164 research outputs found
Mammals of Carlsbad Caverns National Park, New Mexico
Carlsbad Cavern was established as a national park on 14 May 1930, after being designated as a national monument for nearly seven years. The park is located in southeastern New Mexico, and today it encompasses 189.3 km2 (73.1 mi2). Eighty-eight percent of the park lies in the rugged Guadalupe Mountains, while 12% is located on relatively flat land along the base of the mountains. The park contains a variety of habitats ranging from desert scrub at the lowest elevations to coniferous woodlands on the highest summits. Five months after Carlsbad Cavern was declared a national monument, Vernon Bailey conducted a survey of animals in the cavern and surrounding lands. The survey lasted from March to May 1924, and results were published in a monograph titled Animal Life of the Carlsbad Cavern (Bailey 1928). During his survey, Bailey documented 39 species of mammals within the present-day boundaries of Carlsbad Caverns National Park. Approximately 50 years after Bailey’s survey, we conducted surveys of mammals in the park (1973-2000), and results of our surveys are the basis for the present volume. Herein we also report and summarize information from Bailey’s book, other scientific literature, museum specimens, field notes of previous investigators, park documents, and interviews with people associated with the park.
Since Bailey’s survey in 1924, several species of mammals have been extirpated from the park, several species are now present due to introductions by humans, and many others have been confirmed in the park that were not detected by Bailey. In recent years (1949-2000), 63 species of mammals (excluding humans and their domestic animals) have been documented in the park—1 shrew, 15 bats, 2 lagomorphs, 27 rodents, 13 carnivores, and 5 ungulates. For 58 species, records exist from 1990 to 2000. The most recent records for the remaining five species are as follows: western spotted skunk (Spilogale gracilis) 1985, pronghorn (Antilocapra americana) 1965, pocketed free-tailed bat (Nyctinomops femorosaccus) 1956, big free-tailed bat (Nyctinomops macrotis) 1956, and house mouse (Mus musculus) 1949. The present volume includes a descriptive narrative for each of the 63 contemporary species of mammals. We also provide accounts for five species that were extirpated during the past 150 years and for another 11 species with uncertain status. For contemporary species, accounts include detailed information on habitat, reproduction, and collection localities. A distribution map also is available for most species. In addition, we discuss changes in population size or shifts in distribution for the following 12 species: Brazilian free-tailed bat (Tadarida brasiliensis), black-tailed prairie dog (Cynomys ludovicianus), banner-tailed kangaroo rat (Dipodomys spectabilis), Merriam’s kangaroo rat (D. merriami), whitefooted mouse (Peromyscus leucopus), southern plains woodrat (Neotoma micropus), house mouse (Mus musculus), collared peccary (Pecari tajacu), elk (Cervus canadensis), pronghorn (Antilocapra americana), bighorn sheep (Ovis canadensis), and aoudad (Ammotragus lervia). Carlsbad Caverns National Park is one of the most ecologically diverse parks in the United States, and we hope that information in this volume will stimulate additional research on mammals and other organisms in the park. Understanding the distribution, abundance, and types of plants and animals on public lands is important because it provides necessary information for making sound management decisions and for designing accurate interpretive programs for education of the general public
Photographic techniques for enhancing ERTS MSS data for geologic information
Satellite multispectral black-and-white photographic negatives of Luna County, New Mexico, obtained by ERTS on 15 August and 2 September 1973, were precisely reprocessed into positive images and analyzed in an additive color viewer. In addition, an isoluminous (uniform brightness) color rendition of the image was constructed. The isoluminous technique emphasizes subtle differences between multispectral bands by greatly enhancing the color of the superimposed composite of all bands and eliminating the effects of brightness caused by sloping terrain. Basaltic lava flows were more accurately displayed in the precision processed multispectral additive color ERTS renditions than on existing state geological maps. Malpais lava flows and small basaltic occurrences not appearing on existing geological maps were identified in ERTS multispectral color images
First reproductive evidence for the Slender Glass Lizard (\u3ci\u3eOphisaurus attenuatus\u3c/i\u3e) in Nebraska
The Slender Glass Lizard (Ophisaurus attenuatus) reproduces across parts of northern and central Kansas, but its distribution extends into southern Nebraska. In Nebraska, not a single aspect of reproductive activity has been reported for this species in the state. Herein, we report on the first documentation of reproduction in Nebraska. On 22 September 2021, we captured two hatchling Slender Glass Lizards at the Ash Grove Wildlife Management Area in Franklin County, Nebraska. We calculated that those individuals likely hatched around the first week of September. Presence and reproduction of Slender Glass Lizards at the study site likely was associated with ungrazed grasslands. Although Slender Glass Lizards were listed as extinct in the state prior to 2009 due to a lack of sightings for decades, a few recent observations have been reported in southern counties bordering Kansas. In Nebraska, additional surveys and studies are required to better understand the distribution and requirements for this species of conservation need in the state
Bats in a Human-made Forest of Central Nebraska
Increases in wooded habitats have led to expansion in distributions of woodland mammals in the Great Plains. Herein, I report on the occurrence of bats in a human-made forest consisting of over 8,000 hectares in central Nebraska. The forest consisted of monocultures of ponderosa pine (Pinus ponderosa), eastern red cedar (Juniperus virginiana), and jack pine (Pinus banksiana). Individuals of the eastern red bat (Lasiurus borealis) and hoary bat (L. cinereus) were captured in coniferous plantations during summer, and females of both species bore and raised young in the area. The silver-haired bat (Lasionycteris noctivagans) also was captured in plantations but only in spring and early autumn, which suggests that plantations were used as stopover sites during migration. The big brown bat (Eptesicus fuscus) was observed roosting on human-made structures from April to November in riparian woodlands, and none was captured in plantations. Lastly, captures of two western small-footed myotis (Myotis ciliolabrum) on a building in a riparian woodland represent the first records of this species in central Nebraska. Thus, afforestation of grassland habitats in the Sandhill Region of central Nebraska has provided habitat for migratory species such as L. borealis, L. cinereus, and L. noctivagans
Frequency, semantic, and functional characteristics of discontinuous formulaic language: A learner corpus study
This dissertation investigates the frequency, semantic, and functional characteristics of recurring discontinuous formulaic language in a learner corpus of argumentative and literary essays. Discontinuous sequences of words, or ‘frames’, are recurrent sequences of words that have one or more variable slots. For example, in the * of and it is * to, where the asterisks represent variable slots in the sequences of words. A corpus of English argumentative essays authored by native speakers of English, Japanese, and Spanish is analyzed using modern methods in corpus linguistics to determine which frames are used frequently. Frequent frames are compared between the L1 groups to investigate trends in structure, frequency, and variability.
The focus of analysis then narrows to a group of 30 recurring frames comprised of only function words, that is, function word frames such as in the * of, the * of the, and to the * that. The 30 frames are grouped based on structural characteristics, such as noun and preposition-based frames, for further analysis to better understand their semantic and functional characteristics. A lexical database is used to explore the semantic characteristics of fillers of the frames. To determine discourse functions of all instances of each of the 30 target frames, a well-known taxonomy previously applied to continuous sequences of words is adapted and applied to the present context. Discourse functions of the frames are then used as dependent variables in a multinomial logistic regression conducted with four distinct predictor variables: (1) L1, (2) proficiency level, (3) topic of essay, and (4) specific frame. The purpose of the regression is to see which predictor best accounts for discourse function fulfilled by frames from the structural groups.
Findings from the various analyses first indicate that Japanese learners of English use function word frames at far lower rates than the L1 English and Spanish speakers. Secondly, fillers of the structural groups of function word frames tend to be abstract nouns and the frames largely serve the discourse function of intangible framing of a following noun phrase. In terms of predictor variables, the frames themselves, particularly prepositions, best predict discourse function. The results lend support to the idea that function words, despite carrying little meaning in isolation, are semantically motivated and systematically contribute meaning to larger sequences of words. Pedagogical implications of this study include the teaching of function words from a more phraseological perspective as well as highlighting the connection between frames, fillers, and discourse functions
Small mammals in cornfields and associated peripheral habitats in central Nebraska
In the Great Plains, many native grasslands have been converted to agricultural fields during the last two centuries. Peripheral habitats along edges of crop fields generally consist of linear habitats along roads, with many of these habitats used by native fauna. Our study examined capture rates and species composition of small mammals in cornfields, herbaceous roadside ditches, and wooded shelterbelts in central Nebraska. We captured nine species of small mammals. The Prairie Vole (Microtus ochrogaster) and Western Harvest Mouse (Reithrodontomys megalotis) were captured almost exclusively in roadside ditches, the White-footed Deermouse (Peromyscus leucopus) was captured most often in wooded shelterbelts, and the North American Deermouse (Peromyscus maniculatus) was common to abundant in all three habitats. Capture rates of small mammals were greatest in roadside ditches and least in cornfields. Herbaceous roadside ditches contained the greatest species richness with seven species, whereas shelterbelts and cornfields each had five species. Species composition of rodents differed in shelterbelts comprised solely of eastern red-cedars (Juniperus virginiana) compared to those with a mixture deciduous and coniferous trees. Our study demonstrated that roadside ditches associated with agricultural fields serve as habitats for many prairie species whereas wooded shelterbelts along agricultural fields support both woodland and prairie species in central Nebraska. Cornfields mainly were inhabited by North American Deermice but did not support many other species of small mammals. Although agricultural practices have reduced the quantity of grasslands for prairie species across the region, habitats associated with periphery of fields appear to serve as alternative habitats for small mammals throughout the Great Plains
Importance of woodland patches as hibernacula for gartersnakes in a prairie river floodplain of central Nebraska
Gartersnakes are common inhabitants along prairie rivers in the Great Plains, but little information is known about hibernacula among diverse floodplain habitats. We radio-tracked Common Gartersnakes (Thamnophis sirtalis) and Plains Gartersnakes (Thamnophis radix) to hibernacula on islands in a braided river system subject to frequent environmental changes along the Platte River in central Nebraska. We further examined capture rates of gartersnakes in floodplain woodland patches from June to November to examine seasonal use of this habitat. In early and mid-September, movements of snakes with transmitters were in grasslands. From late September to mid-October, the farthest movements were documented, and snakes moved from grasslands into woodland patches. From late October to January, movements were minimal in and around hibernacula in wooded or formerly wooded habitats. Capture rates of gartersnakes in woodland trapping arrays also increased in October and November, further demonstrating woodland use during times when snakes travel to and reside at hibernacula. Although grasslands comprised most of the prairie islands at the study area, observations suggested that the limited woodlands on these islands are important for gartersnakes prior to and during hibernation along the Platte River in central Nebraska. Areas with large trees, such as Plains Cottonwoods (Populus deltoides), appeared to provide overwintering sites. In central Nebraska, riparian woodlands continue to be cleared to enhance habitat for endangered and threatened species such as Whooping Cranes (Grus americana), but some of these islands originally contained trees prior to European settlement. Conservation of at least some woodland habitats appears important for overwintering gartersnakes in central Nebraska
Reexamination of Herpetofauna on Mormon Island, Hall County, Nebraska, with Notes on Natural History
The Platte River in central Nebraska, USA, was historically surrounded by mixed grass and tallgrass prairies and wet meadows, but many of those habitats were lost or altered during the last century with unknown effects on animals that reside in them. Researchers first surveyed herpetofauna on part of a large island preserve in the Platte River, Mormon Island, Hall County, Nebraska, in 1980 when the land was protected for conservation. They documented 10 species, including three species of amphibians and seven species of reptiles. We inventoried herpetofauna after 30 years of conservation management on Mormon Island and adjacent Shoemaker Island. We captured four species of amphibians and 11 species of reptiles, including five species not detected in the previous survey. New species documented on the preserve were the Bullfrog (Lithobates catesbeianus), Eastern Racer (Coluber constrictor), Smooth Green Snake (Liochlorophis vernalis), Redbelly Snake (Storeria occipitomaculata), and Lined Snake (Tropidoclonion lineatum). Smooth Green Snakes represent a new county record, and Redbelly Snakes represent the easternmost published distributional limit for this disjunct population in central Nebraska. Documentation of additional snake species likely reflects a more intensive trapping regime and possibly habitat changes since 1980. Presence of Bullfrogs on Mormon Island probably was linked to excavation of a backwater slough that created a site for overwintering tadpoles. Herein we describe the variable life-history characteristics, habitats, and seasonal activity patterns among these 15 species of herpetofauna on the large river islands. We also discuss how restoration activities and hydrologic changes may influence the presence and abundance of herpetofauna in the region. Understanding the occurrence, habitat use, and seasonality of amphibians and reptiles in this topographically unaltered (i.e., unplowed) reach of river will aid in managing the central Platte River ecosystem to protect and maintain its biological integrity for all organisms
DISTRIBUTION, DIET, AND PREVALENCE OF AMPHIBIAN CHYTRID FUNGUS IN NON-NATIVE AMERICAN BULLFROGS (LITHOBATES CATESBEIANUS) AT THE VALENTINE NATIONAL WILDLIFE REFUGE, NEBRASKA, USA
American Bullfrogs (Lithobates catesbeianus) have been widely introduced beyond their native range in North America and can negatively affect organisms in wetland environments via a suite of mechanisms including interspecific interactions and disease transmission. Bullfrogs were introduced to the Valentine National Wildlife Refuge in the Sandhill Region of Nebraska, USA, yet little is known regarding their distribution, abundance, and potential effects on other vertebrates in the Refuge. Surveys in 1991-1992 documented bullfrogs in only one lake by the Refuge headquarters, and anecdotal historical observations indicated that bullfrogs were present primarily in lakes open to public fishing. In 2012, we determined the distribution of bullfrogs across the Refuge, examined their diets, and sampled them for the occurrence of the pathogenic fungus, Batrachochytrium dendrobatidis. We documented that bullfrogs were almost ubiquitous across the Refuge lakes and wetlands. From diet analyses, we observed that adult bullfrogs consumed several vertebrate species on the Refuge including: a Blanding’s Turtle (Emydoidea blandingii), small bullfrogs, an unidentifiable frog species, and numerous invertebrates, including crayfish. The amphibian chytrid fungus was prevalent on the refuge with 73.7% of bullfrogs testing positive for the fungus in early June and 6.3% in late June-July. Preliminary data indicate that bullfrogs likely have already affected interspecific interactions with native amphibians via predation, competition, and/or disease transmission. Bullfrogs likely cannot be eradicated from the Refuge, but expanding the season of harvest of bullfrogs might reduce their abundance, which may benefit native amphibians and reptiles
Status of the Plains Harvest Mouse (\u3ci\u3eReithrodontomys montanus griseus\u3c/i\u3e) in eastern Nebraska
In eastern Nebraska, current status of the Plains Harvest Mouse (Reithrodontomys montanus griseus) is not well understood. Infrequent captures during the last century have led to a paucity of information regarding this taxon, and some researchers postulate that its distribution has contracted in the state. In 2008, we conducted a field survey for R. m. griseus in eastern Nebraska, amassed prior specimen records, and examined most of the specimens for this subspecies from the state to better understand its distribution, natural history, and subspecific status. In our field efforts, we only captured a single individual despite \u3e 8,000 trap nights in suitable habitats. Our literature review and queries for vouchers yielded 20 specimens of R. m. griseus from eastern Nebraska, based on published distributional limits for this subspecies. In eastern Nebraska, R. m. griseus has been captured in tallgrass prairies, short-grass upland pastures, roadside ditches, and open areas associated with salt flats. Observations across eastern Nebraska in the last 40 years demonstrate that this taxon still exists across the entire region and has been captured more frequently in cooler months. We suspect that some combination of low abundance, trap shyness, and trapping biases towards heavily vegetated habitats and warm seasons likely has led to infrequent captures of R. m. griseus in eastern Nebraska. After examination of many museum specimens of this species from across Nebraska, Kansas, and Missouri, we questioned the delineations in distribution for the two subspecies in the region. On the basis of dorsal gray fur coloration, R. m. albescens appears limited to the Sandhill and Panhandle regions of Nebraska, whereas all of eastern and southern Nebraska as well as Kansas and western Missouri represent R. m. griseus, a subspecies with brown dorsal fur coloration. Based on our proposed distributional changes for these two subspecies in Nebraska, we do not find that either subspecies requires conservation efforts. Reithrodontomys montanus griseus likely will persist at low densities throughout eastern Nebraska in appropriate habitats and persist at higher densities farther westward in southern parts of the state. Reithrodontomys montanus albescens always has been more common in the Sandhill Region of Nebraska, as individuals still are observed and captured with regularity
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