Population Biology Commons^™

The Joint Effect Of Phenotypic Variation And Temperature On Predator–Prey Interactions, Jean Philippe Gibert

School of Biological Sciences: Dissertations, Theses, and Student Research

Understanding the factors underpinning to food web structure and stability is a long-standing issue in ecology. This is particularly important in a context of global climate change, where rising environmental temperatures may impact the way species interact, potentially leading to changes in food web structure and to secondary extinctions resulting from cascading effects. In order to understand and predict these changes, we need to hone our comprehension on the way predators and their prey interact. Recent studies suggest that, in order to do so, we need to focus on the traits controlling those interactions, such as body size. Mean body …

Sea Turtle Conservation: Reviewing The Efficacy Of Land- And Sea-Based Management Strategies For Loggerhead (Caretta Caretta) And Leatherback (Dermochelys Coriacea) Sea Turtles, Glenn D. Goodwin

HCNSO Student Capstones

As cosmopolitan species, loggerhead and leatherback turtles are confronted with a multitude of threats as they progress through their respective life stages. These range from depredation and poaching of eggs, hatchlings, and females on nesting beaches, to incidental hooking in pelagic longline fisheries and capture in trawl fisheries. Some threats are species specific on regional scales, though most impact both species. To confront these threats, various conservation strategies have been developed and implemented, including monitoring and caging of nests and changes to hook shape and trawl design. Here, current conservation methods are presented and discussed on a global scale for …

Reef Fish Spatial Distribution And Benthic Habitat Associations On The Southeast Florida Reef Tract, Dana Fisco

HCNSO Student Theses and Dissertations

The Florida Reef Tract (FRT) extends from the tropical Caribbean up the southeast coast of Florida into a temperate environment where tropical reef assemblages diminish with increasing latitude. This study used data from a three-year comprehensive fishery-independent survey to quantify reef fish spatial distribution along the Southeast FRT and define where the assemblage shifts from tropical to temperate. A total of 1,676 reef fish visual census samples were conducted to assess the populations on a stratified-random selection of sites of marine hardbottom habitats between the Miami River and St. Lucie inlet. Multivariate analyses were used to investigate differences in assemblages …

Occupancy Rates And Detection Probabilities Of Red-Backed Salamanders On The Virginia Fall Line, Jay D. Mcghee

Virginia Journal of Science

To meet the conservation needs of declining amphibian populations, there is a need to assess monitoring techniques in various habitat types and seasons. I assessed detection rates and proportion of area occupied via transect monitoring for red-backed salamanders at a site along the Virginia Fall Line in Doswell, Virginia. I established 24 transects in a 3.2-ha area in both riparian and upland habitats. Objects providing natural cover along these transects were sampled 3 times a week in fall and spring over a two-year period. Models of occupancy and detection were developed and compared using Akaike’s Information Criterion. Based on 113 …

Acoustic Detection Reveals Fine-Scale Distributions Of Myotis Lucifugus, Myotis Septentrionalis, And Perimyotis Subflavus In Eastern Nebraska, Jeremy A. White, Cliff Lemen, Patricia Freeman

School of Natural Resources: Faculty Publications

ABSTRACT.—Before white-nose syndrome arrives in Nebraska, it is important to document the preexposure distributions of cave bats in the state. We examined the distributions of Myotis lucifugus (little brown myotis), Myotis septentrionalis (northern long-eared myotis), and Perimyotis subflavus (tri-colored bat) in eastern Nebraska by setting acoustic detectors for a single night at 105 sites in wooded habitats during summers of 2012 and 2014. We compared 2 methods of determining presence at each site. Results of our analyses are fine-scale distributional maps for these bats and some range extensions from published records. Results for M. septentrionalis and P. subflavus are largely …

Molecular Analysis Confirming The Introduction Of Nile Crocodiles, Crocodylus Niloticus Laurenti 1768 (Crocodylidae), In Southern Florida, With An Assessment Of Potential For Establishment, Spread, And Impacts., Michael R. Rochford, Kenneth L. Krysko, Frank J. Mazzotti, Matthew W. Shirley, Mark W. Parry, Joseph A. Wasilewski, Jeffrey S. Beauchamp, Christpher R. Gillette, Edward F. Metzger Iii, Michiko A. Squires, Louis A. Somma

Papers in Herpetology

The state of Florida, USA, has more introduced herpetofauna than any other governmental region on Earth. Four species of nonnative crocodilians have been introduced to Florida (all since 1960), one of which is established. Between 2000–2014 we field-collected three nonnative crocodilians in Miami-Dade County, Florida, and one in Hendry County, Florida. We used DNA barcoding and molecular phylogenetics to determine species identification and native range origin. Also, we described diet, movement, and growth for one crocodile. Our molecular analyses illustrated that two of the crocodiles we collected are most closely related to Nile Crocodiles (Crocodylus niloticus) from South Africa, suggesting …

Diversity-Dependent Cladogenesis Throughout Western Mexico: Evolutionary Biogeography Of Rattlesnakes (Viperidae: Crotalinae: Crotalus And Sistrurus), Christopher Blair, Santiago Sánchez-Ramírez

Publications and Research

Rattlesnakes (Crotalus and Sistrurus) represent a radiation of approximately 42 species distributed throughout the New World from southern Canada to Argentina. Interest in this enigmatic group of snakes continues to accrue due, in part, to their ecomorphological diversity, contributions to global envenomations, and potential medicinal importance. Although the group has garnered substantial attention from systematists and evolutionary biologists for decades, little is still known regarding patterns of lineage diversification. In addition, few studies have statistically quantified broad-scale biogeographic patterns in rattlesnakes to ascertain how dispersal occurred throughout the New World, particularly among the different major biomes of the …

Avifaunal Community Composition In A Tropical Forest Corridor: A Case Study From The Atherton Tableland, North Queensland, Don Jones

Independent Study Project (ISP) Collection

Bird communities in tropical forest ecosystems are highly threatened by habitat loss and fragmentation. Replanted corridors connecting isolated forest remnants are a popular method of ameliorating certain negative impacts of habitat fragmentation. Such linkages can theoretically facilitate greater dispersal, increase gene flow, and reduce the risk of local extinctions in forest birds. However, relatively few studies have examined the utilization of reforested corridors by birds, and little hard data exists to support claims that this type of resource and time intensive project is the best use of often scarce funding for conservation. This study examined the avifaunal community present in …

Population And Morphological Changes In American Kestrels Through Space And Time, Teresa E. Ely

School of Biological Sciences: Dissertations, Theses, and Student Research

A once common raptor, the American kestrel (Falco sparverius) has experienced population declines in the last two decades throughout North America. Many hypotheses exist about the decline, including mortality from West Nile virus, rodenticide poisoning, climate change, an increase in predators, and core habitat loss or degradation, which could influence food availability. Food availability is key to raptor survival and reproduction, and changes in food availability throughout the year can have lifelong effects on size and body condition. Here we examine how morphology, specifically mass and wing chord, has changed at seven migration sites throughout North America as …

Effects Of Environmental Factors On The Abundance Of Blacklegged Ticks, Jasmine L. Miller, Roger A. Lebrun, Howard S. Ginsberg

Senior Honors Projects

The nymphal stage of the blacklegged tick, Ixodes scapularis, is the major vector of Lyme disease, the most common vector-borne disease in North America. Tick abundance has generally been estimated using either flag/drag samples or samples from hosts. However, the biases of these sampling methods have not been adequately studied. We compared samples using both methods from sites in Massachusetts and Wisconsin. Tick abundance was compared with variables related to weather (temperature, relative humidity, and tick adverse moisture events), vegetation (canopy cover, tree density, shrub density, ground vegetation, and leaf litter cover), and host abundance (mice, small mammals, medium …

Surveys For The Alabama Map Turtle (Graptemys Pulchra) In The Coosa River, Georgia, John B. Jensen

Georgia Journal of Science

The Alabama Map Turtle, found only in Mobile Bay drainages, is state-listed in Georgia as “rare” and has been petitioned for federal listing as “threatened.” Because this species has been poorly studied in Georgia and in the Coosa River especially, a survey was undertaken to determine its status in the Coosa to help inform the federal listing decision. The 2014-2015 survey involved counting basking turtles from a motorboat with the aid of binoculars. The Alabama Map Turtle was the third most abundantly observed turtle species during the survey, preceded by only the Slider and River Cooter. All size/age classes were …

Declining Frequency Of Road-Killed Rabbits In Central Georgia, Anna M. Bosch, Katelyn J. Benson, Alfred J. Mead

Georgia Journal of Science

Cottontail rabbits (Sylvilagus floridanus, Sylvilagus aquaticus, Sylvilagus palustris) are a common component of the mammal fauna of the southeastern United States, yet their numbers have been in decline for at least the past 40 years. Urban sprawl, land use changes, forest maturation, and increased predation have contributed to the decline in Georgia. In the current study we explore the proposition that long-term changes in roadkill frequency track changes in wildlife populations as a whole. Using comparisons of historical data collected by Georgia Department of Natural Resources personnel and recent roadkill census data from Baldwin County, it appears that the overall …

Population Genetic Divergence Of Isle Royale Pearl Dace, Margarita Margariscus (Cyprinidae)., John F. Elder Jr., Jack R. Martin, Isaac J. Schlosser, Larry Kallemeyn

Georgia Journal of Science

In 1949, Hubbs and Lagler described morphological variation among pearl dace (Margariscus margarita) of inland lakes on Isle Royale, Michigan. For Harvey Lake, Hubbs and Lagler, proposed that pearl dace were sufficiently morphologically distinct to warrant subspecific status. They argued that divergence of the Harvey Lake pearl dace was due to allopatric differentiation in isolation from lower elevation lakes. Harvey Lake has been isolated by elevation from lower elevation lakes for approximately 10 to 15 thousand years. No genetic studies have been done on Isle Royale pearl dace to evaluate this hypothesis to date. Here we report the analysis of …

Swans: Their Biology And Natural History, Paul A. Johnsgard

Zea E-Books Collection

The seven species of swans of the world are an easily and universally recognized group of waterfowl, which have historically played important roles in the folklore, myths and legends in many of the world’s cultures. Among the largest of all flying birds, they have also almost universally been used as symbols of royalty, grace and beauty, and largely for these reasons swans have only rarely been considered acceptable as targets for sport hunting. Swans occur on all the continents except Africa, although most species are associated with the temperate and arctic zones of North America and Eurasia. Among birds, swans …

Phylogeography Of Two Species Of The Genus Apochthonius Chamberlin, 1929, In The Pacific Northwest (Arachnida, Pseudoscorpiones), Brandi Lynn Welch

Dissertations and Theses

I used mitochondrial COI sequence data from forty one individuals to investigate phylogenetic relationships among populations of two morphologically similar species of the pseudoscorpion genus Apochthonius, A. minimus and A. occidentalis, in western Washington, Oregon, and northern California. My goal was to assess whether genetic structure in the two species was congruent with geography. Many plant and animal species in the Pacific Northwestern United States have shown patterns of genetic differentiation that follow both north-south and east-west trends, indicating that geologic and climatic events in the past separated populations to the extent that they became genetically differentiated. A distinct geographic …

Comparative Population Genomics Of Latitudinal Variation In Drosophila Simulans And Drosophila Melanogaster, Heather E. Machado, Alan O. Bergland, Katherine R. O'Brien, Emily L. Behrman, Paul S. Schmidt, Dmitri A. Petrov

School of Biological Sciences: Faculty Publications

Examples of clinal variation in phenotypes and genotypes across latitudinal transects have served as important models for understanding how spatially varying selection and demographic forces shape variation within species. Here, we examine the selective and demographic contributions to latitudinal variation through the largest comparative genomic study to date of Drosophila simulans and Drosophila melanogaster, with genomic sequence data from 382 individual fruit flies, collected across a spatial transect of 19 degrees latitude and at multiple time points over 2 years. Consistent with phenotypic studies, we find less clinal variation in D. simulans than D. melanogaster, particularly for the autosomes. Moreover, …

High Genetic Diversity But Low Population Structure In The Frog Pseudopaludicola Falcipes (Hensel, 1867) (Amphibia, Anura) From The Pampas Of South America, José A. Langone, Arley Camargo, Rafael O. De Sá

Biology Faculty Publications

Relative to South America’s ecoregions, the temperate grasslands of the Pampas have been poorly studied from a phylogeographic perspective. Based on an intermediate biogeographic setting between subtropical forest (Atlantic Forest) and arid ecosystems (Chaco and Patagonia), Pampean species are expected to show unstable demographic histories due to the Quaternary climatic oscillations. Herein, we investigate the phylogenetic relatedness and phylogeographic history of Pseudopaludicola falcipes, a small and common frog that is widely distributed across the Pampean grasslands. First, we use molecular data to assess if P. falcipes represents a single or multiple, separately evolving cryptic lineages. Because P. falcipes is …

Tiger Salamanders Disappearing In Region, Dennis M. Ferraro

School of Biological Sciences: Faculty Publications

"Where have all the salamanders gone?" 'This is a question I have been increasingly asked over the past five to six years from area residents. It seems we are observing a dramatic population decline of the western barred tiger salamander in parts of Southeast Nebraska. The western barred tiger salamander (Ambystoma mavortium) is one of only two salamanders in Nebraska. Over the past two years, none have been found in southeast Nebraska.

Salamanders, like all amphibians, are excellent indicator species. In many cases they act like the iconic canary in the mine shaft, telling us when to run …

Marine Ecoregion And Deepwater Horizon Oil Spill Affect Recruitment And Population Structure Of A Salt Marsh Snail, Steven C. Pennings, Scott Zengel, Jacob Oehrig, Merryl Alber, T. Dale Bishop, Donald R. Deis, Donna Devlin, A. Randall Hughes, John J. Hutchens, Jr., Whitney M. Kiehn, Caroline R. Mcfarlin, Clay L. Montague, Sean P. Powers, C. Edward Proffitt, Nicholle Rutherford, Camille L. Stagg, Keith Walters

University Faculty and Staff Publications

Marine species with planktonic larvae often have high spatial and temporal variation in recruitment that leads to subsequent variation in the ecology of benthic adults. Using a combination of published and unpublished data, we compared the population structure of the salt marsh snail, Littoraria irrorata, between the South Atlantic Bight and the Gulf Coast of the United States to infer geographic differences in recruitment and to test the hypothesis that the Deepwater Horizon oil spill led to widespread recruitment failure of L. irrorata in Louisiana in 2010. Size-frequency distributions in both ecoregions were bimodal, with troughs in the distributions consistent …

Genetic Differentiation Among Florida Populations Of Diadema Antillarum, Luke M. Chandler

Honors Undergraduate Theses

This project used molecular genetic markers (microsatellites) to determine the amount of genetic diversity within populations and whether significant differentiation exists among Florida populations of the long-spined sea urchin, Diadema antillarum. Specifically, this project aimed to (1) compare genetic diversity of D. antillarum from six populations in south Florida ranging from Biscayne Bay, the Florida Keys, and Dry Tortugas, and (2) determine whether two broodstock populations of D. antillarum contain variation indicative of native Florida populations. Together, these questions can address whether broodstock populations contain the genetic variation necessary to meet the Florida Fish and Wildlife Conservation Commission’s (FWC’s) genetic …