Genetic monitoring is important in small, fragmented populations that rely on gene flow to maintain genetic diversity. The Selkirk, Yaak, and Cabinet grizzly bear (Ursus arctos) populations are among the smallest in North America and are near the southernmost extent of the species’ range. These populations received little to no effective migration for generations but have recently experienced increased gene flow through natural migration and a population augmentation program. A long-term dataset of grizzly bear microsatellite genotypes from 1973 to 2021 presented a unique opportunity to examine genetic trends in these populations over time. We used this dataset of 464 bears to evaluate if gene flow affected observed heterozygosity (HO), expected heterozygosity (HE), allelic richness (AR), and average pairwise relatedness (r) in each of these populations. We also estimated effective population size (Ne) using the temporal and linkage disequilibrium (LD) methods. Post gene flow, AR increased in the Selkirk and Cabinet populations and r decreased in all three populations. We did not observe any significant changes in HE or HO, but HE values in our populations were significantly higher than those estimated using a model without gene flow. Our Ne estimates were consistent between the temporal and LD methods and ranged from 15.2 to 15.8, 15.4–17.5, and 5.6–8.9 for the Selkirk, Yaak, and Cabinet populations, respectively. Overall, our findings indicate that gene flow is increasing or maintaining genetic diversity in these populations. However, Ne remains low and additional connectivity or augmentation may be needed, particularly in the Cabinet population.

Past functional toxicogenomic studies have indicated that genes relevant to membrane lipid synthesis are important for tolerance to the lanthanides. Moreover, previously reported imaging of patient's brains following administration of gadolinium-based contrast agents shows gadolinium lining the vessels of the brain. Taken together, these findings suggest the disruption of cytoplasmic membrane integrity as a mechanism by which lanthanides induce cytotoxicity. In the presented work we used scanning transmission electron microscopy and spatially resolved elemental spectroscopy to image the morphology and composition of gadolinium, europium, and samarium precipitates that formed on the outside of yeast cell membranes. In no sample did we find that the lanthanide contaminant had crossed the cell membrane, even in experiments using yeast mutants with disrupted genes for sphingolipid synthesis-the primary lipids found in yeast cytoplasmic membranes. Rather, we have evidence that lanthanides are co-located with phosphorus outside the yeast cells. These results lead us to hypothesize that the lanthanides scavenge or otherwise form complexes with phosphorus from the sphingophospholipid head groups in the cellular membrane, thereby compromising the structure or function of the membrane, and gaining the ability to disrupt membrane function without entering the cell. Graphical Abstract High-resolution electron microscope images and corresponding elemental maps showing substantial evidence of extracellular toxicity of lanthanides to exposed yeast cells.

Phylogeographic studies uncover hidden pathways of divergence and inform conservation. Brown bears (Ursus arctos) have one of the broadest distributions of all land mammals, ranging from Eurasia to North America, and are an important model for evolutionary studies. Although several whole genomes were available for individuals from North America, Europe and Asia, limited whole-genome data were available from Central Asia, including the highly imperilled brown bears in the Gobi Desert. To fill this knowledge gap, we sequenced whole genomes from nine Asian brown bears from the Gobi Desert of Mongolia, Northern Mongolia and the Himalayas of Pakistan. We combined these data with published brown bear sequences from Europe, Asia and North America, as well as other bear species. Our goals were to determine the evolutionary relationships among brown bear populations worldwide, their genetic diversity and their historical demography. Our analyses revealed five major lineages of brown bears based on a filtered set of 684,081 single nucleotide polymorphisms. We found distinct evolutionary lineages of brown bears in the Gobi, Himalayas, northern Mongolia, Europe and North America. The lowest level of genetic diversity and the highest level of inbreeding were found in Pakistan, the Gobi Desert and Central Italy. Furthermore, the effective population size (Ne ) for all brown bears decreased over the last 70,000 years. Our results confirm the genetic distinctiveness and ancient lineage of brown bear subspecies in the Gobi Desert of Mongolia and the Himalayas of Pakistan and highlight their importance for conservation.

Abstract Historical persecution of grizzly bears in North America reduced the species range by 55%. Today, dedicated recovery efforts and shifting societal perceptions have supported the recovery and expansion of grizzly bear populations in many areas. With increasing overlap between people and bears, conservation actions and scientific inquiry are now shifting efforts toward supporting coexistence with bears. Here, we assessed the demography and behavior of grizzly bears in a coexistence landscape in southeast British Columbia, Canada, where abundant grizzly bear populations occur among busy, human‐settled valleys. Between 2016 and 2022, we captured 76 individual grizzly bears and monitored their conflict behavior, survival, and reproduction for 160 animal‐years. The cause of death for 14 animals with a functioning collar was human–wildlife conflict (n = 6), road or rail collision (n = 6), unknown but human suspected (n = 1), and natural (n = 1). Subadult survival was the lowest recorded in North America, while adult survival was similar to other studies, suggesting an intense demographic filter for young animals. We estimate that human‐caused mortality is underreported in government databases by 65%, or for every recorded mortality, there are ~2 that go unreported. Reporting was especially low for road and rail mortalities. Grizzly bear mortality in the Elk Valley due to collisions and conflicts with people is an order of magnitude greater than elsewhere in British Columbia. Combining DNA‐ and collar‐based estimates of population growth, we show that grizzly bear abundance is stable due to source‐sink dynamics, whereby ~7 immigrant bears per year offset the high mortality rates in the area. Grizzly bears dispersing into the valley are often young and more conflict‐naïve, creating a conflict spiral that can be interrupted by reducing mortality of young animals. Creating a self‐sustaining population of bears in the Elk Valley that is not reliant on immigration will require targeted efforts to reduce or secure attractants on private property and strategies to minimize collisions with trains and vehicles.

Despite their similar physicochemical properties, recent studies have demonstrated that lanthanides can display different biological behaviors. Hence, the lanthanide series can be divided into three parts, namely early, mid, and late lanthanides, based on their interactions with biological systems. In particular, the late lanthanides demonstrate distinct, but poorly understood biological activity. In the current study, we employed genome-wide functional screening to help understand biological effects of exposure to Yb(III) and Lu(III), which were selected as representatives of the late lanthanides. As a model organism, we used Saccharomyces cerevisiae, since it shares many biological functions with humans. Analysis of the functional screening results indicated toxicity of late lanthanides is consistent with disruption of vesicle-mediated transport, and further supported a role for calcium transport processes and mitophagy in mitigating toxicity. Unexpectedly, our analysis suggested that late lanthanides target proteins with SH3 domains, which may underlie the observed toxicity. This study provides fundamental insights into the unique biological chemistry of late lanthanides, which may help devise new avenues toward the development of decorporation strategies and bio-inspired separation processes.

Understanding how human infrastructure and other landscape attributes affect genetic differentiation in animals is an important step for identifying and maintaining dispersal corridors for these species. We built upon recent advances in the field of landscape genetics by using an individual-based and multiscale approach to predict landscape-level genetic connectivity for grizzly bears (Ursus arctos) across ~100,000 km2 in Canada's southern Rocky Mountains. We used a genetic dataset with 1156 unique individuals genotyped at nine microsatellite loci to identify landscape characteristics that influence grizzly bear gene flow at multiple spatial scales and map predicted genetic connectivity through a matrix of rugged terrain, large protected areas, highways and a growing human footprint. Our corridor-based modelling approach used a machine learning algorithm that objectively parameterized landscape resistance, incorporated spatial cross validation and variable selection and explicitly accounted for isolation by distance. This approach avoided overfitting, discarded variables that did not improve model performance across withheld test datasets and spatial predictive capacity compared to random cross-validation. We found that across all spatial scales, geographic distance explained more variation in genetic differentiation in grizzly bears than landscape variables. Human footprint inhibited connectivity across all spatial scales, while open canopies inhibited connectivity at the broadest spatial scale. Our results highlight the negative effect of human footprint on genetic connectivity, provide strong evidence for using spatial cross-validation in landscape genetics analyses and show that multiscale analyses provide additional information on how landscape variables affect genetic differentiation.

The influence of bottom-up food resources and top-down mortality risk underlies the demographic trajectory of wildlife populations. For species of conservation concern, understanding the factors driving population dynamics is crucial to effective management and, ultimately, conservation. In southeastern British Columbia, Canada, populations of the mostly omnivorous grizzly bear (Ursus arctos) are fragmented into a mosaic of small isolated or larger partially connected sub-populations. They obtain most of their energy from vegetative resources that are also influenced by human activities. Roads and associated motorized human access shape availability of food resources but also displace bears and facilitate human-caused mortality. Effective grizzly bear management requires an understanding of the relationship between habitat quality and mortality risk. We integrated analyses of bottom-up and top-down demographic parameters to understand and inform a comprehensive and efficient management paradigm across the region. Black huckleberry (Vaccinium membranaceum) is the key high-energy food for grizzly bears in much of southeastern British Columbia. Little is known about where and why huckleberries grow into patches that are useful for grizzly bears (i.e., densely clustered fruiting shrubs that provide efficient access to high energy food) and how forage supply and mortality risk influence population vital rates. By following 43 grizzly bears tracked with global positioning system (GPS) collars (57 bear years) in a 14,236-km(2) focal area spanning the Selkirk and Purcell mountain ranges, we developed a model to identify huckleberry patches from grizzly bear use data. Over 2 years we visited 512 sites used by bears, identifying more than 300 huckleberry patches. We used boosted regression tree modeling associating geophysical, ecological, soil, climate, and topographical variables with huckleberry patches. We integrated this modeled food layer depicting an important pre-hibernation resource, into broader bottom-up and top-down analyses. In addition to berries, we examined bottom-up variables indexing vegetative productivity that were previously found to be predictive of bear use (e.g., alpine, canopy cover, greenness, riparian). We also examined top-down variables including road presence, road density, distance-to-road, secure habitat (defined as 500m away from a road open to vehicular access), highways, human development, and terrain ruggedness. We evaluated the relationship of these variables to female habitat selection, fitness, and population density, testing the predictability and interrelatedness of covariates relative to bottom-up and top-down influences. We estimated resource selection functions with 20,293 GPS telemetry locations collected over 10 years from 20 female grizzly bears. We modeled fitness using logistic regression of spatially explicit reproductive data derived from genetically identified family pedigrees consisting of a mother, father, and offspring. Data included 33 mothers and 72 offspring (1-8 offspring per female). We estimated density through spatial capture-recapture analysis of 126 grizzly bears detected with hair-sampled DNA 287 times between 1998 and 2005. In all 3 analyses (habitat selection, fitness, and density), huckleberry patches were the most influential bottom-up factor and secure habitat was the most consistent top-down variable (road density was similarly predictive). All of the best supported models contained bottom-up and top-down variables except the male density model, which only contained a top-down variable (secure habitat). These results suggest that both bottom-up and top-down forces drive several population processes of grizzly bears in the region, especially for females. We found that 38% of huckleberry patches (235 km(2)) predicted by the top model were in non-secure habitat and that these patches were associated with lower fitness and density relative to those in secure habitat. Grizzly bear density was 2.6 times higher in habitat with road densities <0.6 km/km(2), supporting the use of this road density target for management. The models predict that applying motorized access controls to backcountry areas with huckleberry patches would increase grizzly bear abundance by 23% on average across the region and 125% in the lowest density portion of the study area (Yahk). Managing both bottom-up and top-down influences is necessary to best mitigate the expanding human footprint, which is affecting many carnivore species worldwide. We provide evidence that bottom-up forces were more influential for female habitat selection, fitness, and density than top-down effects. We also uncovered a critical pattern in the magnitude of top-down and bottom-up influences on behavioral (habitat selection) and demographic (population density and fitness) responses. We show that the relative influence of top-down influences on habitat selection and fitness are relatively weak compared to bottom-up influences, whereas top-down pressures exert much stronger limiting forces on population density. Forming conservation decisions around behavioral responses alone may misdirect actions and have limited benefits to populations. This insight can facilitate more effective decision-making for grizzly bear conservation. Our findings highlight the importance of considering both bottom-up and top-down influences, suggesting cautious interpretation of habitat selection models for any species. A comprehensive examination with population-level metrics such as density, vital rates, and fitness may be needed for effective management.

Many wildlife species are threatened in Asia, including the five species of terrestrial bears (Asiatic black, Ursus thibetanus; brown, U. arctos; sloth, Melursus ursinus; sun, Helarctos malayanus; giant panda, Ailuropoda melanoleuca): many populations of these bears are thought to be declining or imperiled by small population size. Here our aim is to document how population assessments have been conducted for bears in Asia. We searched the literature and identified 102 studies published during 1999–2021 that investigated the status of an Asian bear population; these occurred in 24 of the 32 bear range countries in Asia. At the most basic level, 11% of studies verified presence of bears in places where they were not known to exist. The most common objective (53% of papers) was a distribution map, often derived from presence locations in a habitat-based model. Occupancy studies (15%) used temporal (time stamps on images from cameras) or spatial (transect segments) replicates, but tended to focus on “use”, so detector spacing was sometimes not appropriate for occupancy. Purported population indices, such as sign density or camera trap encounter rates, were reported in 16% of studies. One third of studies provided a population estimate, but only 10 studies in two decades used a rigorous method (e.g., mark–recapture). Sign surveys and interviews were the most common methods for determining bear presence, and local interviews were heavily relied upon for assessing population trend. Camera trapping has become increasingly prevalent, but only one study obtained a population estimate using photographs to distinguish natural individual markings. Only three studies used hair traps to obtain DNA-based population estimates, and three other studies obtained population estimates from DNA in scats. Just three studies quantitatively measured change in population size or occupancy over time, and none of these showed a decline. Unique rangewide sign surveys of giant pandas showed significant geographic expansion. The opinions of experts and local people, now heavily relied upon for population assessments, are not reliable or sensitive enough for monitoring. Quantitative population assessments are desirable to direct conservation actions toward the most perilous situations, and provide a means to gauge the effectiveness of conservation actions. This paper demonstrates the paucity of rigorous monitoring of Asian bears, and leads off a series of papers that propose improved methods for assessing distribution, occupancy, and density.

ABSTRACT Science and adaptive management form crucial components of the North American model of wildlife management. Under this model, wildlife managers are encouraged to update management approaches when new information arises whose implementation could improve the stewardship and viability of wildlife populations and the well-being of animals. Here we detail a troubling observation of several grizzly bears with amputated toes in southeast British Columbia and assemble evidence to inform management strategies to remedy the issue. During the capture of 59 grizzly bears, we noticed that four individuals (~7%) had amputated toes on one of their front feet. The wounds were all healed and linear in nature. Further opportunistic record collection revealed that similar examples of amputated toes occurred beyond our study area, and that furbearer traps were frequently responsible for toe loss. We found evidence that seasonal overlap between the active season for grizzly bears and the fall trapping seasons for small furbearers with body grip traps and for wolves with foothold traps may explain the issue. Multiple options to reduce or eliminate this issue exist, but have varying degrees of expected efficacy and require differing levels of monitoring. The most certain approach to greatly reduce the issue is to delay the start of the marten trapping season until December 1, when most bears have denned, instead of opening the season on or prior to November 1, when more than 50% of bears are still active. Additionally, innovative solutions, such as narrowing trap entrances to exclude bear feet while still allowing entrance of target furbearers, have the potential to minimize accidental capture of bears, but the effectiveness of these approaches is unknown. Experimental evidence suggested that better anchoring traps was not a viable solution. Solutions that do not involve season changes will require monitoring of efficacy and compliance to ensure success.

Lanthanides are a series of elements essential to a wide range of applications, from clean energy production to healthcare. Despite their presence in multiple products and technologies, their toxicological characteristics have been only partly studied. Recently, our group has employed a genomic approach to extensively characterize the toxicity mechanisms of lanthanides. Even though we identified substantially different behaviors for mid and late lanthanides, the toxicological profiles of early lanthanides remained elusive. Here, we overcome this gap by describing a multidimensional genome-wide toxicogenomic study for two early lanthanides, namely, lanthanum and praseodymium. We used Saccharomyces cerevisiae as a model system since its genome shares many biological pathways with humans. By performing functional analysis and protein-protein interaction network analysis, we identified the main genes and proteins that participate in the yeast response to counter metal harmful effects. Moreover, our analysis also highlighted key enzymes that are dysregulated by early lanthanides, inducing cytotoxicity. Several of these genes and proteins have human orthologues, indicating that they may also participate in the human response against the metals. By highlighting the key genes and proteins in lanthanide-induced toxicity, this work may contribute to the development of new prophylactic and therapeutic strategies against lanthanide harmful exposures.

Efficient and effective monitoring methods are required to assess population status and gauge efficacy of conservation actions for threatened species. Here we review the spectrum of field methods useful for monitoring distribution, occupancy, abundance, and population trend for the five species of Asian terrestrial bears. Methods reviewed include expert opinion, local knowledge, bear sign, visual observations, camera traps, DNA-based methods (hair and scat derived), and radio telemetry. We examine the application of each method in terms of realizing specific monitoring objectives, their assumptions, challenges, and advantages. Our goal is to assist researchers in matching appropriate field methods with sought-after project objectives and to highlight shortfalls and trade-offs. Methods vary greatly in terms of cost, logistics, required number and expertize of staff, and the reliability of the data they provide. Many Asian bear population assessments have relied on expert opinion, local interviews, and sign surveys to provide estimates of distribution, abundance, and trend, in part because these are inexpensive and relatively easy to employ. However, increasing use of camera traps and DNA-based methods now allow for better monitoring via occupancy or rigorous capture–recapture population estimation, with the caveat that these methods may be restricted by inadequate budgets or logistical constraints. For distribution monitoring, camera traps and DNA yield the most definitive records of presence, but in low density bear populations, sign and local knowledge may be more effective. For occupancy, camera traps and DNA are advantageous in providing definitive detections in known time periods. For abundance/density or population trend monitoring in relatively small areas (<10,000 km2), bears must be individually identified and used in a mark-recapture design. This requires DNA from collections of hair or scat, or a camera-based survey in which natural chest marks are clearly visible and individually distinguishable. DNA-methods or camera traps within individual identification is best for population trend when sufficient funding is available. Alternatively, careful use of local knowledge or expert opinion may be viable options, but come with greater uncertainty. For the foreseeable future, we believe that expert opinion will likely continue to play a large part in monitoring Asian bears, but these opinions should be informed by more rigorous data from the other methods we discuss.

Assemblages of large mammal species play a disproportionate role in the structure and composition of natural habitats. Loss of these assemblages destabilizes natural systems, while their recovery can restore ecological integrity. Here we take an ecoregion‐based approach to identify landscapes that retain their historically present large mammal assemblages, and map ecoregions where reintroduction of 1–3 species could restore intact assemblages. Intact mammal assemblages occur across more than one‐third of the 730 terrestrial ecoregions where large mammals were historically present, and 22% of these ecoregions retain complete assemblages across > 20% of the ecoregion area. Twenty species, if reintroduced or allowed to recolonize through improved connectivity, can increase the area of the world containing intact large mammal assemblages by 54% (11 116 000 km2). Each of these species have at least two large, intact habitat areas (> 10 000 km2) in a given ecoregion. Timely integration of recovery efforts for large mammals strengthens area‐based targets being considered under the Convention on Biological Diversity.

Abstract: Hair samples obtained from barbed wire can identify bears from DNA, assess trophic position from stable isotopes, and yield other data. For brown bears (Ursus arctos), a wire height of 50 cm has become standard protocol, but the efficacy of this height has not been evaluated. Here, we briefly review this protocol, and use data from wires across small streams in Alaska to calculate the probability that barbs at a given height obtained samples. We obtained 1,939 hair samples between 2012 and 2019 for an overall daily sampling success rate per barb of 1.55%. Samples were obtained over the range of barb heights (6–97.5 cm), but daily success rate varied from 0.2% at the lowest and highest barbs to 2% from 40 to 70 cm in height. Thus, 50 cm was an effective height and a wider range yielded similar success rates, though wire height may be selective for bears with respect to size and other traits.

Changes in the distribution of a species can be used to as a metric of conservation status and to identify the loss or gain of isolated populations. This mapping process is a primary tool of the IUCN SSC Red List assessment. Most distribution maps are based on expert opinion or species distribution models based on a combination of species detection records and known habitat and landscape affiliations for that species. However, modeling the distribution for some species is difficult due to low levels of sampling, low detectability, and loose or uncertain associations with landscape attributes. These issues may be particularly prevalent for Asian bears that have generalist habitat requirements and are heavily poached across their range. Presently the range of all bear species in Asia is delineated primarily using expert opinion. Members of the IUCN SSC Bear Specialist Group attempted to create a rule set to combine current detections with known habitat and home range preferences to improve distribution maps for the purpose of conservation metrics and monitoring. The results of applying this rule set for giant pandas (Ailuropoda melanoleuca) closely matched the current IUCN mapped range, but the results for Asiatic black bears (Ursus thibetanus) did not corroborate the IUCN map based solely on expert opinion. We present a list of recommended actions for improving distribution mapping for bears in Asia and possibly any species whose current distribution is heavily influenced by poorly measured metrics such as poaching.

Gadolinium is a metal used in contrast agents for magnetic resonance imaging. Although gadolinium is widely used in clinical settings, many concerns regarding its toxicity and bioaccumulation after gadolinium-based contrast agent administration have been raised and published over the last decade. To date, most toxicological studies have focused on identifying acute effects following gadolinium exposure, rather than investigating associated toxicity mechanisms. In this study, we employ functional toxicogenomics to assess mechanistic interactions of gadolinium with Saccharomyces cerevisiae. Furthermore, we determine which mechanisms are conserved in humans, and their implications for diseases related to the use of gadolinium-based contrast agents in medicine. A homozygous deletion pool of 4291 strains were screened to identify biological functions and pathways disturbed by the metal. Gene ontology and pathway enrichment analyses showed endocytosis and vesicle-mediated transport as the main yeast response to gadolinium, while certain metabolic processes, such as glycosylation, were the primary disrupted functions after the metal treatments. Cluster and protein-protein interaction network analyses identified proteins mediating vesicle-mediated transport through the Golgi apparatus and the vacuole, and vesicle cargo exocytosis as key components to reduce the metal toxicity. Moreover, the metal seemed to induce cytotoxicity by disrupting the function of enzymes (e.g. transferases and proteases) and chaperones involved in metabolic processes. Several of the genes and proteins associated with gadolinium toxicity are conserved in humans, suggesting that they may participate in pathologies linked to gadolinium-based contrast agent exposures. We thereby discuss the potential role of these conserved genes and gene products in gadolinium-induced nephrogenic systemic fibrosis, and propose potential prophylactic strategies to prevent its adverse health effects.

Information about population demography is crucial for developing and implementing conservation measures. The brown bear in the Gobi desert of southwestern Mongolia (referred to as the Gobi bear) is one of the smallest and most isolated brown bear populations in the world. We conducted genetic sampling (n = 2660 samples collected) using hair corrals around feeding sites at 13 water sources during 2009, 2013, and 2017 to evaluate population size, survival, and population trend. Bears were identified using 13 microsatellite loci and one sex marker. We detected 51 unique individuals (15F and 36M) from our targeted surveys in 2009, 2013, and 2017. Based on capture-mark-recapture robust design, population estimates were 23 (95% CI: 21-32) in 2009, 28 (95% CI: 25-35) in 2013, and 31 (95% CI: 29-38) individuals in 2017. Spatial capture-recapture analysis suggested abundance was very low (N<^> = 27; 95% CI: 22-35), and there was no significant change from 2009 to 2017. The population density was 0.93 bears/1000 km(2) (95% CI: 0.74-1.17). Our population estimates suggested a stable population trend. However, the population is still very small, and the sex ratio is skewed toward males, raising concerns for future persistence. Annual survival based on Robust design CMR was 0.85. Low abundance and apparent survival for both sexes in this unhunted population coupled with a skewed sex ratio highlight the need for on-the-ground conservation action to conserve this isolated population of bears.

Europium is a lanthanide metal that is highly valued in optoelectronics. Even though europium is used in many commercial products, its toxicological profile has only been partially characterized, with most studies focusing on identifying lethal doses in different systems or bioaccumulation in vivo. This paper describes a genome-wide toxicogenomic study of europium in Saccharomyces cerevisiae, which shares many biological functions with humans. By using a multidimensional approach and functional and network analyses, we have identified a group of genes and proteins associated with the yeast responses to ameliorate metal toxicity, which include metal discharge paths through vesicle-mediated transport, paths to regulate biologically relevant cations, and processes to reduce metal-induced stress. Furthermore, the analyses indicated that europium promotes yeast toxicity by disrupting the function of chaperones and cochaperones, which have metal-binding sites. Several of the genes and proteins highlighted in our study have human orthologues, suggesting they may participate in europium-induced toxicity in humans. By identifying the endogenous targets of europium as well as the already existing paths that can decrease its toxicity, we can determine specific genes and proteins that may help to develop future therapeutic strategies.

Genetic exchange and hybridization appear common among the western long-eared bats from North America. Multiple sources of evidence indicate that lineages within this group are evolving independently, despite genetic exchange. However, evidence of gene flow raises questions about the species-level status of some lineages. C.L. Lausen et al. (2019. Can. J. Zool. 97(3): 267–279) proposed that Myotis evotis (H. Allen, 1864) (long-eared myotis) and Myotis keenii (Merriam, 1895) (Keen’s myotis) are one species, not two. This conclusion is based on analyses of cytochrome b and microsatellite data suggesting gene flow between these taxa. Microsatellites are not reliable markers for identifying species because homoplasy can be a major confounding factor, which appears to be true in this case. We reanalyzed the dataset of C.L. Lausen et al. (2019) and show that it is not reliable to distinguish between gene flow or homoplasy, and that these data do not support the conclusion that M. evotis and M. keenii represent a single species. Previous morphological and genomic studies indicate that these are separate species despite previous genetic exchange between them. Failing to recognize that gene flow can occur between independently evolving lineages is counterproductive for conservation because it can lead to neglect of important independent lineages, and likewise failing to use proper tools to delimit species is counterproductive to efforts to quantify biodiversity and design conservation strategies.