Life Sciences Commons^™

Impact Of Extensive Management On Demography Of One Invasive Species Of Permanent Grasslands, D Magda

IGC Proceedings (1997-2023)

The objective of this study is to show the effect of extensive practices on the population dynamics of a grassland species (Chaerophyllum aureum) in order to control invasion process. Fertilisation intensity (none or 45g/m2), number (none, one or two) and date of cutting (before or after seed maturity) have been experienced on permanent plots in fields to follow consequences on demography of adults and seedlings. Adult density is regulated through cutting effect and intraspecific competition process. Reduction of competition by cutting leads to a paradoxal highest adult survival rate in on cut treatment compared with abandoned invaded fields. …

Seasonal Abundance Of The Nudibranch Dondice Jupiteriensis On The Colonial Hydroid Eudendrium Carneum, Erika Molina, Daniela Gutierrez-Andrade, Samantha Schlegel, Julia Piper, Louis J. Ambrosio, Michael L. Middlebrooks

Gulf and Caribbean Research

Benthic colonial hydroids often serve as a host to a large variety of invertebrate taxa. The colonial hydroid Eudendrium carneum Clarke, 1882 is host to a variety of epifauna, including the recently described nudibranch Dondice jupiteriensis García—Méndez & Valdés, 2022. Like many species of heterobranch sea slugs, little is known about the natural history and population biology of D. jupiteriensis. Here we describe a year—long study recording the population density and size structure of D. jupiteriensis on E. carneum colonies in Tampa Bay, FL USA. We found that the D. jupiteriensis population persists year—round but is the densest during …

An Integrative Approach To Managing A Species Of Conservation Concern: Resource Selection, Spatial Ecology, And Population Genetics Of The Green Salamander (Aneides Aeneus), Megan Novak

All Dissertations

The relationship between wildlife and the environment they inhabit is dependent on both spatial and temporal scales. It is therefore crucial that biological investigations account for ecological scale when analyzing patterns and processes established, particularly when such investigations inform conservation management plans. This dissertation provides extensive insight into the conservation biology of the green salamander (Aneides aeneus), a critically imperiled species in South Carolina. The green salamander is a species that exists in a patchy network of rock outcrops within mountainous forest landscapes, and most studies on habitat suitability for green salamanders have been conducted on the macrohabitat, …

Population Abundance And Growth Of Elk (Cervus Canadensis) In Western North Carolina, Jessica Braunstein

Doctoral Dissertations

In an effort to restore extirpated elk to their previous range, 52 elk were reintroduced to Great Smoky Mountains National Park (GRSM) in North Carolina during 2001 and 2002. Since their reintroduction, elk numbers have increased and their range has extended beyond GRSM boundaries. My primary research objectives included estimating population abundance, apparent survival, per capita recruitment, and population growth rate of elk in North Carolina. I used spatially explicit capture-recapture (SECR) models based on fecal DNA to identify individual elk and estimate population abundance and growth in the region. Technicians and I walked a series of transects throughout the …

Study Of Population Dynamics Of Sugarcane Aphid (Melanaphis Sacchari) In Rio Grande Valley, Texas, Neetu Khanal

Theses and Dissertations

Chapter 1: This chapter incorporates detailed information about the biotype concept, aphids, their types and their biotypes, importance of studying insect biotypes and their role in mediating host plant defenses.

Chapter 2: This chapter explains in detail about the biology, biotypes, feeding behavior, damage, and economic loss caused due to sugarcane aphid infestation. This chapter further elaborates on the need for studying population level differences and justifies the objectives and significance of this research study.

Chapter 3: This chapter provides information about the comprehensive work done on three different populations of sugarcane aphid collected from three different locations in Rio …

Unraveling A Paradox Of Habitat Relationships: Scale-Dependent Drivers Of Temporal Occupancy-Abundance Relationships In A Cooperatively Breeding Bird, Natasha D.G. Hagemeyer, Mario B. Pesendorfer, Walter D. Koenig, Eric L. Walters

Biological Sciences Faculty Publications

Context Spatial occupancy and local abundance of species often positively covary, but the mechanisms driving this widespread relationship are poorly understood. Resource dynamics and habitat changes have been suggested as potential drivers, but long-term studies relating them to abundance and occupancy are rare. In this 34-year study of acorn woodpeckers (Melanerpes formicivorus), a cooperatively breeding species, we observed a paradoxical response to changes in habitat composition: despite a reduction in the availability of high-quality breeding habitat, the population increased considerably.

Objectives We investigated the role of annual variation in food availability and long-term changes in habitat composition as predictors …

Survival-Larval Density Relationships In The Field And Their Implications For Control Of Container-Dwelling Aedes Mosquitoes, Katherine G. Evans, Zoey R. Neale, Brendan Holly, Cecilia C. Canizela, Steven A. Juliano

Faculty Publications – Biological Sciences

Population density can affect survival, growth, development time, and adult size and fecundity, which are collectively known as density-dependent effects. Container Aedes larvae often attain high densities in nature, and those densities may be reduced when larval control is applied. We tested the hypothesis that density-dependent effects on survival are common and strong in nature and could result in maximal adult production at intermediate densities for Aedes aegypti, Aedes albopictus, and Aedes triseriatus. We surveyed naturally occurring densities in field containers, then introduced larvae at a similar range of densities, and censused the containers for survivors. We analyzed the survival-density …

Quantifying Antarctic Krill Connectivity Across The West Antarctic Peninsula And Its Role In Large-Scale Pygoscelis Penguin Population Dynamics, Katherine L. Gallagher, Michael S. Dinniman, Heather J. Lynch

CCPO Publications

Antarctic krill (Euphausia superba) are considered a keystone species for higher trophic level predators along the West Antarctic Peninsula (WAP) during the austral summer. The connectivity of krill may play a critical role in predator biogeography, especially for central-place foragers such as the Pygoscelis spp. penguins that breed along the WAP during the austral summer. Antarctic krill are also heavily fished commercially; therefore, understanding population connectivity of krill is critical to effective management. Here, we used a physical ocean model to examine adult krill connectivity in this region using simulated krill with realistic diel vertical migration behaviors across …

A Simulation Model Of Sustained-Yield Harvest For Northern Bobwhite In South Texas, Joseph P. Sands, Stephen J. Demaso, Fidel Hernández, Leonard A. Brennan, Matthew J. Schnupp, Trent W. Teinert, Dale Rollins, Robert M. Perez

National Quail Symposium Proceedings

Recommended sustainable harvest rates for northern bobwhite (Colinus virginianus) vary greatly and range from 25% to 70% of the prehunt population. Because northern bobwhite populations have declined across their geographic range, determining sustainable harvest levels is critical for effective management. Our objectives were to use simulation modeling to identify sustainable rates of bobwhite harvest, probability of population persistence, and minimum viable population estimates. We also conducted a sensitivity analysis to evaluate the impacts of harvest on northern bobwhite populations in Texas, USA. We constructed a simulation model using Program STELLA 9.0 for a hypothetical northern bobwhite population on …

Exploring Metapopulation-Scale Suppression Alternatives For A Global Invader In A River Network Experiencing Climate Change, Brian D. Healy, Phaedra Budy, Charles B. Yackulic, Brendan P. Murphy, Robert C. Schelly, Mark C. Mckinstry

Wildland Resources Faculty Publications

Invasive species can dramatically alter ecosystems, but eradication is difficult, and suppression is expensive once they are established. Uncertainties in the potential for expansion and impacts by an invader can lead to delayed and inadequate suppression, allowing for establishment. Metapopulation viability models can aid in planning strategies to improve responses to invaders and lessen invasive species’ impacts, which may be particularly important under climate change. We used a spatially-explicit metapopulation viability model to explore suppression strategies for ecologically-damaging invasive brown trout (Salmo trutta), established in the Colorado River and a tributary within Grand Canyon National Park. Our goals …

Migration Ecology Of American White Pelicans: Circannual Movement, Geographic Range, And Annual Survival, Ryo Ogawa

Theses and Dissertations

Responses of migratory birds to seasonal climate and long-term environmental changes have been a central theme of avian migration ecology. Atmospheric conditions (e.g., winds and thermals), climate, and land cover and land use (LCLU) are major factors influencing the flights of soaring birds. Soaring American White Pelicans (Pelecanus erythrorhynchos) (hereafter, AWPEs) migrate between the subtropical Gulf of Mexico (GOM) and the temperate Northern Great Plains. American White Pelicans are also economically important piscivorous birds, causing enormous damages to the commercial Channel Catfish (Ictalurus punctatus) aquaculture in the Southeastern US. My studies aimed to evaluate the effects …

Efficacy Of Conservation Actions For Imperiled Colorado River Fishes In The Grand Canyon, Arizona, Brian D. Healy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many fishes are critically imperiled, particularly in their native rivers, due to human water use and dam construction, which can dramatically alter habitats and block fish migratory routes. The introduction of invasive sport-fishes that prey on native fish further threatens native species that maybe restricted to only a single river basin (i.e., “endemic”). To preserve native fishes in river systems with degraded habitats, managers need to understand the effects of conservation actions to ensure limited resources are applied effectively. Two commonly applied native fish conservation actions include removal of invasive fishes, and translocations of native fish from one place into …

Ocean Quahog (Arctica Islandica) Population Dynamics: Sex-Based Demographics And Regional Comparisons In The Northwest Atlantic, Kathleen M. Hemeon

Dissertations

Arctica islandica (ocean quahog) is the longest-lived bivalve on Earth. Individuals on the deep continental shelf of the Mid-Atlantic (US) can survive for centuries, and when found in the colder, boreal waters of Iceland, ages over 500 years can be reached. The ocean quahog is important in the US, yet very little is known about the resiliency of the ocean quahog stock to fishing activity, and ocean quahog recruitment patterns over time. To quantify and constrain age-reader error prior to age analysis, a triple-method error protocol was developed for A. islandica that included age-reader bias, precision, and error frequency. The …

Evaluating A Possible New Paradigm For Recruitment Dynamics: Predicting Poor Recruitment For Striped Bass (Morone Saxatilis) From An Environmental Variable, Julie M. Gross, Philip Sadler, John M. Hoenig

VIMS Articles

Understanding what causes large year classes and predicting them has been called the holy grail of fisheries science, one of the last great unanswered questions. Recruitment prediction, or forecasting, is an important component for setting fishery catch limits. We propose a new approach, called the “poor-recruitment paradigm”, for predicting recruitment using environmental variables. This approach hypothesizes that it is easier to predict poor recruitment rather than good recruitment because an environmental variable affects recruitment only when its value is extreme (lethal); otherwise, the variable may be benign and not influence recruitment. Thus, good recruitment necessitates all environmental conditions not be …

Non-Linear Relationships Between Density And Demographic Traits In Three Aedes Species, Logan A. Sauers, Steven A. Juliano, Kelsey E. Hawes

Faculty Publications – Biological Sciences

Understanding the relationship of population dynamics to density is central to many ecological investigations. Despite the importance of density-dependence in determining population growth, the empirical relationship between density and per capita growth remains understudied in most systems and is often assumed to be linear. In experimental studies of interspecifc competition, investigators often evaluate the predicted outcomes by assuming such linear relationships, ftting linear functions, and estimating parameters of competition models. In this paper, we experimentally describe the shape of the relationship between estimated population rate of change and initial density using laboratory-reared populations of three mosquito species. We estimated per …

Evidence For Irruptive Fluctuation In Axis Deer Of Hawai‘I, Steven C. Hess, Jonathan Sprague, Jacob Muise

USDA Wildlife Services: Staff Publications

Axis deer on the Hawaiian Islands of Maui, Lāna‘i, and Moloka‘i simultaneously experienced one of the most dramatic population crashes on record in 2020-2021, which coincided with extended drought conditions and prompted an emergency declaration for these islands. This phenomenon has been anecdotally documented during previous drought events in 2011-2012, but never formally studied. Newspaper articles document abundant deer becoming a nuisance to agriculture and natural resources, and then experiencing high mortality during droughts. This phenomenon fits Caughley’s (1970) operational definition of eruptive (sic) fluctuation “…as an increase in numbers over at least two generations, followed by a marked decline.” …

Dynamics Of A Western Anatolian Population Of Natrix Natrix And Natrix Tessellata(Serpentes: Natricidae), Yusuf Bayrakci, Di̇nçer Ayaz

Turkish Journal of Zoology

Due to their secretive nature, snakes are the most challenging animal group for monitoring. Nevertheless, population size estimates are indispensable to accurately determining conservation status and management strategies. We used passive integrated transponder (PIT) tags to track aquatic snakes Natrix natrix and Natrix tessellata in Lake Işıklı, Denizli province, Turkey. 304 N. natrix and 1563 N. tessellata specimens were captured and marked over the four-year sampling period. Of the marked individuals, 14 N. natrix and 97 N. tessellata were recaptured at least once. The three-year average population size was estimated at 1940 ± 1055 for N. natrix, and 10,146 ± …

Factors Influencing Brook Trout Population Dynamics And Resilience In Central Appalachian Headwater Streams, Christopher W. Schwinghamer

Graduate Theses, Dissertations, and Problem Reports

Central Appalachia has a unique history of human perturbation due largely to its historical economic reliance on extractive industry and timber harvest. Legacy impacts from these historic disturbances along with contemporary stressors in the form of continued industry, changing climates, altered land use, habitat fragmentation, and introduced species can present great threats to the region’s aquatic ecosystems. Brook Trout Salvelinus fontinalis are a species that has recreational and economic importance to the communities of central Appalachia but declines in size and abundance have been observed. Given the disturbances that threaten Brook Trout populations, understanding how their populations will respond to …

Population And Migratory Ecology Of Canada Warblers (Cardellina Canadensis) In The Central Appalachian Mountains, West Virginia, Usa, Stephanie H. Augustine

Graduate Theses, Dissertations, and Problem Reports

Nearctic-Neotropical migrant birds experience a wide range of environmental conditions throughout their annual cycle; thus, it is particularly challenging to evaluate the spatial factors that may influence population growth. The Canada Warbler (Cardellina canadensis) faces substantial range-wide population declines, but little study has been conducted regarding elements occurring across the entire year that drive demographic rates. The aims of this research are (1) determine the relationship between Canada Warbler population demographic rates and environmental conditions along an elevation gradient in the central Appalachian Mountains and (2) ascertain the nonbreeding season location and migratory routes used by the central …

Density, Diversity, And Seasonal Fluctuations In Soil Collembola In Three Differentlymanaged Ecosystems In North Khorasan, Iran, Mahmood Mehrafrooz Mayvan, Hussein Sadeghi Namaghi, Masoumeh Shayanmehr, Penelope Greenslade, Grant Palmer

Turkish Journal of Zoology

We examined the density, diversity, and seasonal fluctuation of soil inhabiting Collembola in different ecosystems: agricultural, rangeland, and forest ecosystems in the North Khorasan province of Iran from June 2018 to May 2019. The sampling program was conducted monthly on the three sites. Density was measured on the number of individuals per square meter. Species diversity was calculated using Shannon?Wiener index, Simpson?s diversity, and species richness by Rarefaction method. Fifty-three species belonging to 42 genera and 17 families were collected and identified. The density of Collembola in the forest was higher than in either rangeland or agroecosystem. Highest densities were …

Evaluating Relative Abundance, Fish Length, And Marine Protected Area Effectiveness For Four Key Rocky Reef Species Along The Northern Californian Coast, Leon Davis

Cal Poly Humboldt theses and projects

Marine protected areas (MPAs) were created with the purpose of helping conserve and restore diminished populations of marine organisms. Measuring the effectiveness of MPAs requires long-term monitoring, investigating the abundance and size distributions of the species that utilize the conservation areas, and comparing the results to neighboring reference sites that are not currently protected. In this study, observations from long-term MPA monitoring in northern California (2010-2019) were modeled with substrate, oceanographic, spatial, temporal, and body size variables to describe the variability in abundance and size of three fish groups: Black rockfish (Sebastes melanops), the Blue rockfish group (comprised …

Distribution, Maturity, Age And Growth Of Gray Snapper (Lutjanus Griseus) In The Northwestern Gulf Of Mexico, Joel Anderson, Dusty Mcdonald, Ethan Getz, Roberta Weixelman, Faye Grubbs, Jason Ferguson

Gulf and Caribbean Research

Recent population expansion of Gray Snapper, Lutjanus griseus, in the northern Gulf of Mexico is driving increasing catch in the recreational fishery in Texas. We assessed long—term trends in distribution and abundance of Gray Snapper in Texas using fishery—dependent and fishery—independent data collected by the Texas Parks and Wildlife Department in the years 1980 — 2019. Boosted regression trees (BRT) were used to evaluate factors (water quality, season, depth, bay and inlet distance) driving Gray Snapper presence in fishery—independent samples of juveniles (seines) and subadults (gill nets) found in estuaries. Estuarine Gray Snapper were subsequently sampled from gill nets, …

Intraspecific Variation In Prey Susceptibility Mediates The Consumptive Effect Of Predation: A Case Study Of Yellowstone Elk And Wolves, Lacy M. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The reintroduction of wolves (Canis lupus) to Yellowstone National Park starting in 1995 is an important case study for understanding the consequences of predation on a prey population. Simulation studies conducted prior to and shortly after wolf reintroduction predicted that wolf predation of elk (Cervus canadensis) would have a modest influence on elk abundance. Predation of elk by wolves has been well documented and elk have remained the primary prey for wolves despite a decline in elk abundance. I used two quantitative approaches to estimate the influence of wolf predation on adult female elk survival and …

Livestock Ticks In The Uae: Prevalence, Distribution, Population Dynamics, And Associated Microorganisms, Nighat Perveen

Dissertations

Ticks are important vectors of an array of viral, bacterial, and protozoan pathogens resulting in a wide range of animal and human diseases in the Middle East and North Africa (MENA). In this study, ticks were collected from camels, cows, sheep, and goats in Abu Dhabi, Dubai, and Sharjah in the United Arab Emirates (UAE). The objectives of the study were to (1) identify tick species of livestock through taxonomic keys and using molecular markers, and determine their prevalence and distribution in the UAE, (2) assess Hyalomma dromedarii seasonal population fluctuation over a year under common camel breeding and management …

Invader Removal Triggers Competitive Release In A Threatened Avian Predator, J. David Wiens, Katie M. Dugger, J. Mark Higley, Damon B. Lesmeister, Alan B. Franklin, Keith A. Hamm, Gary C. White, Krista E. Dilione, David C. Simon, Robin R. Bown, Peter C. Carlson, Charles B. Yackulic, James D. Nichols, James E. Hines, Raymond J. Davis, David W. Lamphear, Christopher Mccafferty, Trent L. Mcdonald, Stan G. Sovern

USDA Wildlife Services: Staff Publications

Changes in the distribution and abundance of invasive species can have far-reaching ecological consequences. Programs to control invaders are common but gauging the effectiveness of such programs using carefully controlled, large-scale field experiments is rare, especially at higher trophic levels. Experimental manipulations coupled with long-term demographic monitoring can reveal the mechanistic underpinnings of interspecific competition among apex predators and suggest mitigation options for invasive species. We used a large-scale before-after control-impact removal experiment to investigate the effects of an invasive competitor, the barred owl (Strix varia), on the population dynamics of an iconic old-forest native species, the northern spotted owl …

Temperature Stress And Disease Drives The Extirpation Of The Threatened Pillar Coral, Dendrogyra Cylindrus, In Southeast Florida, Nicholas P. Jones, Lystina Kabay, Kathleen Semon Lunz, David S. Gilliam

Marine & Environmental Sciences Faculty Articles

Rare species population dynamics can elucidate the resilience of an ecosystem. On coral reefs, climate change and local anthropogenic stressors are threatening stony coral persistence, increasing the need to assess vulnerable species locally. Here, we monitored the threatened pillar coral, Dendrogyra cylindrus, population in southeast Florida, USA, in relation to consecutive heat stress events in 2014 and 2015. In the fall of each year, D. cylindrus colonies bleached following intense thermal stress and by June 2020 all monitored colonies died from a white-syndrome type disease. This resulted in the ecological extinction of D. cylindrus in the Southeast Florida Coral …

An Illicit Artisanal Fishery For North Pacific White Sharks Indicates Frequent Occurrence And High Mortality In The Gulf Of California, Daniel J. Madigan, Natalie S. Arnoldi, Nigel E. Hussey, Aaron B. Carlisle

Integrative Biology Publications

Large sharks shape ecosystems across their geographic ranges and have become a top research and conservation priority. Eastern North Pacific (ENP) white shark (Carcharodon carcharias) aggregations off the United States and Mexico are well described, but their population status is currently uncertain. Population assessments of ENP white sharks are complicated by migrations across international boundaries, vulnerability at aggregation sites, and undetermined mortality levels. While protective legislation exists both in the United States and Mexico, ongoing incidental and unreported catch may undermine assessments and management. Here, access to a clandestine artisanal fishery provides evidence for white shark abundance and mortality in …

Studies On The Techniques Of Continuing Control Of Rodent Pests On Grassland, Yuping Yang, Weihui Dong, Liqing Wang

IGC Proceedings (1997-2023)

No abstract provided.

Chondrilla Juncea L.: Post‐Fire Invasiveness In Artemisia Tridentata Communities Of Western North America, Nancy L. Shaw, A. L. Hild, C. L. Kinter

IGC Proceedings (1997-2023)

No abstract provided.

Modelling The Ecology Of Grasshopper (Orthoptera : Acrididae) Pest Species In The Grasslands Of Western Canada, Owen Olfert, R. M. Weiss

IGC Proceedings (1997-2023)

No abstract provided.