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Articles 871 - 900 of 903
Full-Text Articles in Terrestrial and Aquatic Ecology
Mortality Of White-Tailed Deer In Northeastern Minnesota, Michael E. Nelson, L. David Mech
Mortality Of White-Tailed Deer In Northeastern Minnesota, Michael E. Nelson, L. David Mech
United States Geological Survey, Northern Prairie Wildlife Research Center: Publications
Abstract: Two hundred nine white-tailed deer (Odocoileus virginianus) were radiotracked in the central Superior National Forest, Minnesota, from 1973 through winter 1983-84; 85 deaths were recorded. Annual survival was 0.31 for fawns (<1.0 years old), 0.80 for yearling (1.0-2.0 years old) females, 0.41 for yearling males, 0.79 for adult (≥2.0 years old) females, and 0.47 for adult males. Monthly survival rates were high from May through December (0.94-1.00), except for yearling (0.60) and adult (0.69) bucks during the November hunting season. Most mortality occurred from January through April when gray wolf (Canis lupus) predation was an important mortality source for all cohorts. Yearlings males were most vulnerable to hunting and adult males to wolf predation.
Environmental Factors Affecting Nocturnal Migrations Of Macrobenthos, C. Timothy Morris
Environmental Factors Affecting Nocturnal Migrations Of Macrobenthos, C. Timothy Morris
Biological Sciences Theses & Dissertations
Nocturnally dispersing macrobenthic invertebrates of the Lafayette River, Norfolk, Virginia were collected from September 4 to October 4, 1982 to determine environmental factors affecting migrations. A total of 55 taxa were identified from 325 surface and bottom nocturnal plankton tows. Peracaridan crustaceans were the dominant (99.0% of the total density) group collected. Six of the commonly collected species showed a significant (P
Relationship Between Snow Depth And Gray Wolf Predation On White-Tailed Deer, Michael E. Nelson, L. David Mech
Relationship Between Snow Depth And Gray Wolf Predation On White-Tailed Deer, Michael E. Nelson, L. David Mech
United States Geological Survey, Northern Prairie Wildlife Research Center: Publications
Abstract: Survival of 203 yearling and adult white-tailed deer (Odocoileus virginianus) was monitored for 23,441 deer days from January through April 1975-85 in northeastern Minnesota. Gray wolf (Canis lupus)predation was the primary mortality cause, and from year to year during this period, the mean predation rate ranged from 0.00 to 0.29. The sum of weekly snow depths/month explained 51% of the variation in annual wolf predation rate, with the highest predation during the deepest snow.
A Biochemical And Genetic Analysis Of The American Shad Alosa Sapidissima Migrating Into The Chesapeake Bay, Edward Norbert Sismour
A Biochemical And Genetic Analysis Of The American Shad Alosa Sapidissima Migrating Into The Chesapeake Bay, Edward Norbert Sismour
Biological Sciences Theses & Dissertations
Seven enzymes extracted from heart and liver tissues of American shad Alosa sapidissima captured during migrations into the Chesapeake Bay and Nansemond River were electrophoretically surveyed. Malate dehydrogenase and nonspecific esterase displayed polymorphic loci. The esterase polymorphism was used as a biochemical genetic marker to analyze the shad migration through the southern Chesapeake Bay. The genetic composition of the shad migration changed significantly over time indicating that this migration is probably composed of multiple, genetically divergent spawning populations. Results of this study are subject to differing interpretations. Observed temporal heterogeneity may result from separation of northern and James River stocks …
Activity Levels Of Arboreal Rodents Peromysus And Ochrotomys Evaluated With Nest Cans In Seasonally Flooded Forests, John W. Walke
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
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 …
Determinants Of Variation In Avian Mobbing Behavior, Charles Ray Chandler Jr.
Determinants Of Variation In Avian Mobbing Behavior, Charles Ray Chandler Jr.
Biological Sciences Theses & Dissertations
Using three combinations of two experimental stimuli, I initiated mobbing behavior in various species of birds. The objectives of this research were to test the effects of stimuli on mobbing, the predictions of the hypothesis that mobbing functions to drive a predator away, and the effect of other species and individuals on the mobbing behavior of a bird. Mobbing experiments were conducted in a variety of habitats and locations from January 1983 through February 1984.
Only 6.5% of all trials with the mount-only stimulus were successful in attracting birds. Tape-only and mount-and-tape stimuli were equally effective in attracting birds, but …
The Role Of Colonization Predation And Season In Determining Macroinvertebrate Community Structure In A Temperate Lake, Cheryl Lynn Frew
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 …
Simulation Analyses Of Space Use: Home Range Estimates, Variability, And Sample Size, Marc Bekoff, L. David Mech
Simulation Analyses Of Space Use: Home Range Estimates, Variability, And Sample Size, Marc Bekoff, L. David Mech
United States Geological Survey, Northern Prairie Wildlife Research Center: Publications
Simulations of space use by animals were run to determine the relationship among home range area estimates, variability, and sample size (number of locations). As sample size increased, home range size increased asymptotically, whereas variability decreased among mean home range area estimates generated by multiple simulations for the same sample size. Our results suggest that field workers should ascertain between 100 and 200 locations in order to estimate reliably home range area. In some cases, this suggested guideline is higher than values found in the few published studies in which the relationship between home range area and number of locations …
Homing And Ecology In The Southern Flying Squirrel, Glaucomys Volans In Southeastern Virginia, Sherrie Lynn Sawyer
Homing And Ecology In The Southern Flying Squirrel, Glaucomys Volans In Southeastern Virginia, Sherrie Lynn Sawyer
Biological Sciences Theses & Dissertations
The purpose of this study was to determine whether homing occurred in the southern flying squirrel, Glauaomys volans, and if so, the greatest homing distance. Information on the squirrel's ecology, reproductive biology and use of artificial nest boxes was also obtained. The study was conducted from November 1978 through March 1981, using nest boxes placed in a deciduous forest in southeastern Virginia.
For the homing experiments, twenty squirrels were released a total of 29 times along three lines at distances of 250 m to 1.6 km from the homesites. Squirrels were found to home successfully up to 1,000 m.
The …
The Ecology Of The Mottled Sculpin, Cottus Bairdii, In The Clearwater River, Beltrami County, Minnesota, Mark A. Hanson
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 Analysis Of Howling Response Parameters Useful For Wolf Pack Censusing, Fred H. Harrington, L. David Mech
An Analysis Of Howling Response Parameters Useful For Wolf Pack Censusing, Fred H. Harrington, L. David Mech
United States Geological Survey, Northern Prairie Wildlife Research Center: Publications
Gray wolves (Canis lupus) were studied from April 1972 through April 1974 in National Forest in northeastern Minnesota by radio-tracking and simulated howling. Based during 217 of 456 howling sessions, the following recommendations were derived for using howling as a census technique: (1) the best times of day are dusk and night; (2) July, August, and are the best months; (3) precipitation and winds greater than 12 km/hour should be avoided; (of 5 single howls should be used, alternating "flat" and "breaking" howls; (5) trials should 3 times at about 2-minute intervals with the first trial at lower …
Feeding Behavior Of Three Species Of Spionid Polychaetes, Thomas Lane Stokes Jr.
Feeding Behavior Of Three Species Of Spionid Polychaetes, Thomas Lane Stokes Jr.
Biological Sciences Theses & Dissertations
Observations of feeding behavior of three species of spionid polychaetes (Paraprionospio pinnata, Polydora ligni, and Streblospio benedicti) were performed in currents ranging from 0 to 10 cm/sec over fine and coarse sediments and in high and low suspended particle loads. These interface feeders may suspension feed, deposit feed, or both simultaneously using a pair of anterior tentaculate feeding palps. P. ligni and S. benedicti were found to alter their palp behaviors in response to experimental manipulations. P. ligni reacted strongly to currents by suspension feeding with coiled palps. S. benedicti reacted strongly and complexly to food particle type and availability. …
Dynamics, Movements, And Feeding Ecology Of A Newly Protected Wolf Population In Northwestern Minnesota, Steven H. Fritts, L. David Mech
Dynamics, Movements, And Feeding Ecology Of A Newly Protected Wolf Population In Northwestern Minnesota, Steven H. Fritts, L. David Mech
United States Geological Survey, Northern Prairie Wildlife Research Center: Publications
The gray wolf Canis lupus occupies only about 1 percent of its former range in the lower 48 states (Mech 1974a). Most of the range is in northern Minnesota, where the resident population is classified as "threatened" by the U.S. Department of the Interior. Wolves have been and will continue to be the subject of considerable controversy in Minnesota.
The first scientific study of wolves in Minnesota was conducted by Olson (1938a,b). That and all subsequent re- search was in the Superior National Forest (SNF) of northeastern Minnesota even though wolves inhabit approximately the northern third of the state. Consequently, …
Deer Social Organization And Wolf Predation In Northeastern Minnesota, Michael E. Nelson, L. David Mech
Deer Social Organization And Wolf Predation In Northeastern Minnesota, Michael E. Nelson, L. David Mech
United States Geological Survey, Northern Prairie Wildlife Research Center: Publications
The white-tailed deer Odocoileus virginianus has been subject to intensive research and management, yet we are just beginning to understand its social organization. Little is known about home range formation, migration, social bonds, and traditions in this deer, what functions they serve, and what selective forces have affected them.
Predation by wolves Canis lupus, in particular, has not been examined as a factor in deer evolution, yet the intimate interactions between deer and wolf through the millennia no doubt strongly influenced major morphological and behavioral adaptations in both species. It is a reasonable assumption that wolf predation has been …
Population Regulation In Wolves, Jane M. Packard, L. David Mech
Population Regulation In Wolves, Jane M. Packard, L. David Mech
United States Geological Survey, Northern Prairie Wildlife Research Center: Publications
The possibility of social regulation of wolf populations has been discussed in the literature for several years. Some of the first ecological studies of wolves indicated that their populations did not increase as rapidly as was theoretically possible, and that they reached a saturation point apparently not set by food. Subsequent captive studies demonstrated the existence of social mechanisms possibly capable of regulating population growth. However, the importance of these factors in wild populations has not been established. This paper has four objectives: (1) to evaluate the existing concept of "intrinsic limitation," (2) to propose that wolf population dynamics may …
Morphological Variation Among 14 Species Of Callogobius Bleeker (Pisces: Gobiidae), James Francis Mckinney
Morphological Variation Among 14 Species Of Callogobius Bleeker (Pisces: Gobiidae), James Francis Mckinney
Biological Sciences Theses & Dissertations
A survey of the variation among the species of the Callogobius complex has been accomplished in order to determine if recognition of more than one genus is warranted for this assemblage of species. Emphasis has been placed on the osteological variation. Relationships among certain species within the Callogobius complex have been exposed. Although there are two well defined species groups within the complex, it is felt that inclusion of all of the examined species within the single genus Callogobius is the most parsimonious course of action.
Structure Of A Subtidal Benthic Community Near Cape Charles, Virginia, R. Michael Ewing
Structure Of A Subtidal Benthic Community Near Cape Charles, Virginia, R. Michael Ewing
Biological Sciences Theses & Dissertations
Species composition, distribution, and abundance of benthic invertebrates of a subtidal community were examined at a location on the lower Delmarva Peninsula near Cape Charles, Virginia. Macrobenthos was sampled quarterly between June, 1977 and June, 1978 at nine sites along a transect in Old Plantation Creek and the adjacent offshore area. Spatial and temporal patterns of numerically important species are discussed.
Sampling sites and species were grouped by a numerical classification strategy which consisted of the Bray-Curtis similarity measure and group-average clustering. Three faunal assemblages were identified with the aid of constancy and fidelity nodal analyses: (1) a tidal creek …
Seasonal Feeding Habits Of The River Otter (Lutra Canadensis) In Ditches Of The Great Dismal Swamp, Ronnie M. Pierce
Seasonal Feeding Habits Of The River Otter (Lutra Canadensis) In Ditches Of The Great Dismal Swamp, Ronnie M. Pierce
Biological Sciences Theses & Dissertations
To determine the seasonal feeding habits of the river otter (Lutra canadensis) in the Great Dismal Swamp 209 scats were collected, from May 1977 to May 1978, and analyzed for content. Remains of crayfish were found with a frequency of occurrence of 82% while fish remains occurred in 62% of the scat. This is in direct contrast to previous studies (from other areas) which found fish with a greater frequency than crayfish. Fish consumption was believed to increase during periods of low water or low temperatures. Sunfish were represented most frequently and may be the preferred fish. Amphiuma remains …
Swimming As A Determinate To Immigration For Two Small Mammals In Coastal Virginia, Jeffrey Lewis Carter
Swimming As A Determinate To Immigration For Two Small Mammals In Coastal Virginia, Jeffrey Lewis Carter
Biological Sciences Theses & Dissertations
Small mammals were live trapped on the mainland and on an island located in the southeast corner of Virginia. The area was characterized by a mid-Atlantic coastal climate. White-footed mice (Perompsous fsucopus) were trapped on the mainland but not on the island, whereas meadow voles (Microtus psnnsylvimious) inhabited only the island. A series of swimming tests were performed in both the field and in the laboratory on both of these species to determine if swimming abilities could be the factor preventing Pszomysous from colonizing the island.
Both species of small mammals showed good swimming endurance in …
Wolf Howling And Its Role In Territory Maintenance, Fred H. Harrington, L. David Mech
Wolf Howling And Its Role In Territory Maintenance, Fred H. Harrington, L. David Mech
United States Geological Survey, Northern Prairie Wildlife Research Center: Publications
The wolf (Canis lupus) is a wide-ranging social carnivore with a complex spatial organization (MECH, 1972; 1973). The precise manner in which this organization is maintained is unknown, but territory advertisement using olfactory and acoustic modes seems to be involved.
The acoustic mode includes primarily howling. Within a wolf pack, howling may be useful to reassemble separated members (MECH, 1966; THEBERGE & FALLS, 1967), and may communicate information on individual identity, location, and other behavioral and environmental contingencies (THEBERGE & FALLS, 1967). Between packs, however, howling may serve to advertise territory, communicating the locations of packs and thus …
The Fall And Winter Food Habits Of The Black Bear (Ursus Americanus) In The Great Dismal Swamp Of Virginia, Francis Leonard Daniel
The Fall And Winter Food Habits Of The Black Bear (Ursus Americanus) In The Great Dismal Swamp Of Virginia, Francis Leonard Daniel
Biological Sciences Theses & Dissertations
A study was conducted on the food habits of the black bear (Ursus americanus) in the Great Dismal Swamp of Virginia. A total of four stomachs and 42 scats were analyzed. Four samples were collected from September and October of 1975, and the remainder of the samples were collected from September 1976 to February 1977. The study was conducted to obtain information vital to the management of this species in the Great Dismal Swamp. Vitis spp. was the primary food item during the fall comprising 43% of the total diet, followed by fruits of Diospyros virginiana and Asimina triloba, each …
A Mid-Continent Irruption Of Canada Lynx, 1962-63, Harvey L. Gunderson
A Mid-Continent Irruption Of Canada Lynx, 1962-63, Harvey L. Gunderson
University of Nebraska State Museum: Mammalogy Papers
There was a mid-continent irruption of the Canada lynx (Felis lynx) population and subsequent extensive movement into non-lynx habitats during the years 1962-1963. Lynx were found in the prairie provinces of Canada and the prairie areas of Minnesota, and North and South Dakota. They were also found in urban areas such as Minneapolis and St. Paul, Minnesota: Winnipeg, Manitoba: and Calgary, Saskatchewan, Canada. Causes for the irruption remain unknown but speculations include primarily a change in snowshoe hare population, disease, extensive forest fires and extensive spraying. Unusual behavior seemed to be most often reflected by a lack of …
Relating Wolf Scat Content To Prey Consumed, Theodore J. Floyd, L. David Mech, Peter A. Jordan
Relating Wolf Scat Content To Prey Consumed, Theodore J. Floyd, L. David Mech, Peter A. Jordan
United States Geological Survey, Northern Prairie Wildlife Research Center: Publications
In 9 trials, captive wolves (Canis lupus) were fed prey varying in size from snowshoe (Lepus americanus) to adult deer (Odocoileus virginianus), and the resulting scats were counted. collectible scats were distinguished from liquid, noncollectible stools. In collectible scats, the small prey occurred in greater proportion relative to the prey's weight, and in lesser proportion to the prey's numbers, than did the remains of larger prey. A regression equation with an excellent the data (r2 = 0.97) was derived to estimate the weight of prey eaten per collectible scat for With this information …
Productivity, Mortality, And Population Trends Of Wolves In Northeastern Minnesota, L. David Mech
Productivity, Mortality, And Population Trends Of Wolves In Northeastern Minnesota, L. David Mech
United States Geological Survey, Northern Prairie Wildlife Research Center: Publications
Population parameters, mortality causes, and mechanisms of a population decline were studied in wolves (Canis lupus lycaon) from 1968 to 1976 in the Superior National Forest. The main method was aerial radio-tracking of 129 wolves and their packmates. Due to a decline in white-tailed deer (Odocoileus virginianus), the wolf population decreased during most of the study. Average annual productivity varied from 1.5 to 3.3 pups per litter, and annual mortality rates from 7 to 65 percent. Malnutrition and intraspecific strife accounted equally for 58 percent of the mortality; human causes accounted for the remainder. As wolf …
Wolf-Pack Buffer Zones As Prey Reservoirs, L. David Mech
Wolf-Pack Buffer Zones As Prey Reservoirs, L. David Mech
United States Geological Survey, Northern Prairie Wildlife Research Center: Publications
Abstract. In a declining herd, surviving deer inhabited overlapping edges of wolf- pack territories. There, wolves hunted little until desperate, in order to avoid fatal encounters with neighbors. Such encounters reduce wolf numbers and predation pressure and apparently allow surviving deer along territory edges to repopulate the area through dispersal of their prime, less vulnerable offspring into territory cores.
Comparison Of Coyote And Coyote × Dog Hybrid Food Habits In Southeastern Nebraska, Brian R. Mahan
Comparison Of Coyote And Coyote × Dog Hybrid Food Habits In Southeastern Nebraska, Brian R. Mahan
University of Nebraska State Museum: Mammalogy Papers
The recent taxonomic study by Mahan et al. (1978) documented the occurrence of coyote (Canis latrans) x dog (c. familiaris) hybrids in Nebraska. This study, and those by Freeman (1976) in Oklahoma and Gipson et al. (1974) in Arkansas show coyote x dog hybrids, though not abundant, to be numerous in some areas. The purpose of the present study was to compare the stomach contents of coyote x dog hybrids collected by Mahan et al. (1978) from southeastern Nebraska with those of contemporary coyotes.
Stomachs of 12 coyote x dog hybrids and 16 coyotes collected November 1975 …
The Food Habits Of Ictalurus Natalis, Centrarchus Macropterus And Perca Flavescens In Lake Drummond In The Dismal Swamp Of Virginia, Steven C. Russell
The Food Habits Of Ictalurus Natalis, Centrarchus Macropterus And Perca Flavescens In Lake Drummond In The Dismal Swamp Of Virginia, Steven C. Russell
Biological Sciences Theses & Dissertations
The food habits of yellow bullhead catfish (Ictalurus natalis), yellow perch (Perea flavescens), and fliers (Centrarchus macropterus) in Lake Drummond in the Dismal Swamp were examined. Seventy yellow bullheads (42 mm to 255 mm), 136 yellow perch (41 mm to 280 mm), and 110 fliers (81 mm to 140 mm), were collected with gill nets, traps, seins, and electro-fishing gear from June through November of 1975. Frequency of occurrence and volumentric data were used to evaluate the relative importance of food items. Spearman's rank correlation coefficient was determined from the data to test differences …
Sex Pheromone Activity In The Foveal Glands In The Two Species Of Ixodid Ticks: Dermacentor Andersoni (Stiles) And Dermacentor Variabilis (Say), Lynn Anne Collins
Sex Pheromone Activity In The Foveal Glands In The Two Species Of Ixodid Ticks: Dermacentor Andersoni (Stiles) And Dermacentor Variabilis (Say), Lynn Anne Collins
Biological Sciences Theses & Dissertations
Sex pheromone activity in the foveal glands of female Dermacentor andersoni (Stiles) and Dermacentor variabilis (Say) is described. Autoradiography revealed the accumulation of 36Cl in the foveal glands of females during their first 120 hours of feeding on a 36Cl-labeled host. Emissions collected from these females contained a 36Cl-labeled product. This product, however, was absent in emissions collected from the same females with their foveae dorsales obstructed.
Accumulation of 36Cl in the foveal gland, in conjunction with the release of a 36Cl-labeled product through the foveae dorsales, suggest localization of sex pheromone activity within these …
Variation In The Ecology Morphology And Behavior Of The Troglobitic Amphipod Crustacean Crangonyx Antennatus Packard (Crangonchidae) From Different Habitats, Gary Wayne Dickson
Variation In The Ecology Morphology And Behavior Of The Troglobitic Amphipod Crustacean Crangonyx Antennatus Packard (Crangonchidae) From Different Habitats, Gary Wayne Dickson
Biological Sciences Theses & Dissertations
Populations of the troglobitic amphipod Crangonyx antennatus living in two distinct aquatic habitats were examined for possible variations in their ecology, morphology and behavior. Collections were made seasonally for one year in six Lee Co., Virginia caves, three containing mud-bottom, drip pools and three with small gravel stream habitats. Environmental parameters thought to influence population variation were quantitatively and qualitatively recorded in each of the six caves.
Amphipod densities, body length, female maturity, clutch number and stream washout rates were found to be greater in drip pool habitat populations. Variation was also observed in body coloration and antennal segment-body length …