Digital Commons Network^™

Why Are Sheep Sheepish? How Perception Affects Animal Stereotyping, Robert G. Franklin Jr.

Animal Sentience

Marino & Merskin present compelling evidence that many stereotypes of sheep are incorrect. One factor that may play an important role in animal stereotyping is the physical appearance of animals, which can directly lead to stereotyping through automatic mental processes. Sheep have a round and babyish appearance that directly evokes judgments of warmth and docility. Depictions of sheep in art, and especially cartoons, reinforce this stereotype.

Conceptualizing Ecological Responses To Dam Removal: If You Remove It, What’S To Come?, J. Ryan Bellmore, G. R. Press, Jeffrey J. Duda, Jim E. O'Connor, Amy E. East, Melissa M. Foley, Andrew C. Wilcox, Jon J. Major, Patrick Shafroth, Sarah A. Morley, Christopher S. Magirl, Chauncey W. Anderson, James E. Evans, Laura Shawn Craig

School of Earth, Environment and Society Faculty Publications

One of the desired outcomes of dam decommissioning and removal is the recovery of aquatic and riparian ecosystems. To investigate this common objective, we synthesized information from empirical studies and ecological theory into conceptual models that depict key physical and biological links driving ecological responses to removing dams. We define models for three distinct spatial domains: upstream of the former reservoir, within the reservoir, and downstream of the removed dam. Emerging from these models are response trajectories that clarify potential pathways of ecological transitions in each domain. We illustrate that the responses are controlled by multiple causal pathways and feedback …

Variability In Microphytobenthos Biomass And Carbon Isotopic Values In Shallow Coastal Waters Of The Northern Gulf Of Mexico, Sharil N. Deleon, Jeffrey W. Krause, Ronald Baker

Gulf and Caribbean Research

No abstract provided.

Tiger Sharks Eat Songbirds: Reply, J. Marcus Drymon, K. Feldheim, A. M.V. Fournier, A. E. Jefferson, A. M. Kroetz, Sean P. Powers, E. A. Seubert

University Faculty and Staff Publications

In response to our recent paper (Drymon et al. 2019), Yosef (2019) questions the mechanism proposed to explain interactions between tiger sharks (Galeocerdo cuvier) and migratory songbirds, while offering an alternative mechanism based on a single observation. We appreciate the comments from Yosef and the opportunity to respond.

Tiger Sharks Eat Songbirds: Scavenging A Windfall Of Nutrients From The Sky, J. Marcus Drymon, K. Feldheim, A. M.V. Fournier, E. A. Seubert, A. E. Jefferson, A. M. Kroetz, Sean P. Powers

University Faculty and Staff Publications

No abstract provided.

Movement Ecology Of A Cryptic Ambush Predator: Integrating Radio Telemetry And Tri-Axial Accelerometry To Evaluate Spatial Strategies And Activity Patterns By Western Diamond-Backed Rattlesnakes (Crotalus Atrox), Dominic L. Desantis

Open Access Theses & Dissertations

An animal's decision to move from one location to another within its environment is determined by a complex blend of internal and external factors. Teasing apart the relative roles of specific variables in this web of interacting mechanisms has been a long-standing challenge in animal movement ecology. Historically, this problem was viewed as a sort of black box for which a myriad of methodological limitations precluded rigorous study. Recently, a diversity of animal-borne transmitters and dataloggers (i.e., bio-loggers) have circumvented many of these traditional limitations and transformed field studies of animal movement, behavior, and physiology - in some cases, allowing …

A Multi-Scale Analysis Of Jaguar (Panthera Onca) And Puma (Puma Concolor) Habitat Selection And Conservation In The Narrowest Section Of Panama., Kimberly A. Craighead

Antioch University Dissertations & Theses

Over the past two centuries, large terrestrial carnivores have suffered extreme population declines and range contractions resulting from the synergistic anthropogenic threats of land-use change and indirect effects of climate change. In Panama, rapid land use conversion coupled with climate change is predicted to negatively impact jaguar (Panthera onca) and puma (Puma concolor). This dissertation examined the environmental variables and scales influencing jaguar and puma habitat selection by season (annual, wet, and dry), using multi-scale optimized habitat suitability models and a machine-learning algorithm (Random Forests), in the narrowest section of Panama. The models derived from the data of an intensive …

Dust Storms And The Dispersal Of Aquatic Invertebrates In The Chihuahuan Desert Ecoregion, Jose Rivas Jr.

Open Access Theses & Dissertations

The Chihuahuan Desert surrounding El Paso, Texas is one of the most intense sources of dust in the Western Hemisphere. Within this vast desert are ephemeral wetlands with micrometazoan propagules contained within their sediment egg banks. Dispersal of aquatic microinvertebrates between habitats is vital for the success of their populations. Passive dispersal of the propagules provides an escape mechanism from unfavorable conditions. Upon desiccation of these habitats, windstorms can potentially transport propagules mixed within entrained sediments across regional scales. To study this process, I collected falling sediment from 91 windstorms, with 59 samples collected at the University of Texas at …

Deciduous Shrub Encroachment Effects On Tundra Soil Properties, Daniela Aguirre

Open Access Theses & Dissertations

Deciduous shrub abundance is increasing in tundra ecosystems as an effect of rising temperatures which may change tundra physical properties and, in turn, microbial communities and biogeochemical processes. Two mechanisms through which shrub presence may affect tundra ecosystems were examined in this study; the physical presence of the shrubs and effects of increasing shrub litter inputs. In a sub-arctic alpine tundra ecosystem, dominated by the deciduous shrub Betula glandulosa, both shrub presence (shrub present and removed) and litter quantity (no litter/litter removed, ambient litter, and twice ambient litter) were manipulated; multiple ecosystem properties where measured within the treatment plots over …

Microplastic In Aquatic Food Webs: Museum Specimens And Ingestion Experiments Reveal Controls On Microplastic Ingestion By Freshwater Fish, Loren Hou

Master's Theses

Plastic is pervasive in modern economies and ecosystems. Early research suggests freshwater fish commonly ingest microplastic (particles < 5 mm), which may influence fish digestive tissues, but no studies have examined historical patterns in microplastic consumption or rates of microplastic retention in fish. We measured microplastic in digestive tissue of specimens collected and preserved over the last century (Field Museum, Chicago). We selected Micropterus salmoides (largemouth bass), Notropis stramineus (sand shiner), Ictalurus punctatus (channel catfish), and Neogobius melanostomus (round goby) because each was well represented in the museum collection, with specimens from urban rivers. Specimens from 1900-2018 showed increases in microplastic concentration from the 1950's to present. in a second project, we collected round gobies from Lake Michigan in Chicago to conduct feeding experiments to measure microplastic ingestion and retention rates. the majority of microplastic was excreted within 72 hours of ingestion. Results will aid in understanding ecological interactions of microplastic and freshwater fish, informing further work on the movement of microplastic in aquatic food webs.

Natural History Of The Eastern Harvest Mouse In Southeastern Virginia, Robert K. Rose

Biological Sciences Faculty Publications

The Eastern Harvest Mouse, Reithrodontomys humulis, has been studied extensively in southeastern Virginia since 1979, using a combination of live and pitfall trapping methods. This smallest rodent of eastern North America also is one of most versatile, occupying a range of habitats in southeastern Virginia from old fields in different stages of succession, brushy edges, and forests of different types. As with other species of Reithrodontomys, R. humulis often is associated with the Hispid Cotton Rat, Sigmodon hispidus, with both reaching modest densities in old fields. Two capture-mark-release studies of small mammal communities in southern Chesapeake lasting …

Nutrient Uptake Among Urban And Non-Urban Streams Within The Piedmont Physiographic Province Of Virginia, Joseph T. Famularo

Theses and Dissertations

To assess how urbanization impacts stream nutrient uptake, a series of instantaneous (i.e. slug) nutrient additions were conducted in 3 urban and 3 non-urban streams during open and closed canopy conditions. Single additions of N, P, and combined additions of N and P were performed at each site. These data were used to test the hypothesis that high N:P concentrations in urban streams would result in P-limited conditions, and to assess differences in nutrient uptake kinetics (i.e., the relationship between uptake and concentration) between urban and non-urban streams. The results show that there were no consistent differences in N vs. …

Assessment Of Microbial Carbon Processing And Its Implications To The Carbon Budget Of Lake Superior, Lindsey Michelle Koren

Theses and Dissertations

Over the past few decades, there has been increased research focus on carbon cycling within aquatic systems, especially with the changing global climate. Inland waters play a major role in the global carbon cycle, but the fundamental features remain poorly understood, particularly the large lakes of the world. Our experimental approach assessing the carbon budget of Lake Superior, the largest freshwater lake by area, provides spatial and temporal variability that has been previously overlooked but may be critical to our understanding on the biogeochemical processes controlling the lake. Multiple stations were chosen across the lake, both nearshore and offshore, to …

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 …

Testing For Cryptic Diversity And Inference Of Population Structure In The Cosmopolitan Hoplonemertean Emplectonema Gracile (Nemertea), Paul L. Delaney Iv

Theses and Dissertations

Emplectonema gracile (Johnston 1837) is a hoplonemertean of marine intertidal hard-bottom communities and is distributed throughout the Northern Hemisphere. Although possessing a planktonic larval stage in its life history, the range of such cosmopolitan marine invertebrate species is often explained by cryptic speciation and anthropogenic transport. The purpose of this study is to test for possible cryptic species using mtDNA markers (COI and 16S rDNA) and to investigate population structure in E. gracile over a portion of its geographic range using mtDNA markers and ddRADseq nuclear SNP data. The results of both phylogenetic- and tree-based species delimitation revealed that E. …

Ecological Benefits Of Watershed-Scale Restoration In Two Intensively Mined Cold- And Warm-Water Ecosystems, Rebecca Anne Long

Graduate Theses, Dissertations, and Problem Reports (ETD)

Stream restoration projects are increasingly common. However, restoration projects that establish measurable goals, have pre- and post-restoration monitoring, and are implemented at the watershed scale are rare. We conducted a long-term (9-year) before-after-control-impact designed assessment of two watershed-scale acid mine drainage (AMD) remediation programs, one in a warm-water ecosystem and one in a cold-water ecosystem in West Virginia, USA. Restoration was strategically designed to recover biodiversity and improve the native fisheries by restoring chemically degraded water quality and re-establishing riverscape connectivity. We used analysis of variance to quantify responses in water chemistry, benthic macroinvertebrate communities, and fish community composition before …

Host-Plant Specialization And Nesting Biology Of Anthidium Placitum (Megachilidae) In Northwest California, Christopher Pow

Cal Poly Humboldt theses and projects

Premise of the study: Although the study of bees and their pollination services has grown immensely in recent years, the natural history of most solitary bee species is still largely unknown. The goal of this study was to contribute to the natural history dossier of a late-season wool carder bee, Anthidium placitum Cresson (Megachilidae), by establishing which plants it uses as sources of nectar and pollen as well as documenting details of its flower-handling behavior, mating behavior, and nesting biology in northwestern California.

• Methods: Field observations were made at five sites in Del Norte, Humboldt, Siskiyou, and Trinity counties. …

Evaluation Of Range-Wide Occupancy And Survey Methods For The Giant Kangaroo Rat (Dipodomys Ingens), Alyssa E. Semerdjian

Cal Poly Humboldt theses and projects

Though habitat suitability and occupancy are often correlated, they cannot always be inferred from each other. Therefore, a solid understanding of both is essential to effectively manage species. Recent studies have assessed range-wide habitat suitability for the giant kangaroo rat (Dipodomys ingens; GKR), but data regarding occupancy is lacking in parts of its distribution. Satellite and aerial imagery were used to identify GKR burrows across their known range, producing a range-wide occupancy map and non-invasive survey methods including track plates, manned flight, unmanned aerial vehicle, and sign surveys were conducted to determine effective methods for monitoring GKR occupancy. …

Tree Squirrels And Fishers In Northern California: The Effects Of Masting Hardwoods On Stand Use, Andria M. Townsend

Cal Poly Humboldt theses and projects

In western North America, tree squirrels such as western gray (Sciurus griseus) and Douglas squirrels (Tamiasciurus douglasii) are potentially important prey for fishers (Pekania pennanti). Western gray squirrels in particular may be highly ranked due to their large body size. Masting trees including black oak (Quercus kelloggii) and tanoak (Notholithocarpus densiflorus) produce an important food source for tree squirrels; therefore, forest stands containing these trees may be useful to foraging fishers. I hypothesized that; 1) the abundance of western gray and Douglas squirrels in a stand is influenced by the …

Response Of Headwater Amphibians To Long-Term Logging Impacts And Assessing Potential For Restoration In Redwood National And State Parks, Alyssa Marquez

Cal Poly Humboldt theses and projects

The timescale of community response to disturbance varies drastically, and slow-recovering ecosystems such as coastal redwood forests may take hundreds of years to return to old-growth conditions post-logging. Few studies have quantified long-term (>50 years) impacts of disturbance on ecosystems, specifically aquatic ecosystems. This study provides evidence of the persistence of historical logging impacts 50 years post-logging through the comparison of headwater amphibian populations (occupancy and abundance) and stream characteristics using a control-treatment study with a logged watershed, Streelow Creek, as the treatment and a pristine old-growth watershed, Godwood Creek, as the control. The immediately adjacent old-growth watershed acts …

Contribution Of Juvenile Estuarine Residency In A Bar-Built Estuary To Recruitment Of Chinook Salmon (Oncorhynchus Tshawytscha), Emily Katherine Chen

Cal Poly Humboldt theses and projects

Estuaries are commonly touted as nurseries for out-migrating salmonids, providing higher prey availability than streams, a physiological transition zone, and refugee from marine predators. Yet the diversity of estuaries makes it difficult to generalize the effect they have on salmonid recruitment. In bar-built estuaries, sandbars form at the mouth of rivers during periods of low flow, closing access to the ocean and disrupting outmigration. In this thesis, I evaluated how residency in a bar-built estuary affects the growth, survival, and ultimately recruitment of Chinook salmon (Oncorhynchus tshawytscha) in Redwood Creek, California. I conducted a mark-recapture experiment on out-migrating …

Ectomycorrhizal Fungal Community Assembly On Seedlings Of A Neotropical Monodominant Tree, Carolyn Delevich

Cal Poly Humboldt theses and projects

Formation of ectomycorrhizae may facilitate early seedling survival of ectomycorrhizal tree species due to enhanced nutrient acquisition. This could be especially important in heavily shaded understories of tropical monodominant forests where host plant photosynthetic capacity is limited. Little information is available on ectomycorrhizal (ECM) fungal colonization or community development of monodominant seedling cohorts, which have high survival rates. Following a 2016 mast seeding event, we sequentially measured percent colonization and species composition of ECM fungi on live and recently dead seedlings of the tropical monodominant tree Dicymbe corymbosa. We also compared seedling ECM fungi to those of nearby adult …

Distribution Of Sea Star Wasting Disease Symptoms In Pisaster Ochraceus In The Rocky Intertidal Zone, Jana N. Litt

Cal Poly Humboldt theses and projects

Beginning in 2013, many species of sea stars (phylum Echinodermata) along the Pacific coast experienced severe mortality due to sea star wasting disease (SSWD). The ochre sea star, Pisaster ochraceus, experienced one of the highest mortality rates during this outbreak. To test the hypothesis that the intertidal distribution of ochre sea stars influences the incidence and progression of SSWD symptoms, I documented the occurrence of symptoms and survivorship in adult and juvenile stars in the upper and lower portions of the mid-intertidal zone. I also chronicled the progression of SSWD symptoms among individually tagged adult stars to assess changes in …

Riparian Resilience In The Face Of Interacting Disturbances: Understanding Complex Interactions Between Wildfire, Erosion, And Beaver (Castor Canadensis) In Grazed Dryland Riparian Systems Of Low Order Streams In North Central Washington State, Usa, Alexa Whipple

EWU Masters Thesis Collection

Riparian systems of low order streams in the western United States (US) provide critical ecosystem functions and services such as diverse habitat for numerous species, flood attenuation and essential water storage in water limited environments. These systems have experienced long term disturbance from anthropogenic activities including mining, timber harvest, livestock grazing and near extirpation of a keystone riparian species, Castor canadensis (North American beaver). However, increasing frequency of large-scale wildfires and climate change driven weather is altering the severity and scale of riparian disturbance, often shifting highly impacted streams to a stable degraded state, unable to store water or provide …

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. …

Distribution And Habitat Use Of Benthic Fishes In The Lower Kanawha River, West Virginia, Nathaniel V. Owens

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Kanawha River in West Virginia is a historically diverse system in terms of ichthyofauna although, like many other large rivers, it has been subjected to a suite of anthropomorphic perturbations. These include this system being modified to allow the passage of commercial vessels for industry thus altering flow regimes, increased sedimentation, water depth, and channelization, and decreased interactions with its floodplain. Additionally, the fishes of this system have suffered from deleterious historical water quality issues caused by intensive timber operations, mining, and industrial waste. Post Clean Air Act, Clean Water Act, and Surface Mining Control and Reclamation Act water …

Assessing The Robustness Of Time-To-Event Abundance Estimation, Kenneth E. Loonam

Graduate Student Theses, Dissertations, & Professional Papers

Abundance estimates can inform management policies and are used to address a variety of wildlife research questions, but reliable estimates of abundance can be difficult and expensive to obtain. For low-density, difficult to detect species, such as cougars (Puma concolor), the costs and intensive field effort required to estimate abundance can make working at broad spatial and temporal scales impractical. Remote cameras have proven effective in detecting these species, but the widely applied methods of estimating abundance from remote cameras rely on some portion of the population being marked or uniquely identifiable, limiting their utility to populations with naturally occurring …

Across The Great Divide, Debra Merskin

Animal Sentience

Chapman & Huffman’s target article calls for a reevaluation of claims of human uniqueness and superiority. It also adds to the literature on how species differences, as Darwin noted, are more of degree than kind. The threats to environmental health and species survival are a consequence of excluding nonhuman animals from moral concern and consideration. The theory of intersectionality should include speciesism in the array of discriminatory practices.

“I Am Not An Animal”, Lori Marino

Animal Sentience

The answer to Chapman & Huffman’s question — “Why do we want to think humans are different?” — lies in the work of Ernest Becker and the social psychology literature known as Terror Management Theory, according to which our deep anxiety about animality and death can drive our need to feel superior to the other animals.

Phooey On Comparisons, Gwen J. Broude

Animal Sentience

Chapman & Huffman reject the notion that human beings are very different from other animals. The goal is to undermine the claim that human uniqueness and even superiority are reason enough to treat other animals badly. But evaluating human uniqueness for this purpose only plays into the hands of those who exploit invidious comparisons between us and other animals to justify mistreatment of the rest of the animal kingdom. What human uniqueness we may discover would still be no justification for how we behave toward other animals. We should also ask ourselves whether any human-centric criterion can be justification for …