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Ecology and Evolutionary Biology

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Articles 16171 - 16200 of 19704

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An Operational Remote Sensing Algorithm Of Land Surface Evaporation, Kenlo Nishida, Ramakrishna R. Nemani, Steven W. Running, Joseph M. Glassy Jan 2003

An Operational Remote Sensing Algorithm Of Land Surface Evaporation, Kenlo Nishida, Ramakrishna R. Nemani, Steven W. Running, Joseph M. Glassy

Ecosystem and Conservation Sciences Faculty Publications

Partitioning of solar energy at the Earth surface has significant implications in climate dynamics, hydrology, and ecology. Consequently, spatial mapping of energy partitioning from satellite remote sensing data has been an active research area for over two decades. We developed an algorithm for estimating evaporation fraction (EF), expressed as a ratio of actual evapotranspiration (ET) to the available energy (sum of ET and sensible heat flux), from satellite data. The algorithm is a simple two-source model of ET. We characterize a landscape as a mixture of bare soil and vegetation and thus we estimate EF as a mixture of EF …


Soil Microbial Dynamics And Biogeochemistry In Tropical Forests And Pastures, Southwestern Costa Rica, Cory C. Cleveland, Alan R. Townsend, Steven K. Schmidt, Briana C. Constance Jan 2003

Soil Microbial Dynamics And Biogeochemistry In Tropical Forests And Pastures, Southwestern Costa Rica, Cory C. Cleveland, Alan R. Townsend, Steven K. Schmidt, Briana C. Constance

Ecosystem and Conservation Sciences Faculty Publications

Tropical rain forest ecosystems are currently undergoing unprecedented rates of land conversion and land use change. Recent research suggests these activities profoundly influence nutrient cycling, but the principal mechanisms driving variation in nutrient status following land conversion are still not well understood. In this study, we used soils of varying fertility (oxisols and mollisols) in Costa Rica to investigate how conversion of tropical rain forest to cattle pasture affects the size and function of the microbial community, and to explore possible relationships between microbial dynamics and biogeochemistry.

Our pasture sites are relatively lightly managed, and total pools of carbon (C), …


Assessment Of Potential Environmental Impacts Of Nature-Based Tours Originating Within Clark County, Nevada, Beth Domowicz Jan 2003

Assessment Of Potential Environmental Impacts Of Nature-Based Tours Originating Within Clark County, Nevada, Beth Domowicz

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this thesis was to assess the potential magnitude of negative environmental damage of nature-based tours originating in Clark County, Nevada. An ordinal ranking system was used for assessment of five variables. These variables were resource use, noise pollution, soil degradation, vegetation degradation, and wildlife disturbance. There were two proposed answers. The first was that as distance increased, negative tour impact would increase. This was not supported, since tours had high impacts for destinations that were close by and far away. The second was that most tours were not causing high damage to the environment. This hypothesis was …


Bio-Optical Properties Of The Labrador Sea, Glenn F. Cota, W. Glen Harrison, Trevor Platt, Shubha Sathyendranath, Venetia Stuart Jan 2003

Bio-Optical Properties Of The Labrador Sea, Glenn F. Cota, W. Glen Harrison, Trevor Platt, Shubha Sathyendranath, Venetia Stuart

CCPO Publications

Three cruises were conducted during fall and spring in the Labrador Sea to investigate the effects of bio-optical properties on satellite retrievals of phytoplankton chlorophyll in this important high-latitude ecosystem. Taxon-specific and regional differences were found. Diatoms had similar to 1.5 lower chlorophyll-specific absorption but significantly higher reflectance ratios than prymnesiophytes. Particulate absorption at 443 nm for total, phytoplankton, and "detrital'' fractions was related to chlorophyll, but values were lower than reported for lower latitudes. Decreased particulate absorption is attributed primarily to pigment packaging, while low backscattering to scattering ratios result from a lower relative abundance of bacteria and picophytoplankton …


A Monographic Revision Of The Genus Platycoelia Dejean (Coleoptera: Scarabaeidae: Rutelinae: Anoplognathini), Andrew B. T. Smith Jan 2003

A Monographic Revision Of The Genus Platycoelia Dejean (Coleoptera: Scarabaeidae: Rutelinae: Anoplognathini), Andrew B. T. Smith

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

This paper presents a taxonomic revision of the genus Platycoelia Dejean (Coleoptera: Scarabaeidae: Rutelinae: Anoplognathini: Platycoeliina). Phylogenetic analyses of all species in the genus were conducted and the biogeography of the genus is discussed. The phylogenetic analysis supports the monophyly of Platycoelia and divides the genus into four major clades. Based on the cladistic analysis, the generic names Callichloris Burmeister, Leucopelaea Bates, and Epicallichloris Gutiérrez are considered synonyms of Platycoelia. Character states supporting monophyletic clades are discussed. Descriptions and keys to all taxa are included.

The genus Platycoelia was revised and now includes 62 species, 19 of which are described …


The Tadpole Of Phrynobatrachus Mababiensis Fitzsimons, 1932 (Anura, Ranidae, Petropedetinae), Rafael O. De Sá, Alan Channing Jan 2003

The Tadpole Of Phrynobatrachus Mababiensis Fitzsimons, 1932 (Anura, Ranidae, Petropedetinae), Rafael O. De Sá, Alan Channing

Biology Faculty Publications

The puddle frog genus Phrynobatrachus Günther, 1862 comprises about 64 currently recognized species (Frost, 1985). Of these, only the tadpoles of P. natalensis (Smith, 1849) (Power, 1927; Channing, 2001), P. guineensis Guibé & Lamotte, 1961(Rödel,1998) and P. alticola Guibé & Lamotte, 1961 (Rödel & Ernst, 2002) have been described. Phrynobatrachus mababiensis FitzSimons, 1932 (Dwarf Puddle frog, Wager, 1986; Mababe River frog, Frank & Ramus, 1996) is a small frog that usually calls from low in thick vegetation on flooded terrains close to the water. Very little has been published about the biology of this species. Passmore & Carruthers (1979) reported …


Polystomatidae (Monogenea) Of Southern African Anura: Eupolystoma Vanasi N. Sp. Parasitic In Schismaderma Carens (Smith), Louis H. Du Preez, Richard C. Tinsley, Rafael O. De Sá Jan 2003

Polystomatidae (Monogenea) Of Southern African Anura: Eupolystoma Vanasi N. Sp. Parasitic In Schismaderma Carens (Smith), Louis H. Du Preez, Richard C. Tinsley, Rafael O. De Sá

Biology Faculty Publications

Eupolystoma vanasi is described as a new species of the Polystomatidae parasitic in the urinary bladder of Schismaderma carens in Northern Province and KwaZulu-Natal Province, South Africa. This is the third Eupolystoma species described from Africa and the first polystomatid from Schismaderma, an anuran genus that is primitive with respect to the other African bufonids in which Eupolystoma has been recorded. The species is distinguished by body size (this is the largest Eupolystoma known; mean length of adults 6 mm), by genital spine number (4 in comparison with 6-9 in other species), marginal hooklet length (greater than in other …


Bits And Particles: Information And Machines Sufficient To Infer An Intelligent Designer, Timothy G. Standish Jan 2003

Bits And Particles: Information And Machines Sufficient To Infer An Intelligent Designer, Timothy G. Standish

Journal of the Adventist Theological Society

No abstract provided.


Contributions To Creation Theory From The Study Of Nature, L. James Gibson Jan 2003

Contributions To Creation Theory From The Study Of Nature, L. James Gibson

Journal of the Adventist Theological Society

No abstract provided.


Introduction, L. David Mech, Luigi Boitani Jan 2003

Introduction, L. David Mech, Luigi Boitani

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

THE WOLF IS TRULY a special animal. As the most widely distributed of all land mammals, the wolf, formally the gray wolf (Canis lupus), is also one of the most adaptable. It inhabits all the vegetation types of the Northern Hemisphere and preys on all the large mammals living there. It also feeds on all the other animals in its environment, scavenges, and can even eat fruits and berries. Wolves frequent forests and prairies, tundra, barren ground, mountains, deserts, and swamps. Some wolves even visit large cities, and, of course, the wolf's domesticated version, the dog, thrives in …


Wolf Social Ecology, L. David Mech, Luigi Boitani Jan 2003

Wolf Social Ecology, L. David Mech, Luigi Boitani

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

THE FIRST REAL BEGINNING to our understanding of wolf social ecology came from wolf 2204 on 23 May 1972. State depredation control trapper Lawrence Waino, of Duluth, Minnesota, had caught this female wolf 112 km ( 67 mi) south of where L. D. Mech had radio-collared her in the Superior National Forest 2 years earlier. A young lone wolf, nomadic over 100 km2 (40 mi2) during the 9 months Mech had been able to keep track of her, she had then disappeared until Waino caught her. From her nipples it was apparent that she had just been …


References, L. David Mech, Luigi Boitani Jan 2003

References, L. David Mech, Luigi Boitani

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

Abrams, P. A. 2000. The evolution of predator-prey interactions. Annu. Rev. Ecol. Syst. 31:79-105.

Abuladze, K. I. 1964. Osnovy Tsestodologii. Vol. IV. Teniatylentochnye gel' minty zhivotnykh i cheloveka i vyzyvaevaniia. Nauka, Moscow. 530 pp.

Achuff, P. L., and R. Petocz. 1988. Preliminary resource inventory of the Arjin Mountains Nature Reserve, Xinjiang, People's Republic of China. World Wide Fund for Nature, Gland, Switzerland. 78 pp.

Ackerman, B. B., F. A. Leban, M. D. Samuel, and E. 0. Garton. 1990. User's manual for program Home Range. 2d ed. Technical Report no. 15. Forestry, Wildlife, and Range Experiment Station, University ofldaho, Moscow.

Acorn, …


Wolf Population Dynamics, Todd K. Fuller, L. David Mech, Jean Fitts Cochrane Jan 2003

Wolf Population Dynamics, Todd K. Fuller, L. David Mech, Jean Fitts Cochrane

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

A LARGE, DARK WOLF poked his nose out of the pines in Yellowstone National Park as he thrust a broad foot deep into the snow and plowed ahead. Soon a second animal appeared, then another, and a fourth. A few minutes later, a pack of thirteen lanky wolves had filed out of the pines and onto the open hillside.

Wolf packs are the main social units of a wolf population. As numbers of wolves in packs change, so too, then, does the wolf population (Rausch 1967). Trying to understand the factors and mechanisms that affect these changes is what the …


Wolves: Behavior, Ecology, And Conservation: Photo Section Ii, Douglas W. Smith, L. David Mech, Isaac Babcock, Melissa Mccaw Jan 2003

Wolves: Behavior, Ecology, And Conservation: Photo Section Ii, Douglas W. Smith, L. David Mech, Isaac Babcock, Melissa Mccaw

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

Adult wolves are very attentive to the pups. Both parents feed and care for them. Any older siblings similarly participate in pup care and feeding. Kin selection is probably the best explanation for the latter behavior. Top: Photograph by Isaac Babcock. Bottom: Photograph by L. David Mech.


Wolf Interactions With Non-Prey, Warren B. Ballard, Ludwig N. Carbyn, Douglas W. Smith Jan 2003

Wolf Interactions With Non-Prey, Warren B. Ballard, Ludwig N. Carbyn, Douglas W. Smith

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

WOLVES SHARE THEIR ENVIRONMENT with many animals besides those that they prey on, and the nature of the interactions between wolves and these other creatures varies considerably. Some of these sympatric animals are fellow canids such as foxes, coyotes, and jackals. Others are large carnivores such as bears and cougars. In addition, ravens, eagles, wolverines, and a host of other birds and mammals interact with wolves, if only by feeding on the remains of their kills.


Conclusion, L. David Mech, Luigi Boitani Jan 2003

Conclusion, L. David Mech, Luigi Boitani

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

WOLVES CAN LIVE almost anywhere in the Northern Hemisphere, and almost everywhere they do, they are an issue. In the vast emptiness of the northern tundra or the Arabian desert, on the outskirts of a European town or in the safety of an American national park, in meager agricultural lands in India or mountains in rich Norway or Switzerland, wolves always attract people's attention. Wolves form a key part of many ecosystems, and they are considered charismatic creatures by most human cultures. Thus they polarize public opinion and make headlines year after year.

If we look back 6o years to …


Incidence Of Mink, Mustela Vison, And River Otter, Lutra Canadensis, In A Highly Urbanized Area, L. David Mech Jan 2003

Incidence Of Mink, Mustela Vison, And River Otter, Lutra Canadensis, In A Highly Urbanized Area, L. David Mech

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

Mink (Mustela vison) frequently inhabited or traversed a residential. business. and industrial part of the Twin Cities. Minnesota, with little water or natural vegetation. At least one River Otter (Lutra canadensis) also resided on a small pond on a golf course in the area for several winter months.


A Comparative Analysis Of Social Play In Birds, Judy Diamond, Alan B. Bond Jan 2003

A Comparative Analysis Of Social Play In Birds, Judy Diamond, Alan B. Bond

Papers in Behavior in Biological Sciences

Although social play is broadly distributed among mammals, it is infrequently encountered in other vertebrate taxa. It is, however, displayed in a fully realized and complex form in several groups of birds. Unambiguous accounts of social play have been recorded from thirteen species of parrots, seven species of corvids, and several hornbills and Eurasian babblers. We conducted an analysis of the avian play literature, testing for differences between avian taxa, as well as for correlations between play complexity, brain size, and age of first reproduction. Corvids were far more likely to show social object play than parrots. Corvids, parrots, and …


Social Complexity And Transitive Inference In Corvids, Alan B. Bond, Alan Kamil, Russell P. Balda Jan 2003

Social Complexity And Transitive Inference In Corvids, Alan B. Bond, Alan Kamil, Russell P. Balda

Papers in Behavior in Biological Sciences

The social complexity hypothesis asserts that animals living in large social groups should display enhanced cognitive abilities along predictable dimensions. To test this concept, we compared highly social pinyon jays, Gymnorhinus cyanocephalus, with relatively nonsocial western scrub-jays, Aphelocoma californica, on two complex cognitive tasks relevant to the ability to track and assess social relationships. Pinyon jays learned to track multiple dyadic relationships more rapidly and more accurately than scrub-jays and appeared to display a more robust and accurate mechanism of transitive inference. These results provide a clear demonstration of the association between social complexity and cognition in animals.


Searching By Rules: Pigeons’ (Columba Livia) Landmark-Based Search According To Constant Bearing Or Constant Distance, Marcia C. Spetch, Tiana B. Rust, Alan Kamil, Juli E. Jones Jan 2003

Searching By Rules: Pigeons’ (Columba Livia) Landmark-Based Search According To Constant Bearing Or Constant Distance, Marcia C. Spetch, Tiana B. Rust, Alan Kamil, Juli E. Jones

Papers in Behavior in Biological Sciences

Pigeons (Columba livia) searched for a goal location defined by a constant relative spatial relationship to 2 landmarks. For one group, landmark-to-goal bearings remained constant while distance varied. For another group, landmark-to-goal distances remained constant while direction varied. Birds were trained with 4 interlandmark distances and then tested with 5 novel interlandmark distances. Overall error magnitude was similar across groups and was larger than previously reported for Clark’s nutcrackers (Nucifraga columbiana). During training, error magnitude increased with interlandmark distance for constant-bearing but not constant-distance birds. Both groups searched less accurately along the axis parallel to landmarks …


Nontarget Effects—The Achilles’ Heel Of Biological Control? Retrospective Analyses To Reduce Risk Associated With Biocontrol Introductions, Svata M. Louda, R. W. Pemberton, M. T. Johnson, P. A. Follett Jan 2003

Nontarget Effects—The Achilles’ Heel Of Biological Control? Retrospective Analyses To Reduce Risk Associated With Biocontrol Introductions, Svata M. Louda, R. W. Pemberton, M. T. Johnson, P. A. Follett

Papers in Ecology

Controversy exists over ecological risks in classical biological control. We reviewed 10 projects with quantitative data on nontarget effects. Ten patterns emerged: (a) Relatives of the pest are most likely to be attacked; (b) host-specificity testing defines physiological host range, but not ecological range; (c) prediction of ecological consequences requires population data; (d) level of impact varied, often in relation to environmental conditions; (e) information on magnitude of nontarget impact is sparse; ( f ) attack on rare native species can accelerate their decline; (g) nontarget effects can be indirect; (h) agents disperse from agroecosystems; (i) whole assemblages of species …


Bats Of Nevis, Northern Lesser Antilles, Scott C. Pedersen, Hugh H. Genoways, Matthew N. Morton, James W. Johnson, Siân E. Courts Jan 2003

Bats Of Nevis, Northern Lesser Antilles, Scott C. Pedersen, Hugh H. Genoways, Matthew N. Morton, James W. Johnson, Siân E. Courts

University of Nebraska State Museum: Mammalogy Papers

Only one species of bat, Molossus molossus, previously has been documented as occurring on the northern Lesser Antillean island of Nevis. Field research and reviews of existing museum collections have provided documentation based on voucher specimens for an additional seven species occurring on the island — Noctilio leporinus, Brachyphylla cavernarum, Monophyllus plethodon, Ardops nichollsi, Artibeus jamaicensis, Natalus stramineus, and Tadarida brasiliensis. The biological diversity of the chiropteran fauna on Nevis is similar to that found on other islands in the northern Lesser Antilles. Ecologically, this is a simple chiropteran fauna, including one …


Leptodactylus Mystacinus, M. M. Heyer, W. R. Heyer, Rafael O. De Sá Jan 2003

Leptodactylus Mystacinus, M. M. Heyer, W. R. Heyer, Rafael O. De Sá

Biology Faculty Publications

Adult Leptodactylus mystacinus are of moderate size, the head is as wide as long, and the hind limbs are moderately short (see Table; Heyer and Thompson 2000 provided definitions of adult size and leg length categories for Leptodactylus). Male vocal sacs are not visible externally or at best are weakly expanded laterally and slightly darker than female throats. Male snouts are more spatulate than those of females. Male forearms are not hypertrophied. Males lack asperities on the thumbs and chest. One or two pairs of dorsolateral folds (indicated by dark/light outlining in indifferently preserved specimens) are present: one …


Regional Dispersal Of Daphnia Lumholtzi In North America Inferred From Issr Genetic Markers, G. Matthew Groves Jan 2003

Regional Dispersal Of Daphnia Lumholtzi In North America Inferred From Issr Genetic Markers, G. Matthew Groves

Masters Theses

The exotic zooplankter Daphnia lumholtzi is believed to have been introduced into Fairfield Lake, TX in 1983. Since introduction, D. lumholtzi has spread throughout the Midwest and Southeast United States. Due to its large head and tail spines, it may be less susceptible than native species to predation and therefore pose a threat to aquatic ecosystems. Development of management practices calls for study of the dispersal and potential impact of D. lumholtzi on invaded ecosystems.

Inter-simple sequence repeat (ISSR) markers were used in an effort to determine dispersal patterns of D. lumholtzi. Previous studies have shown that ISSRs possess …


Linking Dispersal To Local Population Dynamics: A Case Study Using A Headwater Salamander System, Winsor H. Lowe Jan 2003

Linking Dispersal To Local Population Dynamics: A Case Study Using A Headwater Salamander System, Winsor H. Lowe

Dartmouth Scholarship

Dispersal can strongly influence local population dynamics and may be critical to species persistence in fragmented landscapes. Theory predicts that dispersal by resident stream organisms is necessary to offset the loss of individuals to downstream drift. However, there is a lack of empirical data linking dispersal and drift to local population dynamics in streams, leading to uncertainty regarding the general demographic significance of these processes and the power of drift to explain observed dispersal patterns. I assessed the contribution of dispersal along a first-order stream to population dynamics of the headwater salamander Gyrinophilus porphyriticus (Plethodontidae). I conducted mark–recapture surveys of …


The "Kinds" Of Genesis 1: What Is The Meaning Of Min?, A. Rahel Schafer Jan 2003

The "Kinds" Of Genesis 1: What Is The Meaning Of Min?, A. Rahel Schafer

Journal of the Adventist Theological Society

No abstract provided.


Effects Of Range Size On Species–Area Relationships, Andrew P. Allen, Ethan P. White Jan 2003

Effects Of Range Size On Species–Area Relationships, Andrew P. Allen, Ethan P. White

Biology Faculty Publications

It has been known for some time that the slope of the species–area relationship increases asymptotically at broad spatial scales when richness is plotted against area on logarithmic axes. At continental to global scales, species–area relationships are determined to a large extent by the abundance and size distribution of species ranges. Here we present an analytical model that explicitly quantifies the effects of range size on species–area relationships. The model shows how range size and plot area interact to control the form of species–area relationships at broad spatial scales. It also demonstrates how changes in spatial scale affect biodiversity patterns …


Recognizing Toxic Species In Aquatic Habitats: A Potential Concern In Lake Management, Mikolaj Kokocinski, Harold G. Marshall Jan 2003

Recognizing Toxic Species In Aquatic Habitats: A Potential Concern In Lake Management, Mikolaj Kokocinski, Harold G. Marshall

Biological Sciences Faculty Publications

The importance of distinguishing toxic and non-toxic algal species is becoming a more common problem for management decisions associated with various freshwater and estuarine habitats. An example is given where two dinoflagellates, originally unidentified as closely resembling the toxin producing Pfiesteria spp., have been compared to these species. In order to clarify any relationship to Pfiesteria spp., scanning electron microscopy was used to determine the plate tabulation patterns of these dinoflagellates and make comparisons to the tabulation present in Pfiesteria spp. The results indicated significant differences in the plate tabulations of these taxa to distinguish them from Pfiesteria …


Algal Composition And Abundance In The Neuston Surface Micro Layer From A Lake And Pond In Virginia (U.S.A.), Lubomira Burchardt, Harold G. Marshall Jan 2003

Algal Composition And Abundance In The Neuston Surface Micro Layer From A Lake And Pond In Virginia (U.S.A.), Lubomira Burchardt, Harold G. Marshall

Biological Sciences Faculty Publications

A comparative study was conducted that characterized the algae within the neuston, ca 2 mm below the surface, and the algae in the water column from two freshwater habitats. There were significant differences in total algal abundance and the abundance of diatoms, cyanoprokaryotes, and chlorophytes between the neuston and water column algae of these two regions during each season and at both sites. The pond neuston was dominated by chlorophytes, with total algal abundance ranging seasonally from 0.6 to 59.6 x 10-3 cells ml-1 compared to water column algal concentrations of 4.1 to 40.4 x 10-3 cells ml-1. …


Experimental Investigation Of Elemental Incorporation In The Otoliths Of Larval And Juvenile Fish: Implications For Use As Environmental Recorders, Gretchen Bath Martin Jan 2003

Experimental Investigation Of Elemental Incorporation In The Otoliths Of Larval And Juvenile Fish: Implications For Use As Environmental Recorders, Gretchen Bath Martin

Biological Sciences Theses & Dissertations

Innovative techniques for discerning fish stocks, identifying nursery habitats, locating spawning sites, tracing larval transport pathways, and quantifying the degree of population connectivity are required to meet the goals of sustainable management of marine capture fisheries. One of the most promising techniques is the use of elemental signatures in fish otoliths (ear stones), which record valuable life history data and serve as the link between fish and their environment. To validate the assumption that otolith elemental composition is a function of water elemental concentrations, and to address the possible effects of external variables such as temperature and salinity, the composition …