64 research outputs found

    Small mammals in cornfields and associated peripheral habitats in central Nebraska

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    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

    Reexamination of Herpetofauna on Mormon Island, Hall County, Nebraska, with Notes on Natural History

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    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

    Whooping Cranes Consume Plains Leopard Frogs at Migratory Stopover Sites in Nebraska

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    Whooping cranes (Grus americana) currently consist of a single, wild population that migrates annually from breeding grounds at Wood Buffalo National Park, Canada, to wintering grounds on and around the Aransas National Wildlife Refuge along the Texas coast, USA (NRC 2005). This population reached a low of less than 20 individuals in 1941 (Allen 1952) but has rebounded to over 250 individuals (Chavez-Ramirez and Wehtje 2012, Gil-Weir et al. 2012). Whooping cranes migrate approximately 4,000 km each spring and autumn, traversing much of the North American Great Plains (Lewis 1995) and periodically landing along rivers, wetlands, and other shallow bodies of water for short-duration stopovers (Austin and Richert 2001). Our observations represent some of the few published accounts of a frog species being consumed by whooping cranes along the Central Flyway

    Spatial analysis of borrow pits along the Platte River in south-central Nebraska, USA, in 1957 and 2016

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    The Central Platte River Valley (CPRV) of Nebraska provides critical habitat for wildlife, while serving agricultural, indusĀ­trial, and other human uses. Mining of sand and gravel from the floodplain of the Platte River has supported construction of roads and other uses, and this extraction has created many borrow-pit ponds, lakes, and other small bodies of standing water (hereafter borrow-pits), further transforming riparian and prairie habitats. The objective of this study was to compare the abundance, size, and distribution of borrow pits before construction of Interstate 80 (1957) and at present (2016) from Lexington to Chapman, Nebraska, a length of river spanning about 146 km (90 mi) and sometimes referred to as the Big Bend Reach. Orthorectified aerial imagery of the Platte River was obtained for years 1957 and 2016, and we digitized the standing bodies of water within the floodplain in ArcĀ­GIS. Total numbers of borrow pits and measures of pit shape were calculated and compared between floodplain regions where imĀ­agery overlapped. From 1957 to 2016, the number of borrow pits increased from 300 to 786, total area occupied by pits expanded by 538%, and total shoreline of pits increased by 261%. In 2016, aerial imagery was available for a larger extent of the floodplain and contained a total of 1,062 borrow pits covering 16 km2 (6 mi2), with a total shoreline of 581 km (361 mi). For context, the Platte River channelsā€™ approximate area was 45 km2 (17 mi2) and shoreline 1,582 km (983 mi) between Lexington and Chapman, Nebraska, in 2016. Results provide insight into historical and current presence, distribution, and shape of borrow pits along the Platte River, as well as serve as a reference point for future studies investigating regional landscape change and ecological effects of creating hunĀ­dreds of borrow pits on the floodplain

    Mammals of Nebraska: Checklist, Key, and Bibliography

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    The Recent mammalian fauna of Nebraska is composed of 89 native species, 8 domestic species that can have feral populations, and 4 wild species introduced by humans, but not by intentional action. Thus, the included checklist and dichotomous key contain 101 species of mammals. Of the native species, 36 are rodents, 20 carnivores, 13 bats, 7 shrews and mole, 7 even-toed ungulates, 4 rabbits and hares, 1 armadillo, and 1 opossum. Another 8 species are identified as potentially occurring in peripheral areas of Nebraska. The bibliography includes 1693 entries that each contain data concerning one or more species of mammals from Nebraska

    Longā€term monitoring and experimental manipulation of a Chihuahuan desert ecosystem near Portal, Arizona (1977ā€“2013)

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    Desert ecosystems have long served as model systems in the study of ecological concepts (e.g., competition, resource pulses, topā€down/bottomā€up dynamics). However, the inherent variability of resource availability in deserts, and hence consumer dynamics, can also make them challenging ecosystems to understand. Study of a Chihuahuan desert ecosystem near Portal, Arizona began in 1977. At this site, 24 experimental plots were established and divided among controls and experimental manipulations. Experimental manipulations over the years include removal of all or some rodent species, all or some ants, seed additions, and various alterations of the annual plant community. This dataset includes data previously available through an older data publication and adds 11Ā years of data. It also includes additional ant and weather data not previously available. These data have been used in a variety of publications documenting the effects of the experimental manipulations as well as the response of populations and communities to longā€term changes in climate and habitat. Sampling is ongoing and additional data will be published in the future.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146431/1/ecy1360.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146431/2/ecy1360_am.pd

    Soil foraging animals alter the composition and co-occurrence of microbial communities in a desert shrubland

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    Animals that modify their physical environment by foraging in the soil can have dramatic effects on ecosystem functions and processes. We compared bacterial and fungal communities in the foraging pits created by bilbies and burrowing bettongs with undisturbed surface soils dominated by biocrusts. Bacterial communities were characterized by Actinobacteria and Alphaproteobacteria, and fungal communities by Lecanoromycetes and Archaeosporomycetes. The composition of bacterial or fungal communities was not observed to vary between loamy or sandy soils. There were no differences in richness of either bacterial or fungal operational taxonomic units (OTUs) in the soil of young or old foraging pits, or undisturbed soils. Although the bacterial assemblage did not vary among the three microsites, the composition of fungi in undisturbed soils was significantly different from that in old or young foraging pits. Network analysis indicated that a greater number of correlations between bacterial OTUs occurred in undisturbed soils and old pits, whereas a greater number of correlations between fungal OTUs occurred in undisturbed soils. Our study suggests that digging by soil-disturbing animals is likely to create successional shifts in soil microbial and fungal communities, leading to functional shifts associated with the decomposition of organic matter and the fixation of nitrogen. Given the primacy of organic matter decomposition in arid and semi-arid environments, the loss of native soil-foraging animals is likely to impair the ability of these systems to maintain key ecosystem processes such as the mineralization of nitrogen and the breakdown of organic matter, and to recover from disturbance

    Evidence of Latitudinal Migration in Tri-colored Bats, Perimyotis subflavus

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    Background: Annual movements of tri-colored bats (Perimyotis subflavus) are poorly understood. While this species has been considered a regional migrant, some evidence suggests that it may undertake annual latitudinal migrations, similar to other long distance North American migratory bat species. Methodology/Principal Findings: We investigated migration in P. subflavus by conducting stable hydrogen isotope analyses of 184 museum specimen fur samples and comparing these results (dDfur) to published interpolated dD values of collection site growing season precipitation (dDprecip). Results suggest that the male molt period occurred between June 23 and October 16 and 33 % of males collected during the presumed non-molt period were south of their location of fur growth. For the same time period, 16 % of females were south of their location of fur growth and in general, had not travelled as far as migratory males. There were strong correlations between dDfur from the presumed molt period and both growing season dD precip (males ā€“ r 2 = 0.86; p,0.01; females ā€“ r 2 = 0.75; p,0.01), and latitude of collection (males ā€“ r 2 = 0.85; p,0.01; females ā€“ r 2 = 0.73; p,0.01). Most migrants were collected at the northern (.40uN; males and females) and southern (,35uN; males only) extents of the species ā€™ range. Conclusions/Significance: These results indicate a different pattern of migration for this species than previously documented, suggesting that some P. subflavus engage in annual latitudinal migrations and that migratory tendency varie

    Carrion Availability in Space and Time

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    Introduction Availability of carrion to scavengers is a central issue in carrion ecology and management, and is crucial for understanding the evolution of scavenging behaviour. Compared to live animals, their carcasses are relatively unpredictable in space and time in natural conditions, with a few exceptions (see below, especially Sect. ā€œCarrion Exchange at the Terrestrial-Aquatic Interfaceā€). Carrion is also an ephemeral food resource due to the action of a plethora of consumers, from microorganisms to large vertebrates, as well as to desiccation (i.e., loss of water content; DeVault et al. 2003; Beasley et al. 2012; Barton et al. 2013; MoleĆ³n et al. 2014). With a focus on vertebrate carcasses, here we give an overview of (a) the causes that produce carrion, (b) the rate of carrion production, (c) the factors affecting carrion quality, and (d) the distribution of carrion in space and time, both in terrestrial and aquatic environments (including their interface). In this chapter, we will focus on naturally produced carrion, whereas non-natural causes of animal mortality are described in chapter ā€œHuman-Mediated Carrion: Effects on Ecological Processesā€. However, throughout this chapter we also refer to extensive livestock carrion, because in the absence of strong restrictions such as those imposed in the European Community after the bovine spongiform encephalopathy crisis (DonĆ”zar et al. 2009; Margalida et al. 2010), the spatiotemporal availability of carrion of extensive livestock and wild ungulates is similar
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