The American Midland Naturalist

Articles from Vol. 156, No. 1, July

Abundance of the Long-Nosed Leopard Lizard (Gambelia Wislizeni) Is Influenced by Shrub Diversity and Cover in Southeast Oregon
ABSTRACT.-The abundance and distribution of animal species appears to be limited by availability of suitable habitat, and often a critical component to these suitable habitats is the presence of one or more particular plant species, and/or plant species...
An Evaluation of Pollination Mechanisms for Purple Prairie-Clover, Dalea Purpurea (Fabaceae: Amorpheae)
ABSTRACT.-Purple prairie-clover (Dalea purpurea Ventenat) is a common perennial forb that flowers during mid-summer throughout the Great Plains and adjacent biomes. Seed of D. purpurea is used for prairie restoration. This study characterizes the reproductive...
Archaeological Evidence of Anthropogenically Induced Twentieth-Century Diminution of North American Wapiti (Cervus Elaphus)
ABSTRACT.-Translocated Rocky Mountain wapiti (Cervus elaphus nelsoni) released in the southern Cascade Range of Washington State in the early twentieth century hybridized with resident Roosevelt wapiti (C. e. roosevelti). Archaeological remains of wapiti...
A Test of Philopatry by Common Musk Turtles
ABSTRACT.-We tested philopatry by common musk turtles Sternotherus odoratus in a Virginia lake for 9 wk during summer 2003. Using unbaked crab pots, 10 trapping sites were established in the littoral zone around the lake perimeter and pots were sampled...
Densities and Habitat of American Brook Lamprey (Lampetra Appendix) Larvae in Minnesota
ABSTRACT.-At least one formerly large population of American brook lamprey (Lampetra appendix) has been extirpated in Minnesota, but little is known about the species in the state. We examined densities and age structures of American brook lamprey larvae...
Diatom Genus Diversity and Assemblage Structure in Relation to Salinity at the Salt Plains National Wildlife Refuge, Alfalfa County, Oklahoma
ABSTRACT.-Despite the common geographic occurrence of inland (athalassic) saline habitats, their biota has not been extensively studied. Diatoms have been estimated to contribute as much as 25% to the earth's primary production (Werner, 1977). However,...
Dynamics of Epikarst Communities: Microgeographic Pattern and Environmental Determinants of Epikarst Copepods in Organ Cave, West Virginia
ABSTRACT.-The copepod community occurring in the uppermost part of karst was investigated by collecting animals from 13 ceiling drips in Organ Cave, West Virginia, over a 30 d period. A total of 444 copepods belonging to six genera and ten species were...
Effects of Blowdown on Small Mammal Populations
ABSTRACT.-Over 150,000 ha of standing forest was altered as a result of a large-scale blowdown in the Boundary Waters Canoe Area Wilderness, Minnesota in 1999. We collected data in summers 2000 and 2001 to assess the effects of windthrow perturbation...
Expansion of Round Goby in the Illinois Waterway
ABSTRACT.-Round goby Neogobius melanostomus is expanding its range within Illinois. Prior to 2004, the round goby existed primarily in the Lake Michigan waters of Illinois and was slowly moving inland via the Illinois Waterway. Two fish community monitoring...
Food Habits of Louisiana Black Bears (Ursus Americanus Luteolus) in Two Subpopulations of the Tensas River Basin
ABSTRACT.-The Louisiana black bear (Ursus americanus luteolus) is listed federally as a threatened subspecies and current information about food habits is necessary for developing a sound conservation strategy. We collected and analyzed 251 scats from...
Food Habits of the Federally Threatened Leopard Darter (Percina Pantherina)
ABSTRACT.-We examined food habits of the federally threatened leopard darter in six rivers in southeastern Oklahoma and southwestern Arkansas using guts collected from 1994 to 1997. The families Baetidae and Chironomidae were the most common food items...
Genetic Variation and Genetic Structuring of a Numerically Declining Species of Darter, Etheostoma Moorei Raney & Suttkus, Endemic to the Upper Little Red River, Arkansas
ABSTRACT.-Gene products of 17 putative loci were analyzed to determine the genetic diversity for 85 individuals of Etheostoma moorei Raney & Suttkus, a darter species endemic to Arkansas, that has been subjected to severe habitat and numerical decline....
Isolating the Effects of White-Tailed Deer on the Vegetation Dynamics of a Rare Maritime American Holly Forest
ABSTRACT.-Effects of multiple herbivores were isolated in a rare, old-growth, maritime forest that has been affected by high white-tailed deer (Odocoileus virginianus) populations for several decades. Three decades of change in the plant community was...
Landscape Associations of Road-Killed Virginia Opossums (Didelphis Virginiana) in Central Massachusetts
ABSTRACT.-Knowing the distribution of species at the landscape level can give insight into the proximate mechanisms determining the species' range on a regional scale. We used a survey of road-killed animals to investigate landscape features associated...
Late Seasonal Breeding of River Otters in Yellowstone National Park
ABSTRACT.-Seasonal breeding schedules for wild mammals, such as North American river otters (Lontra canadensis), often vary across their range. Previous studies in temperate regions found that river otters typically breed in March and April. Here we...
Life History and Environmental Factors Influence Population Density and Stage Structure in Hydrophyllum Brownei
ABSTRACT.-Hydrophyllum brownei is a rare endemic species restricted to the Ouachita Mountains of Arkansas. One objective of this study was to model H. brownie population density by investigating the influence of sun exposure, soil characteristics and...
Natural History of Mass-Action in Predator-Prey Models: A Case Study from Wolf Spiders and Grasshoppers
ABSTRACT.-Mass-action models of predator-prey interactions assume that predators encounter prey according to their relative densities as scaled by functional responses, although models seldom specify critical natural history and behavioral mechanisms...
Site Characteristics of River Otter (Lontra Canadensis) Natal Dens in Minnesota
ABSTRACT.-Knowledge of the habitat and spatial characteristics of natal dens used by female river otters (Lontra canadensis) is limited to a few observations. Documentation of these characteristics in human-altered landscapes may improve management opportunities...
Spatial and Temporal Variation of Goldstripe Darter Abundance in First-Order Streams in North-Central Mississippi
ABSTRACT.-Little is known about the spatial and temporal dynamics of abundance and habitat use of the goldstripe darter (Etheostoma parvipinne). We assessed population dynamics, species associates and habitat use of this rarely studied darter in 14 first-order...
Swine Activity Alters Invertebrate and Microbial Communities in a Coastal Plain Watershed
ABSTRACT.-Swine (Sus scrofa Linnaeus) are an invasive species with a negative impact on native terrestrial plant and animal diversity. Further, in its native range, excessive population size has been perceived as a potential problem. The effects of swine...
Use of Stable Isotopes to Test Literature-Based Trophic Classifications of Small-Bodied Stream Fishes
ABSTRACT.Defining the trophic position of stream organisms is a first step in understanding the ecology of lotic systems. Whereas trophic positions of stream fishes have been traditionally assigned based on dietary analysis, stable isotope ratios may...
Variation in the Echolocation Calls of Little Brown Bats (Myotis Lucifugus) in Response to Different Habitats
ABSTRACT.-Among different bat species, echolocation call structure varies predictably according to habitat use. Much of this interspecific variation in echolocation calls reflects the physical constraints of sound propagation and echo formation in open...