Tracing Eastern Wolf Origins From Whole-Genome Data in Context of Extensive Hybridization.

Southeastern Canada is inhabited by an amalgam of hybridizing wolf-like canids, raising fundamental questions regarding their taxonomy, origins, and timing of hybridization events. Eastern wolves (Canis lycaon), specifically, have been the subject of significant controversy, being viewed as either a distinct taxonomic entity of conservation concern or a recent hybrid of coyotes (C. latrans) and grey wolves (C. lupus). Mitochondrial DNA analyses show some evidence of eastern wolves being North American evolved canids. In contrast, nuclear genome studies indicate eastern wolves are best described as a hybrid entity, but with unclear timing of hybridization events. To test hypotheses related to these competing findings we sequenced whole genomes of 25 individuals, representative of extant Canadian wolf-like canid types of known origin and levels of contemporary hybridization. Here we present data describing eastern wolves as a distinct taxonomic entity that evolved separately from grey wolves for the past ∼67,000 years with an admixture event with coyotes ∼37,000 years ago. We show that Great Lakes wolves originated as a product of admixture between grey wolves and eastern wolves after the last glaciation (∼8,000 years ago) while eastern coyotes originated as a product of admixture between "western" coyotes and eastern wolves during the last century. Eastern wolf nuclear genomes appear shaped by historical and contemporary gene flow with grey wolves and coyotes, yet evolutionary uniqueness remains among eastern wolves currently inhabiting a restricted range in southeastern Canada.

Impact of Continuous Renal Replacement Therapy Initiation on Urine Output and Fluid Balance: A Multicenter Study.

INTRODUCTION: The effect of continuous renal replacement therapy (CRRT) on renal function is poorly understood. However, the initiation of CRRT may induce oliguria. We aimed to investigate the impact of CRRT commencement on urine output (UO). METHODS: This was a retrospective cohort study in two intensive care units. We included all patients who underwent CRRT and collected data on hourly UO and fluid balance before and after CRRT commencement. We performed an interrupted time series analysis using segmented regression to assess the relationship between CRRT commencement and UO. RESULTS: We studied 1,057 patients. Median age was 60.7 years (interquartile range [IQR], 48.3-70.6), and the median APACHE III was 95 (IQR, 76-115). Median time to CRRT was 17 h (IQR, 5-49). With start of CRRT, the absolute difference in mean hourly UO and mean hourly fluid balance was -27.0 mL/h (95% CI: -32.1 to -21.8; p value < 0.01) and - 129.3 mL/h (95% CI: -169.2 to -133.3), respectively. When controlling for pre-CRRT temporal trends and patient characteristics, there was a rapid post-initiation decrease in UO (-0.12 mL/kg/h; 95% CI: -0.17 to -0.08; p value < 0.01) and fluid balance (-78.1 mL/h; 95% CI: -87.9 to -68.3; p value < 0.01), which was sustained over the first 24 h of CRRT. Change in UO and fluid balance were only weakly correlated (r -0.29; 95% CI: -0.35 to -0.23; p value < 0.01). CONCLUSION: Commencement of CRRT was associated with a significant decrease in UO that could not be explained by extracorporeal fluid removal.

Frog Virus 3 Genomes Reveal Prevalent Recombination between Ranavirus Lineages and Their Origins in Canada.

Ranaviruses are pathogens associated with the decline of amphibian populations across much of their distribution. In North America, frog virus 3 (FV3) is a widely distributed pathogen with wild populations of amphibians harboring different lineages and putative recombinants between FV3 and common midwife toad virus (CMTV). These recombinants have higher pathogenicity, and CMTV-derived genes associated with virulence are reported in wild strains in Canada. However, while FV3 is linked to amphibian die-offs in North America, CMTVs have been reported only in commercial frog farms in North America. We sequenced complete genomes of 18 FV3 isolates from three amphibian species to characterize genetic diversity of the lineages in Canada and infer possible recombinant regions. The 18 FV3 isolates displayed different signals of recombination, varying from none to interspersed recombination with previously isolated CMTV-like viruses. In general, most recombination breakpoints were located within open reading frames (ORFs), generating new ORFs and proteins that were a mixture between FV3 and CMTV. A combined spatial and temporal phylogeny suggests the presence of the FV3 lineage in Canada is relatively contemporary (<100 years), corroborating the hypothesis that both CMTV- and FV3-like viruses spread to North America when the international commercial amphibian trade started. Our results highlight the importance of pathogen surveillance and viral dynamics using full genomes to more clearly understand the mechanisms of disease origin and spread.IMPORTANCE Amphibian populations are declining worldwide, and these declines have been linked to a number of anthropogenic factors, including disease. Among the pathogens associated with amphibian mortality, ranaviruses have caused massive die-offs across continents. In North America, frog virus 3 (FV3) is a widespread ranavirus that can infect wild and captive amphibians. In this study, we sequenced full FV3 genomes isolated from frogs in Canada. We report widespread recombination between FV3 and common midwife toad virus (CMTV). Phylogenies indicate a recent origin for FV3 in Canada, possibly as a result of international amphibian trade.

Low intraspecific variation of Frog virus 3 with evidence for novel FV3-like isolates in central and northwestern Canada.

Frog virus 3 (FV3) and FV3-like ranaviruses can infect a variety of cold-blooded aquatic species and present a primary threat to amphibians across the globe. Previous studies of FV3-like viruses have largely investigated higher-level phylogenetic distinctions of these pathogens via portions of the conserved major capsid protein (MCP), and the putative virulence gene vIF-2α. Few studies, however, have investigated the spatial distribution of FV3 variants at the population level3-data that can be used to further understand the spatial epidemiology of this disease. In this study, we sequenced the MCP and vIF-2α of 127 FV3-positive amphibians sampled from Canadian water bodies in Ontario, northeastern Alberta, and southern Northwest Territories to explore whether intraspecific genetic variation exists within FV3. There was a lack of variation at the 2 markers across these regions, suggesting that there is a lack of FV3 sequence diversity in Canada, which may hint at a single source of infection that has spread. However, an undocumented variant termed Wood Buffalo ranavirus (WBRV) was detected in samples from 3 sites in Alberta and Northwest Territories that clustered within the FV3-like lineage with 99.3% sequence homology for MCP. For vIF-2α, all sequences were the expected truncated variant except for 6 samples in Ontario. These latter sequences were suggestive of recombination with common midwife toad virus (CMTV). The lack of variation suggests that higher-resolution genome analyses will be required to further explore the spatial spread and intraspecific variation of the disease.

Use of Aborted Fetal Tissue in Vaccines and Medical Research Obscures the Value of All Human Life.

This opinion addresses the licitness, quasi-benefits, and consequences of using aborted fetal tissue in vaccines and in medical research. The Catholic Church permits temporary use of vaccines generated using aborted fetal tissue to protect children from preventable diseases until alternative vaccines that do not use aborted fetal tissue are available. In medical research, cell lines that were generated from elective abortions should be avoided and alternative cell lines of licit origin utilized. The association between in utero Zika virus infections and microcephaly has increased the demand for fetal tissue to establish causality and to understand disease progression. These studies require extensive oversight as they could directly encourage elective abortions. The consequence of the use of fetal tissue from elective abortions is desensitization of beneficiaries to the original illicit act of abortion thereby obscuring the value of all human life and potentially leading to scandal. Summary: The use of fetal tissue from elective abortions is commonplace in the pharmaceutical industry and in medical research. This opinion addresses the licitness, quasi-benefits, and consequences of using fetal tissue from elective abortions in vaccines and in medical research. All people of good conscience have the responsibility to voice opposition to the use of fetal tissue from elective abortions in order to promote development of alternatives, affirm the value of all human life and limit scandal.

A persistently infecting coronavirus in hibernating Myotis lucifugus, the North American little brown bat.

Bats are important reservoir hosts for emerging viruses, including coronaviruses that cause diseases in people. Although there have been several studies on the pathogenesis of coronaviruses in humans and surrogate animals, there is little information on the interactions of these viruses with their natural bat hosts. We detected a coronavirus in the intestines of 53/174 hibernating little brown bats (Myotis lucifugus), as well as in the lungs of some of these individuals. Interestingly, the presence of the virus was not accompanied by overt inflammation. Viral RNA amplified from little brown bats in this study appeared to be from two distinct clades. The sequences in clade 1 were very similar to the archived sequence derived from little brown bats and the sequences from clade 2 were more closely related to the archived sequence from big brown bats. This suggests that two closely related coronaviruses may circulate in little brown bats. Sequence variation among coronavirus detected from individual bats suggested that infection occurred prior to hibernation, and that the virus persisted for up to 4 months of hibernation in the laboratory. Based on the sequence of its genome, the coronavirus was placed in the Alphacoronavirus genus, along with some human coronaviruses, bat viruses and the porcine epidemic diarrhoea virus. The detection and identification of an apparently persistent coronavirus in a local bat species creates opportunities to understand the dynamics of coronavirus circulation in bat populations.

Innate immune responses in raccoons after raccoon rabies virus infection.

Zoonotic wildlife diseases pose significant health risks not only to their primary vectors but also to humans and domestic animals. Rabies is a lethal encephalitis caused by rabies virus (RV). This RNA virus can infect a range of terrestrial mammals but each viral variant persists in a particular reservoir host. Active management of these host vectors is needed to minimize the negative impacts of this disease, and an understanding of the immune response to RV infection aids strategies for host vaccination. Current knowledge of immune responses to RV infection comes primarily from rodent models in which an innate immune response triggers activation of several genes and signalling pathways. It is unclear, however, how well rodent models represent the immune response of natural hosts. This study investigates the innate immune response of a primary host, the raccoon, to a peripheral challenge using the raccoon rabies virus (RRV). The extent and temporal course of this response during RRV infection was analysed using genes predicted to be upregulated during infection (IFNs; IFN regulatory factors; IL-6; Toll like receptor-3; TNF receptor). We found that RRV activated components of the innate immune system, with changes in levels of transcripts correlated with presence of viral RNA. Our results suggest that natural reservoirs of rabies may not mimic the immune response triggered in rodent models, highlighting the need for further studies of infection in primary hosts.

Spatial patterns of neutral and functional genetic variations reveal patterns of local adaptation in raccoon (Procyon lotor) populations exposed to raccoon rabies.

Local adaptation is necessary for population survival and depends on the interplay between responses to selective forces and demographic processes that introduce or retain adaptive and maladaptive attributes. Host-parasite systems are dynamic, varying in space and time, where both host and parasites must adapt to their ever-changing environment in order to survive. We investigated patterns of local adaptation in raccoon populations with varying temporal exposure to the raccoon rabies virus (RRV). RRV infects approximately 85% of the population when epizootic and has been presumed to be completely lethal once contracted; however, disease challenge experiments and varying spatial patterns of RRV spread suggest some level of immunity may exist. We first assessed patterns of local adaptation in raccoon populations along the eastern seaboard of North America by contrasting spatial patterns of neutral (microsatellite loci) and functional, major histocompatibility complex (MHC) genetic diversity and structure. We explored variation of MHC allele frequencies in the light of temporal population exposure to RRV (0-60 years) and specific RRV strains in infected raccoons. Our results revealed high levels of MHC variation (66 DRB exon 2 alleles) and pronounced genetic structure relative to neutral microsatellite loci, indicative of local adaptation. We found a positive association linking MHC genetic diversity and temporal RRV exposure, but no association with susceptibility and resistance to RRV strains. These results have implications for landscape epidemiology studies seeking to predict the spread of RRV and present an example of how population demographics influence the degree to which populations adapt to local selective pressures.

Complete genome analysis of a frog virus 3 (FV3) isolate and sequence comparison with isolates of differing levels of virulence.

BACKGROUND: Frog virus 3 (FV3) is the type species of the genus Ranavirus, and in the past few decades, FV3 infections have resulted in considerable morbidity and mortality in a range of wild and cultivated amphibian species in the Americas, Europe, and Asia. The reasons for the pathogenicity of FV3 are not well understood. FINDINGS: We investigated three FV3 isolates designated SSME, wt-FV3, and aza-Cr, and reported that our wt-FV3 and aza-Cr strains showed similar levels of virulence, while SSME was the least virulent in an in vivo study with Lithiobates pipiens tadpoles. Using 454 GS-FLX sequencing technology, we sequenced SSME and compared it to the published wt-FV3 genome. SSME had multiple amino acid deletions in ORFs 49/50L, 65L, 66L, and 87L, which may explain its reduced virulence. We also investigated repeat regions and found that repeat copy number differed between isolates, with only one group of 3 isolates and 1 pair of isolates being identical at all 3 locations. CONCLUSIONS: In this study we have shown that genetic variability is present between closely related FV3 isolates, both in terms of deletions/insertions, and even more so at select repeat locations. These genomic areas with deletions/insertions may represent regions that affect virulence, and therefore require investigation. Furthermore, we have identified repeat regions that may prove useful in future phylogeographical tracking and identification of ranaviral strains across different environmental regions.

SARS-CoV-2 viral titer measurements in Ontario, Canada wastewaters throughout the COVID-19 pandemic.

During the COVID-19 pandemic, the Province of Ontario, Canada, launched a wastewater surveillance program to monitor SARS-CoV-2, inspired by the early work and successful forecasts of COVID-19 waves in the city of Ottawa, Ontario. This manuscript presents a dataset from January 1, 2021, to March 31, 2023, with RT-qPCR results for SARS-CoV-2 genes and PMMoV from 107 sites across all 34 public health units in Ontario, covering 72% of the province's and 26.2% of Canada's population. Sampling occurred 2-7 times weekly, including geographical coordinates, serviced populations, physico-chemical water characteristics, and flowrates. In doing so, this manuscript ensures data availability and metadata preservation to support future research and epidemic preparedness through detailed analyses and modeling. The dataset has been crucial for public health in tracking disease locally, especially with the rise of the Omicron variant and the decline in clinical testing, highlighting wastewater-based surveillance's role in estimating disease incidence in Ontario.

A review of sebum in mammals in relation to skin diseases, skin function, and the skin microbiome.

Diseases vary among and within species but the causes of this variation can be unclear. Immune responses are an important driver of disease variation, but mechanisms on how the body resists pathogen establishment before activation of immune responses are understudied. Skin surfaces of mammals are the first line of defense against abiotic stressors and pathogens, and skin attributes such as pH, microbiomes, and lipids influence disease outcomes. Sebaceous glands produce sebum composed of multiple types of lipids with species-specific compositions. Sebum affects skin barrier function by contributing to minimizing water loss, supporting thermoregulation, protecting against pathogens, and preventing UV-induced damage. Sebum also affects skin microbiome composition both via its antimicrobial properties, and by providing potential nutrient sources. Intra- and interspecific variation in sebum composition influences skin disease outcomes in humans and domestic mammal species but is not well-characterized in wildlife. We synthesized knowledge on sebum function in mammals in relation to skin diseases and the skin microbiome. We found that sebum composition was described for only 29 live, wild mammalian species. Sebum is important in dermatophilosis, various forms of dermatitis, demodicosis, and potentially white-nose syndrome. Sebum composition likely affects disease susceptibility, as lipid components can have antimicrobial functions against specific pathogens. It is unclear why sebum composition is species-specific, but both phylogeny and environmental effects may drive differences. Our review illustrates the role of mammal sebum function and influence on skin microbes in the context of skin diseases, providing a baseline for future studies to elucidate mechanisms of disease resistance beyond immune responses.

The bear necessities: A sensitive qPCR assay for bear DNA detection from bile and derived products to complement wildlife forensic enforcement.

Demand for bear bile, a prized component of traditional Asian medicines, threaten Asiatic and sun bear population sustainability. While laws exist to prevent poaching and trafficking of bear parts and derivatives, smuggling persists with demand extending to surrogate species, including American black bears (Ursus americanus). Mitochondrial DNA (mtDNA) sequencing can identify products putatively containing biological bear material but can be undermined by PCR inhibitors in bile and a lack of sensitivity at trace levels. Quantitative PCR (qPCR) assays can be used to distinguish between closely related target species, while concomitantly evaluating inhibition and false negative results in low quality/quantity DNA applications. Herein, we develop a multiplexed qPCR assay to detect and differentiate among bear species, including highly diluted bile samples mixed within liquors as common dilutants. The assay detects as little as 10 locus copies/reaction of bear DNA with 95% confidence, distinguishing among sun, Asiatic and American black bears. Demonstrating the sensitivity and applicability of this assay in context of current bile mixture recipes, dilutions of 1:5,000 bile with ethanol, red wine, and spirits, all yielded clear quantifiable detections, where our data suggests as little as 1 drop of bile per 750 mL bottle of alcohol would still exceed the limits of detection (e.g., 1:15000 dilution or <0.05 mL bile per 750 mL bottle). Overall, this study provides a rapid, sensitive, and specific test to identify and distinguish among bear species commonly used for bile production to aid wildlife enforcement applications.

Metabarcoding of fecal pellets in wild muskox populations reveals negative relationships between microbiome and diet alpha diversity.

Microbiome diversity and diet composition concomitantly influence species health, fitness, immunity, and digestion. In environments where diet varies spatially and temporally, microbiome plasticity may promote rapid host adaptation to available resources. For northern ungulates in particular, metabarcoding of noninvasively collected fecal pellets presents unprecedented insights into their diverse ecological requirements and niches by clarifying the interrelationships of microbiomes, key to deriving nutrients, in context of altered forage availability in changing climates. Muskoxen (Ovibos moschatus) are Arctic-adapted species that experience fluctuating qualities and quantities of vegetation. Geography and seasonality have been noted to influence microbiome composition and diversity in muskoxen, yet it is unclear how their microbiomes intersect with diet. Following observations from other species, we hypothesized increasing diet diversity would result in higher microbiome diversity in muskoxen. We assessed diet composition in muskoxen using three common plant metabarcoding markers and explored correlations with microbiome data. Patterns of dietary diversity and composition were not fully concordant among the markers used, yet all reflected the primary consumption of willows and sedges. Individuals with similar diets had more similar microbiomes, yet in contrast to most literature, yielded negative relationships between microbiome and diet alpha diversity. This negative correlation may reflect the unique capacities of muskoxen to survive solely on high-fiber Arctic forage and provide insight into their resiliency to exploit changing dietary resources in a rapidly warming Arctic altering vegetation diversity.

Wastewater surveillance for earlier detection of seniors congregate living COVID-19 outbreaks in Peterborough, Ontario.

The coronavirus disease 2019 (COVID-19) pandemic has disproportionately affected seniors living in congregate living settings. The evolving surveillance context has led to novel use of wastewater surveillance to monitor levels of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in these settings. This study presents a pilot of upstream congregate living wastewater surveillance of SARS-CoV-2 for the detection of COVID-19 outbreaks and the effects of early public health interventions. We monitored localized wastewater SARS-CoV-2 levels from four congregate living settings March 15, 2021 to October 1, 2022 and correlated these levels with suspected and confirmed COVID-19 outbreaks determined by other methods. We identified five wastewater signals that correlated with confirmed outbreaks and three wastewater signals that did not correlate with subsequent outbreaks. In the five confirmed outbreaks, the wastewater signal was detected 2-10 days (median, five days) prior to confirmation of the outbreak by case testing. This pilot demonstrates upstream sampling for SARS-CoV-2 in wastewater may effectively detect outbreaks prior to their detection through symptomatic case testing and could support a balanced approach to outbreak response in congregate living settings, leading to increased wellbeing of these residents.

The genome sequence of the Loggerhead sea turtle, Caretta caretta Linnaeus 1758.

We present a genome assembly of Caretta caretta (the Loggerhead sea turtle; Chordata, Testudines, Cheloniidae), generated from genomic data from two unrelated females. The genome sequence is 2.13 gigabases in size. The assembly has a busco completion score of 96.1% and N50 of 130.95 Mb. The majority of the assembly is scaffolded into 28 chromosomal representations with a remaining 2% of the assembly being excluded from these.

Evidence for evolutionary convergence at MHC in two broadly distributed mesocarnivores.

Variation within major histocompatibility complex (MHC) genes is important in recognizing pathogens and initiating an immune response. These genes are relevant in enhancing our understanding of how species cope with rapid environmental changes and concomitant fluctuations in selective pressures such as invasive, infectious diseases. Disease-based models suggest that diversity at MHC is maintained through balancing selection arising from the coevolution of hosts and pathogens. Despite intensive balancing selection, sequence motifs or even identical MHC alleles can be shared across multiple species; three potential mechanisms have been put forth to explain this phenomenon: common ancestry, convergent evolution, and random chance. To understand the processes that maintain MHC similarity across divergent species, we examined the variation at two orthologous MHC-DRB genes in widespread North American Musteloid species, striped skunks (Mephitis mephitis), and raccoons (Procyon lotor). These species are often sympatric and exposed to a similar suite of diseases (e.g., rabies, canine distemper, and parvovirus). Given their exposure to similar selective pressures from pathogens, we postulated that similar DRB alleles may be present in both species. Our results indicated that similar motifs are present within both species, at functionally relevant polymorphic sites. However, based on phylogenetic analyses that included previously published MHC sequences of several closely related carnivores, the respective MHC-DRB alleles do not appear to have been maintained through common ancestry and unlikely through random chance. Instead, the similarities observed between the two mesocarnivore species may rather be due to evolutionary convergence.

Draft Genome Assembly of an Iconic Arctic Species: Muskox (Ovibos moschatus).

Muskoxen (Ovibos moschatus) are Arctic species within the Caprinae subfamily that are economically and culturally significant to northern Indigenous communities. Low genetic diversity from repeated genetic bottlenecks, coupled with the effects of Arctic warming (e.g., heat stress, changing forage, pathogen range expansions), present conservation concerns for this species. Reference genome assemblies enhance our ecological and evolutionary understanding of species (which in turn aid conservation efforts). Herein, we provide a full draft reference genome of muskox using Illumina Hiseq data and cross-species scaffolding. The final reference assembly yielded a genome of 2,621,890,883 bp in length, a scaffold N50 of ~13.2 million, and an annotation identifying ~19.3 k genes. The muskox genome assembly and annotation were then used to reconstruct a phylogenetic tree which estimated muskoxen diverged from other ungulate species~12 Mya. To gain insight into the demographic history of muskoxen we also performed pairwise sequentially Markovian coalescent (PSMC) that identified two population bottlenecks coinciding with major glaciation events contributing to the notoriously low genetic variation observed in muskoxen. Overall, this genome assembly provides a foundation for future population genomic studies, such as latitudinal analyses, to explore the capacity of muskoxen to adapt to rapidly changing environments.

Erratum to: Skin pH varies among bat species seasons and between wild and captive bats.

[This corrects the article DOI: 10.1093/conphys/coab088.].

MHC class II DRB diversity in raccoons (Procyon lotor) reveals associations with raccoon rabies virus (Lyssavirus).

In North America, the raccoon rabies virus (RRV) is an endemic wildlife disease which causes acute encephalopathies and is a strong selective force on raccoons (Procyon lotor), with estimates of ∼85% of the population succumbing to the disease when epizootic. RRV is regarded as a lethal disease if untreated; therefore, no evolutionary response would be expected of raccoon populations. However, variable immune responses to RRV have been observed in raccoons indicating a potential for evolutionary adaptation. Studies of variation within the immunologically important major histocompatibility complex (MHC) have revealed relationships between MHC alleles and diseases in humans and other wildlife species. This enhances our understanding of how hosts and pathogens adapt and co-evolve. In this study, we used RRV as a model system to study host-pathogen interaction in raccoons from a challenge study and from four wild populations that differ in exposure times and viral lineages. We investigated the potential role of Prlo-DRB polymorphism in relation to susceptibility/resistance to RRV in 113 RRV positive and 143 RRV negative raccoons. Six alleles were found to be associated with RRV negative status and five alleles with RRV positive animals. We found variable patterns of MHC associations given the relative number of selective RRV sweeps in the studied regions and correlations between MHC diversity and RRV lineages. The allelic associations established provide insight into how the genetic variation of raccoons may affect the disease outcome and this can be used to examine similar associations between other rabies variants and their hosts.

Mitochondrial evidence for panmixia despite perceived barriers to gene flow in a widely distributed waterbird.

We examined the mitochondrial genetic structure of American white pelicans (Pelecanus erythrorhynchos) to: 1) verify or refute whether American white pelicans are panmictic and 2) understand if any lack of genetic structure is the result of contemporary processes or historical phenomena. Sequence analysis of mitochondrial DNA control region haplotypes of 367 individuals from 19 colonies located across their North American range revealed a lack of population genetic or phylogeographic structure. This lack of structure was unexpected because: 1) Major geographic barriers such as the North American Continental Divide are thought to limit dispersal; 2) Differences in migratory behavior are expected to promote population differentiation; and 3) Many widespread North American migratory bird species show historic patterns of differentiation resulting from having inhabited multiple glacial refugia. Further, high haplotype diversity and many rare haplotypes are maintained across the species' distribution, despite frequent local extinctions and recolonizations that are expected to decrease diversity. Our findings suggest that American white pelicans have a high effective population size and low natal philopatry. We suggest that the rangewide panmixia we observed in American white pelicans is due to high historical and contemporary gene flow, enabled by high mobility and a lack of effective physical or behavioral barriers.