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Ecology and Evolutionary Biology

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Articles 17731 - 17760 of 19682

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Introduction And Enhancement Of Vegetative Cover At Lake Mead, Jennifer S. Haley, Lisa K. Croft, Suzanne E. Leavitt, Larry J. Paulson Dec 1989

Introduction And Enhancement Of Vegetative Cover At Lake Mead, Jennifer S. Haley, Lisa K. Croft, Suzanne E. Leavitt, Larry J. Paulson

Publications (WR)

Studies done by the Nevada Department of Wildlife (NDOW) and the Arizona Fish and Game between 1978 and 1981 indicate that inadequate cover may be limiting the production and survival of largemouth bass at the Lake Mead National Recreation Area (LMNRA). As a result of these studies, NDOW initiated a contract in 1986 with the Lake Mead Research Center (LMRC) to investigate means of improving habitat for game fish by introducing natural and/or artificial cover. During Phase I (1986-1987) of this contract, the shoreline of Lake Mead was surveyed for aquatic and terrestrial plant growth. Also during this time, submerged …


Population And Social Biology Of Free-Ranging Dogs, Canis Familiaris, Thomas J. Daniels, Marc Bekoff Nov 1989

Population And Social Biology Of Free-Ranging Dogs, Canis Familiaris, Thomas J. Daniels, Marc Bekoff

Ecology Collection

Population size and density, age structure, survivorship patterns, sex ratios, social organization of urban, rural, and feral dog (Canis familiaris) populations were examined in Cd. Juarez, Mexico (urban site) and on the Navajo reservation (rural and wild sites) between June 1983 and December 1984. Urban and rural dogs were less social than expected whereas dogs characteristically lived in packs. Seasonal variation in the structure of feral dog packs influenced by reproduction, both directly (pups born into the pack) and indirectly (pregnant females may temporarily emigrate form the pack to give birth).


Rock Lobster Industry Advisory Committee Report To The Hon Minister For Fisheries., Fisheries Dept. Of Western Australia Nov 1989

Rock Lobster Industry Advisory Committee Report To The Hon Minister For Fisheries., Fisheries Dept. Of Western Australia

Fisheries Management Papers

To ensure full consultation with members of the fishing industry, the Committee arranged a series of meetings at the main coastal centres after the close of the fishing season. Each meeting followed the same format which allowed matters related to research and management to be discussed. After these meetings the Committee met to formulate its advice to the Minister on the matters raised during the Coastal Tour and from Committee discussions.


Can Genetically Engineered Crops Become Weeds?, Kathleen H. Keeler Nov 1989

Can Genetically Engineered Crops Become Weeds?, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

There are significant differences if the distribution of weedy characteristics among weeds, normal plants, and crops. The world’s most serious weeds possess on the average 10 or 11 of these characters, a random collection of British plants have an average seven of the traits, and crop plants only five. For the average crop to become as “weedy” as the average weed, it would need to acquire five weedy traits. Even using the unlikely assumption that those traits are single loci in which a dominant mutation would provide the weedy character, this would require the simultaneous acquisition of five gene substitutions. …


A Revision Of The North American Papillose Allocreadiidae (Digenea) With Independent Cladistic Analyses Of Larval And Adult Forms, Janine N. Caira Oct 1989

A Revision Of The North American Papillose Allocreadiidae (Digenea) With Independent Cladistic Analyses Of Larval And Adult Forms, Janine N. Caira

Bulletin of the University of Nebraska State Museum (1924–2023)

Adult specimens of all 19 North American species of papillose allocreadiids were examined. A description and figure is given for the adult of each species; details of the cirrus sacs are presented for most spesies for the first time. Descriptions were emended where necessary and judgments were made on synonymies. Scanning electron micrographs of the oral sucker of 10 species are presented as is a new key to the 19 species. A cladistic analysis was performed on the group based on adult characters. The analysis indicated that the group is monophyletic on the basis of the ventral papillae associated with …


The Water Vapor Conductance Of Squamate Reptilian Eggs: The Influence Of Scaling On Nesting Ecology., Louis A. Somma Sep 1989

The Water Vapor Conductance Of Squamate Reptilian Eggs: The Influence Of Scaling On Nesting Ecology., Louis A. Somma

Papers in Herpetology

Flexible-shelled eggs of squamate reptiles are strongly influenced by their surrounding microclimate, particularly the hydric conditions of the nest. The eggshell water vapor conductance of an egg can be an indication of its requirement for water from the nest. Ackerman et al. (1985. Physiol. Zool. 58:129-137) have described the scaling relationship for eggshell water vapor conductance (GH2O) of flexible-shelled reptilian eggs (GH2O = 981.8M0.52). This scaling relationship was investigated with water vapor conductance data obtained from 8 species of lizards representing the families Iguanidae (Anolis carolinensis, A. sagrai, Sceloporus woodi, S. virgatus) …


Natural And Disturbance-Induced Demographic Variation In An Infaunal Polychaete, Nephtys Incisa, Roman Zajac, Robert B. Whitlatch Sep 1989

Natural And Disturbance-Induced Demographic Variation In An Infaunal Polychaete, Nephtys Incisa, Roman Zajac, Robert B. Whitlatch

Biology and Environmental Science Faculty Publications

Demography of the infaunal polychaete Nephtys incisa was investigated for periods of 1 yr prior to and following disturbance (dredge material disposal) at a site in central Long Island Sound, USA. Infaunal grab samples were taken at 5 stations 200 m to 3 km apart. The demography of populations at each station was based on age-classes spanning juveniles to adults 4 + yr of age. Age-specific survivorship and fecundity were based on changes in mean density of each cohort and a positive correlation between female size and egg production, respectively. Analyses of population matrix models indicated pre-disposal populations had positive …


Foreign Investment In The Rock Lobster Industry. A Policy Statement By Gordan Hill Mla Minister For Fisheries, Fisheries Dept. Of Western Australia Sep 1989

Foreign Investment In The Rock Lobster Industry. A Policy Statement By Gordan Hill Mla Minister For Fisheries, Fisheries Dept. Of Western Australia

Fisheries Management Papers

Foreign investment in the rock lobster industry become an important issue during 1988 following the purchase of the rock lobster processing establishment INF Pty Ltd by the Japanese company Chungagon. On 24 June 1988 the then Minister for Fisheries, the Hon. Julian Grill, issued a press release setting out that foreign investment in the rock lobster industry would be put under scrutiny. The debate on rock lobster processing, involves not only questions of end-user ownership with the likely concentration on small-sized rock lobsters but also on the location of rock lobster processing establishments along the coast. In September 1988, with …


The Prairie Naturalist Volume 21, No.3 September 1989 Sep 1989

The Prairie Naturalist Volume 21, No.3 September 1989

The Prairie Naturalist

SEED DISPERSAL CHARACTERISTICS OF PLAINS SILVER SAGEBRUSH ▪ C. L. Wambolt, T. Walton, and R. S. White

ON THE TRAIL OF THE ANT, VEROMESSOR LOBOGNATHUS . ▪ G. C. Wheeler and J. Wheeler

LAND USE RELATIONSHIPS TO AVIAN CHOLERA OUTBREAKS IN THE NEBRASKA RAINWATER BASIN AREA ▪ B. J. Smith, K. F. Higgins, and C. F. Gritzner

INCIDENCE OF LEAD SHOT IN THE RAINWATER BASINS OF SOUTH CENTRAL NEBRASKA ▪ . D. W. Oates

REPRODUCTION, RECRUITMENT, AND SURVIVAL OF BROWN AND RAINBOW TROUT IN A PRAIRIE COTEAU STREAM ▪ C. L. Milewski and D. W. Willis

SIZE STRUCTURE AND CATCH …


Effects Of Inter-Specific Density And Food Supply On Survivorship And Growth Of Newly Settled Benthos, Roman Zajac, Robert B. Whitlatch, Richard W. Osman Aug 1989

Effects Of Inter-Specific Density And Food Supply On Survivorship And Growth Of Newly Settled Benthos, Roman Zajac, Robert B. Whitlatch, Richard W. Osman

Biology and Environmental Science Faculty Publications

Using a laboratory model system comprised of newly settled oysters Crassostrea virginica and established fouling species (Botrylloides sp. initially, and others including Styela clava and Ciona intestinalis as the experiment progressed), we tested how differences in food supply and competitor density may affect post-settlement surivorship and growth of sessile marine invertebrates over a 44 d period. After 15 d, results were mixed but indicated that both food and density conditions affected growth and survivorship significantly, with some suggestion of high food levels ameliorating high density effects However, 44 d after settlement, oysters had reduced survivorship and growth when competitors …


A Field Key To Fish Families Reported From South American Fresh Waters, C. Kelly Swing, John S. Ramsey Aug 1989

A Field Key To Fish Families Reported From South American Fresh Waters, C. Kelly Swing, John S. Ramsey

Occasional Papers of the Museum of Natural Science, Louisiana State University

No abstract provided.


Distribution And Marketing Of Western Australia Rock Lobster., P. J. Monaghan Aug 1989

Distribution And Marketing Of Western Australia Rock Lobster., P. J. Monaghan

Fisheries Management Papers

This report describes the marketing and distribution of Western Australian rock lobster products in the major consuming countries namely, USA, Japan and Taiwan. It is based on a study which was commissioned by the Fisheries Department of Western Australia who sought, for the benefit of industry generally, an understanding of the world lobster markets.


Testing Macroevolutionary Hypotheses With Cladistic Analysis: Evidence Against Rectangular Evolution, Cliff A. Lemen, Patricia W. Freeman Jul 1989

Testing Macroevolutionary Hypotheses With Cladistic Analysis: Evidence Against Rectangular Evolution, Cliff A. Lemen, Patricia W. Freeman

School of Natural Resources: Faculty Publications

The properties of cladistic data sets from small monophyletic groups (6-1 2 species) are investigated using computer simulations of macroevolution. Two evolutionary models are simulated: gradualism and the punctuated-equilibrium hypothesis. Under the conditions of our simulations these two models of evolution make consistently different predictions about the distribution of autapomorphies among species. When strict stasis is enforced, the punctuated-equilibrium hypothesis predicts that the most expected number of autapomorphies per species will be zero, no matter how many characters are used in the analysis. As the number of characters used in the analysis increases, the distribution of the number of autapomorphies …


Picoplankton/Phytoplankton Dynamics In Hampton Roads, Virginia, Leslie E. Dorworth Jul 1989

Picoplankton/Phytoplankton Dynamics In Hampton Roads, Virginia, Leslie E. Dorworth

OES Theses and Dissertations

The biomass distribution of the three main size components of the phytoplankton (net, nano, and picoplankton) was examined in the lower Chesapeake Bay. Work was done at two stations during the spring and neap tidal cycles when freshwater flow into the bay was at its seasonal minimum and maximum. Emphasis was placed on how the picoplankton ( < 2.0 μm, > 0.2 μm) reacted during the sampling period.

Picoplankton made up approximately 13% of the total biomass, during the observed time period, at the more oceanic station. The picoplankton fraction contributed up to 16% of the total biomass at the estuarine station. From this …


The Remipedia (Crustacea): A Study Of Their Reproduction And Ecology, Jill Yager Jul 1989

The Remipedia (Crustacea): A Study Of Their Reproduction And Ecology, Jill Yager

Biological Sciences Theses & Dissertations

Remipedes are an unusual group of troglobitic crustaceans that live exclusively in anchialine caves. Since their discovery in 1979, nine species have been described, seven of which are found in caves in the West Indies, one from the Yucatan peninsula of Mexico and one from the Canary Islands. Most of what is known about these animals has come mainly from taxonomic descriptions. Little has been published about their reproductive biology or ecology. The objectives of this dissertation were to investigate the reproductive biology and ecology of the remipedes inhabiting Sagittarius Cave on Grand Bahama Island, Bahamas.

Sagittarius Cave was chosen …


Effects Of Resident Species On Recruitment Into A Community: Larval Settlement Versus Post-Settlement Mortality In The Oyster Crassostrea Virginica, Roman Zajac, Richard W. Osman, Robert B. Whitlatch Jun 1989

Effects Of Resident Species On Recruitment Into A Community: Larval Settlement Versus Post-Settlement Mortality In The Oyster Crassostrea Virginica, Roman Zajac, Richard W. Osman, Robert B. Whitlatch

Biology and Environmental Science Faculty Publications

Laboratory and field experiments revealed that a variety of species of common, sessile invertebrates, including barnacles, ascidians, and bryozoans, affected the settlement and post-settlement abundance of the oyster Crassostrea virginica (Gmelin). While the nature of the effects varied, most species both reduced oyster settlement by covering and removing substrate available for attachment, and increased settlement on adjacent surfaces. The solitary ascidians Ciona intestinalis (L.) and Styela clava (Herdman), were found to be predators of oyster larvae. Post-settlement survivorship and growth were also strongly affected by the presence of sessile species. In most cases the effects were negative and correlated with …


Southern Demersal Gillnet And Longline Fishery., Management Advisory Committee Jun 1989

Southern Demersal Gillnet And Longline Fishery., Management Advisory Committee

Fisheries Management Papers

In its report to the Ministier for Fisheries in November 1986, the Southern Western Australian Shark Working Group recommended the establishment of an Industry/Government Mangement Advisory Committee to provide managememt advice on the fishery to the Minister for Fisheries. The Advisory Committee held its first meeting in Albany on 23 February 1989. After being briefed on the state of shark stocks, the Committee's deliberations fell into three broad categories. In the first category there was sufficient time and information available to make a recommendation to the Minister for Fisheries. In the second category, discussion commenced, but was held over to …


Temporal And Spatial Patterns Of Abundance Of Age 0 Threadfin Shad (Dorosoma Petenense) In Overton Arm, Lake Mead, William Lee Pelle Jun 1989

Temporal And Spatial Patterns Of Abundance Of Age 0 Threadfin Shad (Dorosoma Petenense) In Overton Arm, Lake Mead, William Lee Pelle

Publications (WR)

Temporal and spatial patterns of age 0 threadfin shad (Dorosoma petenense) abundance and growth, in the Overton Arm of Lake Mead, were examined to evaluate the effects of resource availability on the young fish. This was part of a larger, game fishery enhancement study (Lake Mead Fertilization Project), designed to assess feasability of increasing survivorship of larval/juvenile shad by boosting phosphate levels, thereby increasing algal and zooplankton biomass, during the shad spawning period. Shad are the primary forage base for the striped bass (Morone saxatilis) and black bass (Macropterus salmoides) fisheries. Weekly samples were …


Management Of The Perth Metropolitan Purse-Seine Fishery., N. Moore May 1989

Management Of The Perth Metropolitan Purse-Seine Fishery., N. Moore

Fisheries Management Papers

This report outlines the management plan for the limited entry purse-seine fishery for small pelagic fish in coastal waters between Lancelin and Cape Bouvard and seaward to the 200 mile limit of the Australian Fishing Zone. The plan includes Cockburn Sound.


The Prairie Naturalist Volume 21, No.2 June 1989 May 1989

The Prairie Naturalist Volume 21, No.2 June 1989

The Prairie Naturalist

THE MISSISSIPPI KITE IN THE ENVIRONMENTAL HISTORY OF THE SOUTHERN GREAT PLAINS ▪ E. G. Bolen and D. L. Flores

TAPE-RECORDED CHICK CALLS TO LOCATE GRAY PARTRIDGE NESTS ▪ J. P. Carroll

BORROW DISTRIBUTION OF THE THIRTEEN-LINED GROUND SQUIRREL IN GRAZED MIXED-GRASS PRAIRIE: EFFECT OF ARTIFICIAL HABITAT STRUCTURE ▪ D. W. Kaufman and G. A. Kaufman

PIPING PLOVERS NESTING AT NELSON RESERVOIR, MONTANA ▪ D. W. Prellwitz, T. A. Prellwitz, K. L. Stutzman, and J. W. Stutzman

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA - 1988 ▪ R. N. Randall

CHANGING HABITATS IN THE PLATTE RIVER VALLEY OF NEBRASKA ▪ J. …


The Benefits Of Weaning Cattle In The Kimberley, David Pratchett, Stuart Young May 1989

The Benefits Of Weaning Cattle In The Kimberley, David Pratchett, Stuart Young

Animal production and livestock research reports

The Kimberley region was populated with Shorthorn cattle from Queensland and New Sonth Wales in the 1880's. The descendants of these cattle known as Kimberley Shorthorn are still the predominant breed in the region. The relatively poor performance of these cattle under the harsh Kimberley conditions and the fact that changing the genotype can improve productivity was recently published (Pratchett D. WADA Journal No. 4 1988)

While the adoption of Bos indicus breeds is the correct move, improved husbandry can also increase the productivity of the Kimberley Shorthorn cow. The majority of cattle in the Kimberley are not weaned. Sometimes …


An Analysis Of Institutional Approaches For Management Of Common Rangeland Resources In Sub-Saharan Africa, Mohale Gabriel Sekoto May 1989

An Analysis Of Institutional Approaches For Management Of Common Rangeland Resources In Sub-Saharan Africa, Mohale Gabriel Sekoto

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The purpose of this report is to address the issues that are relevant to the management of common rangeland resources in Sub-Saharan Africa. I feel that the issues presented here are among some of those which are important and need to be considered in order to understand the kind of performance perceived about the efforts to develop the range and livestock in pastoral societies. In this report, three case studies have been reviewed, regarding institutional approaches tried to manage common rangelands. These case studies are about group ranches in Kajiado District, Kenya and in Upper Volta and the Sehlabathebe Grazing …


Modeling Forest Dynamics Based On Stand Level Resource Allocation, Geoffrey Candler Poole May 1989

Modeling Forest Dynamics Based On Stand Level Resource Allocation, Geoffrey Candler Poole

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An ecologically based model of forest succession is presented. In the model, trees compete for a share of limited growth resources available from their environment. Competition is reflected by each tree's effect on the resource pool and is not explicitly modeled. Model parameters were fit to field data from subalpine forests of the Rocky Mountains. A technique for estimating model parameters from understory-tolerance rankings and silvical characteristics of each species is also presented. The model's output was consistent with our current understanding of forest dynamics. Emergent properties of the model also mimicked natural processes such as self-thinning, release, and maximum …


Using Computer Imaging To Assess Visual Impacts Of Forest Insect And Disease Pests, Daniel Rabin May 1989

Using Computer Imaging To Assess Visual Impacts Of Forest Insect And Disease Pests, Daniel Rabin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Forest insect and disease pests alter the appearance of trees, thereby impacting visual resources. Because of the complexity of most forest landscapes, the degree of visual impact of pest-infested forest stands is difficult to quantify.

This paper describes a method of measuring visual impacts of pest-infested forest stands. Photographs of healthy Ponderosa pine trees were entered into a computer video-image-processing system. Using this system, images of trees were altered to simulate different degrees of infestation by limb rust, a forest pathogen.

The altered and unaltered images were shown to groups of observers who rated the scenes in terms of "scenic …


Root Exploitation Of Fertile Soil Microsites, Robert B. Jackson May 1989

Root Exploitation Of Fertile Soil Microsites, Robert B. Jackson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Root exploitation of enriched soil microsites was examined for the tussock grasses Agropyron desertorum and Agropyron spicatum and the shrub Artemisia tridentata. Two mechanisms of exploitation of the microsites were examined: root proliferation and changes in nutrient uptake capacity. One day after nutrient solution was applied to small soil patches, the mean relative growth rate of Agropyron desertorum roots in enriched patches was two to four times greater than for roots of the same plants in soil patches treated with distilled water. This rapid and striking root proliferation occurred in response to N-P-K enrichment as well as to P or …


Management, Foraging Behavior, Diet Composition And Forage Quality Of Free-Ranging But Herded Camels In Ceeldheer District, Central Somalia, Ahmed A. Elmi May 1989

Management, Foraging Behavior, Diet Composition And Forage Quality Of Free-Ranging But Herded Camels In Ceeldheer District, Central Somalia, Ahmed A. Elmi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In Somalia, camel (Camelus dromedarius) survivability and milk production has been higher than for other domestic livestock and contributes substantially to the subsistence of Somali pastoralists. The objective of this research was to study management, foraging behavior and nutrition of camels in their natural habitat to determine how production continues under seasonal nutritional stress.

Management systems of Ceeldheer pastoralists are based on available natural pasture and water. The natural rotation grazing system maintained an ecological equilibrium in the District.

Pastoralists manipulate their herds to suit existing environmental conditions, family needs and labor availability for herding. In herd management, …


Fee Hunting Opportunities On Private Land In Utah: An Economic And Policy Analysis, Lucy A. Jordan May 1989

Fee Hunting Opportunities On Private Land In Utah: An Economic And Policy Analysis, Lucy A. Jordan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Objectives of this research were (1) to describe fee hunting as it is currently practiced in Utah and (2) to assess the adequacy of fee hunting efforts in addressing the problems of wildlife habitat and hunter access on private land. To collect information, Utah landowners who charged for deer (Odocoileus hemionus) or elk (Cervus elaphus) hunting in 1986 were surveyed by telephone and mail.

Compared to the average Utah livestock rancher, those involved in fee hunting have larger livestock operations and have owned their property longer. They are Utah natives. Fee hunting is concentrated in northern …


A Review Of The Shark Bay Pearling Industry., D. A. Hancock Apr 1989

A Review Of The Shark Bay Pearling Industry., D. A. Hancock

Fisheries Management Papers

While there are currently only two pearl culture leases in Shark Bay, two new applications for leases have already been received by the W.A. Fisheries Department. Increased interest is being generated about pearl culture in Shark Bay, which will need to be considered against the background of management plans designed to restrict further entry into other areas, notably the pearly industry of W.A from Exmouth Gulf northwards, and the pearling industry of the Northern Territory. Recent successes with pearl culture in both those areas, and the greatly increased revenues and high lease transfer values realised, must inevitably focus interest on …


Wolf Population Survival In An Area Of High Road Density, L. David Mech Apr 1989

Wolf Population Survival In An Area Of High Road Density, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Wolf mortality in a high-road-density area of Minnesota exceeds that in an adjacent wilderness, and is primarily human-caused. The wolf population there is maintained primarily by ingress from the adjacent wilderness areas. A road density of 0.58 km/km2 can be exceeded and the area still support wolves if it is adjacent to extensive roadless areas.


Limnological Monitoring Data For Lake Mead During 1988, Suzanne E. Leavitt, Larry J. Paulson, State Of Nevada: Division Of Environmental Protection Apr 1989

Limnological Monitoring Data For Lake Mead During 1988, Suzanne E. Leavitt, Larry J. Paulson, State Of Nevada: Division Of Environmental Protection

Publications (WR)

Limnological monitoring was conducted in Las Vegas Bay and Boulder Basin from April to December of 1988. The purpose of the monitoring was to (i) document possible changes in water quality resulting from decreased phosphorus loading and increased ammonia in Las Vegas Wash, and (ii) establish a data base for evaluating the adequacy of water quality standards.