Myotis Keenii Research Articles

Comment on “Population genetics reveal Myotis keenii (Keen’s myotis) and Myotis evotis (long-eared myotis) to be a single species”

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.

Reply to the comment by Morales et al. on “Population genetics reveal Myotis keenii (Keen’s myotis) and Myotis evotis (long-eared myotis) to be a single species”

A.E. Morales et al. (2021. Can. J. Zool. 99(5): 415–422) provided no new evidence to alter the conclusions of C.L. Lausen et al. (2019. Can. J. Zool. 97(3): 267–279). We present background information, relevant comparisons, and clarification of analyses to further strengthen our conclusions. The genesis of the original “evotis–keenii” study in British Columbia (Canada) was to differentiate Myotis keenii (Merriam, 1895) (Keen’s myotis), with one of the smallest North American bat distributions, from sympatric Myotis evotis (H. Allen, 1864) (long-eared myotis), using something other than the suggested post-mortem skull size comparison, but no differentiating trait could be found, leading to the molecular genetics examination of C.L. Lausen et al. (2019). We present cumulative data that rejects the 1979 hypothesis of M. keenii as a distinct species. A.E. Morales et al. (2021) inaccurately portray C.L. Lausen et al.’s (2019) question and results; present inaccurate morphological and outdated distribution data; overstate the impact of homoplasy without supporting evidence; and misinterpret evidence of population structure.

Population genetics revealMyotis keenii(Keen’s myotis) andMyotis evotis(long-eared myotis) to be a single species

Recognizing delineations of gene flow among groups of animals can be challenging but is necessary for conservation and management. Of particular importance is the identification of species boundaries. Several physical and genetic traits have been used with mixed success to distinguish Myotis keenii (Merriam, 1895) (Keen’s myotis) and Myotis evotis (H. Allen, 1864) (long-eared myotis), but it is unclear whether species distinction is biologically warranted. We generated 12–14 microsatellite locus genotypes for 275 long-eared Myotis representing four species — M. keenii, M. evotis, Myotis septentrionalis (Trouessart, 1897) (northern myotis), and Myotis thysanodes Miller, 1897 (fringed myotis) — from across northwestern North America and 23 Myotis lucifugus (Le Conte, 1831) (little brown myotis) as the outgroup. Population genetic analyses revealed four well-defined groups (species): M. septentrionalis, M. thysanodes, M. lucifugus, and a single group comprising M. keenii and M. evotis. We document high rates of gene flow within M. evotis/M. keenii. Cytochrome b gene (mtDNA) sequencing failed to resolve morphologically identifiable species. We highlight the importance of geographically thorough investigation of genetic connectivity (nuclear markers) when assessing taxonomic status of closely related groups. We document a morphometric cline within M. evotis/M. keenii that may in part explain earlier analyses that led to the description of the smaller bodied M. keenii (type locality: Haida Gwaii). We conclude that M. keenii does not qualify as a genetic or biological species.

Survey of Bats in Southeast Alaska with Emphasis on Keen's Myotis (Myotis keenii)

Knowledge of the distribution and natural history of bats in Southeast Alaska is limited. We conducted capture and acoustic surveys for bats throughout Southeast Alaska in 2005 and continued surveys on Prince of Wales Island in 2006. We documented capture success, relative abundance, morphology, and periods of reproduction for each species. Capture success varied by species, location, and type of capture site. Little brown myotis (Myotis lucifugus; Le Conte 1831) were captured most frequently, followed by California myotis (M. californicus; Audubon and Bachman 1842), Keen's myotis (M. Keenii; Merriam 1895), and long-legged myotis (M. volans; Allen 1866). We captured little brown myotis throughout the region, Keen's and California myotis as far north as Juneau, and long-legged myotis in the southern part of the region. Silver-haired bats (Lasionycteris noctivagans; Le Conte 1831) were not captured, but were sighted on Prince of Wales Island and acoustic data indicate they may occur as far north as Juneau. Based on low rates of detection, all species appear to occur in low densities in Southeast Alaska. Better understanding of population status and trends, habitat ecology, and response to forest management is needed to identify essential habitat elements and prioritize conservation strategies in this region.

Selection of Day-Roosts By Keen's Myotis (Myotis keenii) at Multiple Spatial Scales

Keen's myotis (Myotis keenii) has one of the most limited geographic distributions of any species of bat in North America. Because there is little knowledge of its roosting ecology, we examined selection of day-roosts in trees by male and female Keen's myotis at 3 spatial scales (tree, tree plot, and landscape) on Prince of Wales Island, southeastern Alaska, from May to September 2006. We selected variables known to influence roost selection by other tree-roosting bats for logistic regression models. We used Akaike 's information criterion to rank all models within and between scales according to their ability to differentiate between characteristics of used and available roosts and we determined the effect of each variable with model-averaged coefficient estimates and associated odds ratios. We tracked 13 females and 6 males to 62 and 24 roosts in trees, respectively. Selection of day-roosts by males and females was most strongly influenced by characteristics of trees. The odds a tree was used for roosting by female Keen's myotis increased with the presence of defects, increasing diameter, and decreasing bark; increasing quadratic mean diameter in the tree plot; and decreasing distance to the nearest stream and increasing proportion of old growth in the landscape. Male Keen's myotis exhibited flexibility in types of roosts chosen, but the odds of a tree being used increased with decreasing bark, the presence of defects, and increasing slope-height. The odds a tree was used as a roost by males also increased with the increasing proportion of trees in early to late decay stages in the tree plot. Some habitat features differed between males and females at each spatial scale and differences are likely a reflection of the energetic demands associated with reproduction. We suggest that maintaining structural components characteristic of old-growth rain forest will promote conservation of Keen's myotis in southeastern Alaska.

Influence of weather on two insectivorous bats in a temperate Pacific Northwest rainforest

Adverse weather conditions frequently have a significant negative influence on survival and reproductive success of insectivorous bats. Low ambient temperatures increase the energetic costs of maintaining euthermia and reduces insect activity, while precipitation likely adds “clutter” making prey more difficult to detect using echolocation. We studied two species of insectivorous bats, Myotis lucifugus (LeConte, 1831) and Myotis keenii (Merriam, 1895), in the Pacific Northwest of Canada, a region that experiences frequent cool, wet weather during spring and summer. Our study took place during the El Niño – La Niña cycle of 1998–1999, which resulted in contrasting years. The summer of 1998 was unusually warm and dry, while the summer of 1999 was unusually cool and wet. We predicted that both species would be adversely affected by the cool, wet conditions of 1999, resulting in prolonged gestation, late fledging of young, and lower reproductive success. However, this was not the case. Myotis lucifugus did experience delays in reproductive timing and lower reproductive success in 1999, as predicted, whereas M. keenii experienced much shorter gestations, earlier fledgings, and no difference in reproductive success between years. We hypothesize that the ability of M. keenii to glean prey enables it to better cope with cool, wet conditions.

Diet of two insectivorous bats, Myotis lucifugus and Myotis keenii, in relation to arthropod abundance in a temperate Pacific Northwest rainforest environment

We assessed the diet of two morphologically similar bats ( Myotis lucifugus (LeConte, 1831) and Myotis keenii (Merriam, 1895)), which both used hydrothermally heated nursery roosts at Gandll K’in Gwaayaay (Hotspring Island), Haida Gwaii (Queen Charlotte Islands), British Columbia, in 1998 and 1999. Our purpose was to determine if they fed opportunistically or actively selected prey, and whether they partitioned prey resources. We determined diet by analyzing feces collected from captured bats and compared it with the relative abundance of insects captured in light traps. Myotis lucifugus fed mainly on lepidopterans, medium-sized to large dipterans, neuropterans, and hymenopterans, while M. keenii fed on lepidopterans, arachnids, medium-sized to large dipterans, and neuropterans. We found that both species were selecting prey, although selection may have been more a function of prey size than particular taxa. Arachnids occurred in feces of both species, implying that both were capable of gleaning prey from surfaces, although only M. keenii regularly fed on spiders. We concluded from the preponderance of flying insects in the diet of M. lucifugus that it was primarily aerial hawking prey, while we took the frequent occurrence of both flying insects and spiders in the diet of M. keenii to indicate that it was both aerial hawking and gleaning prey. Weather conditions between years affected relative abundance of insects and bat diet, with species diversity being lower in light-trap samples and diet of M. lucifugus in 1999, which was cooler and wetter than in 1998. Species diversity in the diet of M. keenii was higher in 1999. Similarities in diet indicated that some interspecific competition was occurring, although this competition was likely minimized by their different foraging strategies.

Keen's Long-eared Bat, Myotis keenii, confirmed in southeast Alaska

Keen's Long-eared Bat, Myotis keenii, confirmed in southeast Alaska

A review of the distribution and taxonomy of Myotis keenii and Myotis evotis in British Columbia and the adjacent United States

Myotis keenii and M. evotis are sympatric in coastal areas of British Columbia and Washington. Some individuals are morphologically intermediate and cannot be identified confidently. This has raised questions about the correct identification of specimens collected in the area of overlap and the systematic relationship of the two taxa. Multiple discriminant function analysis of 12 cranial and 5 body measurements demonstrated the presence of two morphological groups in the area. The results suggest morphological convergence of the two taxa in Washington and that a number of individuals from western Washington were morphometrically intermediate. The intermediates were provisionally interpreted as representing overlapping intraspecific variation rather than intergradation between the taxa. Analysis of molecular data is required to resolve the systematics of these taxa.

Bat rabies in Illinois: 1965 to 1986.

From 1968 to 1986, Illinois (USA) citizens and agencies submitted 4,272 bats to the Illinois Department of Public Health for rabies testing. Of this number, 6% tested positive, a rate comparable to similar studies from other parts of North America. Due to sampling biases, the true infection rate among bats in Illinois is probably lower than 6%. Additional analysis relied on a subsample (n = 2,433) of the specimens collected from 1965 to 1986. Prevalences were significantly different among years, but no linear trends were found over the study period. Evidence for a local outbreak of bat rabies was found. Prevalences for the species with sample sizes adequate for statistical analysis were, from high to low: hoary bat (Lasiurus cinereus), 11%; red bat (L. borealis), 5%; silver-haired bat (Lasionycteris noctivagans), 4%; little brown bat (Myotis lucifugus), 4%; big brown bat (Eptesicus fuscus), 3%; Keen's bat (Myotis keenii), 2%; and evening bat (Nycticeius humeralis), 2%. The higher prevalences found among the non-colonial species (hoary, red and silver-haired bats) were consistent with similar studies. Considerable annual variation in prevalences was found within species, and the prevalence rankings of the species varied over the study period. Prevalences were significantly higher in females (6%) than in males (4%) when species were pooled, but no significant differences between sexes were found within species. In contrast to the other species analyzed, all of which had sex ratios favoring females, the big brown bat sample had a large majority of males. Prevalences were significantly higher in adults (6%) than in juveniles (3%) when species were pooled. Within individual species, significant differences between age groups were found only for hoary and red bats; in two species, juveniles had higher prevalences. Above average prevalences were observed in May and August to November. Southern Illinois had the highest prevalences; prevalences were intermediate in the north and lowest in the central region. Overall, the patterns of rabies prevalence among bats submitted by the public in Illinois from 1965 to 1986 were similar to those reported from other parts of North America.

Food Habits of Cave-Dwelling Bats in the Central Appalachians

The food habits of four species of cave-dwelling bats, Eptesicus fuscus, Myotis keenii, M. lucifugus, and Pipistrellus subflavus, were investigated in the central Appalachians. Information was based primarily on analysis of fecal pellets; however, some stomachs also were examined for food items for comparison with the first procedure. Coleopterans and hemipterans occurred in more than 70% of the adult male E. fuscus samples. All of the hemipterans were green stink bugs, Acrosternum hilare. More than 50% of the adult male M. keenii samples contained coleopteran, lepidopteran, and neuropteran fragments. The neuropterans were represented by the Hemerobiidae (brown lacewings). Coleoptera, Diptera, and Lepidoptera occurred in more than 50% of the adult male M. lucifugus samples. Fifty percent of the Diptera were midges (Chironomidae). Coleopterans and homopterans were present in more than 50% of the adult male P. subflavus samples. Other important prey items for P. subflavus were dipterans, hymenopterans, and lepidopterans. Adult male M. keenii, M. lucifugus, and P. subflavus captured concurrently differed in their food habits. More male M. keenii samples contained Hemerobiidae and Lepidoptera than did M. lucifugus or P. subflavus samples, whereas adult male M. lucifugus and P. subflavus took prey from the same insect orders and in approximately the same proportion. In general, adult male E. fuscus appeared to be dietary specialists, whereas adult male M. keenii, M. lucifugus, and P. subflavus appeared more generalized in their diets.

Foxtail Entangles Bat

Numerous accidental deaths of bats resulting from impalement on barbed wire (Long, 1964, Trans. Kansas Acad. Sci. 67:201), burdocks (Johnson, 1933, J. Mamm. 14:156-157), and desert plants (Barbour and Davis, 1969, Bats of America, Univ. Press Kentucky, Lexington, 286 pp.) have been reported. However, I know of only one documented instance (Dunaway, 1960, J. Mamm. 41:400) of a bat dying after becoming entangled (in Spanish moss). On 4 September 1981 I found a nearly mummified individual (MHP 19,510) of Keen's myotis (Myotis keenii) at a place I mi. N, 31/2 mi. E Burnside (T.87N, R.28W, NE/4 sec. 12), Webster Co., Iowa. The dorsal pelage of the bat was firmly attached to the seed head of a stalk of green foxtail (Seteria viridis). Close examination revealed that the attachment was made by the bristles (involucre) of the influorescence, which were entangled in the fur. The bat was not impaled. The fact that several of the adjacent stalks of foxtail were matted together suggests the bat struggled vigorously to escape. I have no explanation for how the bat became entangled.

Comparative insulation in vespertilionid bats

1. 1. Physical insulation was examined in five North American bats: Lasiurus borealis. Lasiurus cinereus, Myotis lucifugus, Myotis keenii, and Eptesicus fuscus. 2. 2. Lasiurines were more insulated than the other three species, which appears to be related to the habits of these species; lasiurines are solitary, occupying tree roosts, whereas Myotis and Eptesicus species are colonial and commonly occur in environmentally protected roosts, buildings and caves. 3. 3. Seasonal changes were found to occur in insulation with winter pelts being more insulative than summer ones.

The Mammals of Southwestern Minnesota

Ranges of the 45 wild mammals occurring in southwestern Minnesota are discussed and documented. Eight other species that either formerly occurred there or might, but have not yet been discovered, are also discussed. Seven species are recorded from southwestern Minnesota for the first time: Scalopus aquaticus, Myotis keenii, Laslonycteris noctivagans, Marmota monax, Spermophilus franklinii, Tamiasciurus hudsonicus, and Rattus norvegicus. Trans. Kans. Acad. Sci. Vol. 79 (1-2), 1976. The mammalian fauna of southwestern Minnesota is poorly known. Few published reports have dealt with mammals from this part of the Minnesota prairie lands (most mammal research conducted in the state is carried out in the northern forests). The several accounts of the mammals of Minnesota (Herrick, 1892; Surber, 1932; Swanson, Surber, and Roberts, 1945; Gunderson and Beer, 1953) have been largely based on specimens in the collection of the Bell Museum of Natural History, University of Minnesota; a collection poor in specimens from southwestern Minnesota. During the senior author's three year tenure at Southwest State University, Marshall, he was in charge of building up a representative vertebrate collection for class use and to serve as a beginning of a proposed natural history museum (SMSU). The junior author was his chief assistant and conducted a mammal survey of Redwood County. The present report summarizes information gathered in these endeavors as well as specimens in the Bell Museum (UM); The United States National Museum of Natural History (USNM); Morgan School of Biological Science, University of Kentucky (UK); personal collection, Carl H. Ernst (CHE) and records in the literature (the publication of Gunderson and Beer is abbreviated G&B, 1953). The report includes the area bordered outside by Traverse, Steavens, Pope, and Stearns counties on the north and Wright, McLeod, Sibley, Nicollet, Blue Earth, and Fairbault counties

Helminths from Myotis keenii (Merriam) in Eastern Iowa

Helminths from Myotis keenii (Merriam) in Eastern Iowa

Resource Utilization: Temporal and Spatial Components of Bat Activity in Central Iowa

Foraging activity of insectivorous bats was studied from April through October in central Iowa. Temporal activity was quantified by recording capture times throughout feeding periods, and spatial patterns were examined by measuring the abundance and diversity of species in three contrasting habitats. Six species, Myotis lucifugus, Myotis keenii, Lasionycteris noctimgans, Eptesicus fuscus, Lasiurus borealis, and Lasiurus cinereus, were characterized by initial periods of foraging occurring within 5 hours after sunset. Myotis keenii and L. noctivagans had distinct secondary periods of activity, but other species showed only minor secondary periods, or complete cessation of activity, following the initial foraging period. The modes of initial and secondary activity of L. noctivagans, L. borealis and L. cinereus showed almost complete displacement and corresponded to peak periods of nocturnal insect activity, suggesting a mechanism by which some insectivorous bats may partition environmental resources. Those species showing overlap in temporal foraging (M. keenii and L. noctivagans on the one hand, and M. lucifugus, E. fuscus, and L. borealis on the other) may have evolved spatial strategies to reduce competition for resources. Intraspecific foraging patterns of three species examined may reflect resource partitioning or, alternatively, secondary foraging activity owing to different energy demands of young and lactating females.

Food habits of bats from Indiana

The stomachs of 3 Myotis keenii (Merriam), 16 M. lucifugus (Le Conte), 4 M. sodalis (Miller and Allen), 2 Lasionycteris noctivagans (Le Conte), 23 Pipistrellus subflavus (Cuvier), 184 Eptesicus fuscus (Beauvois), 128 Lasiurus borealis (Müller), 3 L. cinereus (Beauvois), and 2 Nycticeius humeralis Rafinesque were examined. The four most common bats of Indiana used as their most common foods, different major groups of insects, beetles in the case of Eptesicus, moths in Lasiurus borealis and Myotis lucifugus and leaf hoppers in Pipistrellus. Eptesicus fuscus did not appear to feed in winter. Weaning in that species appeared to occur about July 1.

A Concentration of Myotis keenii at Caves in Ohio

A Concentration of Myotis keenii at Caves in Ohio

An Annotated Checklist of Bats from Iowa

Early mention of bats in Iowa is found in publications by Allen (1869), Goding (1883), Osborn (1890, 1892), Van Hyning and Pellet (1910), Cory (1912), and Ruthven and Wood (1912). The occurrence in the state of some species listed in these early accounts evidently was not substantiated by specimens. Scott (1937) in his "Mammals of Iowa" reviewed the status of chiropterans in the state. In this paper, six species (Myotis keenii, Myotis lucifugus, Eptesicus u.rcus, Lasiurus horealis, Lasiurus cinereus, and Tadarida macrotis) were authenticated by actual specimens. Scott (1939) later added Pipistrellus subfiavus to the list of Iowa bats, and also identified as Myotis subulatus the one specimen assigned to M. keenii in 1937. This bat was incorrectly identified by Scott and is discussed in the account of Myotis lucifugus. In the past decade, Muir and Polder (1960) recorded Myotis sodalis from Iowa, Kunz (1966) reported Nycticeius humeralis, and Easterla and Watkins (1967) mentioned the first actual specimens of Lasionycteris noctivagans from the state. The first authentic record of Myotis keenii septentrionalis is reported in this paper. Thus, at this writing, a total of 10 species of bats is known certainly to occur in Iowa. In the past few years there has been increased interest in the study of bats in Iowa. We began investigations independently in the state in 1965 and combined our efforts in 1966. One of us (Kunz) is continuing research on the natural history of several species. In the course of recent work, many bats have been banded and released in an attempt to learn more of movements and longevity. Additionally, workers in adjacent states have banded thousands of bats, some of which already have been recaptured in Iowa. Persons finding banded bats are requested to read the band number carefully, and, if possible, release the bat unharmed. Band numbers should be reported to the Bird and Mammal Laboratories, U. S. Fish and Wildlife Service, U. S. National Museum, Washington, D. C. 20560, along with the exact date and place of capture. This paper represents a progress report of our studies and includes specimens obtained by us, those deposited in other institutions, records of

Bats Hibernating in Silica Mines in Southern Illinois

while conducting field investigations of rabies in wildlife, 356 hibernating bats of six species were observed in twenty-four of thirty-five silica mines searched. Mine shafts extended horizontally into hillsides, and varied from a few feet to an estimated 450 feet or more in depth. Sex ratios and representative measurements of 183 bats were obtained. Temperatures at 83 hibernation sites were recorded; these ranged from 30° to 56°F. There was a significant difference between mean temperatures at hibernation sites of a group consisting of Pipistrellus subflavus, Myotis keenii , and Myotis lucifugus , and a group including Eptesicus fuscus, Plecotis rafinesquii , and Lasionycteris noctivagans . The last two species are considered uncommon in Illinois, but 13 P. rafinesquii were observed in nine mines, and 18 L. noctivagans were found in eight of the twenty-four mines having bats.