Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Ecology and Evolutionary Biology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 14551 - 14580 of 19717

Full-Text Articles in Entire DC Network

Consequences Of Recruitmentdecisions And Heterogeneity On Age-Specific Breeding Success In A Long-Lived Seabird, Lise M. Aubry, David N. Koons, Jean Yves Monnat, Emmanuelle Cam Sep 2009

Consequences Of Recruitmentdecisions And Heterogeneity On Age-Specific Breeding Success In A Long-Lived Seabird, Lise M. Aubry, David N. Koons, Jean Yves Monnat, Emmanuelle Cam

Wildland Resources Faculty Publications

An individual’s age at first reproduction and investment in successive reproductive attempts are involved in mechanisms that can impede somatic repair, resulting in a decline in reproductive abilities with age (reproductive senescence). We used long-term data from the Black-legged Kittiwake, a long-lived seabird, to address the relationship between recruitment age, age-specific breeding success (BS), and reproductive senescence, while accounting for breeding experience and temporal variation in BS. We first detected late-life improvement in BS across all recruitment groups, which we recognized as ‘‘within-generation selection’’ or the selective disappearance of ‘‘frail’’ phenotypes. When such heterogeneity was accurately accounted for, we showed …


Interagency Management Action Plan (I-Map) For Quagga Mussels, David Wong, Shawn Gerstenberger Aug 2009

Interagency Management Action Plan (I-Map) For Quagga Mussels, David Wong, Shawn Gerstenberger

Public Lands Institute Publications

Following the discovery of quagga mussels in Lake Mead, a variety of agencies, including National Park Service (NPS) Lake Mead National Recreational Area (LMNRA), Bureau of Reclamation (USBR), Southern Nevada Water Authority (SNWA), Nevada Department of Wildlife (NDOW), U.S. Fish and Wildlife (USFWS), Clean Water Coalition (CWC), and U.S. Geological Survey (USGS) have set up monitoring programs to evaluate and gain information to help minimize the impacts or potential impacts of quagga mussels to their facilities and lake ecology. Current monitoring activities and anticipated environmental impacts are depicted in Figures 1 and 2. While the agencies have worked closely and …


Amphibian Habitat Usage Of Two Restored Bogs In Shady Valley, Johnson County, Tennessee., Amy P. Lucas Aug 2009

Amphibian Habitat Usage Of Two Restored Bogs In Shady Valley, Johnson County, Tennessee., Amy P. Lucas

Electronic Theses and Dissertations

Adjacent terrestrial habitat surrounding wetlands are critical for the survival and success of many species that use them. The primary purpose of this study was to determine amphibian movement from adjacent habitats into Orchard Bog, a restored bog located in Shady Valley, Johnson County, Tennessee. In addition, a secondary bog, Quarry Bog, was also studied determining baseline presence/absence data

A total of 16 species from six families were observed throughout the study sites. Seven species of anurans, Bufonidae, Hylidae, and Ranidae and nine species of caudates in the families Plethodontidae, Ambystomatidae and Salamandridae were identified. Fourteen of the 16 species …


Manipulating Testosterone To Assess Links Between Behavior, Morphology, And Performance In The Brown Anole Anolis Sagrei, Robert M. Cox, Derek S. Stenquist, Justin P. Henningsen, Ryan Calsbeek Aug 2009

Manipulating Testosterone To Assess Links Between Behavior, Morphology, And Performance In The Brown Anole Anolis Sagrei, Robert M. Cox, Derek S. Stenquist, Justin P. Henningsen, Ryan Calsbeek

Dartmouth Scholarship

Survival and reproductive success are determined by the complex interplay between behavior, physiology, morphology, and performance. When optimal trait combinations along these various phenotypic axes differ between sexes or across seasons, regulatory mechanisms such as sex steroids can often facilitate sex‐specific and/or seasonal trait expression. In this study, we used surgical castration and replacement of exogenous testosterone in adult male brown anoles (Anolis sagrei) to simultaneously examine the effects of testosterone on a suite of morphological (dewlap area, body size), physiological (immune function), behavioral (dewlap, head bob, and push‐up displays), and performance (stamina, sprint speed, bite force) traits. …


Baseline Microbial Characterizations Of An Imperiled Aquatic Diversity Hotspot: Ash Meadows National Wildlife Refuge, Jessica Newburn, Jim Bruckner, Jenny C. Fisher, Duane P. Moser Aug 2009

Baseline Microbial Characterizations Of An Imperiled Aquatic Diversity Hotspot: Ash Meadows National Wildlife Refuge, Jessica Newburn, Jim Bruckner, Jenny C. Fisher, Duane P. Moser

Undergraduate Research Opportunities Program (UROP)

Located in the discharge zone of the Death Valley Flow System, Ash Meadows National Wildlife Refuge is a spring-fed desert oasis and biodiversity hotspot about 90 miles northwest of Las Vegas. These critical wetlands are potentially threatened by groundwater pumping, exotic species invasions, and climate change. Although a major component of the lower food web, very little is known about the microbial makeup of this ecosystem. As a first step towards understanding the microbial and biogeochemical aspects of this system, a detailed molecular-based characterization of microbial communities, baseline chemistry, and physical characteristics of various springs of Ash Meadows will be …


Point And Nonpoint Source Analysis Of Nutrients, Metals, And Pathogens In The Sediment And Water Column In Las Vegas Wash, Christine Simmons, Kumud Acharya Aug 2009

Point And Nonpoint Source Analysis Of Nutrients, Metals, And Pathogens In The Sediment And Water Column In Las Vegas Wash, Christine Simmons, Kumud Acharya

Undergraduate Research Opportunities Program (UROP)

Formerly an ephemeral watercourse, Las Vegas Wash is now a perennial system due to urban runoff and wastewater treatment plant (WWP) effluent. Las Vegas Wash flows into Lake Mead, where the discharge point is only a few miles upstream of Las Vegas’ main water intake. This small water cycle establishes the necessity to evaluate water quality especially due to non point sources pollution, wherein my research lies. Several points along Las Vegas Wash upstream and downstream of WWP have been chosen to represent different landuse types such as commercial, residential, wastewater treatment plants, etc. At each location, parameters including arsenic, …


Undergraduate Research Opportunities Program, University Of Nevada Las Vegas, College Of Sciences Aug 2009

Undergraduate Research Opportunities Program, University Of Nevada Las Vegas, College Of Sciences

Undergraduate Research Opportunities Program (UROP)

No abstract provided.


Assessment Of The Endangered Species Podarcis Carbonelli On A Microgeographic Scale: A Molecular, Morphological And Physiological Approach, Maria Clara Figueirinhas Do Amaral Aug 2009

Assessment Of The Endangered Species Podarcis Carbonelli On A Microgeographic Scale: A Molecular, Morphological And Physiological Approach, Maria Clara Figueirinhas Do Amaral

Masters Theses & Specialist Projects

The lizard Podarcis carbonelli is an endangered species endemic to the Iberian Peninsula. One location where this species occurs is at the Berlengas Natural Preserve, an Atlantic archipelago off the coast of Portugal. These island populations are geographically separated from nearby mainland populations. The fundamental question is, are these insular individuals distinct from the mainland populations? Four localities were chose for comparison: two island populations and two nearby coastal populations. We assessed this question using three distinct approaches: molecular, morphological and physiological approach. We sequenced the 12S RNA, the mtDNA Control Region and the 7th intron of the !-fibrinogen gene …


Fisheries Management Paper No.245 - Aquaculture Of Coral, Live Rocks And Associated Products. Aquaculture Policy, Department Of Fisheries, Western Australia Aug 2009

Fisheries Management Paper No.245 - Aquaculture Of Coral, Live Rocks And Associated Products. Aquaculture Policy, Department Of Fisheries, Western Australia

Fisheries Management Papers

Aquarium enthusiasts use corals, live rock and associated products (e.g. live sand) for display and to maintain healthy water quality conditions in their marine aquariums. There is a large and growing market for these products. While the wild harvest fisheries for aquarium products in Western Australia are sustainably managed, output is capped, so increased product is needed to meet the market demand. With a trend towards the capping of wild harvest and additional pressures, such as the introduction of Marine Parks and other marine protected areas, the aquaculture of these products is set for industry development and expansion.

The large …


Ecological Impact Of Epigeal Termitaria On Vertebrates In The Tsavo Region Of Southeast Kenya, Margaret M. Mahan Aug 2009

Ecological Impact Of Epigeal Termitaria On Vertebrates In The Tsavo Region Of Southeast Kenya, Margaret M. Mahan

Masters Theses & Specialist Projects

Termites ecologically engineer their environment by producing termitaria (mounds) used by many other species as dens, lookouts or food sources. The role of termite mounds in biological communities is relatively unknown, despite their ubiquitous nature. I investigated their impact on vertebrates in the Tsavo region of Kenya. Through the characterization of mounds, trapping, direct observation, and collecting microclimate data, I was able to determine the importance of mounds to vertebrates. I found uniform dispersion of mounds, that soil type is correlated with the size of mounds, and that vertebrate activity increases with mound size. I also found no significant differences …


Summer/Fall 2009, Nsu Oceanographic Center Aug 2009

Summer/Fall 2009, Nsu Oceanographic Center

Currents

No abstract provided.


Ice Storm Effects On The Canopy Structure Of A Northern Hardwood Forest After 8 Years, Brian C. Weeks, Steven P. Hamburg, Matthew A. Vadeboncoeur Aug 2009

Ice Storm Effects On The Canopy Structure Of A Northern Hardwood Forest After 8 Years, Brian C. Weeks, Steven P. Hamburg, Matthew A. Vadeboncoeur

All Materials

Ice storms can cause severe damage to forest canopies, resulting in differential mortality among tree species and size classes and leading to long-lasting changes in the vertical structure and composition of the forest. An intense ice storm in 1998 damaged large areas of the northern hardwood forest, including much of the Hubbard Brook Experimental Forest, New Hampshire (USA). Following up on detailed poststorm assessments, we measured changes in the vertical structure of the forest canopy 8 years poststorm. We focused on how the presence of disease-induced advance regeneration of American beech (Fagus grandifolia Ehrh.) has affected canopy structure in the …


The Very Basics Of Sustainability - An Alternative Viewpoint (Slides With Audio) (Large File! To Speed Up Download, Right-Click On "Download" Link To Save To Own Pc.), Jim Mcgovern Aug 2009

The Very Basics Of Sustainability - An Alternative Viewpoint (Slides With Audio) (Large File! To Speed Up Download, Right-Click On "Download" Link To Save To Own Pc.), Jim Mcgovern

Other resources

This presentation sets out the very basics of ‘sustainability’, although a definition of sustainability is not attempted. Some of the very basics are the context in which the Earth and humankind exist in space and time, the Earth’s climate, the Earth’s population and humankind’s options and choices. The author advocates keeping an open mind on all available options, including the use of oil, gas, coal, tar sands, carbon capture and sequestration, nuclear power etc., as well as the technologies that are more widely considered ‘green’. The author also argues that, in addressing the challenges that humankind faces, globally concerted effort …


Effect Of Environmental Density And Buoyancy On Growth And Gravitropic Response In Maize Roots, Jessy Robbins Aug 2009

Effect Of Environmental Density And Buoyancy On Growth And Gravitropic Response In Maize Roots, Jessy Robbins

All-Inclusive List of Electronic Theses and Dissertations

The mechanism by which plants sense gravity is not fully understood. The statolith theory states that plants sense gravity based on the sedimentation of starch granules called statoliths. However, not all plants contain statoliths. The hydrostatic model was proposed to explain gravitropic sensing in systems which lack statoliths. This model states that the gravity sensor in a plant cell is the entire protoplast; gravitropic sensing depends on the buoyancy of the protoplast relative to the density of its external environment. The ability of maize roots to sense gravity when grown in media of differing densities is examined in these studies. …


Projected Climate Change Effects On Nuthatch Distribution And Diversity Across Asia, Shaily Menon, M. Zafar-Ul Islam, A. Townsend Peterson Aug 2009

Projected Climate Change Effects On Nuthatch Distribution And Diversity Across Asia, Shaily Menon, M. Zafar-Ul Islam, A. Townsend Peterson

Peer Reviewed Publications

We used ecological niche modeling approaches to explore climate change implications for one family of birds, the Sittidae, in Asia. Quantitative niche models based on present-day distributions for each of 13 species were projected onto future climate change scenarios. Species’ potential distributional areas tended to be predicted to retract along their fringes, and at lower elevations along mountain ranges. As observed in other studies, montane systems were relatively more robust to the horizontal effects of climate change on species’ distributions compared to flatland systems, so range contractions were focused in Southeast Asia and peninsular India.


Factors Influencing The Environmental Quality Of The Bay Of Saint Louis, Mississippi And Implications For Evolving Coastal Management Policies, Pradnya Ankush Sawant Aug 2009

Factors Influencing The Environmental Quality Of The Bay Of Saint Louis, Mississippi And Implications For Evolving Coastal Management Policies, Pradnya Ankush Sawant

Dissertations

The Bay of St. Louis, MS is a small northern Gulf of Mexico estuary that has been identified by the Mississippi Department of Environmental Quality (MDEQ) as an impaired waterbody for its designated uses, mainly due to the presence of pollutant pathogens. A systematic study of this estuary was important to understand the behavior and responses of the bay to several natural and anthropogenic forcing factors. A 14- month long study (bimonthly sampling) to evaluate its environmental quality was undertaken from April 2003 to May 2004. Environmental quality was defined as "the health of an ecosystem characterized in terms of …


Predicting Leptodactylus (Amphibia, Anura, Leptodactylidae) Distributions: Broad-Ranging Versus Patchily Distributed Species Using A Presence-Only Environmental Niche Modeling Technique, Miguel Fernández, Daniel Cole, W. R. Heyer, Stephen Reichle, Rafael O. De Sá Aug 2009

Predicting Leptodactylus (Amphibia, Anura, Leptodactylidae) Distributions: Broad-Ranging Versus Patchily Distributed Species Using A Presence-Only Environmental Niche Modeling Technique, Miguel Fernández, Daniel Cole, W. R. Heyer, Stephen Reichle, Rafael O. De Sá

Biology Faculty Publications

Locality data available for many, if not most, species of Neotropical frogs are based on written descriptions of the collecting sites, not on GPS device determined coordinate data. The pre-GPS device data are imprecise relative to GPS data. Niche modeling is a powerful technique for predicting geographic distributions that provides the best results when the locality data are precise. The purpose of this study is to determine whether imprecise historical locality data are sufficient such that niche modeling techniques can yield realistic new insights to species-level distributions. Two sets of frogs of the genus Leptodactylus that have known different kinds …


Population Ecology Of The Floodplain Herb Macbridea Caroliniana (Lamiaceae) With Investigations On The Species' Habitat, Breeding System And Genetic Diversity, Katherine Weeks Aug 2009

Population Ecology Of The Floodplain Herb Macbridea Caroliniana (Lamiaceae) With Investigations On The Species' Habitat, Breeding System And Genetic Diversity, Katherine Weeks

All Dissertations

The perennial herbaceous mint Macbridea caroliniana is known from 36 locations in discrete watersheds of the Carolinas and Georgia. It is one of relatively few conspicuously flowering herbs that occupy bottomland hardwood forests. The general project goal was to gain knowledge that is applicable to the species' conservation both at the Congaree National Park (CNP) where the largest known population of this species occurs and range-wide. Specific objectives were to (1) quantify the population size and describe the distribution of M. caroliniana within CNP, and determine the extent of co-occurrence with wild hogs and the non-native Murdannia keisak; (2) identify …


Introduction And Spread Of Bromus Tectorum (Cheatgrass) Into Midwestern United States: Population Genetic And Evolutionary Consequences, Temsha D. Huttanus Aug 2009

Introduction And Spread Of Bromus Tectorum (Cheatgrass) Into Midwestern United States: Population Genetic And Evolutionary Consequences, Temsha D. Huttanus

Boise State University Theses and Dissertations

High propagule pressure is correlated with invasion success, and has important implications for the genetic diversity and evolutionary potential of a species in its introduced range. Here, I examine an invasive annual grass Bromus tectorum and document the population genetic consequences that resulted from multiple introductions of genotypes native to different Eurasian regions into the North American Midwest. Herbarium collections showed that B. tectorum was first recorded near-contemporaneously throughout the Midwest in the late 1800s. Allozyme diversity data from 60 populations were used to assess the origin and frequency of introductions into the Midwest. Genetic variation and structure was compared …


Monitoring Of Heavy Metal Loading Into The Wetlands South Of Lake Victoria Basin, Nothern Tanzania, M K D Mutakyahwa, J R Ikingura, G Y S Mtui Jul 2009

Monitoring Of Heavy Metal Loading Into The Wetlands South Of Lake Victoria Basin, Nothern Tanzania, M K D Mutakyahwa, J R Ikingura, G Y S Mtui

Tanzania Journal of Science

The paper discusses sources, concentrations and physicochemical parameters of heavy metals of environmental concern in the wetlands of Lake Victoria basin in Tanzania. The metals investigated include copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), chromium (Cr), nickel (Ni), arsenic (As), manganese (Mn), cobalt (Co) and mercury (Hg). These metals are released into the wetlands via weathering and erosion of rock formations, mining operations and industrial activities, discharge of municipal and domestic waste, and use of agrochemicals. The levels of these heavy metals in soil, sediment, water, and biota differ. Wetlands impacted by gold mining activities in the South Lake …


Effects Of Selection For Cooperation And Attention In Dogs, Márta Gácsi, Paul Mcgreevy, Edina Kara, Ádám Miklósi Jul 2009

Effects Of Selection For Cooperation And Attention In Dogs, Márta Gácsi, Paul Mcgreevy, Edina Kara, Ádám Miklósi

Cooperative Behavior Collection

Background: It has been suggested that the functional similarities in the socio-cognitive behaviour of dogs and humans emerged as a consequence of comparable environmental selection pressures. Here we use a novel approach to account for the facilitating effect of domestication in dogs and reveal that selection for two factors under genetic influence (visual cooperation and focused attention) may have led independently to increased comprehension of human communicational cues.

Method: In Study 1, we observed the performance of three groups of dogs in utilizing the human pointing gesture in a two-way object choice test. We compared breeds selected to work while …


Rapid Fixation Of Non-Native Alleles Revealed By Genome-Wide Snp Analysis Of Hybrid Tiger Salamanders, Benjamin M. Fitzpatrick, Jarrett R. Johnson, D. Kevin Kump, H. Bradley Shaffer, Jeramiah J. Smith, S. Randal Voss Jul 2009

Rapid Fixation Of Non-Native Alleles Revealed By Genome-Wide Snp Analysis Of Hybrid Tiger Salamanders, Benjamin M. Fitzpatrick, Jarrett R. Johnson, D. Kevin Kump, H. Bradley Shaffer, Jeramiah J. Smith, S. Randal Voss

Biology Faculty Publications

BACKGROUND: Hybrid zones represent valuable opportunities to observe evolution in systems that are unusually dynamic and where the potential for the origin of novelty and rapid adaptation co-occur with the potential for dysfunction. Recently initiated hybrid zones are particularly exciting evolutionary experiments because ongoing natural selection on novel genetic combinations can be studied in ecological time. Moreover, when hybrid zones involve native and introduced species, complex genetic patterns present important challenges for conservation policy. To assess variation of admixture dynamics, we scored a large panel of markers in five wild hybrid populations formed when Barred Tiger Salamanders were introduced into …


Habitat-Based Intraguild Predation By Caribbean Reef Octopus Octopus Briareus On Juvenile Caribbean Spiny Lobster Panulirus Argus, Mark J. Butler Iv, Jennifer A. Lear Jul 2009

Habitat-Based Intraguild Predation By Caribbean Reef Octopus Octopus Briareus On Juvenile Caribbean Spiny Lobster Panulirus Argus, Mark J. Butler Iv, Jennifer A. Lear

Biological Sciences Faculty Publications

Intraguild predation occurs when species simultaneously compete for resources and interact as predator and prey, which describes the interaction between juvenile Caribbean spiny lobster Panulirus argus and Caribbean reef octopus Octopus briareus in the Florida Keys, USA. Octopuses are notorious predators of decapod crustaceans, and their use of crevice shelters suggests that they may also compete for shelter with their lobster prey. Lobsters use mainly chemical cues to detect and avoid octopus, so we hypothesized that the negative association between these species may be as much the consequence of avoidance of a superior competitor as it is of direct predation. …


Quantification Of Bt-Endotoxin Exposure Pathways In Carabid Food Webs Across Multiple Transgenic Events, Julie A. Peterson, John J. Obrycki, James D. Harwood Jul 2009

Quantification Of Bt-Endotoxin Exposure Pathways In Carabid Food Webs Across Multiple Transgenic Events, Julie A. Peterson, John J. Obrycki, James D. Harwood

West Central Research and Extension Center, North Platte

Despite the reported specificity of Bacillus thuringiensis proteins against target pests, a number of studies have indicated that the uptake of Bt-endotoxins from bioengineered crops could have negative effects on natural enemies. It is therefore essential to quantify exposure pathways in non-target arthropod food webs across multiple transgenic events. Adult ground beetles (Coleoptera: Carabidae) were collected from transgenic corn fields expressing lepidopteran-specific Cry1Ab, coleopteran-specific Cry3Bb1, and both Cry1Ab and Cry3Bb1 (stacked event), as well as a non-transgenic isoline. Carabid gut-contents were screened for Cry1Ab Bt-endotoxin using enzyme-linked immunosorbent assay. Significant numbers of carabids tested positive for Cry1Ab from the lepidopteran-specific …


Collective Batesian Mimicry Of Ant Groups By Aggregating Spiders, Ximena J. Nelson, Robert R. Jackson Jul 2009

Collective Batesian Mimicry Of Ant Groups By Aggregating Spiders, Ximena J. Nelson, Robert R. Jackson

All Peer-Reviewed Publications

Many predators are averse to attacking ants and many palatable arthropods are Batesian mimics of ants. We considered whether aggregating Batesian mimics of ants can become more repelling to ant-averse predators by, as a group, resembling groups of ants (collective mimicry). Myrmarachne melanotarsa is a gregarious ant-like jumping spider (Salticidae) that resembles and associates with the ant Crematogaster sp. We used three large ant-averse salticids as predators in experiments. Besides M. melanotarsa and Crematogaster we used midges (Chaoborus sp.) and a small nonant-like, but gregarious, salticid (Menemerus sp.) as prey. The predators readily attacked both live midges and the nonant-like …


Biotic And Abiotic Characteristics Influencing Nest Location And Trophic Relationships Of The Fungus-Growing Ant Trachymyrmex Septentrionalis (Formicidae: Attini), Jonathan Paul Howell Jul 2009

Biotic And Abiotic Characteristics Influencing Nest Location And Trophic Relationships Of The Fungus-Growing Ant Trachymyrmex Septentrionalis (Formicidae: Attini), Jonathan Paul Howell

Biological Sciences Theses & Dissertations

Trachymyrmex septentrionalis represents the only species of fungus-growing ant in the southeastern United States. T. septentrionalis cultivates a symbiotic fungus on which the ants feed. Worker ants collect plant and animal debris to feed the fungus. These ants are common in Florida, but increasingly scarce as they near the northern extent of their range in New Jersey. Colonies of T. septentrionalis occur in patches throughout Blackwater Ecological Preserve, a longleaf pine forest in southeastern Virginia. Blackwater Ecologic Preserve is a 129 hectare tract of land, located in Isle of Wight county, that is undergoing a regimen of controlled burning to …


Effect Of The Herbivorous Channel Clinging Crab (Mithrax Spinosissimus) On Patch Reef Algal Communities In The Florida Keys, Florida (Usa), Angela M. Mojica Osorio Jul 2009

Effect Of The Herbivorous Channel Clinging Crab (Mithrax Spinosissimus) On Patch Reef Algal Communities In The Florida Keys, Florida (Usa), Angela M. Mojica Osorio

Biological Sciences Theses & Dissertations

Coral reefs worldwide are undergoing dramatic habitat modification from coral to macroalgal dominance due to water pollution, coral diseases, global. warming, and the loss of herbivores. This phase-shift bas been particularly severe on Caribbean reefs due in large measure to the decline of piscine and echinoderm grazers, whose presence appears crucial for stemming the decline of coral reefs and enhancing their resilience. Virtually unknown, however, is the role of other macrograzers in coral reef ecosystems. This is the first study to examine the feeding ecology and grazer effect of the herbivorous West Indian spider crab (Mithrax spinosissimus) on inshore patch …


Changing Fecundity And Reproductive Output In Females Of A Chesapeake Bay Population Of Blue Crab, Callinectes Sapidus, Shannon L. Wells Jul 2009

Changing Fecundity And Reproductive Output In Females Of A Chesapeake Bay Population Of Blue Crab, Callinectes Sapidus, Shannon L. Wells

OES Theses and Dissertations

The Chesapeake Bay blue crab, Callinectes sapidus, is an important species both ecologically and as a fishery. Fishery dependent and independent data indicate that the population declined abruptly in the mid-1990s and has remained low. Previous work prior to the decline in population abundance found a significant relationship between size and fecundity for mature females. As with many heavily fished populations, this population has experienced a reduction in the size at maturity. The objectives of this study were to reassess the fecundity of the population, determine the lipid and protein energy allocated for reproduction, and to examine the concentrations …


Pines And The Ecology Of Carnaby‘S Black-Cockatoos (Calyptorhynchus Latirostris) In The Gnangara Sustainability Strategy Area, Hugh Finn, William Stock, Leonie Valentine Jul 2009

Pines And The Ecology Of Carnaby‘S Black-Cockatoos (Calyptorhynchus Latirostris) In The Gnangara Sustainability Strategy Area, Hugh Finn, William Stock, Leonie Valentine

Research outputs pre 2011

This study examined the behavioural ecology of Carnaby‘s Black-Cockatoo in the Gnangara Sustainability Strategy study area, with a focus on habitat use of pine plantations. The study confirms that the pine is the main food source for Carnaby‘s Black-Cockatoos within the GSS area during the non-breeding season (January-June). The value of the Gnangara-Pinjar-Yanchep pine plantations as a food source for Carnaby‘s Black-Cockatoo should not be underestimated. Large congregations of birds (~3000) utilised the pine plantations for an extended period, mainly January-March but with birds continuing to feeding within the plantations through June. The pine plantations have provided an important and …


Modeling And Analysis Of Biological Populations, Joan Lubben Jul 2009

Modeling And Analysis Of Biological Populations, Joan Lubben

Department of Mathematics: Dissertations, Theses, and Student Research

Asymptotic and transient dynamics are both important when considering the future population trajectory of a species. Asymptotic dynamics are often used to determine whether the long-term trend results in a stable, declining or increasing population and even provide possible directions for management actions. Transient dynamics are important for estimating invasion speed of non-indigenous species, population establishment after releasing biocontrol agents, or population management after a disturbance like fire. We briefly describe here the results in this thesis.

(1) We consider asymptotic dynamics using discrete time linear population models of the form n(t + 1) = An(t) where …