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Habitat Selection By Desert Carnivores: How Water, Intraguild Predation, And Prey Impact Animal Space Use, Nadine A. Pershyn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Across North America large carnivores have lost nearly half of their historic range, creating openings for smaller (< 15 kg) carnivores to take over their ecological roles. Coyotes (Canis latrans) have seen a significant range expansion, including into arid deserts. It was believed that the addition of artificial water sources by humans allowed coyotes to expand into desert ecosystems where they were previously unable to survive. The kit fox (Vulpes macrotis) is a small, desert-adapted carnivore with declining populations that faces threats from coyotes of intraguild predation. This is when carnivores compete over the same prey, and the larger carnivore (intraguild predator) kills the smaller carnivore (intraguild …

Roles And Interaction Of Blow Flies (Diptera: Calliphoridae) And Introduced Fire Ants (Hymenoptera: Formicidae: Solenopsis Invicta And S. Invicta X Richteri) In Carrion Decomposition In The Southeastern United States, Grant De Jong

Theses and Dissertations

Invasive fire ants (Solenopsis invicta and its hybrid with S. richteri) have been reported from carrion in the southeastern United States and are considered a part of the succession community. Alteration of ecological processes by fire ants could affect forensic interpretation of entomological data; therefore, I conducted studies to investigate the relative roles and interactions of fire ants and blow flies in carrion decomposition. The blow fly species composition in Mississippi has not been studied since 16 species were reported in 1983. Specimens from the Mississippi Entomological Museum were used to update the checklist of the blow flies of Mississippi …

Predators As Agents Of Selection And Diversification, Jerald B. Johnson, Mark C. Belk

Faculty Publications

Predation is ubiquitous in nature and can be an important component of both ecological and evolutionary interactions. One of the most striking features of predators is how often they cause evolutionary diversification in natural systems. Here, we review several ways that this can occur, exploring empirical evidence and suggesting promising areas for future work. We also introduce several papers recently accepted in Diversity that demonstrate just how important and varied predation can be as an agent of natural selection. We conclude that there is still much to be done in this field, especially in areas where multiple predator species prey …

Cats And Conservationists: The Debate Over Who Owns The Outdoors, Dara M. Wald, Anna L. Peterson

New Directions in the Human-Animal Bond

Cats and Conservationists is the first multidisciplinary analysis of the heated debate about free-roaming cats. The debate pits conservationists against cat lovers, who disagree both on the ecological damage caused by the cats and the best way to manage them. An impassioned and spirited conflict, it also sheds light on larger questions about how we interpret science, incorporate diverse perspectives, and balance competing values in order to encourage constructive dialogue on contentious social and environmental issues.

On one side of the cat debate stand many environmentalists, especially birders and conservation organizations, who believe that outdoor cats seriously threaten native wildlife. …

Stable Isotopic Niche Predicts Fitness Of Prey In A Wolf–Deer System, C. T. Darimont, P. C. Paquet, T. E. Reimchen

Chris Darimont, Ph.D.

Interindividual variation in niche presents a potentially central object on which natural selection can act. This may have important evolutionary implications because habitat use governs a suite of selective forces encountered by foragers. In a free‐living native black‐tailed deer, Odocoileus hemionus, population from coastal British Columbia, we used stable isotope analysis to identify individual variation in foraging niche and investigated its relationship to fitness. Using an intragenerational comparison of surviving and nonsurviving O. hemionus over 2 years of predation by wolves, Canis lupus, we detected resource‐specific fitness. Individuals with isotopic signatures that suggested they foraged primarily in cedar ( …

Eternal Enemies, Or Incidental Encounters? Structure And Patterns Of Interspecific Killing In Carnivora, Tor G. Bertin

Theses and Dissertations

Lethal interactions between carnivorans (interspecific killing) may influence their population dynamics, behavior, and other important aspects of their ecology. In this study, I expand upon previous research on the broad-scale patterns of interspecific killing in Carnivora (Palomares & Caro 1999, Donadio & Buskirk 2006) with a greatly expanded dataset (inclusion of scat and stomach data and more intensive sampling of the literature), and suggest avenues for future research. While like previous studies, I found a positive effect of relative body size between killer species and killed species on the likelihood of forming a killing interaction, I failed to find evidence …

Density And Distribution Of Piscivorous Fishes In The Sacramento – San Joaquin Delta, Christopher M. Loomis

Cal Poly Humboldt theses and projects

Predatory fishes, including numerous introduced species, are common to the Sacramento – San Joaquin Delta, but abundance data for most species is insufficient to determine the Delta-wide distribution and ecological impacts of these species. Predatory fishes (e.g. Striped Bass, Largemouth Bass have long been suspected of contributing to the decline of native species, including salmonids, but data has been insufficient to investigate this hypothesis. In this study, I present a novel method to assess predator fish populations across the southern Delta using DIDSON acoustic cameras and analyze the environmental associations that form the landscape and fine-scale distribution of predatory fishes. …

Population Dynamics Of The Threatened Staghorn Coral, Acropora Cervicornis, And The Development Of A Species-Specific Monitoring Protocol, Elizabeth Goergen

HCNSO Student Theses and Dissertations

Historically, Acropora cervicornis was found in high densities on many Caribbean, Florida, and Gulf of Mexico reefs. A disease outbreak in the late 1970s and 80s caused up to 99% loss of A. cervicornis cover at some sites, leaving populations sparsely distributed throughout its range and typically found as isolated colonies. Even though populations are depauperate causing a decrease in sexual reproduction, its fast growth rate and ability to reproduce through asexual fragmentation affords this species the potential for quick recovery and population growth. However, limited to no natural recovery has been documented. Many of these populations are poorly studied …

An Historical Overview And Update Of Wolf-Moose Interactions In Northeastern Minnesota, L. David Mech, John Fieberg, Shannon M. Barber-Meyer

USGS Northern Prairie Wildlife Research Center

Wolf (Canis lupus) and moose (Alces americanus) populations in northeastern Minnesota, USA, have fluctuated for decades and, based on helicopter counts, moose numbers declined to a new low from 2006 to about 2012. Other steep declines were found in 1991 and 1998 during periods when moose counts were done with fixed-wing aircraft; these declines also appeared to be real. Winter wolf numbers, monitored in part of the moose range, had been increasing since about 2002 to the highest population in decades in 2009. However, from 2009 to 2016, wolves decreased precipitously, and the moose- population decline leveled …

Annual Variation In Northern Bobwhite Survival And Raptor Migration, R. Douglas Holt, L. Wes Burger Jr., Bruce D. Leopold, K. David Godwin

National Quail Symposium Proceedings

We estimated survival of radio-marked northern bobwhite (Colinus virginianus) on a managed prairie site in northeast Mississippi during 2 disparate winters (15 Sep-14 Apr 2000–2002). We retrospectively examined factors that may influence bobwhite survival. Pooled survival rates differed substantially between years (S 1⁄4 0.03 6 0.02 in 2000–2001 and S 1⁄4 0.36 6 0.16 in 2001–2002). Regional relative abundance of 3 species of raptors thought to be important predators of bobwhite was greater during 2000 compared to 2001 based on kriging of Christmas Bird Count (CBC) data. We demonstrate an approach for characterizing annual variation in spatial distribution of migratory …

The Evolution Of Fear Ecology: A Fruit Fly (Drosophila Melanogaster) Perspective, Itachi Mills

Theses

Several mechanisms underlie how evolutionary lineages respond to predation pressures or predation risk. Further mechanisms link evolutionary predation responses to how animals forage, or find mates. However, gaps remain in our understanding about how predation and foraging interact in an evolutionary context.

In my first chapter, I elaborate on how predation and foraging relate in to one another in ecological, evolutionary and behavioral contexts. I start out with an overview of fear ecology. Then, I outline how trade-offs influence the evolution of morphological, chemical and behavioral responses to predation. I further elaborate on how these trade-offs influence reproduction. Finally, I …

Climate Change And The Threat Of Novel Marine Predators In Antarctica, Kathryn E. Smith, Richard B. Aronson, Brittan V. Steffel, Margaret O. Amsler, Sven Thatje, Hanumant Pratap Singh, Jeffrey S. Anderson, Cecilia J. Brothers, Alastair Brown, Daniel S. Ellis, J. N. Havenhand, W. R. James, P.-O. Moksnes, A. W. Randolph, T. Sayre-Mccord, J. B. Mcclintock

Ocean Engineering and Marine Sciences Faculty Publications

Historically low temperatures have severely limited skeleton-breaking predation on the Antarctic shelf, facilitating the evolution of a benthic fauna poorly defended against durophagy. Now, rapid warming of the Southern Ocean is restructuring Antarctic marine ecosystems as conditions become favorable for range expansions. Populations of the lithodid crab Paralomis birsteini currently inhabit some areas of the continental slope off Antarctica. They could potentially expand along the slope and upward to the outer continental shelf, where temperatures are no longer prohibitively low. We identified two sites inhabited by different densities of lithodids in the slope environment along the western Antarctic Peninsula. Analysis …

Population And Trophic Dynamics Of Striped Bass And Blueback Herring In The Connecticut River, Justin P. Davis

Doctoral Dissertations

Case studies of the ramifications of predator management for prey population dynamics can play a valuable role in developing ecosystem fisheries management. My dissertation focuses on the predator-prey interaction between Striped Bass (Morone saxatilis), an abundant predatory finfish, and an imperiled prey population of anadromous Blueback Herring (Alosa aestivalis). Annual returns of Blueback Herring to the Holyoke Dam on the Connecticut River in southern New England collapsed during the 1980-2000s, coincident with Striped Bass recovery. I studied the abundance and demography of both species in the Connecticut River during 2005-08, measured predation levels, and surveyed the …

Where And How Wolves (Canis Lupus) Kill Beavers (Castor Canadensis), Thomas Gable, Steve K. Windels, John G. Bruggink, Austin T. Homkes

Journal Articles

Beavers (Castor canadensis) can be a significant prey item for wolves (Canis lupus) in boreal ecosystems due to their abundance and vulnerability on land. How wolves hunt beavers in these systems is largely unknown, however, because observing predation is challenging. We inferred how wolves hunt beavers by identifying kill sites using clusters of locations from GPS-collared wolves in Voyageurs National Park, Minnesota. We identified 22 sites where wolves from 4 different packs killed beavers. We classified these kill sites into 8 categories based on the beaver-habitat type near which each kill occurred. Seasonal variation existed in …

Spatial Dynamics Of Vegetated Seascapes And The Influence On Fish And Crustaceans, Rolando O. Santos Corujo

Open Access Dissertations

My dissertation adopted concepts and spatial tools of seascape ecology, the marine counterpart of landscape ecology, to understand the broad-scale structural attributes that make submerged aquatic vegetation (SAV) seascapes resilient to anthropogenic disturbances, drivers of fauna community structure, and productive fisheries habitats. My research was designed to address the relative and interrelated ecological effects of broad-scale changes in SAV habitat amount (habitat loss) and configuration (fragmentation). SAV seascapes in nearshore areas of Biscayne Bay have been subject to constant anthropogenic disturbances associated to freshwater pulses from canals over the last 50 years; thus, these seascapes served as a model system …

Ecosystem Fragmentation Drives Increased Diet Variation In An Endemic Livebearing Fish Of The Bahamas, Marcio S. Araujo, R. Brian Langerhans, Sean T. Giery, Craig A. Layman

Department of Biological Sciences

One consequence of human-driven habitat degradation in general, and habitat fragmentation in particular, is loss of biodiversity. An often-underappreciated aspect of habitat fragmentation relates to changes in the ecology of species that persist in altered habitats. In Bahamian wetlands, ecosystem fragmentation causes disruption of hydrological connectivity between inland fragmented wetlands and adjacent marine areas, with the consequent loss of marine piscivores from fragmented sections. We took advantage of this environmental gradient to investigate effects of ecosystem fragmentation on patterns of resource use in the livebearing fish Gambusia hubbsi (Family Poeciliidae), using both population- and individual-level perspectives. We show that fragmentation-induced …

Presence And Function Of Tetrodotoxin In Terrestrial Vertebrates And Invertebrates, Amber N. Stokes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tetrodotoxin (TTX) is a potent neurotoxin found in a variety of species. This toxin has long been of concern to human health as it is found in puffer fish, which are a delicacy in Japan. Since the distribution of this toxin is so great, there are many questions regarding the evolution and ecology of organisms that have TTX. My research has focused on further investigating three topics with this research: production, predation, and identification of novel TTX bearing taxa. In order to perform this research I first refined a Competitive Inhibition Enzymatic Immunoassay methodology to quantify levels of TTX in …

The Need To Address Black-Backed Jackal And Caracal Predation In South Africa, David L. Bergman, Ho De Waal, Nico L. Avenant, Michael J. Bodenchuk, Michael C. Marlow, Dale L. Nolte

Wildlife Damage Management Conference Proceedings

Prior to 1990, the four provincial governments of South Africa had a variety of programs in place to manage predation by black-backed jackals and caracals through lethal and nonlethal manage-ment in close cooperation with livestock farmers. During the 1990s the official programmes were phased out due to a multitude of factors including lower predation rates. Today, thousands of livestock (primari-ly sheep and goats, but also cattle and wildlife) are lost each day in South Africa due to black-backed jackal and caracal predation. The actual numbers are not known because not all losses are accounted or reported. It also does not …

Propulsion In Cubomedusae: Mechanisms And Utility, Sean Colin, John H. Costello, Kakani Katija, Jamie Seymour, Kristen Kiefer

Arts & Sciences Faculty Publications

Evolutionary constraints which limit the forces produced during bell contractions of medusae affect the overall medusan morphospace such that jet propulsion is limited to only small medusae. Cubomedusae, which often possess large prolate bells and are thought to swim via jet propulsion, appear to violate the theoretical constraints which determine the medusan morphospace. To examine propulsion by cubomedusae, we quantified size related changes in wake dynamics, bell shape, swimming and turning kinematics of two species of cubomedusae, Chironex fleckeri and Chiropsella bronzie. During growth, these cubomedusae transitioned from using jet propulsion at smaller sizes to a rowing-jetting hybrid mode …

Development Of Camera Technology For Monitoring Nests, W. Andrew Cox, M. Shane Pruett, Thomas J. Benson, Scott J. Chiavacci, Frank R. Thompson Iii

USGS Northern Prairie Wildlife Research Center

Photo and video technology has become increasingly useful in the study of avian nesting ecology. However, researchers interested in using camera systems are often faced with insufficient information on the types and relative advantages of available technologies. We reviewed the literature for studies of nests that used cameras and summarized them based on study objective and the type of technology used. We also designed and tested two video systems that we used for three nest predator and behavioral studies. We found 327 studies that recorded 255 bird species spanning 19 orders. Cameras were most commonly used to study nest predators …

Morphological Convergence During Pregnancy Among Predator And Nonpredator Populations Of The Livebearing Fish Brachyrhaphis Rhabdophora (Teleostei: Poeciliidae), Jeff S. Wesner, Eric J. Billman, Adam Meier, Mark C. Belk

Faculty Publications

Predation can drive morphological divergence in prey populations, although examples of divergent selection are typically limited to nonreproductive individuals. In livebearing females, shape often changes drastically during pregnancy, reducing speed and mobility and enhancing susceptibility to predation. In the present study, we document morphological divergence among populations of nonreproductive female livebearing fish (Brachyrhaphis rhabdophora) in predator and nonpredator environments. We then test the hypothesis that shape differences among nonreproductive females are maintained among reproductive females between predator and nonpredator environments. Nonreproductive females in predator environments had larger caudal regions and more fusiform bodies than females in nonpredator environments; …

Natural History Of Belonuchus Nordmann Spp. And Allies (Coleoptera: Staphylinidae) In Heliconia L. (Zingiberales: Heliconiaceae) Flower Bracts, J. H. Frank, R. Barrera

Insecta Mundi

Adults, and in some species larvae, of several members of Belonuchus Nordmann (Coleoptera: Staphylinidae: Staphylininae) and a few related genera seem to be to various degrees consistently associated with flower bracts of the genus Heliconia (Zingiberales: Heliconiaceae). They are predators and eat various dipterous and lepidopterous larvae in that habitat. Adults of at least Belonuchus cephalotes (Sharp) and Odontolinus fasciatus Sharp are able to immerse completely in water to capture larvae and/or pupae of mosquitoes (Culicidae).

Adults and larvae of Belonuchus satyrus Erichson, and adults of B. cacao Blackwelder and B. rufipennis (F.) were found in water-filled flower bracts of …

Understanding The Use Of Barrier Islands As Nesting Habitat For Louisiana Birds Of Concern, Cecilia Marie Leumas

LSU Master's Theses

Colonial nesting seabirds are threatened by habitat loss and degradation, human disturbance, predation, and climate change. Several species of conservation concern concentrate high percentages of their total U.S. populations in Louisiana breeding colonies. We studied seabirds, including Royal Terns, Sandwich Terns, and Black Skimmers, nesting on Isles Dernieres barrier islands along the Gulf coast of Louisiana. Two of the four islands in this chain host extensive seabird colonies and two do not. We used an experimental approach to test the hypothesis that large terns and skimmers are prevented from nesting on Trinity Island, the largest of the Isles Dernieres, by …

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

Faculty Publications

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

Estimating Predation On Declining River Herring: Tag-Recapture Study Of Striped Bass In The Connecticut River, Eric T. Schultz, Justin P. Davis, Jason Vokoun

EEB Articles

Populations of anadromous alewife Alosa pseudoharengus and blueback herring Alosa aestivalis, collectively referred to as river herring, have declined in the Connecticut River. A hypothesis for why river herring have declined is that predation pressures have increased associated with recent increases in abundance of striped bass Morone saxatilis. Information on striped bass abundance, size structure, and consumption rates are required to test this hypothesis. This study was designed to provide estimates of striped bass population size in the Connecticut River during the spring migration season, via an intensive mark-recapture exercise and either an open or robust mark-recapture model. …

Factors Influencing Predation On Juvenile Ungulates And Natural Selection Implications, S. M. Barber-Meyer, L. D. Mech

USGS Northern Prairie Wildlife Research Center

Juvenile ungulates are generally more vulnerable to predation than are adult ungulates other than senescent individuals, not only because of their relative youth, fragility, and inexperience, but also because of congenital factors. Linnell et al.’s (Wildl. Biol. 1: 209-223) extensive review of predation on juvenile ungulates concluded that research was needed to determine the predisposition of these juveniles to predation. Since then, various characteristics that potentially predispose juvenile ungulates have emerged including blood characteristics, morphometric and other condition factors, and other factors such as birth period, the mother’s experience, and spatial and habitat aspects. To the extent that any of …

Effects Of Coyote Population Reduction On Swift Fox Demographics In Southeastern Colorado, Seija M. Karki, Eric M. Gese, Mead L. Klavetter

USDA Wildlife Services: Staff Publications

The distribution and abundance of swift foxes (Vulpes velox) has declined from historic levels. Causes for the decline include habitat loss and fragmentation, incidental poisoning, changing land use practices, trapping, and predation by other carnivores. Coyotes (Canis latrans) overlap the geographical distribution of swift foxes, compete for similar resources, and are a significant source of mortality amongst many swift fox populations. Current swift fox conservation and management plans to bolster declining or recovering fox populations may include coyote population reduction to decrease predation. However, the role of coyote predation in swift fox population dynamics is not …

The Decline Of Fowler's Toad (Bufo Fowleri) In Southern Louisiana: Molecular Genetics, Field Experiments And Landscape Studies, Laura Sanders Vogel

University of New Orleans Theses and Dissertations

Two of the most pervasive threats to species biodiversity are invasive species and habitat loss and degradation. Invasive species are often relatively insensitive to disturbance and many expand their range into disturbed and fragmented habitats. This dissertation uses an interdisciplinary approach to investigate how anthropogenic habitat disturbance is precipitating a range expansion in an invasive toad species, Bufo nebulifer, which is driving a decline in its native congener, B. fowleri. I employed a remote sensing and GIS study using historical data to compare changes in the two species distributions and habitat changes, a molecular genetic study to identify interspecific hybrids …

Ecology Of An Invasive Predator In Hawaii, Steven C. Hess, Heidi Hansen, Paul C. Banko

Managing Vertebrate Invasive Species

Cats (Felis catus) brought to Hawaii in the 1700s now occupy most habitats throughout the islands, including montane and sublapine zones. We studied home range, population genetics, diseases, and diet of feral cats on Hawai`i Island. Feral cats on Mauna Kea live in low densities and exhibit some of the largest reported home ranges. While 95% kernel home range estimates for 4 males ( x = 1418 ha) were nearly twice as large as 3 female home ranges ( x = 772 ha), one male maintained a home range of 2050 ha. Population genetics revealed that Mauna Kea …

Fish Predation Alters Community Predictability In Small Ponds, Elizabeth Gabor Biro

Theses

Predation can have large but variable impacts on prey species diversity. Although the effects of predation are often deterministic, stochastic processes can often influence the outcome on community assembly regardless of predator presence. Top predators can alter several properties of the community, including the abundance and richness of species, as well as the traits of species that can persist with predators. These properties, in turn, may influence the pattern of community assembly and the predictability of community structure from site to site. In this study, we investigated whether the presence of fish predators influenced the site-to-site predictability (similarity in community …