Ecology and Evolutionary Biology Commons^™

Limitations On Spatial Memory In Mice, Robert H.I. Dale, Martin Bedard

Robert H. I. Dale

Rats have an impressive ability to remember locations they have visited. Two experiments used an eight-arm radial maze to determine whether mice showed two important characteristics of this spatial memory: its durability, and its dependence on stimuli outside the maze (extreme stimuli). In Experiment 1, food-deprived mice were allowed to eat from four of the eight arms of the maze then, after delays of 5 sec, 1 min, or 5 min, they were permitted to choose the remaining arms. Choice accuracy declined significantly with the longer delays, but always remained above chance. In Experiment 2, the maze was rotated 180° …

The Hippocampus As Episodic Encoder: Does It Play Tag?, Robert H.I. Dale

Robert H. I. Dale

Rawlins’s characterization of the hippocampus as a “high-capacity, immediate-term memory store” captures the essential idea in a number of previous models. For example, Gaffan (1974), Gray (1984), Hirsh (1980), Kesner (Bierley, Kesner & Novak 1983), Olton (Olton, Becker & Handelmann 1979), Solomon (1980), and Winocur (1980) all agree that hippocampal animals show memory deficits when required to identify, for whatever reason, one specific event out of a list of recent events. Although these authors disagree on a number of details, Rawlins has identified their models common ground, the core of each model. (It is only fair to note that Gaffan …

Remembrance Of Places Lasts: Proactive Inhibition And Patterns Of Choice In Rat Spatial Memory, William A. Roberts, Robert H.I. Dale

Robert H. I. Dale

A series of experiments was carried out to evaluate the notion that rats given a sequence of massed daily trials on the radial maze reset working memory at the end of each trial by deleting its contents. Although curves presented by D. S. Olton [Scientific American, 1977, 236, 82-98: In S. H. Hulse, H. Fowler, & W. K. Honig (Eds.), Cognitive processes in animal behavior, 1978, Hillsdale, N.J.: Erlbaum] show that rats return to errorless performance at the beginning of each trial after the first, the fact that accuracy falls less rapidly over choices on Trial 1 …

Radial-Maze Performance In The Rat Following Lesions Of Posterior Neocortex, Melvyn A. Goodale, Robert H.I. Dale

Robert H. I. Dale

The present experiment was designed to investigate the role of posterior neocortex (areas 17, 18 and 18a) in the maintenance of performance on the radial maze. Following training to criterion on the 8-arm radial maze, rats received either sham operations, bilateral eye enucleations, lesions of posterior neocortex, or combined enucleations and lesions of posterior neocortex. While the enucleated animals with intact brains showed a slight, but significant performance decrement relative to the sham-operated group, the other two groups, with lesions of areas 17, 18 and 18a, each showed a massive deficit. This large deficit was observed even in the group …

Parallel-Arm Maze Performance Of Sighted And Blind Rats: Spatial Memory And Maze Structure, Robert H.I. Dale

Robert H. I. Dale

Sighted and peripherally blinded groups of rats learned to obtain a small reward from each arm of an eight-arm parallel maze, and a sighted group was similarly trained on a radial maze. The parallel-sighted and parallel-blind groups were equally slow, and much slower than the radial-sighted group, to attain criterion performance. The three groups shared several response characteristics: selectively avoiding the most recently entered arms, frequently choosing adjacent arms, and an absence of 'spatial generalization' among the arms. The findings support a simple model proposing how subjects identify and choose among the maze-arms.

Dynamic Effects Of Food Magnitude On Interim-Terminal Interaction, Alliston K. Reid, Robert H.I. Dale

Robert H. I. Dale

We tested the assumption of a facilitatory relation between periodic food presentation and schedule-induced drinking by examination of (a) elicited drinking, (b) drinking in anticipation of food delivery, and (c) possible indirect effects of food delivery on drinking. We exposed rats to a fixed-time 60-second schedule in which interfood intervals ended in either one or four food pellets with equal probability. In Phases 1 and 3, a stimulus signaled the magnitude of upcoming food presentation. In Phase 2, the stimulus was eliminated. Changes in drinking and "head-in-feeder" distributions within interfood intervals demonstrated that head-in-feeder was controlled directly by food presentation, …

Interactions Between Response Stereotypy And Memory Strategies On The Eight-Arm Radial Maze, Robert H.I. Dale, Nancy K. Innis

Robert H. I. Dale

Three groups of water-deprived rats collected water from the ends of the 8 arms of an 8-arm radial maze. Sighted subjects, and subjects blinded either with or without pre-enucleation experience on the radial maze, all retrieved the water efficiently. Most of the subjects exhibited the same response stereotypy, regularly choosing 8 adjacent arms of the maze, then stopping in the center of the maze. The strategies underlying this performance were analyzed by interrupting trials and rotating the maze 180° after the subject had made 3 choices. Sighted subjects depended on extramaze stimuli, naive-blind subjects depended on intramaze stimuli and experienced-blind …

Concurrent Drinking By Pigeons On Fixed-Interval Reinforcement Schedules, Robert H.I. Dale

Robert H. I. Dale

Three experienced pigeons were exposed to at least ten consecutive 100-min sessions on each of three food-reinforced fixed-interval (FI) schedules: FI 50-sec, FI 100-sec and FI 200-sec. Water was freely available. Drinking was largely confined to the first third of each fixed interval, and the mean sessional water intake was directly related to the food-reinforcement rate for each animal. The animals drank very quickly, i.e., 3-4 ml/sec, but the drinking bouts were brief, i.e., 0.8-1.4 sec, and infrequent, i.e., 2-5/hr. The parameters describing concurrent drinking in the pigeon are strikingly different from those describing rats’ drinking under similar reinforcement schedules, …

Temporal Variations In The Abundance And Composition Of Biofilm Communities Colonizing Drinking Water Distribution Pipes, John J. Kelly, Nicole Minalt, Alessandro Culotti, Marsha Pryor, Aaron Packman

Biology: Faculty Publications and Other Works

Pipes that transport drinking water through municipal drinking water distribution systems (DWDS) are challenging habitats for microorganisms. Distribution networks are dark, oligotrophic and contain disinfectants; yet microbes frequently form biofilms attached to interior surfaces of DWDS pipes. Relatively little is known about the species composition and ecology of these biofilms due to challenges associated with sample acquisition from actual DWDS. We report the analysis of biofilms from five pipe samples collected from the same region of a DWDS in Florida, USA, over an 18 month period between February 2011 and August 2012. The bacterial abundance and composition of biofilm communities …

National Park Service Cave Ecology Inventory And Monitoring Framework, Gretchen M. Baker, Steven J. Taylor, Shawn Thomas, Rick Olson, Kathy Lavoie, Marie Denn, Steven Thomas, Hazel Barton, Kurt Helf, Rene Ohms, Joel Despain, Jim Kennedy, David Larson

Hazel Barton

A team developed the Cave Ecology Inventory and Monitoring Framework for National Park Service (NPS) units. It contains information for NPS cave managers across the United States to determine how to inventory and monitor cave ecology. Due to the wide geographical scope of NPS caves and their many different types, the document does not prescribe exact protocols. Instead, it provides guidance for what types of inventory and monitoring are possible, a framework for deciding how to prioritize inventory and monitoring activities, and references to specific protocols that are already in place at NPS cave parks. Keywords: cave ecology, cave microbiology, …

Joint Phenotypes, Evolutionary Conflict And The Fundamental Theorem Of Natural Selection, David C. Queller

Biology Faculty Publications & Presentations

Multiple organisms can sometimes affect a common phenotype. For example, the portion of a leaf eaten by an insect is a joint phenotype of the plant and insect and the amount of food obtained by an offspring can be a joint trait with its mother. Here, I describe the evolution of joint phenotypes in quantitative genetic terms. A joint phenotype for multiple species evolves as the sum of additive genetic variances in each species, weighted by the selection on each species. Selective conflict between the interactants occurs when selection takes opposite signs on the joint phenotype. The mean fitness of …

Comparative Biology Of Three Species Of Costa Rican Haeterini, Laura Alexander

University of New Orleans Theses and Dissertations

Documenting life history characteristics of populations, especially of herbivorous insects such as butterflies, is fundamental to the ecological study of tropical rainforests. However, we know relatively little about tropical forest butterflies. Here, I combine information gathered using the mark-release-recapture (MRR) approach with manipulative and observational experiments in a natural environment to explore aspects of the population biology of three closely-related species of Costa Rican fruit-feeding understory butterflies (Cithaerias pireta, Dulcedo polita, and Pierella helvina), specifically: vertical stratification, attraction to and persistence in fruit-baited traps, relative abundance and distribution, movement patterns, probabilities of recapture and daily survival, …

Use Of Coastal Islands By Seabirds: A Tool To Guide Future Marine Protected Areas In California, Dana A. Page

Master's Projects and Capstones

Seabird breeding colonies on islands off the coast of California offer a unique tool to help guide marine spatial planning. The life histories of seabirds can be used to develop locations of ecological importance along the coast of California. Tracking methodologies and habitat modeling related to seabird habitat utilization can be used to inform management approaches which can aid in the expansion of marine protected areas (MPAs). Protecting ocean habitats will help mitigate impacts of climate change and ensure the ecosystem services provided by marine environments. Areas within the Monterey Bay National Marine Sanctuary were analyzed to locate candidate MPA …

Environmental Flow Regime Recommendations For The Promotion Of Salicaceae Seedling Recruitment In California’S Central Valley, Nicholas J. Torrez

Master's Projects and Capstones

Rivers around the world are being degraded due to alteration of natural flow regimes caused by the creation of dams and diversions to serve human needs for water. Alteration to natural flow regime affects a river’s flow magnitude, frequency, duration, timing, and rate of change of flow. These changes have major repercussions on the processes that drive riparian ecosystems. Repercussions to river processes are manifested in the degradation of riparian forest health. This is evident in the rivers of California’s Central Valley, where altered flow regimes are present in all of its major rivers. As a result, Salicaceae spp. are …

Arthropod Abundance And Diversity In Restored Longleaf Pine Savannas At Abita Creek Flatwoods Preserve, Cara B. Nighohossian

University of New Orleans Theses and Dissertations

The objective of this study is to determine whether changes in arthropod community structure in restored longleaf pine savannas corresponds to differences in vegetation structure often associated with burn frequency. Longleaf pine savannas are fire-maintained ecosystems characteristic of the southeastern United States and have experienced severe declines (around 97%) since European settlement. Changes in fire regime have been instrumental in the declines. Restoration of these ecosystems has involved reinstitution of periodic burnings to promote and maintain vegetative characteristics of the savannas. This study investigates trends in arthropod communities from areas heavily invaded by hardwood shrubs against those dominated by longleaf …

Harvest Incentives: A Tool For Managing Aquatic Invasive Species, Bob Wiltshire, Nathan Stone, Marshall Meyers, Bill Hyatt, Lori Williams, Jason Goldberg, Susan Pasko, Leah Elwell

National Invasive Species Council

Conclusion

The success of any harvest incentive program to address aquatic invasive species will depend upon numerous biological, socioeconomic, and legal considerations. Programs that encourage harvest may be a successful management tool in targeting small, distinct populations; in high priority areas within a larger invasion; or they may play a supplementary role within larger control programs. Their use, however, will require careful review, planning, and monitoring to ensure success and that they do not unintentionally lead to further spread of invasive species, cause additional harm to native species, or waste valuable resources.

Dissolved Nutrient Ratios And Concentrations Affect Fungal Reproduction And Community Structure Associated With Submerged Leaf Litter And Wood, Jennifer Fitzgerald

Electronic Theses and Dissertations

Litter-associated fungi are important intermediaries in carbon and energy flow in streams. They can obtain nitrogen (N) and phosphorus (P) from both the substrate and the water column. I tested the effects of dissolved nutrients (dissolved inorganic nitrogen (DIN) 40-975 µg/L, soluble reactive phosphorus (SRP) 2-135 µg/L, N:P ratios 2:1, 16:1, 128:1) on fungi associated with leaf litter (maple and rhododendron) and wood in streamside channels at Coweeta Long Term Ecological Research site, North Carolina. This study addressed two main questions: (1) will fungal reproduction (sporulation rate of aquatic hyphomycetes) peak at a dissolved N:P ratio similar to nutrient stoichiometry …

An Ecological Approach To Experiential Learning In An Inner-City Context, Pauline Garcia-Reid, Robert Reid, Bradley Forenza

Department of Family Science and Human Development Scholarship and Creative Works

In‐depth, qualitative interviewing was employed to describe processes and competencies experienced by family science interns, who practiced in a high‐risk ecological context. Twenty interns from a 3‐year period were recruited. All had interned on the same federally funded, HIV/substance abuse prevention grant in the same focal city. Within this sample, it was determined that experiential learning—vis‐à‐vis the internship—facilitated both intrapersonal processes and ecological competencies for family science interns, who may otherwise have lacked this knowledge when assuming professional roles. Implications for policy and practice are discussed.

The Role Of Nitrogen And Phosphorus In The Growth, Toxicity, And Distribution Of The Toxic Cyanobacteria, Microcystis Aeruginosa, James Parrish

Master's Projects and Capstones

Microcystis aeruginosa is among the most common harmful algal-blooming species in the world. Potent microcystins released by M. aeruginosa have been linked to liver failure and death in aquatic mammals, like the endangered California sea otter, and provide a serious public health risk to humans. Once characterized as a freshwater problem, M. aeruginosa is expanding on a global scale, making persistent returns in freshwater, brackish, and coastal marine ecosystems. Though commonly observed dominating aquatic ecosystems in low N:P atomic ratios less than 44:1, the reliability of N:P ratios as a tool for managing and predicting M. aeruginosa blooms is explored …

Role Model Fathers Or Deadbeat Dads? A Study Of Peromyscus Paternal Behavior, Taylor Wapshott

Senior Theses

Paternal behavior is a largely understudied and poorly understood topic, especially in mammalian species. Many current mammalian models for paternal behavior use a comparative approach, taking advantage of natural differences in behavior between closely related species. This study compared paternal behavior in two rodent species, namely Peromyscus maniculatus (BW) and Peromyscus polionotus (PO). PO rodents have been shown to be monogamous, but there have been no studies of their paternal behavior at this time. 10 PO males and 12 BW males were filmed in their home cage for a 10 minute period following initial disturbance of their nest and removal …