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Full-Text Articles in Population Biology

Morphological Variation Of Lingual Glands In Wild American Alligator (Alligator Mississippiensis) Populations, Benjamin Angalet May 2026

Morphological Variation Of Lingual Glands In Wild American Alligator (Alligator Mississippiensis) Populations, Benjamin Angalet

Master's Theses

American alligators (Alligator mississippiensis) inhabit diverse aquatic ecosystems including freshwater wetlands, swamps, and estuarine rivers. As apex predators, their physiological resilience has implications for ecosystem stability and long-term conservation. With projected sea-level rise and increasing saltwater intrusion into coastal freshwater habitats, understanding the osmoregulatory capacity of alligators is increasingly important. Unlike marine-tolerant crocodilians such as the saltwater crocodile (Crocodylus porosus), which possess specialized salt-secreting lingual glands in addition to renal and cloacal mechanisms, the morphology and physiological significance of lingual glands in wild American alligators remain poorly understood. This study examined lingual gland morphology and plasma …


Hidden Diversity In A Clonal Endemic: Insights Into Clematis Socialis From A Population Genetics Perspective, Joanna M. Lapoint Apr 2026

Hidden Diversity In A Clonal Endemic: Insights Into Clematis Socialis From A Population Genetics Perspective, Joanna M. Lapoint

Theses

Clematis socialis (Kral) is a rare, federally endangered perennial species restricted to a small number of fragmented populations in Alabama and Georgia. The species exhibits extensive clonality and limited sexual recruitment, characteristics that complicate expectations regarding genetic diversity and population connectivity. Despite its conservation significance, genome-wide assessments of population structure have been lacking. We used genotyping-by-sequencing (GBS) to generate a genome-wide SNP dataset for 170 individuals sampled from six natural populations. Population structure and genetic differentiation were evaluated using Bayesian clustering, analysis of molecular variance (AMOVA), pairwise FST estimates, and network-based visualization. Analyses revealed strong genetic structuring among populations and …


Coho Salmon (Oncorhynchus Kisutch) Response To Habitat Restoration Through Space And Time: Monitoring Growth, Survival, And Movement In A Restored Habitat Network, Carter Perez Adamson Jan 2026

Coho Salmon (Oncorhynchus Kisutch) Response To Habitat Restoration Through Space And Time: Monitoring Growth, Survival, And Movement In A Restored Habitat Network, Carter Perez Adamson

Cal Poly Humboldt theses and projects

Despite the decline of coho salmon (Oncorhynchus kisutch), Prairie Creek, a tributary of Redwood Creek in northern California, remains a coho salmon stronghold. The restoration of juvenile coho rearing habitat was identified as a recovery objective in this watershed by the National Marine Fisheries Service. Among the restoration projects addressing this objective are an ongoing project on Prairie Creek and its tributary Skunk Cabbage Creek, and a prior effort on Strawberry Creek (a tributary of Redwood Creek’s estuary). Standard monitoring methods for assessing project success have limitations and may be improved by measuring salmon use of restored habitats …


Factors Influencing Swift Fox Reintroduction Success To Fort Belknap Reservation, Montana, Dana Nelson Aug 2025

Factors Influencing Swift Fox Reintroduction Success To Fort Belknap Reservation, Montana, Dana Nelson

All Dissertations

Reintroductions are an important conservation tool for reestablishing wildlife populations, and studying the factors influencing reintroduction outcomes is important to improving success rates over time. Swift fox are a small canid native to the short- and mixed grass prairies of western North America that have experienced severe population declines due to habitat loss and poisoning in the late 1800s. While swift fox now occupy approximately 40% of their historic range, reintroduction to northern Montana may promote the species’ long-term persistence, encourage connectivity in an existing range gap, and return species to areas where it is culturally significant. We studied the …


Nitrogen Addition Additively Boosts Climate-Driven Salsola Tragus (Russian Thistle) Invasion Into Southwestern Usa Grasslands, Melissa A. Bacigalupa Jul 2025

Nitrogen Addition Additively Boosts Climate-Driven Salsola Tragus (Russian Thistle) Invasion Into Southwestern Usa Grasslands, Melissa A. Bacigalupa

Biology ETDs

Effective management of invasive, non-native plants requires understanding key drivers of invasion, including nitrogen enrichment from atmospheric deposition and agriculture. Long-term studies are essential for capturing complex invasion dynamics yet remain uncommon. We used 22 years of observations and 14 years of nitrogen experiments to examine invasion by Salsola tragus (Russian thistle) into three semi-arid grasslands of central New Mexico. Invasion patterns varied, with rapid expansion in Chihuahuan Desert grassland and the Desert-Plains ecotone but stability in Plains grassland. Under ambient nitrogen, precipitation most strongly correlated with Russian thistle biomass and high native grass biomass was associated with Russian thistle …


Jaguar (Panthera Onca) Population Status And Conservation Needs In Panama Revealed Using Spatial Density And Occupancy Models., Rebeca E. Becdach Jan 2025

Jaguar (Panthera Onca) Population Status And Conservation Needs In Panama Revealed Using Spatial Density And Occupancy Models., Rebeca E. Becdach

Cal Poly Humboldt theses and projects

Jaguars (Panthera onca) are key predators and the largest felid in the Americas. The species is listed as near threatened globally due to habitat loss, fragmentation, and human persecution. Their population decline can negatively affect the structure and functioning of the ecosystems they inhabit. Conservation efforts for jaguars and their habitat require understanding jaguar populations and how they are impacted by human presence across their range. This information is lacking in Panama, a critical portion of the Jaguar range. Panama forms a narrow land bridge connecting Central and South America, integral to wildlife movement, including jaguars, across both …


Surveys Of Aphonopelma Hentzi In Missouri: Conservation Efforts Through Population, Genetics, And Habitat Studies, Anderson B. Spencer Mr., Becky Hansis-O'Niell Jan 2024

Surveys Of Aphonopelma Hentzi In Missouri: Conservation Efforts Through Population, Genetics, And Habitat Studies, Anderson B. Spencer Mr., Becky Hansis-O'Niell

Undergraduate Research Symposium

Aphonopelma hentzi and other tarantula species are greatly understudied organisms. In the Missouri regions there is little knowledge on their mating patterns, gene diversity, or population sizes. The focal glades in this experiment display regional fragmentation, which could prevent tarantulas from traveling and mating between regions of their glades. Due to the lack of knowledge surrounding them, methods for determining gene diversity are harmful to the organism. Our recent work has shown that it is possible to extract genetic information from the molts of burrowing tarantulas. This will allow us to safely determine the lineages and interbreeding patterns of the …


Changing Fire Regimes And Nuanced Impacts On A Critically Imperiled Species, Jeremy T. Rockweit, Katie M. Dugger, Damon B. Lesmeister, Raymond J. Davis, Alan B. Franklin, J. Mark Higley Jan 2024

Changing Fire Regimes And Nuanced Impacts On A Critically Imperiled Species, Jeremy T. Rockweit, Katie M. Dugger, Damon B. Lesmeister, Raymond J. Davis, Alan B. Franklin, J. Mark Higley

United States Department of Agriculture Wildlife Services: Staff Publications

Wildfire activity throughout western North America is increasing which can have important consequences for species persistence. Native species have evolved disturbance-adapted traits that confer resilience to natural disturbance provided disturbances operate within their historical range of variability. This resilience can erode as disturbance regimes change and begin operating outside this range. We assessed wildfire impacts during 1987–2018 on the northern spotted owl, an imperiled species with complex relationships with late and early seral forest in the Pacific Northwest, USA. We analyzed population- and individual-level wildfire impacts across the frequent-fire portion of the owl’s geographic range at two spatial scales and …


Population Response Of Eastern Wild Turkey To Removal Of Wild Pigs, Matthew T. Mcdonough, Stephen J. Zenas, Robert A. Gitzen, Mark D. Smith, Kurt C. Vercauteren, Stephen S. Ditchkoff Jan 2024

Population Response Of Eastern Wild Turkey To Removal Of Wild Pigs, Matthew T. Mcdonough, Stephen J. Zenas, Robert A. Gitzen, Mark D. Smith, Kurt C. Vercauteren, Stephen S. Ditchkoff

United States Department of Agriculture Wildlife Services: Staff Publications

There is insufficient understanding of interspecific interactions with the eastern wild turkey (Meleagris gallopavo silvestris) and wild pigs (Sus scrofa). Wild pigs compete with wild turkeys and predate nests and adults; however, population‐level effects on wild turkeys are not clear. Using cameras, we assessed responses of wild turkey populations to wild pig removal in central Alabama, USA, from 2018–2021. We compared wild turkey relative abundance and occupancy on 3 large‐scale pigremoval treatment sites (3,407–5,531 ha) relative to a control site (2,510 ha) during 1 pre‐treatment year and 2 posttreatment years, with analyses including a covariate expressing the cumulative …


Environmental Influences On The Growth Of Inland Cisco Populations In Three Minnesota Sentinel Lakes, Edward Carlson Dec 2022

Environmental Influences On The Growth Of Inland Cisco Populations In Three Minnesota Sentinel Lakes, Edward Carlson

Biology Graduate Theses

Cisco Coregonus artedi are a pelagic cold-water fish that are widely distributed throughout many inland lakes across the northern Midwest and play an important role as forage for large piscivores. Inland Cisco populations have been observed to vary in their overall size and recruitment potential based on the system in which they are found. Cisco are sensitive to oxythermal stress and with climate change, land use, and invasive species effects becoming more prevalent in Minnesota, aspects of lake ecosystems are changing, ultimately making Cisco more susceptible to these stressors. To investigate how different factors were affecting the population dynamics of …


Breeding Season Survival And Reproduction In A High-Density Bobwhite Population: A Case Study, William E. Palmer, Shane D. Wellendorf, D. Clay Sisson Sep 2022

Breeding Season Survival And Reproduction In A High-Density Bobwhite Population: A Case Study, William E. Palmer, Shane D. Wellendorf, D. Clay Sisson

National Quail Symposium Proceedings

The demographic behavior of northern bobwhite (Colinus virginianus; hereafter, bobwhite) populations at high densities could provide important insights into why bobwhite populations fluctuate. Therefore, we documented breeding season demographics of bobwhites to understand how prebreeding density influenced reproductive effort and postbreeding density on an intensively managed property in Leon County, Florida, USA, 2002–2006. We estimated prebreeding bobwhite density each April using multi-observer strip-transects and postbreeding densities each November using covey call grid surveys. We radio-tagged 217 bobwhites in March and located bobwhites at least 5 days/week, 15 April–30 September to determine vital rates. Prebreeding density ranged from 1.5–8.6 …


Mississippi Sandhill Crane Conservation Update 2017–2019, Scott G. Hereford, Angela J. Dedrickson Jan 2022

Mississippi Sandhill Crane Conservation Update 2017–2019, Scott G. Hereford, Angela J. Dedrickson

Proceedings of the North American Crane Workshop

To manage crane habitat on the Mississippi Sandhill Crane National Wildlife Refuge during 2017-2019, 5,822 ha were treated with prescribed burns, 648 ha of woody vegetation were removed, 97 ha of invasive plants were chemically treated, and 1.2 ha of crops were planted. Mississippi sandhill crane (Grus canadensis pulla) use responded to habitat treatment; 348 of 349 VHF radio locations were in treated areas. There were 316 target predators removed. Eighteen captive-reared juveniles were acclimated and released. We detected an average of 38 nests per year, including a record 40 nests in 2019. Fifteen chicks fledged in 2019, …


Drivers Of Annual Fledging In The Mississippi Sandhill Crane Population 1991–2018, Henry W. Woolley, Scott G. Hereford, Jerome J. Howard Jan 2022

Drivers Of Annual Fledging In The Mississippi Sandhill Crane Population 1991–2018, Henry W. Woolley, Scott G. Hereford, Jerome J. Howard

Proceedings of the North American Crane Workshop

We studied trends in nesting, number of chicks fledged annually, and their environmental and biotic drivers in the wild population of Mississippi sandhill cranes (Grus canadensis pulla) on Mississippi Sandhill Crane National Wildlife Refuge during 1991-2018. Population size, number of nests, and number of chicks fledged annually increased slowly but significantly over the course of the study. Increases in population size were related to both number of wild-reared chicks fledged annually and number of captive-reared chicks released each year, but wild-reared chicks had significantly higher survivorship than captive-reared chicks. Hurricanes transiently raised mortality rates but only Hurricane Katrina …


Changes In The Minnesota Northern Pike Population Over The Past Thirty Years, Joey Severin Jan 2022

Changes In The Minnesota Northern Pike Population Over The Past Thirty Years, Joey Severin

Journal of Earth and Life Science

Northern pike Esox lucius are one of the most popular game fish in Minnesota. Many anglers have noticed that northern pike seemed to decrease in size throughout much of this state. Catch per unit of effort (CPUE) drives average weight for northern pike; within lakes, as CPUE goes up average weight decreases. Decreases in size has led the Minnesota Department of Natural Resources (MNDNR) to implement new regulations on northern pike. The MNDNR noticed that not all the state has this same problem with Northern Pike, and has broken down the state into three zones, with different protected slots and …


The Effects Of Commercial Harvest On The Density And Demography Of Aquatic Turtles In Arkansas, Andrhea Darleen Massey Dec 2021

The Effects Of Commercial Harvest On The Density And Demography Of Aquatic Turtles In Arkansas, Andrhea Darleen Massey

Graduate Theses and Dissertations

The United States is home to the second highest concentration of turtle species in the world, after Asia. As of 2018, there are 57 turtle species recognized within the US, 40% of which are listed as threatened or endangered, with the primary threats to population persistence identified as over-consumption and/or habitat loss. Within the US, the Mississippi Alluvial Valley (MAV) region represents the second highest turtle species richness, after the Mobile River Basin. The MAV region of Arkansas is one of the least regulated in terms of commercial aquatic turtle harvest and has undergone large-scale habitat conversion from bottomland hardwood …


Assessing The Dispersal And Recruitment Of Stocked Walleye Fry In A Northern Minnesota Chain Of Lakes, Joseph W. Amundson Oct 2021

Assessing The Dispersal And Recruitment Of Stocked Walleye Fry In A Northern Minnesota Chain Of Lakes, Joseph W. Amundson

Biology Graduate Theses

As part of Minnesota's Walleye Sander vitreus egg take practice, 10% of eggs taken for hatchery purposes are stocked back into the donor lake. For Andrusia, part of the Cass Lake Chain of Lakes (Chain), this practice can result in elevated fry densities (mean: 17,000 fry/littoral hectare). However, if fry are able to disperse and use all available littoral hectares throughout the Chain, fry densities would be intermediate to typical stocking densities for Minnesota lakes (1,200 - 2,400 fry/littoral hectare). In 2016-2018, 3-3.5 million fry were mass-marked by immersion in oxytetracycline (OTC) prior to stocking into Andrusia to allow differentiation …


Noninvasive Genetic Sampling With A Bayesian Spatial Capture-Recapture Analysis To Estimate Abundance Of Roosevelt Elk (Cervus Canadensis Roosevelti), Makenzie Henk Jan 2021

Noninvasive Genetic Sampling With A Bayesian Spatial Capture-Recapture Analysis To Estimate Abundance Of Roosevelt Elk (Cervus Canadensis Roosevelti), Makenzie Henk

Cal Poly Humboldt theses and projects

Determining abundance of Roosevelt elk (Cervus canadensis roosevelti) in central Humboldt County, California has presented a unique challenge to wildlife managers due to the dense forest habitat and the animals’ elusive behavior. As the elk population has increased, so has human-wildlife conflict, and wildlife agencies need efficient and repeatable methods for determining abundance to inform management decisions. Traditional monitoring methods such as helicopter surveys are ineffective due to low sighting probability and strong behavioral responses to the aircraft. They also often lead to biased sex ratios when the distribution of males and females varies across the landscape. Non-invasive …


Evaluating Moose Alces Alces Population Response To Infestation Level Of Winter Ticks Dermacentor Albipictus, Daniel D. Ellingwood, Peter J. Pekins, Henry Jones, Anthony R. Musante May 2020

Evaluating Moose Alces Alces Population Response To Infestation Level Of Winter Ticks Dermacentor Albipictus, Daniel D. Ellingwood, Peter J. Pekins, Henry Jones, Anthony R. Musante

United States Department of Agriculture Wildlife Services: Staff Publications

Many wildlife populations are experiencing a variety of environmental pressures due to the direct and indirect consequences of a changing climate. In the northeast, USA, moose Alces alces are declining in large part because of the increasing parasitism by winter tick Dermacentor albipictus, facilitated by high host density and optimal environmental conditions. To test this hypothesis, and better understand the influence of this interaction on the stability of the regional population, we constructed a population viability model using data collected through comprehensive survival and productivity studies in 2002–2005 and 2014–2018 in northern New Hampshire. Years of heavy tick infestation (epizootics) …


Sea Level Rise Vulnerability Analysis Of Mangrove Ecosystems Using Gis, Kayla Caldwell Apr 2020

Sea Level Rise Vulnerability Analysis Of Mangrove Ecosystems Using Gis, Kayla Caldwell

HCNSO Student Theses and Dissertations

Climate change is accelerating beyond what is natural due to excessive emissions from human activities. The sea level has been rising for many years and is currently at a rate of 3.6 mm/yr. Mangroves are known to only keep pace with a sea level rate of less than 1.2 mm/yr. Mangroves are particularly vulnerable to rising sea levels if they are not able to keep pace through vertical sediment accretion or inland migration. To test the vulnerability of the south Florida mangrove ecosystems to sea level rise, this study analyzed changes in the mangrove forest coverage of the Oleta River …


Time Specific Population Dynamics Of Diatoms In Artificial Environments, Sydney Brown Apr 2020

Time Specific Population Dynamics Of Diatoms In Artificial Environments, Sydney Brown

Georgia College Student Research Events

Algae serve as the base trophic level of aquatic systems, energetically supporting entire aquatic communities. Culturing in a laboratory setting requires significant phycological background and ecological knowledge to mimic their natural environmental conditions. The purpose of this research was to explore the effects of time on the growth of algal cultures. Gomphonema parvulum was the species investigated, falling into a class of algae known as diatoms- which are defined by cell walls composed of silica. Due to this unique morphological feature, asexual reproduction results in a diminution of cell size each generation in which restoration of natural sizes is initiated …


Urbanization And Population Growth: Projected Impacts Of Growth On Ecological Resources In Ontario1, Laura J. Bozzelli Dec 2019

Urbanization And Population Growth: Projected Impacts Of Growth On Ecological Resources In Ontario1, Laura J. Bozzelli

International ResearchScape Journal

No abstract provided.


Mammal Species Inventory Using Various Trapping Methods In Zone 4 Of Billy Barquedier National Park, Belize During Rainy Season, Mersady Redding Dec 2019

Mammal Species Inventory Using Various Trapping Methods In Zone 4 Of Billy Barquedier National Park, Belize During Rainy Season, Mersady Redding

Animal Science Undergraduate Honors Theses

Belize is a small country, but it is extremely ecologically diverse. Based on the few studies conducted in Belize, the abundance of mammals is low but diversity is high. Particular findings note the number and identity of species differed between four sites in the Maya Mountains of Belize, indicating that a data set from a single site is not representative of the Neotropical region. Insufficient data is available to estimate current species richness of many areas in Belize, including Billy Barquedier National Park (BBNP). The objective of this study was to explore trapping and documentation methods of terrestrial mammals in …


Spatial And Temporal Variability In Post-Larval Yellow Perch Density, Steve Hauschildt Feb 2019

Spatial And Temporal Variability In Post-Larval Yellow Perch Density, Steve Hauschildt

Biology Graduate Theses

Yellow Perch Perca flavescens are important as forage for other species and for sport fishing in many northern lakes. However, estimating post-larval Yellow Perch populations can be difficult because of many environmental factors that cause unexplained variation. The objective of this study was to help reduce unexplained variation by determining a post-larval Yellow Perch population density estimate on Blackduck Lake, MN, provide guidance to help determine the number of trawls required for trawling-based recruitment indices to achieve varying levels of precision, and test for the effects of wind speed and direction on post-larval Yellow Perch spatial variability. This study estimated …


Adult Atlantic Sturgeon Population Dynamics In The York River, Virginia, Jason E. Kahn Jan 2019

Adult Atlantic Sturgeon Population Dynamics In The York River, Virginia, Jason E. Kahn

Graduate Theses, Dissertations, and Problem Reports (ETD)

Sturgeon first appear in the fossil record in the Triassic Period just over 200 million years ago and are among the most primitive of the bony fishes. Despite their large size and historic presence along the East Coast, Atlantic sturgeon were not targeted for their meat and caviar as a commercial fishery until 1880. By 1905 they had declined to less than one percent of their pre-fishing abundance but the fishery continued. Prior to 1980, there had been very little research on Atlantic sturgeon, primarily limited to documenting landing location and poundage, maximum longevity, or weight of eggs per fish. …


Adult Walleye Abundance And Subsequent Fry Production In The Tamarac River, Mn, Phillip Oswald Sep 2018

Adult Walleye Abundance And Subsequent Fry Production In The Tamarac River, Mn, Phillip Oswald

Biology Graduate Theses

Walleye reproductive success is of critical interest for the Red Lakes as this system is maintained entirely by natural reproduction and supports robust commercial and recreational fisheries. The Tamarac River, a major tributary to the Red Lakes, hosts a substantial Walleye spawning migration annually. The river drains the largest peat bog in the lower 48 states and thus experiences low dissolved oxygen at times. It is largely unknown how the potential anoxic bog water affects Walleye reproductive success each year and subsequent year class strength. Fyke nets were set from 2014-2018 to assess the relative abundance of adult Walleye spawning …


Growth Of Pelagic Age-0 Yellow Perch In Relation To Hatch Dates And Water Temperature In North-Central Minnesota Lakes, Ethan Karppinen Aug 2018

Growth Of Pelagic Age-0 Yellow Perch In Relation To Hatch Dates And Water Temperature In North-Central Minnesota Lakes, Ethan Karppinen

Biology Graduate Theses

Exposure to consistent water warming rates and access to abundant populations of edible sized zooplankton affects growth and increases the probability of survival for newly hatched Yellow Perch Perca flavescens. Seven lakes with varying physical characteristics were selected in north-central Minnesota to study abiotic (water temperature) and biotic (zooplankton community and fish growth) progressions during the spring and early summer (April-June). Mean water temperatures from ice-out to 28 June (11.98-14.62 °C) had significant relationships with mean depth (P < 0.01, R? = 0.85), max depth (P < 0.01, R? = 0.73), and total volume (P < 0.01, R2 = 0.54). Hatch periods ranged from 13 to 19 days in 2015 and 13 to 25 days in 2016. Cumulative degree-days (CDD) were used to predict Yellow Perch hatch periods and explain growth. CDD predicted 21-81% of hatch periods in 2015 and 11-50% in 2016. Mean predicted total lengths at 28 June were 19.65-30.41 mm in 2015 and 20.88-28.54 mm in 2016. There was a significant relationship between CDD and predicted total length (R? = 0.62, P < 0.01) to explain differences in Yellow Perch total length while inhabiting the pelagic zone. Observed gape measurements were highly correlated with predicted gapes from the Schael formula (R? = 0.89, P < 0.01) that was used to assess the availability of edible sized zooplankton for age-0 Yellow Perch in each lake. No predator-prey mismatches were found and earlier hatch dates produced age-0 Yellow Perch with greater predicted total lengths in late June on the majority of lakes. This suggests that earlier hatched Yellow perch have an advantage over later hatched Yellow Perch in attaining greater lengths by late June. Our study provides information on a variety of physical and biological progressions in lakes, which may be used for fisheries management practices in the future.


Evaluating Lethal And Nonlethal Management Options For Urban Coyotes, Stewart W. Breck, Sharon A. Poessel, Mary Ann Bonnell Sep 2017

Evaluating Lethal And Nonlethal Management Options For Urban Coyotes, Stewart W. Breck, Sharon A. Poessel, Mary Ann Bonnell

Human–Wildlife Interactions

Human-coyote conflict in urban environments is a growing issue in cities throughout the United States with the primary problem being the development of problem individuals that are overly bold and aggressive with people and pets. Little research has focused on management options to deal with this conflict. We better define lethal and nonlethal management strategies associated with proactive and reactive management of coyotes with an emphasis on management of problem individuals. We then provide data from research in the Denver Metropolitan Area (DMA) that focused on reactive lethal removal of problem coyotes and reactive nonlethal hazing (i.e., community-level hazing, a …


Biotic And Abiotic Factors Predicting The Global Distribution And Population Density Of An Invasive Large Mammal, Jesse S. Lewis, Mathew L. Farnsworth, Christopher L. Burdett, David M. Theobald, Miranda Gray, Ryan S. Miller Mar 2017

Biotic And Abiotic Factors Predicting The Global Distribution And Population Density Of An Invasive Large Mammal, Jesse S. Lewis, Mathew L. Farnsworth, Christopher L. Burdett, David M. Theobald, Miranda Gray, Ryan S. Miller

Other Publications in Wildlife Management

Biotic and abiotic factors are increasingly acknowledged to synergistically shape broad-scale species distributions. However, the relative importance of biotic and abiotic factors in predicting species distributions is unclear. In particular, biotic factors, such as predation and vegetation, including those resulting from anthropogenic land-use change, are underrepresented in species distribution modeling, but could improve model predictions. Using generalized linear models and model selection techniques, we used 129 estimates of population density of wild pigs (Sus scrofa) from 5 continents to evaluate the relative importance, magnitude, and direction of biotic and abiotic factors in predicting population density of an invasive large mammal …


Effect Of The 2013-2015 California Drought On Small Mammal Abundance And Diversity In Chaparral, Oak Woodland And Riparian Habitats, Nicole Desideri Jun 2016

Effect Of The 2013-2015 California Drought On Small Mammal Abundance And Diversity In Chaparral, Oak Woodland And Riparian Habitats, Nicole Desideri

Biological Sciences

Long-term biodiversity surveys are a useful tool for assessing the impacts of stochastic events on wildlife and their communities. A recent stochastic event to affect the state of California is the historic 2013-2015 drought. This drought, described as a one-in-one-thousand year event, brought precipitation to a historic low; the statewide rainfall reaching 34% below average (Swain et al. 2014). While humans are feeling the impact of this water shortage, the effects on native ecosystems and wildlife populations are poorly documented. Baseline small mammal biodiversity data collected in 2011, before the drought, allows us the opportunity to study the impacts of …


Global Warming And Population Responses Among Great Plains Birds, Paul A. Johnsgard Feb 2015

Global Warming And Population Responses Among Great Plains Birds, Paul A. Johnsgard

Zea E-Books Collection

Based on an analysis of 47 years (1967–2014) of Audubon Christmas Bird Counts (CBC), evidence for population changes and shifts in early winter (late December) ranges of nearly 150 species of birds in the Great Plains states is summarized, a region defined as including the Dakotas, Nebraska, Kansas, Oklahoma, and the Texas panhandle. The rationale for this study had its origins in Terry Root’s 1988 Atlas of North American Wintering Birds. Root’s landmark study provided a baseline for evaluating the nationwide winter distributions of 253 North American birds in the mid-20th century, using data from the National Audubon Society’s …