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At least 1,117 records · Page 62Linked to original sources

USGS2012

Fat or lean: adjustment of endogenous energy stores to predictable and unpredictable changes in allostatic load

1. The ability to store energy endogenously is an important ecological mechanism that allows animals to buffer predictable and unpredictable variation in allostatic load. The secretion of glucocorticoids, which reflects changes in allostatic load, is suggested to play a major role in the adjustment of endogenous stores to these varying conditions. 2. Although crucially important, the relationship between allostatic load and energy stores remains largely unexplored. Two contrasting hypotheses describe how stores may be adjusted: animals may use low allostatic loads to increase stores to a maximum possible (‘fat and fit’), or they can attain a lean physique due to fitness advantages of a low body mass (‘lean and fit’). 3. We compiled observational and experimental data available for a long-lived seabird to examine the relationship between glucocorticoids and stored energy at two life history stages (incubation and chick-rearing). Data were collected across multiple years and colonies in the North Pacific, thereby reflecting the wide range of environmental conditions birds' encounter in the marine environment. During experimental manipulations, allostatic load was minimized by supplementing food to free-living birds. 4. We found that the relationship between allostatic load and energy stores was clearly curvilinear at both life history stages. Observational data suggested that energy stores remained relatively stable under low allostatic load and decreased under high loads. Experimental data showed that birds did not maximize energy stores under favourable conditions but maintained energy stores below a physiologically attainable level. 5. Energy stores remained consistently lower during chick-rearing compared to incubation across the wide range of variations in allostatic load suggesting that stage-specific trade-offs limit the accumulation of energy during favourable environmental conditions. Secretion of glucocorticoids did not appear to mediate this shift in energy stores between the life history stages. 6. Overall, results of this study support the ‘lean and fit’ hypothesis. We conclude that increased energy stores may not necessarily reflect better environmental conditions experienced by individuals or predict their higher fitness. A major advantage of adopting a lean physique when environmental conditions allow may be the avoidance of additional energetic costs for moving a heavy body. In breeding seabirds, this advantage may be more important during chick-rearing. In the focal species, the secretion of glucocorticoids might be involved in regulation of energy stores within a life history stage but does not appear to mediate an adaptive shift in energy stores between the incubating and chick-rearing stages of reproduction.

Functional Ecology↗

USGS2009

Trend estimation in populations with imperfect detection

1. Trends of animal populations are of great interest in ecology but cannot be directly observed owing to imperfect detection. Binomial mixture models use replicated counts to estimate abundance, corrected for detection, in demographically closed populations. Here, we extend these models to open populations and illustrate them using sand lizard Lacerta agilis counts from the national Dutch reptile monitoring scheme. 2. Our model requires replicated counts from multiple sites in each of several periods, within which population closure is assumed. Counts are described by a hierarchical generalized linear model, where the state model deals with spatio-temporal patterns in true abundance and the observation model with imperfect counts, given that true state. We used WinBUGS to fit the model to lizard counts from 208 transects with 1–10 (mean 3) replicate surveys during each spring 1994–2005. 3. Our state model for abundance contained two independent log-linear Poisson regressions on year for coastal and inland sites, and random site effects to account for unexplained heterogeneity. The observation model for detection of an individual lizard contained effects of region, survey date, temperature, observer experience and random survey effects. 4. Lizard populations increased in both regions but more steeply on the coast. Detectability increased over the first few years of the study, was greater on the coast and for the most experienced observers, and highest around 1 June. Interestingly, the population increase inland was not detectable when the observed counts were analysed without account of detectability. The proportional increase between 1994 and 2005 in total lizard abundance across all sites was estimated at 86% (95% CRI 35–151). 5. Synthesis and applications . Open-population binomial mixture models are attractive for studying true population dynamics while explicitly accounting for the observation process, i.e. imperfect detection. We emphasize the important conceptual benefit provided by temporal replicate observations in terms of the interpretability of animal counts.

Journal of Applied Ecology↗

USGS2011

Development of an aquatic pathogen database (AquaPathogen X) and its utilization in tracking emerging fish virus pathogens in North America

The AquaPathogen X database is a template for recording information on individual isolates of aquatic pathogens and is freely available for download (http://wfrc.usgs.gov). This database can accommodate the nucleotide sequence data generated in molecular epidemiological studies along with the myriad of abiotic and biotic traits associated with isolates of various pathogens (e.g. viruses, parasites and bacteria) from multiple aquatic animal host species (e.g. fish, shellfish and shrimp). The cataloguing of isolates from different aquatic pathogens simultaneously is a unique feature to the AquaPathogen X database, which can be used in surveillance of emerging aquatic animal diseases and elucidation of key risk factors associated with pathogen incursions into new water systems. An application of the template database that stores the epidemiological profiles of fish virus isolates, called Fish ViroTrak, was also developed. Exported records for two aquatic rhabdovirus species emerging in North America were used in the implementation of two separate web-accessible databases: the Molecular Epidemiology of Aquatic Pathogens infectious haematopoietic necrosis virus (MEAP-IHNV) database (http://gis.nacse.org/ihnv/) released in 2006 and the MEAP- viral haemorrhagic septicaemia virus (http://gis.nacse.org/vhsv/) database released in 2010.

Journal of Fish Diseases↗

USGS2012

Gene flow and pathogen transmission among bobcats (Lynx rufus) in a fragmented urban landscape

Urbanization can result in the fragmentation of once contiguous natural landscapes into a patchy habitat interspersed within a growing urban matrix. Animals living in fragmented landscapes often have reduced movement among habitat patches because of avoidance of intervening human development, which potentially leads to both reduced gene flow and pathogen transmission between patches. Mammalian carnivores with large home ranges, such as bobcats (Lynx rufus), may be particularly sensitive to habitat fragmentation. We performed genetic analyses on bobcats and their directly transmitted viral pathogen, feline immunodeficiency virus (FIV), to investigate the effects of urbanization on bobcat movement. We predicted that urban development, including major freeways, would limit bobcat movement and result in genetically structured host and pathogen populations. We analysed molecular markers from 106 bobcats and 19 FIV isolates from seropositive animals in urban southern California. Our findings indicate that reduced gene flow between two primary habitat patches has resulted in genetically distinct bobcat subpopulations separated by urban development including a major highway. However, the distribution of genetic diversity among FIV isolates determined through phylogenetic analyses indicates that pathogen genotypes are less spatially structured--exhibiting a more even distribution between habitat fragments. We conclude that the types of movement and contact sufficient for disease transmission occur with enough frequency to preclude structuring among the viral population, but that the bobcat population is structured owing to low levels of effective bobcat migration resulting in gene flow. We illustrate the utility in using multiple molecular markers that differentially detect movement and gene flow between subpopulations when assessing connectivity.

California↗

USGS2006

Population structure, persistence, and seasonality of autochthonous Escherichia coli in temperate, coastal forest soil from a Great Lakes watershed

The common occurrence of Escherichia coli in temperate soils has previously been reported, however, there are few studies to date to characterize its source, distribution, persistent capability and genetic diversity. In this study, undisturbed, forest soils within six randomly selected 0.5 m2 exclosure plots (covered by netting of 2.3 mm2 mesh size) were monitored from March to October 2003 for E. coli in order to describe its numerical and population characteristics. Culturable E. coli occurred in 88% of the samples collected, with overall mean counts of 16 MPN g-1, ranging from <1 to 1657 (n = 66). Escherichia coli counts did not correlate with substrate moisture content, air, or soil temperatures, suggesting that seasonality were not a strong factor in population density control. Mean E. coli counts in soil samples (n = 60) were significantly higher inside than immediately outside the exclosures; E. coli distribution within the exclosures was patchy. Repetitive extragenic palindromic polymerase chain reaction (Rep-PCR) demonstrated genetic heterogeneity of E. coli within and among exclosure sites, and the soil strains were genetically distinct from animal (E. coli) strains tested (i.e. gulls, terns, deer and most geese). These results suggest that E. coli can occur and persist for extended periods in undisturbed temperate forest soils independent of recent allochthonous input and season, and that the soil E. coli populations formed a cohesive phylogenetic group in comparison to the set of fecal strains with which they were compared. Thus, in assessing E. coli sources within a stream, it is important to differentiate background soil loadings from inputs derived from animal and human fecal contamination. ?? 2005 Society for Applied Microbiology and Blackwell Publishing Ltd.

Environmental Microbiology↗

USGS1997

Tonganoxichnus, a new insect trace from the Upper Carboniferous of eastern Kansas

Upper Carboniferous tidal rhythmites of the Tonganoxie Sandstone Member (Stranger Formation) at Buildex Quarry, eastern Kansas, USA, host a relatively diverse arthropod-dominated ichnofauna. Bilaterally symmetrical traces displaying unique anterior and posterior sets of morphological features are well represented within the assemblage. A new ichnogenus, Tonganoxichnus , is proposed for these traces. T. buildexensis , the type ichnospecies, has an anterior region characterized by the presence of a frontal pair of maxillary palp impressions, followed by a head impression and three pairs of conspicuous thoracic appendage imprints symmetrically opposite along a median axis. The posterior region commonly exhibits numerous delicate chevron-like markings, recording the abdominal appendages, and a thin, straight, terminal extension. T. buildexensis is interpreted as a resting trace. A second ichnospecies, T. ottawensis , is characterized by a fan-like arrangement of mostly bifid scratch marks at the anterior area that records the head- and thoracic-appendage backstrokes against the substrate. The posterior area shows chevron-like markings or small subcircular impressions that record the abdominal appendages of the animal, also ending in a thin, straight, terminal extension. Specimens display lateral repetition, and are commonly grouped into twos or threes with a fix point at the posteriormost tail-like structure. T. ottawensis is interpreted as a jumping structure, probably in connection with feeding purposes. The two ichnospecies occur in close association, and share sufficient morphologic features to support the same type of arthropod producer. T. buildexensis closely mimics the ventral anatomy of the tracemaker, whereas T. ottawensis records the jumping abilities of the animal providing significant ethologic and paleoecologic information. The presence of well-differentiated cephalic, thoracic, and abdominal features, particularly in T. buildexensis , resembles the diagnostic tagmosis and segmentation of insects. Detailed analysis of trace morphology and comparison with described Paleozoic insect fossils and extant related forms suggest a monuran as the most likely tracemaker.

Kansas↗

USGS2006

Evidence for the role of infectious disease in species extinction and endangerment

Infectious disease is listed among the top five causes of global species extinctions. However, the majority of available data supporting this contention is largely anecdotal. We used the IUCN Red List of Threatened and Endangered Species and literature indexed in the ISI Web of Science to assess the role of infectious disease in global species loss. Infectious disease was listed as a contributing factor in <4% of species extinctions known to have occurred since 1500 (833 plants and animals) and as contributing to a species' status as critically endangered in <8% of cases (2852 critically endangered plants and animals). Although infectious diseases appear to play a minor role in global species loss, our findings underscore two important limitations in the available evidence: uncertainty surrounding the threats to species survival and a temporal bias in the data. Several initiatives could help overcome these obstacles, including rigorous scientific tests to determine which infectious diseases present a significant threat at the species level, recognition of the limitations associated with the lack of baseline data for the role of infectious disease in species extinctions, combining data with theory to discern the circumstances under which infectious disease is most likely to serve as an agent of extinction, and improving surveillance programs for the detection of infectious disease. An evidence-based understanding of the role of infectious disease in species extinction and endangerment will help prioritize conservation initiatives and protect global biodiversity.

Conservation Biology↗

USGS2007

Hierarchical spatiotemporal matrix models for characterizing invasions

The growth and dispersal of biotic organisms is an important subject in ecology. Ecologists are able to accurately describe survival and fecundity in plant and animal populations and have developed quantitative approaches to study the dynamics of dispersal and population size. Of particular interest are the dynamics of invasive species. Such nonindigenous animals and plants can levy significant impacts on native biotic communities. Effective models for relative abundance have been developed; however, a better understanding of the dynamics of actual population size (as opposed to relative abundance) in an invasion would be beneficial to all branches of ecology. In this article, we adopt a hierarchical Bayesian framework for modeling the invasion of such species while addressing the discrete nature of the data and uncertainty associated with the probability of detection. The nonlinear dynamics between discrete time points are intuitively modeled through an embedded deterministic population model with density-dependent growth and dispersal components. Additionally, we illustrate the importance of accommodating spatially varying dispersal rates. The method is applied to the specific case of the Eurasian Collared-Dove, an invasive species at mid-invasion in the United States at the time of this writing. ?? 2006, The International Biometric Society.

Biometrics↗

USGS2009

Sinks without borders: Snowshoe hare dynamics in a complex landscape

A full understanding of population dynamics of wide-ranging animals should account for the effects that movement and habitat use have on individual contributions to population growth or decline. Quantifying the per-capita, habitat-specific contribution to population growth can clarify the value of different patch types, and help to differentiate population sources from population sinks. Snowshoe hares, Lepus americanus , routinely use various habitat types in the landscapes they inhabit in the contiguous US, where managing forests for high snowshoe hare density is a priority for conservation of Canada lynx, Lynx canadensis . We estimated density and demographic rates via mark–recapture live trapping and radio-telemetry within four forest stand structure (FSS) types at three study areas within heterogeneous managed forests in western Montana. We found support for known fate survival models with time-varying individual covariates representing the proportion of locations in each of the FSS types, with survival rates decreasing as use of open young and open mature FSS types increased. The per-capita contribution to overall population growth increased with use of the dense mature or dense young FSS types and decreased with use of the open young or open mature FSS types, and relatively high levels of immigration appear to be necessary to sustain hares in the open FSS types. Our results support a conceptual model for snowshoe hares in the southern range in which sink habitats (open areas) prevent the buildup of high hare densities. More broadly, we use this system to develop a novel approach to quantify demographic sources and sinks for animals making routine movements through complex fragmented landscapes.

Oikos↗

USGS2010

Stable isotopes differentiate bottlenose dolphins off west-central Florida

Distinguishing discrete population units among continuously distributed coastal small cetaceans is challenging and crucial to conservation. We evaluated the utility of stable isotopes in assessing group membership in bottlenose dolphins ( Tursiops truncatus ) off west-central Florida by analyzing carbon, nitrogen, and sulfur isotope values (δ 13 C, δ 15 N, and δ 34 S) of tooth collagen from stranded dolphins. Individuals derived from three putative general population units: Sarasota Bay (SB), nearshore Gulf of Mexico (GULF), and offshore waters (OFF). Animals of known history (SB) served to ground truth the approach against animals of unknown history from the Gulf of Mexico (GULF, OFF). Dolphin groups differed significantly for each isotope. Average δ 13 C values from SB dolphins (−10.6‰) utilizing sea grass ecosystems differed from those of GULF (−11.9‰) and OFF (−11.9‰). Average δ 15 N values of GULF (12.7‰) and OFF (13.2‰) were higher than those of SB dolphins (11.9‰), consistent with differences in prey trophic levels. δ 34 S values showed definitive differences among SB (7.1‰), GULF (11.3‰), and OFF (16.5‰) dolphins. This is the first application of isotopes to population assignment of bottlenose dolphins in the Gulf of Mexico and results suggest that isotopes may provide a powerful tool in the conservation of small cetaceans.

Florida↗

USGS2007

Nitrite toxicity of Litopenaeus vannamei in water containing low concentrations of sea salt or mixed salts

The uptake, depuration and toxicity of environmental nitrite was characterized in Litopenaeus vannamei exposed in water containing low concentrations of artificial sea salt or mixed salts. In 2 g/L artificial sea salts, nitrite was concentrated in the hemolymph in a dose-dependent and rapid manner (steady-state in about 2 d). When exposed to nitrite in 2 g/L artificial sea salts for 4 d and then moved to a similar environment without added nitrite, complete depuration occurred within a day. Increasing salinity up to 10 g/L decreased uptake of environmental nitrite. Nitrite uptake in environments containing 2 g/L mixed salts (combination of sodium, potassium, calcium and magnesium chlorides) was similar to or lower than rates in 2 g/L artificial sea salt. Toxicity was inversely related to total dissolved salt and chloride concentrations and was highest in 2 g/L artificial sea salt (96-h medial lethal concentration = 8.4 mg/L nitrite-N). Animals that molted during the experiments did not appear to be more susceptible to nitrite than animals that did not molt. The shallow slope of the curve describing the relationship between toxicity and salinity suggests that management of nitrite toxicity in low-salinity shrimp ponds by addition of more salts may not be practical.

Journal of the World Aquaculture Society↗

USGS2007

Nutrients discharged to the Mississippi River from eastern Iowa watersheds, 1996-1997

The introduction of nutrients from chemical fertilizer, animal manure, wastewater, and atmospheric deposition to the eastern Iowa environment creates a large potential for nutrient transport in watersheds. Agriculture constitutes 93 percent of all land use in eastern Iowa. As part of the U.S. Geological Survey National Water Quality Assessment Program, water samples were collected (typically monthly) from six small and six large watersheds in eastern Iowa between March 1996 and September 1997. A Geographic Information System (GIS) was used to determine land use and quantify inputs of nitrogen and phosphorus within the study area. Streamliow from the watersheds is to the Mississippi River. Chemical fertilizer and animal manure account for 92 percent of the estimated total nitrogen and 99.9 percent of the estimated total phosphorus input in the study area. Total nitrogen and total phosphorus loads for 1996 were estimated for nine of the 12 rivers and creeks using a minimum variance unbiased estimator model. A seasonal pattern of concentrations and loads was observed. The greatest concentrations and loads occur in the late spring to early summer in conjunction with row-crop fertilizer applications and spring nmoff and again in the late fall to early winter as vegetation goes into dormancy and additional fertilizer is applied to row-crop fields. The three largest rivers in eastern Iowa transported an estimated total of 79,000 metric tons of total nitrogen and 6,800 metric tons of total phosphorus to the Mississippi River in 1996. The estimated mass of total nitrogen and total phosphorus transported to the Mississippi River represents about 19 percent of all estimated nitrogen and 9 percent of all estimated phosphorus input to the study area.

Iowa↗

USGS2009

Estimating nitrogen loading to ground water and assessing vulnerability to nitrate contamination in a large karstic springs Basin, Florida

A nitrogen (N) mass-balance budget was developed to assess the sources of N affecting increasing ground-water nitrate concentrations in the 960-km 2 karstic Ichetucknee Springs basin. This budget included direct measurements of N species in rainfall, ground water, and spring waters, along with estimates of N loading from fertilizers, septic tanks, animal wastes, and the land application of treated municipal wastewater and residual solids. Based on a range of N leaching estimates, N loads to ground water ranged from 262,000 to 1.3 million kg/year; and were similar to N export from the basin in spring waters (266,000 kg/year) when 80-90% N losses were assumed. Fertilizers applied to cropland, lawns, and pine stands contributed about 51% of the estimated total annual N load to ground water in the basin. Other sources contributed the following percentages of total N load to ground water: animal wastes, 27%; septic tanks, 12%; atmospheric deposition, 8%; and the land application of treated wastewater and biosolids, 2%. Due to below normal rainfall (97.3 cm) during the 12-month rainfall collection period, N inputs from rainfall likely were about 30% lower than estimates for normal annual rainfall (136 cm). Low N-isotope values for six spring waters (??15N-NO3 = 3.3 to 6.3???) and elevated potassium concentrations in ground water and spring waters were consistent with the large N contribution from fertilizers. Given ground-water residence times on the order of decades for spring waters, possible sinks for excess N inputs to the basin include N storage in the unsaturated zone and parts of the aquifer with relatively sluggish ground-water movement and denitrification. A geographical-based model of spatial loading from fertilizers indicated that areas most vulnerable to nitrate contamination were located in closed depressions containing sinkholes and other dissolution features in the southern half of the basin. ?? 2009 American Water Resources Association.

Journal of the American Water Resources Associatio↗

USGS2011

Spatial capture-recapture models for search-encounter data

1. Spatial capture–recapture models make use of auxiliary data on capture location to provide density estimates for animal populations. Previously, models have been developed primarily for fixed trap arrays which define the observable locations of individuals by a set of discrete points. 2. Here, we develop a class of models for 'search-encounter' data, i.e. for detections of recognizable individuals in continuous space, not restricted to trap locations. In our hierarchical model, detection probability is related to the average distance between individual location and the survey path. The locations are allowed to change over time owing to movements of individuals, and individual locations are related formally by a model describing individual activity or home range centre which is itself regarded as a latent variable in the model. We provide a Bayesian analysis of the model in WinBUGS, and develop a custom MCMC algorithm in the R language. 3. The model is applied to simulated data and to territory mapping data for the Willow Tit from the Swiss Breeding Bird Survey MHB. While the observed density was 15 territories per nominal 1 km 2 plot of unknown effective sample area, the model produced a density estimate of 21∙12 territories per square km (95% posterior interval: 17–26). 4. Spatial capture–recapture models are relevant to virtually all animal population studies that seek to estimate population size or density, yet existing models have been proposed mainly for conventional sampling using arrays of traps. Our model for search-encounter data, where the spatial pattern of searching can be arbitrary and may change over occasions, greatly expands the scope and utility of spatial capture–recapture models.

Methods in Ecology and Evolution↗

USGS2017

Movements of four native Hawaiian birds across a naturally fragmented landscape

Animals often increase their fitness by moving across space in response to temporal variation in habitat quality and resource availability, and as a result of intra and inter-specific interactions. The long-term persistence of populations and even whole species depends on the collective patterns of individual movements, yet animal movements have been poorly studied at the landscape level. We quantified movement behavior within four native species of Hawaiian forest birds in a complex lava-fragmented landscape: Hawai‛i ‘amakihi Chlorodrepanis virens , ‘oma‘o Myadestes obscurus , ‘apapane Himatione sanguinea , and ‘i‘iwi Drepanis coccinea . We evaluated the relative importance of six potential intrinsic and extrinsic drivers of movement behavior and patch fidelity: 1) forest fragment size, 2) the presence or absence of invasive rats ( Rattus sp.), 3) season, 4) species, 5) age, and 6) sex. The study was conducted across a landscape of 34 forest fragments varying in size from 0.07 to 12.37 ha, of which 16 had rats removed using a treatment-control design. We found the largest movements in the nectivorous ‘apapane and ‘i‘iwi, intermediate levels in the generalist Hawai‛i ‘amakihi, and shortest average movement for the ‘oma‘o, a frugivore. We found evidence for larger patch sizes increasing patch fidelity only in the ‘oma‘o, and an effect of rat-removal increasing patch fidelity of Hawai‛i ‘amakihi only after two years of rat-removal. Greater movement during the non-breeding season was observed in all species, and season was an important factor in explaining higher patch fidelity in the breeding season for ‘apapane and ‘i‘iwi. Sex was important in explaining patch fidelity in ‘oma‘o only, with males showing higher patch fidelity. Our results provide new insights into how these native Hawaiian species will respond to a changing environment, including habitat fragmentation and changing distribution of threats from climate change.

Journal of Avian Biology↗

USGS2016

Reevaluating geographic variation in life-history traits of a widespread Nearctic amphibian

Animals from cold environments are usually larger than animals from warm environments, which often produce clines in body size. Because variation in body size can lead to trade-offs between growth and reproduction, life-history traits should also vary across climatic gradients. To determine if life-history traits of wood frogs Rana sylvatica vary with climate, we examined female and male body length, clutch size, and ovum size from 37 locations across an unprecedented 32° of latitude. In conflict with recent research, body size, and ovum size decreased in cold climates and at higher latitudes. Clutch size did not vary with climate or latitude, but reproductive effort (clutch size:female size) did, suggesting selection for a life-history traits that favors maximizing propagule number over propagule size in cold climates. With accelerating climate change that will expose populations to novel environmental conditions, it is important to identify the limits of adaptation, which can be informed by greater understanding of variation in life-history traits.

Journal of Zoology↗

USGS2025

Double agents: Invasive Burmese pythons (Python bivittatus) and Argentine black and white tegus (Salvator merianae) as potential seed dispersers in south Florida

Invasive species can reshape ecological processes, including seed dispersal, through both direct and indirect pathways. In this study, we explore how invasive reptiles influence seed dispersal dynamics in the Greater Everglades ecosystem using two case studies: the Burmese python ( Python bivittatus ) and the Argentine black and white tegu ( Salvator merianae ). Guided by a conceptual framework, we investigate three primary mechanisms through which invasive species may alter seed outcomes: direct seed consumption, predation on seed dispersers before seed ingestion, and secondary seed dispersal via predation on animals that have already consumed seeds. Burmese pythons, as apex predators, may contribute to seed dispersal through diploendozoochory while simultaneously driving trophic cascades that restructure the seed disperser community. Tegus, as omnivorous frugivores, directly consume and disperse a wide diversity of plant seeds. We documented 25 seed morphotypes in python diets and 73 in tegu diets, spanning a broad 38 families and including native, endangered, and invasive plant species. Using a binary interaction network, we found that these reptiles exhibit high generalization, nestedness, and connectance—suggesting they are becoming functionally integrated into Everglades seed dispersal networks. These findings reveal that invasive reptiles not only disrupt native plant–animal interactions but may also reshape them, with implications for ecosystem stability, restoration, and management.

Florida↗

USGS2025

Urbanization and host relatedness shape virome composition in a widespread, generalist carnivore

Urban wildlife species have the potential to serve as links in disease transmission between wildlife, humans and domestic animals at the wildland–urban interface (WUI), contributing to both sustained cross-species transmission of pathogens and the emergence of diseases in susceptible populations. However, the relative roles of host and environmental factors in shaping the composition of pathogen communities in urban wildlife is understudied. In this study, we integrated DNA and RNA virome data with host genomic and GPS datasets to investigate factors shaping virome composition in bobcats ( Lynx rufus ) at the WUI in the Tucson Mountains, Arizona, USA. Using a hybrid-capture approach for 31 scats and 17 buccal swabs, we identified multiple viruses that could affect carnivore health at the WUI, including canine parvovirus, feline astrovirus, Felis catus papillomaviruses 2 and 3 and Lyon-IARC polyomavirus. Models of virome composition and distribution of viral taxa indicated contributions of host genetic relatedness and factors relating to urbanisation (such as percentages of urban land cover, road and building densities and distances to roads). Genetic associations with virome compositions were particularly influenced by females. While females exhibit significant isolation by distance, partial Mantel tests revealed a significant correlation between beta diversity and host genetic distance in females only. To our knowledge, this study represents the first assessment of factors shaping virome composition in a wild felid. Our finding of known feline and canine pathogens in bobcats underscores the potential of the WUI to facilitate cross-species transmission between wild and domestic animals.

Arizona↗