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Please note: These are preprints and have not been peer reviewed. Data may be preliminary.
Neophytes may promote hybridization and adaptations to a changing planet
Jana Ebersbach
Ingmar

Jana Ebersbach

and 1 more

March 21, 2023
Human activities are breaking down geographic barriers to species dispersal, providing previously isolated taxa with unprecedented new opportunities for hybridization. Empirical studies on the effects of neophytes on hybridization and on the evolutionary consequences of these processes remain, however, scarce. Here we integrated Kew’s Plants of the World Online database with the Global Naturalized Alien Flora database to study the spatial and taxonomic overlap of hybrids and neophytes. Using the largest dated plant phylogeny to date, we compared diversification rates of genera containing hybrids and neophytes to genera containing neither. In addition, we used the well-studied hybrid flora of Britain to ask whether hybrids are adapted to anthropogenic disturbance and occur in habitats with a higher human footprint than their native and neophyte parents. Overall, we document positive ties between contemporary biodiversity redistribution and hybridization. Neophyte incidence was positively related to hybrid incidence both spatially (across countries) and taxonomically (across genera). Diversification rates were nearly three times higher in genera with both hybrids and neophytes than in genera containing neither. Hybrids occurred, on average, in areas with a higher human footprint than their parents, with little evidence that hybrids threaten native species throughout their range in more native habitats. Together, our results suggest species naturalizations and hybridizations need not have only negative evolutionary outcomes. Against a backdrop of rapid global change, anthropogenic hybridization may promote recombination of genetic variation and help conserve genetic diversity in disturbed environments.
Complete mitochondrial genomes of two moths in the tribe Trichaeini (Lepidoptera: Cra...
Ci Tang
Xicui Du

Ci Tang

and 1 more

March 21, 2023
The complete mitochondrial genomes of two Prophantis species in the tribe Trichaeini (Lepidoptera: Crambidae) were sequenced using high-throughput sequencing technology. They were assembled and annotated: the complete mitogenomes of P. octoguttalis and P. adusta were 15,197 bp and 15,714 bp, respectively, and contain 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and an A + T-rich region. Their arrangement was consistent with the first sequenced mitogenome of Lepidoptera, from Bombyx mori (Bombycidae). The nucleotide composition was obviously AT-biased, and all protein-coding genes, except for the cox1 gene (CGA), used ATN as the start codon. Except for trnS1, which lacked the DHU arm, all tRNA genes could fold into the clover-leaf structure. Phylogenetic trees of Crambidae were reconstructed based on mitogenomic data using Maximum likelihood (ML) and Bayesian inference (BI) analysis methods. Results showed that Trichaeini in this study robustly constitute a monophyletic group in Spilomelinae, with the relationships (Trichaeini + Nomophilini) + ((Spilomelini + (Hymeniini + Agroterini)) + Margaroniini). However, the affinities of the six subfamilies Acentropinae, Crambinae, Glaphyriinae, Odontiinae, Schoenobiinae and Scopariinae within the “non-PS Clade” in Crambidae remained doubtful with unstable topologies or low supports.
A novel mosquito species identification method based on PCR and capillary electrophor...
Estelle Chabanol
Ottavia Romoli

Estelle Chabanol

and 6 more

March 21, 2023
In the Anopheles genus, various mosquito species are able to transmit Plasmodium parasites responsible for malaria, while others are non-vectors. In an effort to better understand the biology of Anopheles species and to quantify transmission risk in an area, the identification of mosquito species collected on the field is an essential but problematic task. Morphological identification requires expertise, well-preserved specimens and high-quality equipment, and it does not allow any subsequent verification when samples are later used in a destructive treatment. Moreover, it involves physical manipulations that are not compatible with experiments requiring fast sampling and processing of specimens, hence species identification is often based on DNA sequencing of reference genes or region such as the Internal Transcribed Spacer 2 (ITS2) region of nuclear ribosomal DNA. Sequencing ITS2 for numerous samples is costly, but the design of species-specific PCR primers is not always possible when local species diversity is high. Here, we introduce a molecular technique of species identification based on precise determination of ITS2 length combined with a simple visual observation, the color of mosquito hindleg tip. DNA extracted from field-collected Anopheles mosquitoes was amplified with universal Anopheles ITS2 primers and analyzed with a capillary electrophoresis device, which precisely determines the size of the fragments. We defined windows of amplicon sizes combined with fifth hind tarsus color, which allow to discriminate the major Anopheles species found in our collections. We validated our parameters via Sanger sequencing of the ITS2 amplicons. This method can be particularly useful in situations with a moderate species diversity, i.e. when the number of local species is too high to define species-specific primers but low enough to avoid individual ITS2 sequencing. This tool will be of interest to evaluate local malaria transmission risk and this approach may further be implemented for other mosquito genera.
Post-pollination barriers contribute to coexistence of partially pollinator-sharing A...
Luo Zeng
Wei-Jie Shu

Luo Zeng

and 5 more

March 20, 2023
Reproductive isolation plays an important role in maintaining the species integrity of sympatric close relatives. For sympatric Arisaema species, interspecific gene flow is expected to be effectively prevented by pre-pollination barriers, particularly strong pollinator isolation mediated by fungus gnats. However, due to the lack of quantitative studies combining multiple pre- and post-pollination barriers, it is not known whether pre-pollination isolation is complete, and whether post-pollination barriers also contribute to reproductive isolation among some Arisaema species. We studied five pre- and post-pollination barriers (geographic isolation, phenological isolation, pollinator isolation, hybrid fruit production, and hybrid seed formation) among three sympatric Arisaema species (A. bockii, A. lobatum, and A. erubescens). The strength of individual barriers and their contribution to total isolation were quantified.The habitat elevations of the three Arisaema species mostly overlapped. Although phenological isolation and pollinator isolation reduced the frequencies of interspecific pollen transfer among these species, the partial overlap of flowering times and pollinator assemblages resulted in pre-pollination isolation that does not adequately prevent interspecific hybridization. Post-pollination barriers also contributed to reproductive isolation at the hybrid fruit and seed formation stages.We propose that, although pre-pollination barriers are expected to contribute more to total isolation than post-pollination barriers in Arisaema, pre-pollination barriers may not completely prevent interspecific pollen transfer among some Arisaema species. Post-pollination barriers, which are generally ignored, may also have contributed significantly to reproductive isolation in Arisaema.
Local weather affects body condition of three North American songbird species on the...
Michael McCloy
Selma Glasscock

Michael McCloy

and 2 more

March 16, 2023
Body condition is a frequently used physiological indicator of avian health and is affected by an array of environmental variables. Although a number of studies have investigated the specific effects of individual weather variables on body condition in birds, few have analyzed the effects of both temperature and precipitation within the context of an extreme weather event such as hurricanes. In this study we examined the relationship between breeding season body condition and daily maximum temperature, daily minimum temperature, and monthly total precipitation for three passerine bird species at the Welder Wildlife Refuge near Rockport, Texas. We also evaluated yearly changes in body condition over a twelve-year period for northern cardinals (Cardinalis cardinalis), painted buntings (Passerina ciris), and white-eyed vireos (Vireo griseus), focusing on the extreme precipitation event of Hurricane Harvey which caused heavy localized flooding. We found that body condition declined with average daily minimum and maximum temperatures, while precipitation had varied, species-specific effects in the three species analyzed. Our results also suggest that northern cardinals experienced a notable reduction in average body condition in the two years following Hurricane Harvey. Taken together, we conclude that short-term precipitation and temperature drivers can be important correlates of body condition in songbirds and that severe weather events may reduce body condition in some bird species.
Distribution and predictive niche modeling of five endangered raptors species in Keny...
Peggy Ngila
David Chiawo

Peggy Ngila

and 4 more

March 16, 2023
Raptors are apex predators threatened globally by electrocution, collisions, and habitat fragmentation. Most species of raptors are understudied and largely unexplored. Top predators like raptors depend on the sustainability of the ecosystems in which they live and migrate. Knowing how endangered raptors are geographically dispersed, as well as the factors that may influence how they use their habitat, is critical for their protection. This research focuses on Kenya, where there are gaps in knowledge on appropriate habitats and raptor dispersal patterns. With several species of raptors endangered, it is crucial to determine their distribution patterns for management and conservation. To evaluate the size of the realized niches for five Kenyan raptor species at the risk of extinction, we applied species distribution models (SDMs) through an ensembling approach using occurrence data from the Global Biodiversity Information Facility (GBIF) and environmental covariates. These species were: Martial eagle, Secretarybird, Bateleur, Steppe Eagle, and Southern ground hornbill. The five raptors’ distribution within and outside protected areas and the role of key environmental predictors in predicting their distribution was estimated. Our findings indicate raptor distribution in several areas in Kenya that is predominantly in the south-western region, extending into the country’s central region. Martial eagle had the largest niche range amounting to ca.49,169 km2 while the Southern ground hornbill had the smallest niche range amounting to ca.4,145 km2. Secretarybird had the highest distribution outside protected areas at 77.57% followed by the Martial eagle at 76.89%. Significant predictors of raptor species distribution in Kenya were; precipitation during the warmest quarter, precipitation during the driest month, and precipitation during the coldest quarter. Key areas for raptor conservation listed here could serve as foundation for a number of additional Important Bird Areas (IBAs) in Kenya, according to the A1 Global IBA Criterion for species that are globally threatened.
DNA matching exotic species detected in samples from sedentary birds and the environm...
Coen Westerduin
Marko Suokas

Coen Westerduin

and 5 more

November 17, 2022
The development of DNA-based methods in recent decades has opened the door to numerous new lines of research in the biological sciences. While their speed and accuracy are clearly beneficial, the sensitivity of these methods has the adverse effect of increased susceptibility to false positives resulting from contamination in field or lab. Here, we present findings from a metabarcoding study on the diet of and food availability for several insectivorous birds, in which multiple lepidopteran species not known to occur locally were discovered. After describing the pattern of occurrences of these non-local species in the samples, we discuss various potential origins of these sequences. First, we assess that the taxonomic assignments appear reliable, and local occurrences of many of the species can be plausibly ruled out. Then, we look into the possibilities of natural environmental contamination, judging it to be unlikely, albeit impossible to fully falsify. Finally, while the pattern of occurrences did not suggest lab contamination, we find overlap with material handled in the same lab, which was undoubtedly not coincidental. Even so, not all exact sequences were accounted for in these locally conducted studies, nor was it clear if these and other sequences could remain detectable years later. Although the full explanation for the observations of non-local species remains inconclusive, these findings highlight the importance of critical examination of metabarcoding results, and showcase how species-level taxonomic assignments utilizing comprehensive reference libraries may be a tool in detecting potential contamination events, and false positives in general.
Fieldfare nestlings and fledglings feeding and adoption by the European Blackbird
Dariusz Wysocki
Katarzyna Wawryniuk

Dariusz Wysocki

and 3 more

March 13, 2023
Inter-specific adoption is an intriguing topic in behavioural and evolutionary ecology. Being a rare phenomenon is rarely documented in the literature and thus reports of inter-specific adoption based on solid data are particularly valuable. Here, owing to a long-term and extensive monitoring of a local population of the European blackbird (Turdus merula, hereafter blackbird), we describe observations of alloparental behaviour exhibited by blackbirds towards fieldfare (Turdus pilaris) nestlings (single nest, first record ever) and fledglings (twelve cases in total). We discuss the observations in respect to available literature.
Is infrasound the main driver of evolutionary size growth of some Mammalian taxa? Tho...
László Bujtor

László Bujtor

March 10, 2023
Tendency of the vertebrates to increase body sizes during evolution is recognized in the 19th century. Beside the contradictory Cope’s rule, other ‘rules’ were recognized, however not fully explained the evolutionary size growth phenomenon. Recently the resource rule offered a plausible explanation to this, although it left open the rapid evolutionary size growth of the Mysticeti (Mammalia, Vertebrata). Here, the rapid and significant evolutionary size growth of Mysticeti and the odontocete sperm whale is explained by the innovative application of the long-range communication channels. Regarding all analysed extant species using infrasound either in aquatic or terrestrial environs for long-range communication, a correlation between the body size/mass and maximum propagation of the applied infrasound is recognized. Correlation of the body sizes of these infrasound generating vertebrate taxa with the maximum range of audibility reflects the acoustical characteristics of the applied long-range communication channels. The wider the audibility in the communication channel is, the greater the body size of the species using the SOFAR channel for long-range communication. Other, non-aquatic, terrestrial vertebrate species (African elephants, cassowary) also present the same phenomenon suggesting that application of the long-range communication channels may have universal role in evolutionary size growth among social animals.
Optimising the automated recognition of individual animals to support population moni...
Tijmen de Lorm
Catharine Horswill

Tijmen de Lorm

and 6 more

March 10, 2023
Reliable estimates of population size and demographic rates are central to assessing the status of threatened species. However, obtaining individual-based demographic rates requires long-term data, which is often costly and difficult to collect. Photographic data offer an inexpensive, non-invasive method for individual-based monitoring of species with unique markings, and could therefore increase available demographic data for many species. However, selecting suitable images and identifying individuals from photographic catalogues is prohibitively time-consuming. Automated identification software can significantly speed up this process. Nevertheless, automated methods for selecting suitable images are lacking, as are studies comparing the performance of the most prominent identification software packages. In this study, we develop a framework that automatically selects images suitable for individual identification, and compare the performance of three commonly used identification software packages; Hotspotter, I3S-Pattern, and WildID. As a case study, we consider the African wild dog Lycaon pictus, a species whose conservation is limited by a lack of cost-effective large-scale monitoring. To evaluate intra-specific variation in the performance of software packages, we compare identification accuracy between two populations (in Kenya and Zimbabwe) that have markedly different coat colouration patterns. The process of selecting suitable images was automated using Convolutional Neural Nets that crop individuals from images, filter out unsuitable images, separate left and right flanks, and remove image backgrounds. Hotspotter had the highest image-matching accuracy for both populations. However, the accuracy was significantly lower for the Kenyan population (62%), compared to the Zimbabwean population (88%). Our automated image pre-processing has immediate application for expanding monitoring based on image-matching. However, the difference in accuracy between populations highlights that population-specific detection rates are likely and may influence certainty in derived statistics. For species such as the African wild dog, where monitoring is both challenging and expensive, automated individual recognition could greatly expand and expedite conservation efforts.
The Joint Effects of Forest Habitat Area and Fragmentation on Dung beetles
David Mbora
Morris Mutua

David Mbora

and 1 more

March 10, 2023
Habitat loss and habitat fragmentation usually occur together, at the same time and place. However, while there is consensus that habitat loss is the preeminent threat to biodiversity, the effects of fragmentation are contentious. Some argue that habitat fragmentation is not bad for biodiversity, and even that it is good. Generally, the studies that find no harm or positive outcomes of fragmentation invariably assume that it is independent of habitat loss. However, dissociating the effects of habitat fragmentation from habitat loss is questionable because of the two are essentially coupled. Accordingly, we evaluated how forest area and fragmentation (via edge effects) influenced dung beetles per se, and through their effects on the abundance of mammals, using structural equation modeling (SEM). Dung beetles are very sensitive to forest habitat loss and fragmentation, and to changes in the abundance of mammals on which they depend for dung. Our study area was in the Tana River, Kenya, where forest fragments are depauperate of mammals except for two endemic species of monkeys. We mapped 12 forests, counted the resident monkeys, and sampled 113,959 beetles from 288 plots. Most of the 87 species of beetles were small, affirming the endemic monkeys as the main source of dung. After implementing a fully latent Structural Regression SEM, the optimal model explained a significant 26% of the variance in abundance, and 89% of diversity. The main drivers of beetle abundance were positive, direct, effects of forest area and number of monkeys, and negative edge effects. The main drivers of diversity were the direct effects of the beetle abundance, indirect effects of forest area and abundance of mammals, and indirect negative edge effects. Thus forest area, fragmentation (via edge effects) and the number of monkeys jointly influenced the abundance and diversity of the beetles directly and indirectly.
Prediction Model and Demonstration of Regional Agricultural Carbon Emissions Based on...
Yanwei Qi
Huailiang Liu

Yanwei Qi

and 2 more

March 08, 2023
The prediction of regional agricultural carbon emissions is of great significance to regional environmental protection and sustainable development of regional agriculture. This paper puts forward a combined prediction model integrating Partial Least Squares (PLS), Simulated Annealing (SA) and Adaptive Boosting (AdaBoost) to predict regional agricultural carbon emissions, which overcomes the shortcomings of insufficient accuracy of a single model prediction. This paper conducts a demonstrative study on the agricultural carbon emissions in Fujian Province, China to verify the feasibility and effectiveness of the PLS-SA-AdaBoost combined prediction model. The experimental results show that PLS-SA-AdaBoost combined prediction model has a higher precision than SA-AdaBoost model and PLS-SA-AdaBoost model; meanwhile PLS-SA-AdaBoost combined prediction model shows obvious advantages compared with other combined prediction models. In terms of five different scenarios, the paper adopts PLS-SA-AdaBoost combined prediction model to predict the future trend of agricultural carbon emissions in Fujian Province.
Phylogeography of the Sunda pangolin, Manis javanica: implications for taxonomy, cons...
Frankie Sitam
Milena Salgado-Lynn

Frankie Sitam

and 14 more

March 08, 2023
Aim: The Sunda pangolin (Manis javanica) is the most widely distributed Asian pangolin species. It is one of the most trafficked mammals in the world, which not only negatively impacts wild Sunda pangolin populations, but also poses a potential disease risk to other species, including humans and livestock. Despite the imminent threat to the species’ survival and its prevalence in the wildlife trade, the phylogeography and evolution of the Sunda pangolin is not well understood. We aimed to investigate the species’ phylogeography across its distribution to improve our understanding of the species’ evolutionary history, elucidate any taxonomic uncertainties and enhance the species’ conservation genetic management and wildlife forensics applications. Location: Southeast Asia and southern China. Methods: We sequenced mtDNA genomes from 23 wild Sunda pangolins from Borneo and Peninsular Malaysia. We used these data in conjunction with previous generated mtDNA and nuclear datasets from across the species’ range to perform various phylogenetic and population genetic analyses. Results: We identified an evolutionarily distinct mtDNA lineage in north Borneo, which was estimated to be ~1.6 million years divergent from lineages in west/south Borneo and the mainland, comparable to the divergence time of the Palawan pangolin. There appeared to be mitonuclear discordance, with no apparent genetic structure across Borneo based on analysis of nuclear SNPs. Main conclusions: These findings are consistent with the ‘out of Borneo hypothesis’, whereby Sunda pangolins diversified in Borneo before subsequently migrating throughout Sundaland, and/or a secondary contact scenario between mainland and Borneo. We have elucidated possible taxonomic issues in the Sunda/Palawan pangolin complex, and highlight the critical need for additional georeferenced samples to accurately apportion its range-wide genetic variation into appropriate taxonomic and conservation units. Additionally, these data have improved forensic species identification testing involving these species and permit the implementation of geographic provenance testing in some scenarios.
The response of ecological security to land use change in east and west subtropical C...
mengjia luo
Jinliang Wang

mengjia luo

and 9 more

March 07, 2023
Regional land use change and ecological security have received considerable attention in recent years. The rapid economic development of Kunming and Fuzhou has resulted in environmental damage. It is important to conduct a comparative analysis of the ecological security response to land use/land cover change (LUCC) in different natural zones. With the support of Google Earth Engine (GEE) platform, the random forest and support vector machine methods were used to classify land cover types in the study area, then the ArcGIS platform was used to analyze LUCC. The driving force-pressure-state-impact-response (DPSIR) model and entropy weight method was used to construct an ecological security evaluation system, and gray correlation was used to compare the ecological security responses to LUCC in Kunming and Fuzhou. The findings revealed that: (1) The average dynamic degrees of comprehensive land use in Kunming and Fuzhou from 1995 to 2020 were 1.05% and 0.55%, respectively; (2) From 1995 to 2020, the ecological security index values for Kunming and Fuzhou increased from 0.42 to 0.52 and from 0.36 to 0.68, respectively, indicating that Fuzhou’s index is rising more quickly; and (3) The response of ecological security to LUCC varies across regions; increases in the woodland area had a positive effect on the ecological security of Kunming and Fuzhou, whereas the expansion of construction land significantly impeded the improvement of ecological security in Fuzhou, and the status of water resources had a significant impact on the ecological security of Kunming.
Nutrient Dynamics in a Coupled Terrestrial Biosphere and Land Model (ELM-FATES)
Ryan G Knox
Charles D. Koven

Ryan G Knox

and 14 more

March 06, 2023
We present a representation of nitrogen and phosphorus cycling in the vegetation demography model the Functionally Assembled Terrestrial Ecosystem Simulator (FATES), within the Energy Exascale Earth System (E3SM) land model. This representation is modular, and designed to allow testing of multiple hypothetical approaches for carbon-nutrient coupling in plants. The model tracks nutrient uptake, losses via turnover from both live plants and mortality into soil decomposition, and allocation during tissue growth for a large number of size- and functional-type-resolved plant cohorts within a time-since-disturbance-resolved ecosystem. Root uptake is governed by fine root biomass, and plants vary in their fine root carbon allocation in order to balance carbon and nutrient limitations to growth. We test the sensitivity of the model to a wide range of parameter variations and structural representations, and in the context of observations at Barro Colorado Island, Panama. A key model prediction is that plants in the high-light-availability canopy positions allocate more carbon to fine roots than plants in low-light understory environments, given the widely different carbon versus nutrient constraints of these two niches within a given ecosystem. This model provides a basis for exploring carbon-nutrient coupling with vegetation demography within Earth System Models (ESMs).
Large-scale assessment of ecological and anthropogenic drivers of beetle communities...
Bounsanong Chouangthavy
Yoan  Fourcade

Bounsanong Chouangthavy

and 1 more

March 02, 2023
Rapid economic development can pose a threat to the biodiversity of tropical countries. In Laos, this is manifested by the conversion of natural forests into plantations, even though this area is one of the biodiversity hotspots of Southeast Asia. Beetle communities can be good indicators of the impact of anthropogenic pressure on natural ecosystems. In this study, we analyzed for the first time a countrywide inventory of Coleoptera to assess the ecological and anthropogenic drivers of beetle communities in Laos. We examined beetle communities (described at the family level) across the country, located in distinct habitat types, in order to understand the impact a rapid increase in human activities has on the region’s biodiversity. We found that beetle abundance had declined in plantations compared to natural forests. At the same time, we observed fewer beetle families in plantations overall, but at the scale of sampling sites there was no difference in local diversity compared to natural forests, suggesting a homogenization of beetle communities in anthropogenic habitats. Although results are certainly sensitive to our coarse classification of beetle specimens into families, the negative impact of the conversion of natural tropical forests into agriculture area can still be clearly demonstrated. Our findings highlight that it is possible to make use of unstructured large-scale inventories to explore how beetle communities responds to landscape changes induced by human activities. We suggest that sampling beetle communities can be used as an ecological indicator to monitor anthropogenic impacts on tropical ecosystems.
Species delimitation and integrative taxonomy of the Reithrodontomys mexicanus (Roden...
Daily Martinez
Elizabeth Arellano

Daily Martinez

and 4 more

March 02, 2023
Species boundaries are difficult to establish in groups with very similar morphology. As an alternative, it has been suggested to integrate multiple sources of data to clarify taxonomic problems in taxa where cryptic speciation processes have been reported. This is the case of the harvest mouse Reithrodontomys mexicanus, which has a problematic taxonomy history as it is considered a complex species. Here, we evaluate the cryptic diversity of R. mexicanus using an integrative taxonomy approach in order to detect candidate lineages at the species-level. The molecular analysis used one mitochondrial (cytb) and two nuclear (Fgb-I7 and IRBP) genes. Species hypotheses were suggested based on three molecular delimitation methods (mPTP, bGMYC, and STACEY), and cytb genetic distances values. Skull and environmental space differences between the delimited species were also tested to complement the discrimination of candidate species. Based on the consensus across the delimitation methods and genetic distance values, four species were proposed, which were mostly supported by morphometric and ecological data: R. mexicanus clade I, R. mexicanus clade IIA, R. mexicanus clade IIIA, and R. mexicanus clade IIIB. In addition, the evolutionary relationships between the species that comprise the R. mexicanus group were discussed from a phylogenetic approach. Our findings present important taxonomic implications for Reithrodontomys, as the number of known species for this genus increases. Furthermore, we highlight the importance of the use of multiple sources of data in systematic studies to establish robust delimitations between species considered taxonomically complex.
Minimal tissue inputs produce a chromosome-scale genome assembly of the rusty patched...
Jonathan Koch
Sheina Sim

Jonathan Koch

and 4 more

February 11, 2023
The rusty patched bumble bee, Bombus affinis, is an important pollinator in North America and a federally listed endangered species. Due to habitat loss and large declines in population size, B. affinis is facing imminent extinction unless human intervention and recovery efforts are implemented. To better understand B. affinis biology and population genetic and genomic landscapes, we sequenced and assembled the B. affinis genome from a single male. Whole genome HiFi sequencing on PacBio coupled with HiC sequencing resulted in a complete and highly contiguous contig assembly that was scaffolded into a chromosomal context, resolving 18 chromosomes for this species. All material for both HiFi and HiC sequencing was derived from a single abdominal tissue segment from the one male. These assembly results, coupled with the minimal amount of tissue destructively sampled, demonstrates methods for generating contiguous and complete genomic resources for a rare and endangered species with limited material available and highlights the importance of sample preservation. Precise methods and applications of these methods are presented for potential applications in other species with similar limitations in specimen availability and curation considerations.
Factors affecting the nesting success of Swainson’s thrush (Catharus ustulatus) along...
Sarah Deckel
William DeLuca

Sarah Deckel

and 3 more

February 25, 2023
Montane birds experience a range of challenges that may limit their breeding success, including nest predation and severe climactic conditions. The continuing effects of climate change are causing shifts in biotic and abiotic factors that may compound these threats to montane bird species. In northeastern montane forests, many bird species are shifting downslope, potentially as the result of increased precipitation and temperature at higher elevations. Although lower elevations might be more favorable in terms of climactic conditions, nest predation is higher at lower elevations. Thus, montane birds might be faced with the opposing pressures of adverse climactic conditions at higher elevations and increased predation at lower elevations. We monitored nests of Swainson’s thrush (Catharus ustulatus) along an elevation gradient in the White Mountain National Forest in New Hampshire in 2016, 2018, 2019 and 2021 to examine the effect of biotic and abiotic factors on nest survival. We found a significant negative effect of rain intensity (millimeters per hour per day) on daily nest survival, suggesting that heavier rain per hour decreases Swainson’s thrush daily daily nest survival. Moreover, we found a negative interaction effect of elevation in conjunction with minimum daily temperature and average daily temperature, suggesting that at higher elevations, temperature, specifically on colder days, decreases Swainson’s thrush nest survival. Our results provide evidence for a potential mechanism of how climate change will affect nesting survival of montane breeding birds as heavier precipitation events become more frequent and intense, a likely outcome due to the changing climate within the White Mountains and other montane ecosystems, putting other passerine species at risk in this system.
Conservation detection dogs: A critical review of efficacy and methodology
Beth McKeague
Caroline Finlay

Beth McKeague

and 2 more

February 25, 2023
1. Conservation detection dogs (CDD) use their exceptional olfactory abilities to assist a range of conservation projects. CDD are generally quicker, can cover wider areas, and find more samples than humans and other analytical tools. However, their efficacy varies between studies; methodological standardisation in the field is lacking. Considering the cost of deploying a CDD team and the limited financial resources within conservation, it is vital that their performance is quantified and reliable. This review aims to summarise what is currently known about the use of detection dogs in conservation and elucidate which factors affect efficacy. 2. We describe the efficacy of CDD across species and situational contexts like training and field work. Reported sensitivities (i.e., proportion of target samples found out of total available) ranged from 23.8% to 100% and precision rates (i.e., proportion of alerts that are true positives) from 28% to 100%. CDD are consistently shown to be better than other techniques, but performance varies substantially across the literature. There is no consistent difference in efficacy between training, testing, and field work, hence we need to understand the factors affecting this. 3. We highlight the key variables that alter CDD performance. External effects include target odour, training methods, sample management, search methodology and environment, and the CDD handler. Internal effects include dog breed, personality, diet, age, and health. Unfortunately, much of the research fails to provide adequate information on the dogs, handlers, training, experience, and samples. This results in an inability to determine precisely why an individual study has high or low efficacy. 4. It is clear that CDD can be applied to possibly limitless scenarios but moving forward researchers must provide more consistent and detailed methodologies so that comparisons can be conducted, results are more easily replicated, and progress can be made in standardising CDD work.
Multi-marker DNA metabarcoding reveals spatial and sexual variation in the diet of a...
Ewan Stenhouse
Paul Bellamy

Ewan Stenhouse

and 8 more

February 22, 2023
Avian diet can be affected by site-specific variables, such as habitat, as well as intrinsic factors such as sex. This can lead to dietary niche separation, which reduces competition between individuals, as well as impacting how well avian species can adapt to environmental variation. Estimating dietary niche separation is challenging, due largely to difficulties in accurately identifying food taxa consumed. Consequently, there is limited knowledge of the diets of woodland bird species, many of which are undergoing serious population declines. Here, we show the effectiveness of multi-marker faecal metabarcoding to provide in-depth dietary analysis of a declining passerine, the Hawfinch (Coccothraustes coccothraustes). We collected faecal samples from (n=262) UK Hawfinches prior to, and during the breeding seasons in 2016-2019. We detected 49 and 90 plant and invertebrate taxa, respectively. We found Hawfinch diet varied spatially, as well as between sexes, indicating broad dietary plasticity and the ability of Hawfinches to utilise multiple resources within their foraging environments.
Habitat protection and planning for Leonurus japonicus using the Maxent and Marxan mo...
Yongji Wang
Liyuan Xie

Yongji Wang

and 5 more

February 20, 2023
To predict suitable growing regions for Leonurus japonicus and to provide scientific sopport for the habitat conservation and the exploitation and utilization of germplasm resources under climate change conditions, this study combined niche and priority conservation models to assess the future potential distribution of L. japonicus in China. To this end, distribution points and samples of L. japonicus were gathered through online and field surveys. The Maxent model with optimized parameters was used for predicting the suitable habitats of L. japonicus at different stages, and the Marxan model was used to determine the priority of protected areas. The results showed that the highest temperature in the hottest month, the lowest temperature in the coldest month, the precipitation in the wettest month, the precipitation in the driest month, and altitude were the main environmental factors influencing the distribution of L. japonicus. Under the three climate change scenarios, the centroid of the suitable area of L. japonicus migrated northward, and the migration position tended to expand further northwest. In the future, there would be no significant niche differentiation of L. japonicus; the Marxan results showed that priority protected areas for L. japonicus were in southwestern central China, Lingnan, southern east China, and Guizhou. Overall, the results of this research can provide a strategy for the determination of priority protection areas for Leonurus japonicus in China.
Effects of herbivory and non-growing seasonality on plant secondary metabolites: a me...
Lotte Skovmand
Rose O'Dea

Lotte Skovmand

and 4 more

February 17, 2023
Plant secondary metabolites (PSMs) are produced by plants to overcome environmental challenges, both biotic and abiotic. We were interested in characterizing how non-growing seasonality in temperate climates affects overall PSM production in comparison to herbivory. Typically, herbivory is measured from spring to summer when plants have high resource availability and are prioritizing growth and reproduction. However, autumn seasonality also challenges plants as they cope with limited resources and prepare survival for winter. Using meta-analysis, we recorded overall PSM concentrations across 22 different PSM classes from 58 published papers, as well as compared concentrations of five phenolics PSM classes – hydroxybenzoic acid, flavan-3-ol, flavonol, hydrolysable tannin, and condensed tannin. We then calculated effect sizes for herbivory (absence to presence) and seasonality (growing to non-growing), while considering other variables (e.g., plant type, time after herbivory, temperature, and precipitation). We found that neither herbivory nor seasonality affect overall PSM production. However, we discovered different trends among the individual phenolics classes, including herbivory having a positive effect on flavonol production and non-growing seasonality having a positive effect on flavan-3-ol and condensed tannin production. We discuss how these responses stem from three factors: 1. some PSMs are constitutively produced by plants whereas others are induced only during herbivory or non-growing seasonality, 2. plants produce metabolites with higher costs only during seasons when other resources for growth and reproduction are less available, and 3. some PSM classes serve more than one function for plants and such functions can be season-dependent. The final outcome of our meta-analysis is that non-growing seasonality does affect PSM production differently from herbivory, and we therefore see value in further investigating how non-growing seasonality impacts interactions between PSM production and herbivory.
Extinction shapes the history of the communities of specialist birds in the white-san...
Gisiane Lima
Lucas Jardim

Gisiane Lima

and 3 more

February 14, 2023
Understanding how bird species from white sand ecosystems (WSEs) have managed to inhabit and specialize in insular environment in the middle of the Amazon Rainforest is fundamental to understand the evolutionary processes in birds restricted to one type of habitat. We sought to evaluate the diversification processes of the specialist bird species of the white sand ecosystems of the Rio Negro basin by comparing them with the pool of bird species of riparian environments. Many WSEs may be ancient riverbeds, which may favor current riparian species to be potential colonizers and settle within the WSEs. For this, we used an extension of biogeographic evolutionary models to verify state-dependent speciation and extinction models that specifically explain the presence of unmeasured factors that can affect the estimated diversification rates for the states of any observed trait. Thus, it was possible to evaluate the evolutionary processes that most acted in the formation of bird communities of WSEs. The results showed that WSEs specialist bird species have different functional diversity to what was expected on a random basis and evolutionary models have higher extinction and speciation rates in WSEs specialist bird communities. This evidences that source-sink processes maintain WSEs over time, and that they receive generalist and specialist species from riparian ecosystems. According to the models analyzed, once the species have the high degree of adaptation required by an ecosystem with severe conditions, they cannot colonize other ecosystems. Extinction is an important process for the dynamics of biodiversity in the Amazon since, as many species are lost, there is also speciation and high adaptation. This work is one of the first to use local evolutionary analyses in Amazonian ecosystems and was effective in showing that extinction is recurrent, which is a cause for concern due to the severe and rapid ecological changes currently occurring.
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