mesophotic interface in a subtropical coral reef using eDNA metabarcoding and baited cameras

Mesophotic Coral Ecosystems (MCEs) occur in the middle to lower photic zone ([~]30-150 m) of tropical and subtropical regions, are often extensions of shallow reef communities, and generally hold great importance for local commercial fisheries. Compared to their shallower counterpart, MCEs have been traditionally understudied, primarily due to their inaccessibility with traditional monitoring methodologies. In this study, we aim to provide an interdisciplinary assessment of the biodiversity of Bermudan reef fish communities from the upper/lower mesophotic interface (60 m) by utilising a combination of environmental DNA (eDNA) metabarcoding and baited remote underwater videos (BRUVs). In total, 155 species from 137 genera were detected by eDNA metabarcoding whilst a total of 85 species from 53 genera were detected by BRUVs. The combined species detections totalled 182 species with approximately half of those detections unique to this study when compared to previous studies. Both methodologies found differences in -diversity between study locations, with each method independently detecting the highest species richness at the same location. The species assemblage at each location was dominated ([~]80%) by species known to occur throughout the shallow reef system and the upper mesophotic, whilst species only known to inhabit mesophotic ecosystems accounted for [~]6% at each location. These findings suggest a high level of species continuity with the adjacent shallower reef systems. The complementary nature of eDNA metabarcoding and BRUVs allows for a more accurate characterisation of fish biodiversity at the upper/lower mesophotic interface, which can lead to a more comprehensive understanding of ecosystem structure and more informed management decisions.

ecology↗

bioRxiv2024

Performance of eDNA capture methods for monitoring fish biodiversity in a hyper-tidal estuary

Environmental DNA (eDNA) has become an established and efficient method for monitoring biodiversity in aquatic systems. However, there is a need to compare and standardise sampling methods across ecosystem types, particularly complex ecosystems such as estuaries where unique challenges for monitoring fish populations are present due to fluctuating environmental factors. Here, we compare fish biodiversity metrics obtained from eDNA metabarcoding data using four different eDNA filtering methods: three manual filtering methods with different pore sizes (0.45, 1.2 and 5 {micro}m) and a newly established passive method, the metaprobe. The study was applied across a salinity gradient in a hyper-tidal estuarine ecosystem. Overall, 44 fish species were detected across the four methods used. The 0.45 {micro}m filter recovered the highest richness (39 species), then the metaprobe method (35), followed by the 1.2 {micro}m (34) and 5 {micro}m (33) filters. Filter performance between salinity gradients revealed that the 0.45 {micro}m and the 1.2 {micro}m methods recovered the highest species richness across all sampled zones. The 0.45 {micro}m also had the most consistent detection probabilities using representative species from each zone. While the 0.45 {micro}m method appeared to be the optimal method, each of the methods can be considered as a viable and comparable option for biomonitoring in dynamic ecosystems such as estuaries and rivers. In particular, the passive metaprobe (used in a freshwater system for the first time here) performed well in comparison to the manual filtering methods despite a short deployment time. This study provides critical insights for optimising fish biodiversity assessments using eDNA metabarcoding in estuarine ecosystems, providing a valuable framework for future monitoring efforts in similar systems worldwide.

molecular biology↗

bioRxiv2023

DNA barcoding reveals an increased diversity within the genus Culex (Diptera: Culicidae) in Ireland

Arthropod populations are changing globally due to the combined impacts of climate change, land-use transformation, globalisation and trade. Changes in arthropod populations can potentially result in the decline and extinction of some native and/or endemic species, while other species that potentially pose threats may increase. Such dynamics lead to weakened ecosystem resilience, which can facilitate the establishment and spread of species with vector capabilities, such as mosquitoes. While many of the mosquito species present in Ireland possess vector capabilities, populations have not been nationally surveyed since 1991. At that time, species identification relied on morphological examination, a method that was even then recognised as inadequate for differentiating certain species within complexes. In this study, we present the first DNA barcoding investigation of Irish mosquito populations and reveal species and hidden diversity not previously recognised in Ireland. These include two potential new species/ecotypes, Culex torrentium and Culex pipiens form pipiens, which were recorded for the first time in Ireland. We demonstrate that barcoding with Cytochrome C Oxidase Subunit 1 (COI) based primers is suitable for the majority of species-level identifications. However, additional primer sets targeting the Internal Transcribed Spacer regions 1 and 2 (ITS1 and ITS2) were necessary to differentiate species within the Culex pipiens complex. The multi-locus approach employed in this study can enhance national surveillance efforts, especially in monitoring mosquitoes that may transmit vector-borne diseases, and in recognising increased species diversity from a biodiversity perspective.

ecology↗

bioRxiv2023

Using Environmental DNA to Reconstruct Amphibian Communities at Sites Infected with Batrachochytrium salamandrivorans in the Netherlands

AO_SCPLOWBSTRACTC_SCPLOWThe recently discovered Batrachochytrium salamandrivorans (Bsal) fungus can cause high mortality rates in some European salamanders and newts (urodelans) and has the potential to expand its currently small invasive range in Europe. Therefore, monitoring its distribution and better understanding both the species threatened and the mechanics of infection are essential in mitigating the damage Bsal may cause. Environmental DNA (eDNA) has emerged as a promising non-invasive method for detecting both this fungal pathogen and the amphibian communities in infected areas. We applied these methods in the province Gelderland, the Netherlands where the pathogen has previously been detected and is expanding its range, with the goal of detecting the natural amphibian community present. We sampled 27 water bodies in the region surrounding the known outbreak sites. We used data from a Bsal-specific qPCR assay to determine its presence-absence and applied an eDNA metabarcoding approach to characterize the amphibian communities using two different primer sets. The 12S vertebrate primer set outperformed the 16S amphibian primer set and detected all the expected amphibians in the study area: Bufo bufo, Lissotriton vulgaris, Pelobates fuscus, Pelophylax spp., Rana temporaria and Triturus cristatus. Bsal was detected at eight of the ponds. A distance-based redundancy analysis found a weak but significant relationship between Bsal presence and the composition of amphibian communities using eDNA. This study provides the foundation for future studies on Bsal and its relationship with amphibian communities in Europe, highlighting the need for further research into the mechanisms of persistence and transmission between water bodies.

ecology↗

bioRxiv2022

Shark-dust: High-throughput DNA sequencing of processing residues unveils widespread trade in threatened sharks and rays

Illegal fishing, unregulated bycatch, and market demand for certain products (e.g. fins) are largely responsible for the rapid global decline of shark and ray populations. Controlling trade of endangered species remains difficult due to product variety, taxonomic ambiguity and trade complexity. The genetic tools traditionally used to identify traded species typically target individual tissue samples, are time-consuming and/or species-specific. Here, we performed high-throughput sequencing of trace DNA fragments retrieved from dust and scraps left behind by trade activities. We metabarcoded shark-dust samples from seven processing plants in the worlds biggest shark landing site (Java, Indonesia), and identified 54 shark and ray taxa (representing half of all chondrichthyan orders), half of which could not be recovered from tissue samples collected in parallel from the same sites. Importantly, over 80% of shark-dust sequences were found to belong to CITES-listed species. We argue that this approach is likely to become a powerful and cost-effective monitoring tool wherever wildlife is traded. One-Sentence SummaryShark-dust, the traces of biological material left behind from the processing of shark products, can now be DNA-sequenced in bulk to accurately reconstruct the biodiversity underlying trade.

genetics↗

bioRxiv2022

Universal closed-tube barcoding for monitoring the shark and ray trade in megadiverse conservation hotspots

Trade restrictions for many endangered elasmobranch species exist to disincentivise their exploitation and curb their declines. However, the variety of products and the complexity of import/export routes make trade monitoring challenging. We investigate the use of a portable, universal, DNA-based tool which would greatly facilitate in-situ monitoring. We collected shark and ray samples across the Island of Java, Indonesia, and selected 28 species (including 22 CITES-listed species) commonly encountered in landing sites and export hubs to test a recently developed real-time PCR single-assay originally developed for screening bony fish. We employed a deep learning algorithm to recognize species based on DNA melt-curve signatures. By combining visual and machine learning assignment methods, we distinguished 25 out of 28 species, 20 of which were CITES-listed. With further refinement, this method can provide a practical tool for monitoring elasmobranch trade worldwide, without the need for a lab or the bespoke design of species-specific assays. HighlightsO_LIWe applied a portable, universal, closed-tube DNA barcoding approach originally developed for bony fishes to distinguish between shark and ray species traded in Indonesia. C_LIO_LIWe built a deep machine learning model to automatically assign species from the qPCR fluorescence spectra produced by two barcodes C_LIO_LIThe model achieved 79.41% accuracy for classifying 28 elasmobranch species, despite the barcode regions being designed for teleost species C_LIO_LIThis tool can serve as a potent single-assay in-situ diagnostic tool to regulate trade operations and it will be significantly enhanced by further optimisation of the barcode regions to fit elasmobranch DNA sequence variation C_LI

genetics↗

bioRxiv2022

Resource competition drives an invasion-replacement event among shrew species on an island

O_LIInvasive mammals are responsible for the majority of native species extinctions on islands. While most of these extinction events will be due to novel interactions between species (e.g. exotic predators and naive prey), it is more unusual to find incidences where a newly invasive species causes the decline/extinction of a native species on an island when they normally coexist elsewhere in their overlapping mainland ranges. C_LIO_LIWe investigated if resource competition between two insectivorous small mammals was playing a significant role in the rapid replacement of the native pygmy shrew (Sorex minutus) in the presence of the recently invading greater white-toothed shrew (Crocidura russula) on the island of Ireland. C_LIO_LIWe used DNA metabarcoding of gut contents from >300 individuals of both species to determine each species diet and measured the size of individuals (weight and length) during different stages of the invasion in Ireland (before, during and after the species come into contact with one another) and on a French island where both species have long coexisted (acting as a natural control site). Dietary composition, niche width and overlap and size were compared in these different stages. C_LIO_LIThe size of the invasive C. russula and composition of its diet changes between when it first invades an area and after it becomes established. Individuals are larger and they consume larger invertebrates at the invasion front, before switching towards the smaller prey taxa that are more essential for the survival of the native species after establishment. As a result, the level of interspecific dietary overlap increases from between 11-14% when they first come into contact with each other to between 39-46% after the invasion. C_LIO_LIHere we show that an invasive species can quickly alter its dietary niche in a new environment, leading to negative impacts that were not previously predicted based on the coexistence of these species in other parts of their mainland ranges. As well as causing the replacement of a native small mammal, the invasive shrew may be rapidly exhausting local resources of larger invertebrate species. These subsequent changes in terrestrial invertebrate communities could have severe impacts further downstream on ecosystem functioning and services. C_LI

ecology↗

bioRxiv2021

Mapping differences in mammalian distributions and diversity using environmental DNA from rivers

AimFinding more efficient ways to monitor, and estimate the diversity of, mammalian communities is a major step towards their management and conservation. Environmental DNA (eDNA) from river water has recently been shown to be a viable method for biomonitoring mammalian communities. Yet, most of the studies to date have focused on the potential for eDNA to detect individual species, with little focus on describing patterns of community diversity and structure. In this study, we focus on the sampling effort required to reliably map the diversity and distribution of semi-aquatic and terrestrial mammals and allow inferences of community structure surrounding rivers. LocationSoutheastern England MethodsWe used eDNA metabarcoding on water samples collected along two rivers and a beaver enclosure over two days, targeting terrestrial and semi-aquatic mammals. Mammalian community diversity and composition was assessed based on species richness and {beta}-diversity. Differences between river communities were calculated and partitioned into nestedness and turnover, and the sampling effort required to rapidly detect semi-aquatic and terrestrial species was evaluated based on species accumulation curves and occupancy modelling. ResultseDNA metabarcoding efficiently detected 25 wild mammal species from five orders in two days of sampling, representing the vast majority (82%) of the species expected in the area. The required sampling effort varied between orders, with common species (generally rodents, deer and lagomorph species) more readily detected, with carnivores detected less frequently. Measures of species richness differed between rivers (both overall and within each mammalian order) and patterns of {beta}-diversity revealed the importance of species replacement in sites within each river, against a pattern of species loss between the two rivers. Main conclusionseDNA metabarcoding demonstrated its capability to rapidly detect mammal species, allowing inferences of community composition that will better inform future sampling strategies for this Class. Importantly, this study highlights the potential use of eDNA data for investigating mammalian community dynamics over different spatial scales.

ecology↗

bioRxiv2021

Primer biases in the molecular assessment of diet in multiple insectivorous mammals

Our understanding of trophic interactions of small insectivorous mammals has been drastically improved with the advent of DNA metabarcoding. The technique has continued to be optimised over the years, with primer choice repeatedly being a vital factor for dietary inferences. However, the majority of dietary studies examining the effect of primer choice often rely on in silico analyses or comparing single-niche species. Here we apply DNA metabarcoding to empirically compare the prey detection capabilities of two widely used primer sets when assessing the diets of a flying (lesser horseshoe bat; Rhinolophus hipposideros) and two ground dwelling insectivores (greater white-toothed shrew; Crocidura russula and pygmy shrew; Sorex minutus). Although R. hipposideros primarily rely on two prey orders (Lepidoptera and Diptera), the unique taxa detected by each primer shows that a combination of primers may be the best approach to fully describe bat trophic ecology. However, random forest classifier analysis suggest that one highly degenerate primer set detected the majority of both shrews diet despite higher levels of host amplification. The wide range of prey consumed by ground-dwelling insectivores can therefore be accurately documented from using a single broad-range primer set, which can decrease cost and labour. The results presented here show that dietary inferences will differ depending on the primer or primer combination used for insectivores occupying different niches (i.e. hunting in the air or ground) and demonstrate the importance of performing empirical pilot studies for novel study systems.

ecology↗

bioRxiv2021

Estuarine molecular bycatch as a landscape-wide biomonitoring tool

Environmental DNA analysis is rapidly transforming biodiversity monitoring and bolstering conservation applications worldwide. This approach has been assisted by the development of metabarcoding PCR primers that are suited for detection of a wide range of taxa. However, little effort has gone into exploring the value of the non-target DNA sequences that are generated in every survey, but subsequently discarded. Here we demonstrate that fish-targeted markers widely employed in aquatic biomonitoring can also detect birds and mammals present in the surrounding habitats. We showcase this feature in three temperate estuaries over multiple seasons, where dozens of bird and mammal species offer valuable insights into spatial and temporal faunal variation. Our results indicate that existing metabarcode sequence data sets are suitable for mining and exploration of this molecular by-catch, and that any future eDNA-based surveys can be designed to accommodate this enhanced property of this widely applicable tool.

ecology↗

bioRxiv2021

eDNA in a bottleneck: obstacles to fish metabarcoding studies in megadiverse freshwater systems

The current capacity of environmental DNA (eDNA) to provide accurate insights into the biodiversity of megadiverse regions (e.g., the Neotropics) requires further evaluation to ensure its reliability for long-term monitoring. In this study, we first evaluated the taxonomic resolution capabilities of a short fragment from the 12S rRNA gene widely used in fish eDNA metabarcoding studies, and then compared eDNA metabarcoding data from water samples with traditional sampling using nets. For the taxonomic discriminatory power analysis, we used a specifically curated reference dataset consisting of 373 sequences from 264 neotropical fish species (including 47 newly generated sequences) to perform a genetic distance-based analysis of the amplicons targeted by the MiFish primer set. We obtained an optimum delimitation threshold value of 0.5% due to lowest cumulative errors. The barcoding gap analysis revealed only a 50.38% success rate in species recovery (133/264), highlighting a poor taxonomic resolution from the targeted amplicon. To evaluate the empirical performance of this amplicon for biomonitoring, we assessed fish biodiversity using eDNA metabarcoding from water samples collected from the Amazon (Adolpho Ducke Forest Reserve and two additional locations outside the Reserve). From a total of 84 identified Molecular Operational Taxonomic Units (MOTUs), only four could be assigned to species level using a fixed threshold. Measures of -diversity analyses within the Reserve showed similar patterns in each site between the number of MOTUs (eDNA dataset) and species (netting data) found. However, {beta}-diversity revealed contrasting patterns between the methods. We therefore suggest that a new approach is needed, underpinned by sound taxonomic knowledge, and a more thorough evaluation of better molecular identification procedures such as multi-marker metabarcoding approaches and tailor-made (i.e., order-specific) taxonomic delimitation thresholds.

ecology↗

bioRxiv2020

Disentangling the shark and ray trade in Indonesia to reconcile conservation with food security

Indonesian marine resources are among the richest on the planet, sustaining highly diverse fisheries and includes the largest elasmobranch landings in the world, making Indonesia one of the worlds largest exporters of shark and ray products. Socio-economic and food security considerations pertaining to Indonesian communities add further layers of complexity to the management and conservation of these vulnerable species. This study investigates how shark and ray trade flows in and out of Indonesia and attempts to examine patterns and drivers of the current scenario. We identify substantial discrepancies between reported landings and declared exports, and between Indonesian exports in shark fin and meat products and the corresponding figures reported by importing countries. These mismatches are estimated to amount to over $43.6M and $20.9M for fins and meat, respectively, for the period between 2012 and 2018. Although the declared exports are likely to be an underestimation because of significant unreported or illegal trading activities, we find that domestic consumption of shark and ray products plays a significant role in explaining these discrepancies due to the increasing local demand for meat. The study also unearths a general scenario of unsystematic data collection and lack of granularity of product terminology, which is inadequate to meet the challenges of over-exploitation, illegal trade and food security in Indonesia. We discuss how to improve data transparency to support trade regulations and governance actions, by improving inspection measures, and conserving elasmobranch populations without neglecting the socio-economic dimension of this complex system.

scientific communication and education↗

bioRxiv2020

Space-time dynamics in monitoring neotropical fish communities using eDNA metabarcoding

The biodiverse Neotropical ecoregion remains insufficiently assessed, poorly managed, and threatened by unregulated human activities. Novel, rapid and cost-effective DNA-based approaches are valuable to improve understanding of the biological communities and for biomonitoring in remote areas. Here, we evaluate the potential of environmental DNA (eDNA) metabarcoding for assessing the structure and distribution of fish communities by analysing sediments and water from 11 locations along the Jequitinhonha River catchment (Brazil). Each site was sampled twice, before and after a major rain event in a five-week period and fish diversity was estimated using high-through-put sequencing of 12S rRNA amplicons. In total, 252 Molecular Operational Taxonomic Units (MOTUs) and 34 fish species were recovered, including endemic, introduced, and previously unrecorded species for this basin. Spatio-temporal variation of fish assemblages was detected, richness during the first campaign was nearly twice as high as in the second sampling round; though peaks of diversity were primarily associated with only four locations. No correlation between {beta}-diversity and longitudinal distance or presence of dams was detected, but low species richness observed at sites located near dams indicates that these anthropogenic barriers might have an impact on local fish diversity. Unexpectedly high -diversity levels recorded at the river mouth suggest that these sections should be further evaluated as putative "eDNA reservoirs" for rapid monitoring. By uncovering spatio-temporal changes, unrecorded biodiversity components, and putative anthropogenic impacts on fish assemblages, we further strengthen the potential of eDNA metabarcoding as a biomonitoring tool, especially in regions often neglected or difficult to access.

ecology↗

bioRxiv2019

Assessing the potential of environmental DNA metabarcoding for monitoring Neotropical mammals: a case study in the Amazon and Atlantic Forest, Brazil

The application of environmental DNA (eDNA) metabarcoding as a biomonitoring tool has greatly increased in the last decade. However, most studies have focused on aquatic macro-organisms in temperate areas (e.g., fishes). We apply eDNA metabarcoding to detect the mammalian community in two high-biodiversity regions of Brazil, the Amazon and Atlantic Forest. We identified critically endangered and endangered mammalian species in the Atlantic Forest and Amazon respectively and found congruence with species identified via camera trapping in the Atlantic Forest. In light of our results, we highlight the potential and challenges of eDNA monitoring for mammals in these high biodiverse areas.

ecology↗

bioRxiv2019

Fine-scale seascape genomics of an exploited marine species, the common cockle Cerastoderma edule, using a multi-modelling approach

Population dynamics of marine species that are sessile as adults are driven by oceanographic dispersal of larvae from spawning to nursery grounds. This is mediated by life-history traits such as the timing and frequency of spawning, larval behaviour and duration, and settlement success. Here, we use 1725 single nucleotide polymorphisms (SNPs) to study the fine scale spatial genetic structure in the commercially important cockle species Cerastoderma edule and compare it to environmental variables and current-mediated larval dispersal within a modelling framework. Hydrodynamic modelling employing the NEMO Atlantic Margin Model (AMM15) was used to simulate larval transport and estimate connectivity between populations during spawning months (April - September), factoring in larval duration and seasonal variability of ocean currents. Results at neutral loci reveal the existence of three separate genetic clusters (mean FST=0.021) within a relatively fine spatial scale in the northwest Atlantic. Environmental association (EA) analysis indicates that oceanographic currents and geographical distance between the populations explain over 20% of the variance observed at neutral loci, while genetic variance (71%) at outlier loci was explained by sea surface temperatures extremes. These results fill an important knowledge gap in the management of a commercially important, overexploited species, and bring us closer to understanding the role of larval dispersal in connecting populations at a fine geographical scale.

evolutionary biology↗

bioRxiv2019

Fishing for mammals: landscape-level monitoring of terrestrial and semi-aquatic communities using eDNA from lotic ecosystems

O_LIEnvironmental DNA (eDNA) metabarcoding has revolutionised biomonitoring in both marine and freshwater ecosystems. However, for semi-aquatic and terrestrial animals, the application of this technique remains relatively untested.\nC_LIO_LIWe first assess the efficiency of eDNA metabarcoding in detecting semi-aquatic and terrestrial mammals in natural lotic ecosystems in the UK by comparing sequence data recovered from water and sediment samples to the mammalian communities expected from historical data. Secondly, we evaluate the detection efficiency of eDNA samples compared to multiple conventional non-invasive survey methods (latrine surveys and camera trapping) using occupancy modelling.\nC_LIO_LIeDNA metabarcoding detected a large proportion of the expected mammalian community within each area. Common species in the areas were detected at the majority of sites. Several key species of conservation concern in the UK were detected by eDNA in areas where authenticated records do not currently exist, but potential false positives were also identified for several non-native species.\nC_LIO_LIWater-based eDNA samples provided comparable results to conventional survey methods in per unit of survey effort for three species (water vole, field vole, and red deer) using occupancy models. The comparison between survey effort to reach a detection probability of [≥]0.95 revealed that 3-6 water replicates would be equivalent to 3-5 latrine surveys and 5-30 weeks of single camera deployment, depending on the species.\nC_LIO_LISynthesis and Applications. eDNA metabarcoding represents an extremely promising tool for monitoring mammals, allowing for the detection of multiple species simultaneously, and provides comparable results to widely-used conventional survey methods. eDNA from freshwater systems delivers a terrestrial dividend by detecting both semi-aquatic and terrestrial mammalian communities, and provides a basis for future monitoring at a landscape level over larger spatial and temporal scales (i.e. long-term monitoring at national levels).\nC_LI

ecology↗

bioRxiv2019

Environmental DNA (eDNA) metabarcoding of pond water as a tool to survey conservation and management priority mammals

O_LIEnvironmental DNA (eDNA) metabarcoding is largely used to survey aquatic communities, but can also provide data on terrestrial taxa utilising aquatic habitats. However, the entry, dispersal, and detection of terrestrial species DNA within waterbodies is understudied. C_LIO_LIWe evaluated eDNA metabarcoding of pond water for monitoring semi-aquatic, ground-dwelling, and arboreal mammals, and examined spatiotemporal variation in mammal eDNA signals using experiments in captive and wild conditions. C_LIO_LIWe selected nine focal species of conservation and management concern: European water vole, European otter, Eurasian beaver, European hedgehog, European badger, red deer, Eurasian lynx, red squirrel, and European pine marten. We hypothesised that eDNA signals (i.e. proportional read counts) would be stronger for semi-aquatic than terrestrial species, and at sites where mammals exhibited behaviours (e.g. swimming, urination). We tested this by sampling waterbodies in enclosures of captive focal species at specific sites where behaviours had been observed ( directed sampling) and at equidistant intervals along the shoreline ( stratified sampling). We then surveyed natural ponds (N = 6) where focal species were present using stratified water sampling, camera traps, and field signs. eDNA samples were metabarcoded using vertebrate-specific primers. C_LIO_LIAll focal species were detected in captivity. eDNA signal strength did not differ between directed and stratified samples across or within species, between species lifestyles (i.e. semi-aquatic, ground-dwelling, arboreal), or according to behaviours. Therefore, eDNA was evenly distributed within artificial waterbodies. Conversely, eDNA was unevenly distributed in natural ponds. eDNA metabarcoding, camera trapping, and field signs detected beaver, red deer, and roe deer. Badger and red fox were recorded with cameras and field signs, but not eDNA metabarcoding. However, eDNA metabarcoding detected small mammals missed by cameras and field signs, e.g. water vole. Terrestrial mammal eDNA signals were weaker and detected in fewer samples than semi-aquatic mammal eDNA signals. C_LIO_LIeDNA metabarcoding has potential for inclusion in mammal monitoring schemes by enabling large-scale, multi-species distribution assessment for priority and difficult to survey species, and could provide early indication of range expansions or contractions. However, eDNA surveys need high spatiotemporal resolution and metabarcoding biases require further investigation before this tool is routinely implemented. C_LI

molecular biology↗