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Articles 18481 - 18510 of 19672

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The Coyote (Canis Latrans) In Panama, Eustorgio Méndez, Francisco Delgádo, Demetrio Miranda Jan 1981

The Coyote (Canis Latrans) In Panama, Eustorgio Méndez, Francisco Delgádo, Demetrio Miranda

Conservation Collection

This report reveals that the coyote, Canis Iatrans, has recently extended its southern range to Panama. The skin of one adult female coyote killed by hunters at Los Pirales, a farm near Gualaca in Chiriqui Province, western Panama, has been deposited in the Gorgas Memorial Laboratory Vertebrate Collection. Other coyotes have been observed in Alanje, Boquete and Boqueron, other localities of the same province. The probable range of the coyote in Panama is indicated, and the need for an urgent management strategy for this canid in the Republic is also expressed.


Getting Educated At The Zoo, Nancy Heneson Jan 1981

Getting Educated At The Zoo, Nancy Heneson

Zoos and Aquariums Collection

In this issue we present three papers that deal with the subject of the zoo. Although the focal concern of each paper is different and the positions of the authors range from whole-hearted support of the institution to frank skepticism, all express a belief in the potential educational value of zoos. This editorial, however, has a different premise. It is not meant to criticize the other papers, but rather to raise questions from another point of view.


The Buller-Steer Syndrome, Richard Ulbrich Jan 1981

The Buller-Steer Syndrome, Richard Ulbrich

Ethology Collection

Bulling among steers is an abnormal behavioral trait and is a common health and economic problem in feedlot operations. Factors associated with the buller-steer syndrome are hormonal implantation, seasonality and environmental conditions, stress, overcrowding, and social interaction between individuals. Research has examined relationships between these and other factors and buller occurrence. Boredom of feedlot cattle may contribute to buller occurrence and other undesirable behavior more than we might suspect. Research is needed to determine the feasibility of enriching the environment of penned livestock in general, the goal of which would be, in theory, the elimination of undesirable behavior as well …


An Overview Of Zoo Goals And Exhibition Principles, Randall L. Eaton Jan 1981

An Overview Of Zoo Goals And Exhibition Principles, Randall L. Eaton

Zoos and Aquariums Collection

It is not uncommon among progressive-minded zoo professionals these days to hear disdain for the function of zoos as recreational. This attitude is understandable in that traditionally, zoos have done little but offer amusement along with parklands or picnic facilities. The progressive zoo person sets his or her goals above the old-fashioned recipe of crowding as many exotic animals as possible into an amusement-oriented menagerie to an authentic theme for exhibition intended to educate the public, offer research possibilities, and preserve and propagate species. Nevertheless, recreation remains a primary function of zoos. Most zoo visitors do not seek education in …


Equine Behavior Problems In Relation To Humane Management, Katherine A. Houpt Jan 1981

Equine Behavior Problems In Relation To Humane Management, Katherine A. Houpt

Equines Collection

The behavior problems of horses are frequently related to management practices. Behaviors that are termed stall vices appear to be either stereotyped behaviors that occur in reaction to stress, or patterns that emerge when natural behaviors such as grazing are prevented. The behavior cases presented to the New York State College of Veterinary Medicine, Cornell University, were tabulated: 27% were stall vices and 27% were some form of aggression. The stall vices were circling, digging, kicking the stall, chewing wood, swallowing air or self-mutilation. Management of horses on pasture rather than in stalls prevents the development of many of these …


The Role And Responsibility Of Zoos: An Animal Protection Viewpoint, John E. Cooper Jan 1981

The Role And Responsibility Of Zoos: An Animal Protection Viewpoint, John E. Cooper

Zoos and Aquariums Collection

The aim of this paper is to look at zoological collections from the viewpoint of the animal and, in particular, to draw attention to areas where welfare considerations should be paramount. I do not intend to cover the capture and transportation of zoo animals, although this is obviously of great importance and must be included in any overall consideration of the welfare of zoo animals. In this paper, however, I shall concentrate upon the care of the animal within the zoo environment.


The Foods And Associated Feeding Behavior Of The Yellow-Bellied Marmot, Marmota Flaviventris, Mark William Jonasson Jan 1981

The Foods And Associated Feeding Behavior Of The Yellow-Bellied Marmot, Marmota Flaviventris, Mark William Jonasson

Theses Digitization Project

No abstract provided.


Tornadoes West Of The Divide: A Climatology, Richard P. Mcnulty Jan 1981

Tornadoes West Of The Divide: A Climatology, Richard P. Mcnulty

National Oceanographic and Atmospheric Administration: Technical Reports and Related Materials

A climatology of tornado occurrence west of the Continental Divide is presented. These tornadoes are a small but significant part of severe weather occurrences over the United States. Data are examined from both the spatial and temporal point of view. The influence of population and topography is highly evident.


Giving-Up As A Poisson Process: The Departure Decision Of The Green Lacewing, Alan B. Bond Jan 1981

Giving-Up As A Poisson Process: The Departure Decision Of The Green Lacewing, Alan B. Bond

Alan Bond Publications

Predators that forage for aggregated prey appear to require a decision rule for determining the point at which to discontinue their search in a given prey patch and move on to another. Although the optimum rule depends heavily on features of the searching behavior of the predator and the distribution of the prey (Oaten 1977), most previous authors have assumed that the decision must involve an assessment of the capture rate within a patch and a comparison with the mean capture rate in the environment as a whole (Krebs 1978). When the perceived quality of the given patch becomes significantly …


Die Erforschung Der Herpetofauna Der Mongolischen Volksrepublik: Situation Und Perspektiven, Günther Peters Jan 1981

Die Erforschung Der Herpetofauna Der Mongolischen Volksrepublik: Situation Und Perspektiven, Günther Peters

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

First paragraph:

Die Landschaften der Mongolei sind arm an Reptilien- und Amphibienarten. Dieser Umstand mag die Frage aufwerfen, ob herpetologische Untersuchungen in Beschränkung auf das Territorium der MVR eine nennenswerte Perspektive haben könnten, nachdem Artenspektrum und Verbteitung der Species annähernd vollständig erkundet sind. Ein Herpetologe wird zweifellos für seine Arbeit auch in diesem Land eine Zukunft sehen, doch muß wohl von vornherein eingestanden werden, daß das Volumen der Probleme dieses Faches hinter denen der übrigen Disziplinen der Vertebratenzoologie und der Entomologie in einem bescheidenerem Rahmen verbleibt. Dies gilt sowohl im rein wissenschaftlichen als erst recht auch im angewandten Bereich ihrer …


Physiological Research On Adventitious Shoot Development In Aspen, George A. Schier Jan 1981

Physiological Research On Adventitious Shoot Development In Aspen, George A. Schier

Aspen Bibliography

No abstract provided.


Ecology And Regeneration Of Aspen In Relation To Managment, R.K. Tew Jan 1981

Ecology And Regeneration Of Aspen In Relation To Managment, R.K. Tew

Aspen Bibliography

No abstract provided.


Tree Biomass Estimates For Minnesota's Aspen-Birch Forest Survey Unit, Gerhard K. Raile, Pamela J. Jakes Jan 1981

Tree Biomass Estimates For Minnesota's Aspen-Birch Forest Survey Unit, Gerhard K. Raile, Pamela J. Jakes

Aspen Bibliography

No abstract provided.


Occurrence Of The Land Planarians Bipalium Kewense And Geoplana Sp. In Arkansas, James J. Daly, Julian T. Darlington Jan 1981

Occurrence Of The Land Planarians Bipalium Kewense And Geoplana Sp. In Arkansas, James J. Daly, Julian T. Darlington

Journal of the Arkansas Academy of Science

No abstract provided.


Correlation Of Hook-And-Line Vulnerability Of Largemouth Bass (Micropterus Salmoides) With Selected Physicochemical Parameters At Ridge Lake, Dale P. Burkett Jan 1981

Correlation Of Hook-And-Line Vulnerability Of Largemouth Bass (Micropterus Salmoides) With Selected Physicochemical Parameters At Ridge Lake, Dale P. Burkett

Masters Theses

Fluctuation in kilograms of largemouth bass caught per man-hour of fishing pressure (catch rate) in Ridge Lake (a 6.8ha impoundment located in Fox Ridge State Park, Coles County, Illinois) was positively correlated with dissolved oxygen concentration (r=0.7490), conductivity (r=0.7439), pH (r=0.5965), and alkalinity (r=0.7531). Negative correlations were found between largemouth bass catch rate and turbidity (r=-0.5145), as well as ammonia (r=-0.4694). No significant (p<0.05) correlations were found between catch rate and column water temperature, air temperature, barometric pressure, water level, maximum water temperature, minimum water temperature, maximum air temperature, or minimum air temperature.

Models describing the relationships of the most significant physicochemical parameters to catch rate of largemouth bass were chosen to represent the effects of environment …


Minnesota's Aspen Resource, Pamela J. Jakes Jan 1981

Minnesota's Aspen Resource, Pamela J. Jakes

Aspen Bibliography

No abstract provided.


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 …


Seasonal Abundance, Movement And Diversity Of Fishes In An Ozark Stream, Michael R. Dewey Jan 1981

Seasonal Abundance, Movement And Diversity Of Fishes In An Ozark Stream, Michael R. Dewey

Journal of the Arkansas Academy of Science

Seasonal fluctuations in fish abundance in Mud Creek occurred throughout the year at all sampling stations. At the two upper stations abundance was high and unstable during winter and early spring and decreased after heavy rainfall in mid-April. Abundance was low throughout the summer months, increasing in the fall due to large numbers of young-of-the-year. However, a different seasonal cycle occurred at the lower station which included deeper pools. Numbers were low and stable throughout the winter and early spring but high and unstable during the summer. Bigeye shiners (Notropis boops) and bluntnose minnows (Pimephales notatus) were the most mobile …


Preliminary Report On The Fishes Of The Upper Saline River, Polk And Howard Counties, Arkansas, And Observations On Their Relationships With Land Use And Physiochemical Conditions, Stephen A. Sewell Jan 1981

Preliminary Report On The Fishes Of The Upper Saline River, Polk And Howard Counties, Arkansas, And Observations On Their Relationships With Land Use And Physiochemical Conditions, Stephen A. Sewell

Journal of the Arkansas Academy of Science

The Saline River of southwest Arkansas was impounded by Dierks Lake in 1975. Intensive collecting efforts were made in the river system above Dierks Lake during March, April, and May 1980. Collected specimens were compared with ichthyofaunal lists prior to impoundment. Historic occurrants which were not collected include Notropis amnis, Notropis ortenburgeri, Moxostoma duquesnei, Ammocrypta vivax, and Percina copelandi. Additions to the ichthyofaunal list for the drainage include Fundulus notatus, Etheostoma spectabile, and Percina caprodes. The evidence indicates that 33 species representing six families inhabit the system from the headwaters in Polk County, Arkansas, to Dierks Lake, Howard County, Arkansas. …


Crowley's Ridge Biological Station--An Educational Center, Jewel E. Moore, Inez Hartsoe Jan 1981

Crowley's Ridge Biological Station--An Educational Center, Jewel E. Moore, Inez Hartsoe

Journal of the Arkansas Academy of Science

No abstract provided.


Spatial Memory And The Performance Of Rats And Pigeons In The Radial-Arm Maze, Alan B. Bond, Robert G. Cook, Marvin R. Lamb Jan 1981

Spatial Memory And The Performance Of Rats And Pigeons In The Radial-Arm Maze, Alan B. Bond, Robert G. Cook, Marvin R. Lamb

Papers in Behavior in Biological Sciences

The resource-distribution hypothesis states that the ability of an animal to remember the spatial location of past events is related to the typical distribution of food resources for the species. It appears to predict that Norway rats would perform better than domestic pigeons in tasks requiring spatial event memory. Pigeons, tested in an eight-arm radial maze, exhibited no more than half of the memory capacity observed in rats in the same apparatus and may not have used spatial memory at all. The results were interpreted as supporting the hypothesis.


Cover Of Plants With Extrafloral Nectaries At Four Northern California Sites, Kathleen H. Keeler Jan 1981

Cover Of Plants With Extrafloral Nectaries At Four Northern California Sites, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Percent cover of plants with extrafloral nectaries was investigated in three California habitats with the same physiognomy as habitats previously studied in Nebraska (perennial native grassland, riparian forest, deciduous forest). In contrast to Nebraska where cover of plants with extrafloral nectaries reached 14 percent, no plants with extrafloral nectaries were found in any California transect. Chaparral was also studied; no plants with extrafloral nectaries were found.


Revetment Clearing, Its Influence On Riparian Mammal Communities, Robert E. Willis Jan 1981

Revetment Clearing, Its Influence On Riparian Mammal Communities, Robert E. Willis

Dissertations and Theses

Over 115 miles of rock revetment have been constructed in the Willamette Basin to protect river banks. This study examines the effect on riparian mammals of maintaining these revetments by vegetation and debris clearing. Differences between cleared and uncleared revetments were measured using a canopy coverage method of vegetation analysis; mammals were studied by trapping, by direct observation, and by noting such signs as scats, tracks, etc.


Attributes Of Dispersing Meadow Voles In Open-Grid Populations, Raymond D. Dueser, Marcia L. Wilson, Robert K. Rose Jan 1981

Attributes Of Dispersing Meadow Voles In Open-Grid Populations, Raymond D. Dueser, Marcia L. Wilson, Robert K. Rose

Biological Sciences Faculty Publications

Dispersal was investigated in two open-grid populations of meadow voles, Microtus pennsylvanicus (Ord, 1815) an central Virginia (U.S.A.) from November 1974 to April 1978. "Dispersal" was defined as immigration onto open, occupied population grids. Dispersers were distinguished from residents by weight at first capture. Individuals first captured at weights <30 g were classified as residents; those first captured at >30 g were classified as dispersers. Three independent lines of evidence support the validity of the 30-g criterion for recognizing dispersers in these vole populations. With frequent trapping and high trappability, particularly of young animals, this open-grid method of study offers two advantages in the study of dispersal. First, dispersers identified …


A Study Of Leslie Model Under Stochastic Environments, Kamran Shaukat Jan 1981

A Study Of Leslie Model Under Stochastic Environments, Kamran Shaukat

Dissertations and Theses

The prediction and analysis of changes in the numbers of biological populations rest on mathematical formulations of demographic events (births and deaths) classified by the age of individuals. The development of demographic theory when birth and death rates vary statistically over time is the central theme of this work. A study of the standard Leslie model for the demographic dynamics of populations in variable environments is made. At each time interval a Leslie matrix of survival rates and fertilities of a population is chosen according to a Markov process and the population numbers in different age classes are computed. Analytical …


Karyology And Morphometrics Of Three Species Of Akodon (Mammalia: Muridae) From Northwestern Argentina, Rubén M. Barquez, Daniel F. Williams, Michael A. Mares, Hugh H. Genoways Dec 1980

Karyology And Morphometrics Of Three Species Of Akodon (Mammalia: Muridae) From Northwestern Argentina, Rubén M. Barquez, Daniel F. Williams, Michael A. Mares, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Chromosomal and morphometric studies were conducted on a sample from an assemblage of Akodon spp. occurring in various patterns of sympatry from the provinces of Catamarca, Jujuy, Salta, and Tucumán, Argentina. Results showed three distinct morphometric groups based upon size. Size also varied with age, but there were no significant differences in measurements of males and females. The three morphometric groups have distinct karyotypes. Akodon caenosus Thomas is the smallest of the three, and has a karyotype of 2n = 34, FN = 40. A. boliviensis tucumanensis J. A. Allen is intermediate in size and has 2n = 40, FN …


Results Of The Alcoa Foundation-Suriname Expeditions. Iv. A New Species Of Bat Of The Genus Molossops (Mammalia: Molossidae), Stephen L. Williams, Hugh H. Genoways Dec 1980

Results Of The Alcoa Foundation-Suriname Expeditions. Iv. A New Species Of Bat Of The Genus Molossops (Mammalia: Molossidae), Stephen L. Williams, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

A new species of molossid bat of the genus Molossops is described from Suriname. The new species is a member of the subgenus Molossops where it is distinguished from the other two member species, temminckii and aequatorianus, by larger external and cranial size. A single specimen of the species was taken in northern Suriname in an area of savannah and secondary forest.


Seasonal Variations In Water Chemistry And Primary Productivity In Four Alkaline Lakes In The Sandhills Of Western Nebraska, John A. Schnagl Dec 1980

Seasonal Variations In Water Chemistry And Primary Productivity In Four Alkaline Lakes In The Sandhills Of Western Nebraska, John A. Schnagl

Open Access Master's Theses (through 2010)

Between the Platte and Niobrara Rivers in western and central Nebraska lie over 25,000 square kilometers of dune sand. The dunes have lost their sculptured shapes and windswept edges, being shrouded beneath a mantle of grass and fine loess soil. Only at the blowouts, where wind has cut away this mantle forming cavities in the sides of hills, is the sand exposed.

Dotting this rolling prairie grassland in the depressions between the dunes are small lakes. Over 2000 lakes of widely varied salinities and alkalinities accent the topography of the dunes.

Blue Lake, Roundup Lake, Goose Lake, and Bob’s Lake, …


Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson Dec 1980

Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson

Publications (WR)

This manual contains detailed descriptions of biological, chemical and physical sampling and analytical procedures used at the Lake Mead Limnological Research Center. The manual was prepared in response to requests made by numerous individuals involved in the Las Vegas Valley Water Quality Program. This manual represents what we consider to be a reasonably complete compilation of methods useful in studying both general and specific limnological questions. While each section is sufficiently detailed to be of use to investigators with little experience in limnological methodology, the methods can be used on a wide variety of lakes and reservoirs, with relatively little …


Geochemical And Biogeochemical Interactions In A Hot Spring, William Delis Knox Oct 1980

Geochemical And Biogeochemical Interactions In A Hot Spring, William Delis Knox

Dissertations and Theses

Southeast Harney Lake Hot Spring and its effluent channel were examined for spatial and temporal variations in the concentrations of several chemical species, viz. dissolved oxygen, pH, alkalinity, phosphate-phosphorous, nitrate and nitrite-nitrogen, conductivity, chloride, flouride, temperature, calcium, magnesium, potassium, and sodium. Phosphate-phosphorous and nitrate-nitrogen both exhibited downstream increases in concentration. pH and alkalinity increased also, mainly due to CO2 evolution and temperature mediated carbon species redistribution. The diurnal pH and alkalinity curves exhibited depressions during the daylight hours due to the oxidation of ammonia to nitrate within the pool and effluent stream.