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Rabbit Abundance Relative To Rainfall And Plant Production In Northern Chihuahuan Desert Grassland And Shrubland Habitats, David C. Lightfoot, Ana D. Davidson, Christopher M. Mcglone, Dara G. Parker Dec 2010

Rabbit Abundance Relative To Rainfall And Plant Production In Northern Chihuahuan Desert Grassland And Shrubland Habitats, David C. Lightfoot, Ana D. Davidson, Christopher M. Mcglone, Dara G. Parker

Western North American Naturalist

No abstract provided.

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Desiccation Sensitivity And Heat Tolerance Of Prunus Ilicifolia Seeds Dispersed By American Black Bears (Ursus Americanus), Mark Borchert, Claudia M. Tyler Dec 2010

Desiccation Sensitivity And Heat Tolerance Of Prunus Ilicifolia Seeds Dispersed By American Black Bears (Ursus Americanus), Mark Borchert, Claudia M. Tyler

Western North American Naturalist

Carnivore consumption of fruit is a principle means by which many fleshy-fruited plant species achieve long-distance seed dispersal. We examined carnivore dispersal of hollyleaf cherry (Prunus ilicifolia) seeds, specifically assessing the survival, desiccation sensitivity, and germination of seeds found in bear scats. Studies were conducted both in the laboratory and in 2 burn areas in Los Padres National Forest, California. Bear scats containing P. ilicifolia seeds were collected in burned and unburned chaparral. We counted seeds in each scat and noted whether endocarps had tooth punctures or rattled audibly when shaken. For comparative germination trials, we also collected …

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Nesting Ecology Of Yellow Warblers (Dendroica Petechia) In Montane Chaparral Habitat In The Northern Sierra Nevada, Diana L. Humple, Ryan D. Burnett Oct 2010

Nesting Ecology Of Yellow Warblers (Dendroica Petechia) In Montane Chaparral Habitat In The Northern Sierra Nevada, Diana L. Humple, Ryan D. Burnett

Western North American Naturalist

The Yellow Warbler (Dendroica petechia) is considered a riparian specialist in much of western North America, but in California it also breeds in a second habitat type: montane chaparral of the Sierra Nevada and southern Cascades. We monitored Yellow Warbler nests in montane chaparral and assessed their poorly known nesting ecology in this habitat. We also conducted point counts in upland habitat throughout the region. We determined habitat associations for Yellow Warblers based on nest site and point-count vegetation data; nests were predominantly in bush chinquapin (Chrysolepis sempervirens) and greenleaf manzanita (Arctostaphylos patula), and …

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A Late-Pleistocene/Holocene Biotic Community From Marmot End Alcove, Escalante River Basin, Colorado Plateau, Usa, Manny Kropf Oct 2010

A Late-Pleistocene/Holocene Biotic Community From Marmot End Alcove, Escalante River Basin, Colorado Plateau, Usa, Manny Kropf

Western North American Naturalist

Skeletal remains of the extinct mountain goat Oreamnos harringtoni and Marmota (marmot), an extralimital species, were recovered from Marmot End Alcove along with remains of montane plants that included Pseudotsuga menziesii (Douglas-fir), Picea (spruce), Pinus flexilis (limber pine), and Juniperus communis (common juniper). The alcove is located in Harris Wash, a semiarid tributary in an unstudied portion of the Escalante River Basin on the Colorado Plateau in southern Utah. A Marmota incisor tooth and montane plant needles returned late Pleistocene AMS dates ranging from 12,300 yr BP to 15,600 yr BP.

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Sleep, Bmi, And Work-Family Conflict: A Gender Comparison Of U.S. Workers, Blake Lee Jones Aug 2010

Sleep, Bmi, And Work-Family Conflict: A Gender Comparison Of U.S. Workers, Blake Lee Jones

Theses and Dissertations

This study used structural equation modeling (SEM) to examine how sleep problems, Body Mass Index (BMI), and poverty were related to several work, personal, and family variables in a sample of married male and female workers in the United States. The data for this study came from the National Study of the Changing Workforce (NSCW) 2008. This large, nationally representative dataset provided a resource for examining potential gender differences in variables that have been linked to sleep problems and increases in BMI, as well as how each of these variables relate to several work, personal, and family life outcomes, including …

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Multidisciplinary Assessment And Documentation Of Past And Present Human Impacts On The Neotropical Forests Of Petén, Guatemala, Christopher Stephen Balzotti Jul 2010

Multidisciplinary Assessment And Documentation Of Past And Present Human Impacts On The Neotropical Forests Of Petén, Guatemala, Christopher Stephen Balzotti

Theses and Dissertations

Tropical forests provide important habitat for a tremendous diversity of plant and animal species. However, limitations in measuring and monitoring the structure and function of tropical forests has caused these systems to remain poorly understood. Remote-sensing technology has provided a powerful tool for quantification of structural patterns and associating these with resource use. Satellite and aerial platforms can be used to collect remotely sensed images of tropical forests that can be applied to ecological research and management. Chapter 1 of this article highlights the resources available for tropical forest remote sensing and presents a case-study that demonstrates its application to …

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Present Effects Of Past Wildfires On Leaf Litter Breakdown In Stream Ecosystems, Peter Koetsier, Teresa R. B. Krause, Quenton M. Tuckett Jul 2010

Present Effects Of Past Wildfires On Leaf Litter Breakdown In Stream Ecosystems, Peter Koetsier, Teresa R. B. Krause, Quenton M. Tuckett

Western North American Naturalist

We investigated the present effects from a 10-year-old wildfire on leaf litter breakdown rates in 3 headwater streams in central Idaho. These systems experienced a massive debris flow one year after the fire. Based on soil instability and burn patterns, we identified 3 stream conditions: unburned, burned only, and burned/scoured. We placed leaf bags containing willow leaves (Salix sp.) in each stream type and removed bags at various time intervals until all bags were collected 100 days after their introduction. Leaf material was dried and weighed, and decay rate coefficients were calculated. Macroinvertebrates colonizing the bags were enumerated and …

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Pollen Evidence Of Historical Forest Disturbance On The Wasatch Plateau, Utah, Jesse L. Morris, Andrea R. Brunelle, A. Steven Munson Jul 2010

Pollen Evidence Of Historical Forest Disturbance On The Wasatch Plateau, Utah, Jesse L. Morris, Andrea R. Brunelle, A. Steven Munson

Western North American Naturalist

Environmental indicators from lake sediments provide excellent opportunities to improve understanding of forest disturbance processes and corresponding changes in forest composition. Our research provides a methodology for assessing recent, historic, and prehistoric disturbances using lacustrine sediment records. We collected sediment cores from Blue Lake, a small subalpine lake on the Wasatch Plateau in central Utah. These cores record environmental changes caused by both spruce beetle (Dendroctonus rufipennis Kirby) and human (logging and livestock grazing) modification. We observed deteriorated insect remains in the lake sediments. These remains correspond temporally with a historic spruce beetle outbreak, though alkaline conditions in the …

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Remote Sensing Time Series For Modeling Invasive Species Distribution: A Case Study Of Tamarix Spp. In The Us And Mexico, Anna F. Cord, Doris Klein, Stefan Dech Jul 2010

Remote Sensing Time Series For Modeling Invasive Species Distribution: A Case Study Of Tamarix Spp. In The Us And Mexico, Anna F. Cord, Doris Klein, Stefan Dech

International Congress on Environmental Modelling and Software

Detecting invasive species and predicting their potential distribution are crucial to coordinate management responses. Remote sensing data are now available in several spatial and temporal resolutions and can supply environmental models with additional information. This study uses the Maximum Entropy algorithm to model the current distribution of the saltcedar (Tamarix spp.) in the US and Mexico and to identify suitable habitats, both already inhabited and not yet occupied. Tamarisk is restricted to specific habitats such as riparian zones, wetlands and agricultural or disturbed areas, which are typically not only characterized by climate. To describe vegetation phenology and thermal seasonality in …

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Habitat Models As A Research Gap In Biodiversity Conservation In Tropical Rain Forest Of Southeast Asia, Mona Nazeri, Jusoff Kamaruzzaman, Nima Madani Jul 2010

Habitat Models As A Research Gap In Biodiversity Conservation In Tropical Rain Forest Of Southeast Asia, Mona Nazeri, Jusoff Kamaruzzaman, Nima Madani

International Congress on Environmental Modelling and Software

Tropical rain forests, the richest terrestrial ecosystem on earth are disappearing due to land use changes mainly agricultural activities and timber logging. Habitat alteration and as a result fragmentation have direct effect on species survival trough lose of connectivity between suitable habitats. Without a doubt the traditional strategies for protecting different wildlife species in this region was not successful enough to guarantee the survival of remaining biodiversity. Distribution modelling which, very little has been studied in the region, is significantly important for biodiversity conservation programs. Distribution data can determine all the areas that can have high potential of occupancy by …

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Remote Sensing Time Series For Modeling Invasive Species Distribution: A Case Study Of Tamarix Spp. In The Us And Mexico, Anna F. Cord, Doris Klein, Stefan Dech Jul 2010

Remote Sensing Time Series For Modeling Invasive Species Distribution: A Case Study Of Tamarix Spp. In The Us And Mexico, Anna F. Cord, Doris Klein, Stefan Dech

International Congress on Environmental Modelling and Software

Detecting invasive species and predicting their potential distribution are crucial to coordinate management responses. Remote sensing data are now available in several spatial and temporal resolutions and can supply environmental models with additional information. This study uses the Maximum Entropy algorithm to model the current distribution of the saltcedar (Tamarix spp.) in the US and Mexico and to identify suitable habitats, both already inhabited and not yet occupied. Tamarisk is restricted to specific habitats such as riparian zones, wetlands and agricultural or disturbed areas, which are typically not only characterized by climate. To describe vegetation phenology and thermal seasonality in …

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The Application Of Artificial Neural Network For Forecasting Dam Spillage Events., Anita Talib, Yahya Abu Hasan Jul 2010

The Application Of Artificial Neural Network For Forecasting Dam Spillage Events., Anita Talib, Yahya Abu Hasan

International Congress on Environmental Modelling and Software

Artificial Neural Network (ANN ) is applied for forecasting of dam spillage using a 10year hydrological dataset of Ahning Dam in the northern Malaysia at the Pedu-Mudaarea. During the rainy season, the Ahning Dam will overflow due to heavy rainfall.Increased siltation due to logging could contribute to worsen the overflow during thistime. This will lead to increasingly destructive floods downstream. Rainfall in the Pedu-Muda area is not constant. It is highly influenced by the monsoon seasons. During the dryseason, the dams may dry up. Siltation will further hamper the dams’ capability to storewater for irrigation.This study has shown that a …

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The Application Of Artificial Neural Network For Forecasting Dam Spillage Events., Anita Talib, Yahya Abu Hasan Jul 2010

The Application Of Artificial Neural Network For Forecasting Dam Spillage Events., Anita Talib, Yahya Abu Hasan

International Congress on Environmental Modelling and Software

Artificial Neural Network (ANN ) is applied for forecasting of dam spillage using a 10year hydrological dataset of Ahning Dam in the northern Malaysia at the Pedu-Mudaarea. During the rainy season, the Ahning Dam will overflow due to heavy rainfall.Increased siltation due to logging could contribute to worsen the overflow during thistime. This will lead to increasingly destructive floods downstream. Rainfall in the Pedu-Muda area is not constant. It is highly influenced by the monsoon seasons. During the dryseason, the dams may dry up. Siltation will further hamper the dams’ capability to storewater for irrigation.This study has shown that a …

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Habitat Models As A Research Gap In Biodiversity Conservation In Tropical Rain Forest Of Southeast Asia, Mona Nazeri, Jusoff Kamaruzzaman, Nima Madani Jul 2010

Habitat Models As A Research Gap In Biodiversity Conservation In Tropical Rain Forest Of Southeast Asia, Mona Nazeri, Jusoff Kamaruzzaman, Nima Madani

International Congress on Environmental Modelling and Software

Tropical rain forests, the richest terrestrial ecosystem on earth are disappearing due to land use changes mainly agricultural activities and timber logging. Habitat alteration and as a result fragmentation have direct effect on species survival trough lose of connectivity between suitable habitats. Without a doubt the traditional strategies for protecting different wildlife species in this region was not successful enough to guarantee the survival of remaining biodiversity. Distribution modelling which, very little has been studied in the region, is significantly important for biodiversity conservation programs. Distribution data can determine all the areas that can have high potential of occupancy by …

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Large-Scale Effects On Bird Assemblages In Desert Grasslands, Giselle Block, Michael L. Morrison Apr 2010

Large-Scale Effects On Bird Assemblages In Desert Grasslands, Giselle Block, Michael L. Morrison

Western North American Naturalist

During winter 1996–1997 and summer 1997, we surveyed birds at 26 study sites in desert grasslands of Arizona and New Mexico to determine tolerance of birds to variability in plant composition and structure. The relationship between bird abundance and vegetative characteristics might be an important consideration in the development of management and restoration plans. Of the 49 bird species we observed, we examined 13 and 16 species in detail for winter and summer seasons, respectively. A noticeable shift in species composition occurred between 3% and 10% woody plant cover. During winter, Chestnut-collared Longspurs (Calcarius ornatus) and Horned Larks …

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Diversity And Abundance Of The Dark Kangaroo Mouse, Microdipodops Megacephalus, In Communities Of Nocturnal Granivorous Rodents In Western North America, Ashley Sagers Haug Mar 2010

Diversity And Abundance Of The Dark Kangaroo Mouse, Microdipodops Megacephalus, In Communities Of Nocturnal Granivorous Rodents In Western North America, Ashley Sagers Haug

Theses and Dissertations

The dark kangaroo mouse, Microdipodops megacephalus, is a sensitive species in the Great Basin Desert. This thesis explores the structure of desert rodent communities of the Great Basin to better understand M. megacephalus' place in the community and the conditions that promote large and stable populations. To determine community structure, I used nestedness analysis to evaluate 99 communities of nocturnal granivorous rodents. I found that the community structure was non-random, indicating the existence of assembly rules and ecological constraints. I also found that M. megacephalus was the second most vulnerable species in the community. To explore the correlation …

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Taxonomy And Applied Biogeography Of Mongolian Stoneflies (Insecta: Plecoptera), Sarah Walker Judson Mar 2010

Taxonomy And Applied Biogeography Of Mongolian Stoneflies (Insecta: Plecoptera), Sarah Walker Judson

Theses and Dissertations

Since the early 1900s, efforts have been made to catalogue the stoneflies of Mongolia. Taxonomic work from 1960 to 1980 greatly expanded basic lists of stoneflies in Mongolia, but no comprehensive survey or synthesis of this dispersed literature has been completed. In conjunction with a modern survey of the aquatic insects of Mongolia, we collected Plecoptera on a series of expeditions to the Selenge (north) and Altai (west) regions of Mongolia. A total of 48 species distributed in 24 genera and 8 families were documented, including 3 of the 5 Mongolian endemics, 2 new species records for Mongolia, and 1 …

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Parental Factors As A Moderator Of The Co-Occurrence Of Substance Use And Depression In Hispanic Adolescents, Rebecca Shoff Mar 2010

Parental Factors As A Moderator Of The Co-Occurrence Of Substance Use And Depression In Hispanic Adolescents, Rebecca Shoff

Theses and Dissertations

The purpose of this study was to evaluate the relationship between parenting factors and Hispanic adolescent substance use and depression. Specifically, the study examined the relationship between parental support, parental knowledge, and parental psychological control among Hispanic adolescents' use of alcohol, tobacco, marijuana, hard drugs and depressive symptoms. The sample included 839 Hispanic (primarily Mexican) 9th – 12th graders from west Texas area school districts who were given a self-reported survey to assess parental behaviors, substance use, and adolescent depression. Using structural equation modeling (SEM), findings indicated that higher levels of maternal support were related to lower levels of depressive …

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Avian Use Of Harvested Crop Fields In North Dakota During Spring Migration, Alegra M. Galle, George M. Linz, H. Jeffrey Homan, William J. Bleier Dec 2009

Avian Use Of Harvested Crop Fields In North Dakota During Spring Migration, Alegra M. Galle, George M. Linz, H. Jeffrey Homan, William J. Bleier

Western North American Naturalist

Broad-spectrum herbicide applications and improved harvesting efficiency of crops have reduced the availability of weed seeds and waste grains for game and nongame wildlife. Over the last decade, corn and soybean plantings have steadily increased in the Prairie Pothole Region (PPR) of North Dakota, while sunflower plantings have declined. The PPR is an important corridor for migratory birds, and changes in food availabilities at stopover habitats may affect how food resources are used. In early spring 2003 and 2004, we compared bird use of harvested fields of sunflower, soybeans, small grains, and corn in the PPR of North Dakota. Across …

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Arthropod And Plant Communities As Indicators Of Land Rehabilitation Effectiveness In A Semiarid Shrubsteppe, Eric T. Gardner, Val J. Anderson, Robert L. Johnson Dec 2009

Arthropod And Plant Communities As Indicators Of Land Rehabilitation Effectiveness In A Semiarid Shrubsteppe, Eric T. Gardner, Val J. Anderson, Robert L. Johnson

Western North American Naturalist

We describe a case study evaluating the ecological impact of Bromus tectorum L. (cheatgrass) invasion following fire disturbance and the effectiveness of revegetation as a means of rehabilitation in a degraded semiarid shrubsteppe system. The effectiveness of rehabilitation efforts was assessed relative to arthropod richness, vegetation and arthropod community composition, and ground-cover characteristics in 3 habitats: undisturbed, burned and weed infested (B. tectorum), and burned then rehabilitated with native and nonnative vegetation. Arthropods were collected in each habitat using pitfall traps. Differences in arthropod richness were compared using rarefaction curves. Nonmetric multidimensional scaling and nonparametric multivariate statistical procedures, …

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Population Ecology And Reproduction Of The Mexican Mud Turtle (Kinosternon Integrum) In Tonatico, Estado De México, Rodrigo Macip-Ríos, Maria De Lourdes Arias Cisneros, Xochitl S. Aguilar-Miguel, Gustavo Casas-Andreu Dec 2009

Population Ecology And Reproduction Of The Mexican Mud Turtle (Kinosternon Integrum) In Tonatico, Estado De México, Rodrigo Macip-Ríos, Maria De Lourdes Arias Cisneros, Xochitl S. Aguilar-Miguel, Gustavo Casas-Andreu

Western North American Naturalist

Ecological data directly from the field are important in understanding the life history strategies of kinosternid species in the tropics. Herein we summarize the basic population ecology and life history of Kinosternon integrum in the municipality of Tonatico (southeastern Estado de México, México). From October 2003 to November 2004, we marked a total of 204 turtles and recaptured 118 of them. Mean population size using the Jolly-Seber model was 197 (95% CI 128–416) individuals, with a sex ratio of 1:1.7, biased to females. Males were larger than females in carapace length and plastron length. The reproductive season starts in late …

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Note On The Occurrence Of Siphlonurus Autumnalis (Ephemeroptera: Siphlonuridae) In A Montana Spring Brook, Robert L. Newell, Michelle L. Anderson Dec 2009

Note On The Occurrence Of Siphlonurus Autumnalis (Ephemeroptera: Siphlonuridae) In A Montana Spring Brook, Robert L. Newell, Michelle L. Anderson

Western North American Naturalist

The little-known mayfly Siphlonurus autumnalis McDunnough (Ephemeroptera: Siphlonuridae) was collected from several locations in its floodplain habitats along the Middle Fork of the Flathead River in western Montana. To confirm identification, nymphs were reared along with an associated species, S. occidentalis Eaton (Ephemeroptera: Siphlonuridae). Adults emerged from 6 September until 16 October. Habitats are described and the first photos of the 2 sexes are provided.

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The Ecological Importance Of Extrinsic And Intrinsic Drivers Of Animal Movement, Josh Earl Rasmussen Dec 2009

The Ecological Importance Of Extrinsic And Intrinsic Drivers Of Animal Movement, Josh Earl Rasmussen

Theses and Dissertations

The movement of individuals is foundational to many ecological processes. For example, the movement of an organism from one place to another alters population density at both sites and has potential for affecting the genetic dynamics within the new population. Individual movement events may be in synchrony with overall trends in populations, e.g. spawning migrations, or may be atypical (asynchronous). This latter movement type can affect population and metapopulation dynamics, depending on its prevalence within a population. Nevertheless, given the complexity of interactions, the causative factors of movement are understood vaguely, much less for aquatic organisms. Drivers of movement are …

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Distribution Records And Comments On Mammals In Western South Dakota, Steven G. Platt, Zannita Fast Horse, Thomas R. Rainwater, Stanlee M. Miller Oct 2009

Distribution Records And Comments On Mammals In Western South Dakota, Steven G. Platt, Zannita Fast Horse, Thomas R. Rainwater, Stanlee M. Miller

Western North American Naturalist

The mammal fauna of western South Dakota is imperfectly known; in particular there is a notable paucity of data from Indian reservations in the region. We collected mammals from January 2003 through May 2006 using a variety of standard methodologies, including trapping with snap-traps and Macabee traps, shooting, and salvaging road- and hunter-killed animals. Herein we provide 23 specimen-based county records representing 17 species of mammals. In addition, a photo record constitutes the first report of Dasypus novemcinctus from South Dakota and the northernmost record in the United States. The possible local extirpation of Marmota flaviventris in the southern Black …

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Ectoparasites Of The Occult Bat, Myotis Occultus (Chiroptera: Vespertilionidae), Ernest W. Valdez, Christopher M. Ritzi, John O. Whitaker Jr. Oct 2009

Ectoparasites Of The Occult Bat, Myotis Occultus (Chiroptera: Vespertilionidae), Ernest W. Valdez, Christopher M. Ritzi, John O. Whitaker Jr.

Western North American Naturalist

Only a single previous study has examined ectoparasites of the occult bat (Myotis occultus), from which only 2 species of fleas were identified. For our study, we examined 202 individuals, 52 fresh hosts and 150 museum specimens, from New Mexico and southern Colorado for ectoparasites. We recorded 2158 ectoparasites, 634 from fresh hosts and 1524 from museum specimens. Ectoparasites belonged to 10 families and 13 genera of insect or acari and represent new host and locality records. In general, ectoparasites collected from fresh hosts and museum specimens were represented by 4 major species of mite: Macronyssus crosbyi, Alabidocarpus …

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Large, Wetland-Associated Mayflies (Ephermeroptera) Of Glacier National Park, Montana, Robert L. Newell, Blake R. Hossack Oct 2009

Large, Wetland-Associated Mayflies (Ephermeroptera) Of Glacier National Park, Montana, Robert L. Newell, Blake R. Hossack

Western North American Naturalist

We describe species richness and habitat associations of mayflies (Ephemeroptera) collected during amphibian surveys of 355 water bodies in Glacier National Park (NP), Montana, in 2006–2008. We collected 9 taxa (in 7 genera) of mayflies that were identifiable to species. Callibaetis ferrugineus hageni was collected most frequently, followed by Siphlonurus occidentalis, S. phyllis, Ameletus celer, A. similior, Parameletus columbiae, Ephemerella dorothea infrequens, Baetis bicaudatus, and Leptophlebia cupida. Siphlonurus phyllis had not been reported in the western United States prior to our surveys, and P. columbiae is a species of concern in the region. The identifications of 4 additional taxa were …

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Differential Mortality Drives Life-History Evolution And Population Dynamics In The Fish Brachyrhaphis Rhabdophora, Jerald B. Johnson, J. Jaime Zuniga-Vega Aug 2009

Differential Mortality Drives Life-History Evolution And Population Dynamics In The Fish Brachyrhaphis Rhabdophora, Jerald B. Johnson, J. Jaime Zuniga-Vega

Faculty Publications

Life-history theory predicts that populations experiencing different levels of extrinsic mortality will evolve divergent reproductive strategies. Previous work in the live bearing fish Brachyrhaphis rhabdophora shows that individuals from populations that occur with piscivorous fish mature earlier and at smaller sizes and have more and smaller offspring than fish from populations without predators. However, until now, there have been no data to demonstrate that differences in mortality rates actually exist between predator and predator free sites. Here we present the results of a serial mark-recapture field study designed to estimate mortality rates in natural populations of B. rhabodophora from Costa …

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Camel Spider (Solifugae) Use Of Prairie Dog Colonies, B. D. Duval, W. G. Whitford Jul 2009

Camel Spider (Solifugae) Use Of Prairie Dog Colonies, B. D. Duval, W. G. Whitford

Western North American Naturalist

Solifugids (camel spiders) are widespread throughout arid regions of western North America and are thought to be important in structuring desert arthropod communities. Despite the ubiquity of camel spiders, little is known about their ecology. Black-tailed prairie dogs (Cynomys ludovicianus) are also widespread in western North America and are important ecosystem engineers, but they have been reduced in extent because of human activity. Here we report significantly greater numbers of camel spiders on black-tailed prairie dog colonies in southern New Mexico. The difference in vegetation structure created by prairie dog activity is likely the reason for the increased …

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Co-Occurrence With A Congeneric Species Predicts Life History And Morphological Diversification In The Mexican Livebearing Fish Poelicopsis Baenschi, Laura E. Scott Jul 2009

Co-Occurrence With A Congeneric Species Predicts Life History And Morphological Diversification In The Mexican Livebearing Fish Poelicopsis Baenschi, Laura E. Scott

Theses and Dissertations

Understanding why some species coexist and others do not remains one of the fundamental challenges of ecology. While several lines of evidence suggest that closely related species are unlikely to occupy the same habitat because of competitive exclusion, there are many cases where closely related species do co-occur. Research comparing sympatric and allopatric populations of co-occurring species provides a framework to understand the role of phenotypic diversification in species coexistence. In this study I focus on the livebearing fish Poeciliopsis baenschi and ask if differences in phenotypic traits among populations can be explained by the presence or absence of the …

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Regional And Seasonal Diet Of The Western Burrowing Owl In South Central Nevada, Derek B. Hall, Paul D. Greger, Jeffrey R. Rosier Apr 2009

Regional And Seasonal Diet Of The Western Burrowing Owl In South Central Nevada, Derek B. Hall, Paul D. Greger, Jeffrey R. Rosier

Western North American Naturalist

We examined diets of Western Burrowing Owls (Athene cunicularia hypugaea) based on contents of pellets and large prey remains collected year-round at burrows in each of the 3 regions in south central Nevada (Mojave Desert, Great Basin Desert, and Transition region). The most common prey items, based on percent frequency of occurrence, were crickets and grasshoppers, beetles, rodents, sun spiders, and scorpions. The most common vertebrate prey was kangaroo rats (Dipodomys spp.). True bugs (Hemiptera), scorpions, and western harvest mice (Reithrodontomys megalotis) occurred most frequently in pellets from the Great Basin Desert region. Kangaroo rats …

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