Open Access. Powered by Scholars. Published by Universities.®

Terrestrial and Aquatic Ecology Commons

Open Access. Powered by Scholars. Published by Universities.®

Population Biology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1831 - 1860 of 1892

Full-Text Articles in Terrestrial and Aquatic Ecology

Estructura Del Ovario De Chthonerpeton Indistinctum (Reinhardt Y Lutken, 1862) (Amphibia: Gymnophiona) Durante La Gestación, Rafael O. De Sá, Nibia Berois Jan 1985

Estructura Del Ovario De Chthonerpeton Indistinctum (Reinhardt Y Lutken, 1862) (Amphibia: Gymnophiona) Durante La Gestación, Rafael O. De Sá, Nibia Berois

Biology Faculty Publications

La morfología e histología del ovario para varias especies del orden Gymnophiona ha sido reportada por Wake (1968, J. Morphol. 126, 291) y para C. indistinctum por los autores (1984, XXIV Reunión de Comunicaciones, Soc. Zool. Uruguay).

Continuando con los estudios sobre el aparato genital de esta especie vivípara, se presenta ahora la estructura del ovario durante la gestación.

Se procesaron con fines histológicos, ovarios de dos hembras grávidas colectadas en las costas de los Dep. Montevideo y San José en abril, 1983. El número de ejemplares trabajados es muy reducido dado lo difícil que resulta su colecta …


Demographic Analysis And Microhabitat Relationships Of A Small Mammal Community In Clearings Of The Great Dismal Swamp, Jean Ferguson Stankavich Oct 1984

Demographic Analysis And Microhabitat Relationships Of A Small Mammal Community In Clearings Of The Great Dismal Swamp, Jean Ferguson Stankavich

Biological Sciences Theses & Dissertations

Small mammals were trapped for 14 months on two grids located within a powerline right-of-way in the Great Dismal Swamp National Wildlife Refuge. During 12,354 trap nights, individuals of 10 different species were captured. They included, from highest to lowest density, Reithrodontomys humulis, Ochrotomys nuttalli, Peromyscus leucopus, Blarina brevicauda, Synaptomys cooperi, Microtus pennsylvanicus, Microtus pinetorum, Sigmodon hispidus, Mus musculus and Oryzomys palustris. The demography (densities, reproduction, home range and dispersal) of each species was analyzed when possible. Most of the species were present in relatively low densities, with a number being captured only during the latter months of the study. …


Activity Levels Of Arboreal Rodents Peromysus And Ochrotomys Evaluated With Nest Cans In Seasonally Flooded Forests, John W. Walke Jul 1984

Activity Levels Of Arboreal Rodents Peromysus And Ochrotomys Evaluated With Nest Cans In Seasonally Flooded Forests, John W. Walke

Biological Sciences Theses & Dissertations

The diversity and density of small mammals in the Dismal Swamp are believed to be small. To test this, four 1.96 ha grids were established and operated in the Dismal Swamp National Wildlife Refuge, from September 1981 to November 1982. Number 10 metal cans covered with plastic lids were placed as nest boxes at 0.5 to 1.5 m height on trees. A 2.5 cm hole allowed access by arboreal rodents, to each nest can. The activity level of the two arboreal rodents, Peromyscus leucopus and Ochrotomys nuttalli, was evaluated by observing types of activity ranging from presence of mice to …


Life History Aspects Of Reithrodontomys Humulis In Southeastern Virginia, Michelle Cawthorn Chandler Jul 1984

Life History Aspects Of Reithrodontomys Humulis In Southeastern Virginia, Michelle Cawthorn Chandler

Biological Sciences Theses & Dissertations

Reithrodontomys humulis, the eastern harvest mouse, is a small cricetid rodent which is common in old field communities in the eastern U.S. A live-trapping study was conducted in Suffolk, Virginia from March 1983 through February 1984 in order to learn the details of its life history and the vegetational characteristics which best describe its microhabitat. Specifically, population densities, trap-revealed survival times, home ranges, plant species composition of the study area, and vegetational structure were examined. In order to trap as many Reithrodontomys as possible, special traps which excluded animals weighing over 20 g were constructed. Densities of harvest mice …


The Role Of Colonization Predation And Season In Determining Macroinvertebrate Community Structure In A Temperate Lake, Cheryl Lynn Frew Jul 1984

The Role Of Colonization Predation And Season In Determining Macroinvertebrate Community Structure In A Temperate Lake, Cheryl Lynn Frew

Biological Sciences Theses & Dissertations

Field experiments were conducted to examine the effects of distance from shore, vertebrate predation, and season on macroinvertebrate colonization dynamics in a temperate lake in Suffolk, VA. In a year-long colonization study, artificial plants, half of which were caged to exclude vertebrate predators, were deployed in patches at three distances from shore (2m, 15m, 50m). Artificial plant subsamples were removed at weekly intervals over 28 days during four seasons to monitor colonization by macroinvertebrates. Colonization of artificial plants occurred more quickly in the summer and spring than in fall and winter. The interactive effect of distance from shore and cage …


Muscongus Bay, Marine Wildlife Inventory And Evaluation, Alan E. Hutchinson, Sandra J. Lovett Feb 1984

Muscongus Bay, Marine Wildlife Inventory And Evaluation, Alan E. Hutchinson, Sandra J. Lovett

Maine Collection

Muscongus Bay, Marine Wildlife Inventory and Evaluation

by Alan E. Hutchinson and Sandra J. Lovett

Maine Department of Inland Fisheries and Wildlife

Augusta, Maine, February, 1984.

Contents: Preface / Acknowledgment / List of Tables / List of Figures / Introduction / Resource Inventory / Resource Evaluation / Resource Impact Assessment / Conclusions and Recommendations / References / Appendix


Protection Of Endangered Gray Bat (Myotis Grisescens) Colonies In Arkansas, Michael J. Harvey Jan 1984

Protection Of Endangered Gray Bat (Myotis Grisescens) Colonies In Arkansas, Michael J. Harvey

Journal of the Arkansas Academy of Science

No abstract provided.


Effect Of The Payment-In-Kind (Pik) Program On The Psorophora Columbiae Mosquito Population Of A Northeast Arkansas Ricefield Community, Larry A. Olson, Julia L. Reid Jan 1984

Effect Of The Payment-In-Kind (Pik) Program On The Psorophora Columbiae Mosquito Population Of A Northeast Arkansas Ricefield Community, Larry A. Olson, Julia L. Reid

Journal of the Arkansas Academy of Science

No abstract provided.


Influence Of Degray Reservoir On Zooplankton Populations In The Caddo And Ouachita Rivers, Ralph B. Roseberg, Mark Karnes Jan 1984

Influence Of Degray Reservoir On Zooplankton Populations In The Caddo And Ouachita Rivers, Ralph B. Roseberg, Mark Karnes

Journal of the Arkansas Academy of Science

No abstract provided.


The Effects Of Dredged Materials On The Copeod, Acartia Tonsa, Renee Suzanne Crouch Oct 1983

The Effects Of Dredged Materials On The Copeod, Acartia Tonsa, Renee Suzanne Crouch

Biological Sciences Theses & Dissertations

A study was conducted to determine the potential impact of open ocean disposal of sediments dredged from a highly industrialized seaport. Sediments from three potential dredge sites along the Southern Branch of the Elizabeth River, Hampton Roads, Virginia were evaluated for acute toxicity. The suspended particulate fractions of dredged materials were tested in a series of 96-hour, static bioassays using the calanoid copepod, Acartia tonsa Dana. Significant mortalities were observed for all three sites with the sediments from the most heavily industrialized site producing immediate and severe mortality. Analysis of results indicates that mortality was highly related to the volatile …


The Effects Of Dominant Species Removal On Subtidal Community Development, H. Russell Barker Jr. Oct 1983

The Effects Of Dominant Species Removal On Subtidal Community Development, H. Russell Barker Jr.

Biological Sciences Theses & Dissertations

Acrylic panels were used to follow the development of the fouling community at Channel Points, Lynnhaven Bay, Virginia, from April through October 1979. The roles of Membranipora tenuis, an encrusting ectoproct, and Molgula manhattensis, a solitary tunicate, were studied by removing each species from the developing community on a weekly basis.

Early colonization was dominated by Membranipora followed by Corophium spp. (Amphipoda), Polydora ligni (Polychaeta), and Balanus eberneus (Arthropoda). Molgula colonized the panels later in the study and became a dominant occupier of primary space by the end of the study.

The removal of Membranipora and Molgula …


The Effects Of The Mud Snail Ilyanassa Obsoleta (Say) Upon The Benthic Community Of Broad Bay, Virginia, Wick Timothy Harlan Oct 1983

The Effects Of The Mud Snail Ilyanassa Obsoleta (Say) Upon The Benthic Community Of Broad Bay, Virginia, Wick Timothy Harlan

Biological Sciences Theses & Dissertations

The effects of the presence of the mud snail Ilyanassa obsoleta (Say) upon the benthic community of Broad Bay, Virginia were examined through artificial removal and exclusion of the snail and artificial increase of the snail population. The enclosure treatment exhibited a significantly higher number of macrofaunal individuals than the control. The control had a significantly higher number of meiofaunal individuals than either treatment. There were no significant differences for the chlorophyll a. The increase in macrofauna and corresponding decrease in meiofauna were probably due to cage effects and not snail densities. The presence of the fences can act as …


A Quantitative Study Of The Aquatic Macroinvertebrates In An Irregularly Flooded Salt Marsh, Smith Island, Virginia, Leon L. Robert Jr. Apr 1983

A Quantitative Study Of The Aquatic Macroinvertebrates In An Irregularly Flooded Salt Marsh, Smith Island, Virginia, Leon L. Robert Jr.

Biological Sciences Theses & Dissertations

Little is known about the aquatic macroinvertebrate community structure in coastal salt marshes. This study investigated the aquatic macroinvertebrate community structure in a coastal Virginia salt marsh. Sixteen samples were taken weekly from two different sites on Smith Island, Virginia, from April to mid-October 1982. Bimonthly samples were taken during the months March and November due to low density of organisms and reduced growth rates at these times.

A total of 46 taxa were collected with 17 occurring regularly, indicating a relatively diverse fauna. Wide fluctuations in the physical parameters were observed; however, temporal changes in the macroinvertebrate community cannot …


Twenty-Two New Species Of Spiders For The Arkansas Checklist, Mary L. Beck, Peggy Rae Dorris Jan 1983

Twenty-Two New Species Of Spiders For The Arkansas Checklist, Mary L. Beck, Peggy Rae Dorris

Journal of the Arkansas Academy of Science

No abstract provided.


Zooplankton Population Structure In Three Reservoirs Near The Ouachita Mountain-Gulf Coastal Plain Interface, Stephen B. Smith, Thomas E. Moen Jan 1983

Zooplankton Population Structure In Three Reservoirs Near The Ouachita Mountain-Gulf Coastal Plain Interface, Stephen B. Smith, Thomas E. Moen

Journal of the Arkansas Academy of Science

No abstract provided.


The Ecology Of The Mottled Sculpin, Cottus Bairdii, In The Clearwater River, Beltrami County, Minnesota, Mark A. Hanson Aug 1982

The Ecology Of The Mottled Sculpin, Cottus Bairdii, In The Clearwater River, Beltrami County, Minnesota, Mark A. Hanson

Biology Graduate Theses

No abstract provided.


An Ecological Study Of The Troglobitic Cirolanid Isopod Antrolana Lira Bowman From Madisons Saltpetre Cave And Stegers Fissure, Augusta Co., Virginia, T. Lynn Collins Jul 1982

An Ecological Study Of The Troglobitic Cirolanid Isopod Antrolana Lira Bowman From Madisons Saltpetre Cave And Stegers Fissure, Augusta Co., Virginia, T. Lynn Collins

Biological Sciences Theses & Dissertations

An ecological study of the troglobitic cirolanid isopod, Antrolana lira Bowman, was begun in August 1979 and continued through September 1980. The isopod is restricted to two phreatic lakes in Madisons Saltpetre Cave and one phreatic lake in nearby Stegers Fissure, Augusta Co., Virginia.

All three phreatic lakes were scuba dived and surveyed. No direct connections were found between the lakes. However, physical similarities suggest that the lakes are made up of the same body of phreatic water.

Random samples were taken monthly and seasonally from the east lake in Madisons Saltpetre Cave and the lake in Stegers Fissure. Specimens …


Distributions, Densities, And Relative Abundances Of Grasshoppers (Orthoptera: Acrididae) In A Nebraska Sandhills Prairie, Anthony Joern Jun 1982

Distributions, Densities, And Relative Abundances Of Grasshoppers (Orthoptera: Acrididae) In A Nebraska Sandhills Prairie, Anthony Joern

Entomology Papers from Other Sources

Grasshoppers (Orthoptera: Acrididae) represent a conspicuous and often important component of grassland systems (Odum et al. 1962, Smalley 1960, Sinclair 1975, Van Hook 1971, Wiegert 1965). Often, assemblages of grasshoppers are quite diverse and may, on occasion, consume a large fraction of the available vegetation (Hewitt 1977, Hewitt et al. 1976, Mitchell and pfadt 1974). As such, grasshoppers have the potential of being very important in the nutrient and energy flow in grassland ecosystems. However, to understand the impact of grasshoppers at the ecosystem level requires that the densities and fluctuations of populations as well as the species composition of …


Preliminary Report Of Colony Survivorship In The Western Harvetser Ant (Pogonomyrmex Occidentalis) In Western Nebraska, Kathleen H. Keeler May 1982

Preliminary Report Of Colony Survivorship In The Western Harvetser Ant (Pogonomyrmex Occidentalis) In Western Nebraska, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Colonies of Pogonomyrmex occidentalis Cresson (Hymenoptera: Formicidae) may live an average of 22 to 43 years. The population dynamics of individual colonies of P. occidentalis adjacent to the Univ. Nebraska's Cedar Point Biol. Sta., Keith Co., Nebraska, is the subject of an ongoing investigation. The habitat is a moderately grazed shortgrass prairie dominated by Bouteloua hirsuta, B. gracilis, and Buchloe dactyloides, with Stipa comata, Aristida spp., and various forbs. The colonies studied are in a triangular area about 400 m long and 100 m across at the widest point. The area appears to be at carrying …


A Structural Analysis Of Phytoplankton In The Chesapeake Bay Plume And Adjacent Shelf Waters, Charles K. Rutledge Apr 1982

A Structural Analysis Of Phytoplankton In The Chesapeake Bay Plume And Adjacent Shelf Waters, Charles K. Rutledge

Biological Sciences Theses & Dissertations

Community structures of phytoplankton populations from the southern portion of the Chesapeake Bight were examined and associated to real and environmental spaces. The sampling design was specifically intended to examine the small scale three dimensional structure of the Chesapeake Bay plume as characterized by its phytoplankton populations. The phytoplankton were sampled at 101 stations, non-synoptically, over a five day period in mid-June, 1980.

Several multivariate numerical techniques were used to determine the relationships between the phytoplankton species distributions and pattern the low salinity plume distribution. A pattern of distribution which approximated the salinity plume resulted from several clustering procedures. Environmental …


Mice Of The Genus Peromyscus In Guadalupe Mountains National Park, Texas, John E. Cornely, David J. Schmidly, Hugh H. Genoways, Robert J. Baker Oct 1981

Mice Of The Genus Peromyscus In Guadalupe Mountains National Park, Texas, John E. Cornely, David J. Schmidly, Hugh H. Genoways, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

Mice of the genus Peromyscus are found in virtually every habitat type in Guadalupe Mountains National Park in West Texas. Because of their abundance and wide distribution, they comprise an important component of the park's ecosystem. The first known specimens of Peromyscus from the area now included in the park were collected by Vernon Bailey in 1901 (Bailey, 1905). He collected specimens of Peromyscus boyIii in Dog and McKittrick canyons. Davis (1940) collected P. leucopus at Frijole in 1938 and P. boylii in The Bowl in 1938 and 1939. Davis and Robertson (1944) reported collecting P. pectoralis from along Bell …


The Effects Of Copper On Skeletonema Costatum (Greville) Cleve, Susanne Sybille Jackman Oct 1981

The Effects Of Copper On Skeletonema Costatum (Greville) Cleve, Susanne Sybille Jackman

Biological Sciences Theses & Dissertations

Copper levels and dominant phytoplankton species composition were examined from six sites in Kings Creek on Virginia's Eastern Shore from March to August 1980. Creek copper levels were determined by an APDCMIBK extraction procedure and ranged from 0.003 to 0.020 mg/1. Diatoms were the dominant phytoplankters with Skeletonema costatum (Greville) Cleve emerging as a major late summer species.

Subsequent laboratory studies involved 96-hour experiments using Skeletonema costatum (clone Skel) grown in enriched natural seawater. The water was collected from Kings Creek and enriched to Guillard and Ryther's (1962) f/2 media levels. Cupric sulfate was added to the experimental culture media …


Breeding Birds Of Two Atlantic White Cedar Stands In The Great Dismal Swamp, Karen Terwilliger Jul 1981

Breeding Birds Of Two Atlantic White Cedar Stands In The Great Dismal Swamp, Karen Terwilliger

Biological Sciences Theses & Dissertations

Breeding birds were censused during two years in two Atlantic white cedar stands of the Great Dismal Swamp, and a comparison was made with census results of the predominant swamp community, maple-gum. The maple-gum site had a higher bird species diversity than either cedar site but supported only half the density. The century-old cedar site had the highest species richness while the younger cedar site had the highest density.

Cluster analysis placed the avifauna into distinct groups which closely corresponded to the vegetative strata of the stands. Species were ordered along the height gradient using principal coordinate and detrended correspondence …


Flying Insect Populations As Sampled By Malaise Trap On Crowley's Ridge In Northeast Arkansas, Lynita M. Cooksey, Harvey E. Barton Jan 1981

Flying Insect Populations As Sampled By Malaise Trap On Crowley's Ridge In Northeast Arkansas, Lynita M. Cooksey, Harvey E. Barton

Journal of the Arkansas Academy of Science

Malaise trap collections from woodlot and open field sampling sites on Crowley's Ridge yielded 10,830 individuals during the months of May, July and September, 1980. Greatest numbers of insects were collected in May, with fewest in September. Four orders comprised 97% of the total catch: Diptera (57%), Lepidoptera (17%), Hymenoptera (15%) and Homoptera (8%). Coleoptera, Hemiptera, Neuroptera, Odonata and Orthoptera comprised the remaining 3%. Ordinal composition and seasonal occurrence patterns are discussed and compared for the two sampling sites.


Microhabitat Distribution And Its Effect Of Prey Utilization In Sympatric Populations Of Plethodon Glutinosus And Plethodon Dorsalis In Northwestern Arkansas, James M. Britton Jan 1981

Microhabitat Distribution And Its Effect Of Prey Utilization In Sympatric Populations Of Plethodon Glutinosus And Plethodon Dorsalis In Northwestern Arkansas, James M. Britton

Journal of the Arkansas Academy of Science

A study was done on sympatric populations of Plethodon glutinosus and P. dorsalis in northwestern Arkansas to determine the relative distribution of the two species and the relationship between their distribution and the utilization of available prey. Upon capture, total length, location, and habitat type were recorded for each salamander. Stomach content samples were obtained by forced regurgitation, and the animals were released. Samples of the local litter fauna were taken to determine prey availability. Habitat data were obtained for 171 salamanders; 76 P. glutinosus and 95 P. dorsalis. Stomach content samples were taken from 67 salamanders; 32 P. glutinosus …


An Evaluation Of Small Rodent Populations In Four Dismal Swamp Plant Communities, Fiona Elizabeth Breidling Oct 1980

An Evaluation Of Small Rodent Populations In Four Dismal Swamp Plant Communities, Fiona Elizabeth Breidling

Biological Sciences Theses & Dissertations

Diversity and density of small rodents in the Dismal Swamp are believed to be low. Reasons for this may be excessive predation, heavy interspecific pressure from larger rodents, lack of suitable habitat, low food availability or flooding.

Rodent populations were evaluated using live-traps and pitfall traps in four different Dismal Swamp plant communities. Habitat was compared on the basis of phytomass studies previously reported. Flood levels were recorded during live-trapping sessions. Mast from trees was collected in modified mast collectors, and fed to Peromyscus leucopus in the laboratory. Mast was analyzed for caloric value and nutrient content.

Only two …


Demographic And Reproductive Parameters Of The Yellow-Cheeked Pocket Gopher (Pappogeomys Castanops), Michael J. Smolen, Hugh H. Genoways, Robert J. Baker May 1980

Demographic And Reproductive Parameters Of The Yellow-Cheeked Pocket Gopher (Pappogeomys Castanops), Michael J. Smolen, Hugh H. Genoways, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

A population of Pappogeomys castanops simulans was live-trapped on a 3.5-ha study area in Lubbock, Texas, from September 1971 to September 1973. Seasonal and annual differences in population size were observed, with the population fluctuating between 20 and 25 gophers. Female reproductive activity began in January and continued until October, with an obvious period of recruitment lacking; however, a peak was observed in March and April. Females produced as many as three litters per reproductive season. Females born early in the year were sexually mature within the reproductive season of their birth. Females had an average survival rate of 56 …


Macrobenthic Communities Of An Industrialized Seaport Ecosystem: The Southern Branch Of The Elizabeth River, Virginia, Steven D. Hawthorne Apr 1980

Macrobenthic Communities Of An Industrialized Seaport Ecosystem: The Southern Branch Of The Elizabeth River, Virginia, Steven D. Hawthorne

Biological Sciences Theses & Dissertations

Macrobenthic invertebrates of an industrialized seaport ecosystem were studied seasonally from October, 1977 through July, 1978. Five stations were selected along the Southern Branch of the Elizabeth River, Virginia. The stations ranged from an area of heavy industrialization to a non-urbanized environment. At each station, bottom water was measured for salinity, temperature, dissolved oxygen, and pH. Within each sampling area, macrobenthic infauna! invertebrates were collected from in and out of channel sites along with sediment samples for various types of physicochemical analysis.

Community structure was spatially homogeneous at station sites and throughout the stations along the River. Slightly acidic pH …


Nebraska Trapping, George Schildman, Frank Andelt, Jim Brunner Jan 1980

Nebraska Trapping, George Schildman, Frank Andelt, Jim Brunner

Nebraska Game and Parks Commission: Publications

Fur bearers and trapping played an important role in the exploration and development of Nebraska. The harvest of our fur-bearer resource is part of every Nebraskan's heritage. Wise use of the resource and consideration for other people's property and personal rights can insure that trapping will remain a part of the heritage of future generations. The purpose of this publication is to help insure this heritage ... through the educational process. Knowledge of and respect for the resource, as well as consideration for other people, are the keys to perpetuating trapping as an outdoor activity. While primarily designed to assist …


Estimated Growth And Standing Crop Of Largemouth Bass (Micropterus Salmoides) From Lake Elmdale, Alex Zdinak Jr., Raj V. Kilambi, Marvin L. Galloway, John E. Mcclanahan, Clark Duffe Jan 1980

Estimated Growth And Standing Crop Of Largemouth Bass (Micropterus Salmoides) From Lake Elmdale, Alex Zdinak Jr., Raj V. Kilambi, Marvin L. Galloway, John E. Mcclanahan, Clark Duffe

Journal of the Arkansas Academy of Science

Electro-fishing gear was used to make shoreline population estimates of largemouth bass (Micropterus salmoldes) in Lake Elmdale, Washington County, Arkansas, during September 1979. The population density was estimated to be 1541 bass/Km² with a standing crop of 30.4 kg/ha. The length-weight relationship was calculated as W = 0.00001 504L^2.97, and the total length-scale radius relationship as L = 41.75 + 1.23 St. The average condition coefficient(K) was 1.31. In comparison with four other Arkansas lakes the population density of largemouth bass was highest in Lake Elmdale while the growth rate was lowest.