Population Biology Commons^™

Fauna Census Of Intertidal Cliffs, Mangapwani, Zanzibar, Emily Jankowski

Independent Study Project (ISP) Collection

Due to their extreme variations in condition over the course of a day, intertidal zones are challenging environments. Organisms that live there must be prepared to cope with both exposure and submersion, not to mention the temperature variations that accompany these conditions. The differing tolerances and adaptations of various organisms to these conditions generally cause patterns of vertical zonation to occur in the intertidal zone, especially when the shore is steep and rocky. Understanding the ecology of shore environments is important to future conservation and management efforts. This study was conducted on a beach in Mangapwani, Zanzibar at at 6˚ …

The Behavioral Causes Of Reproductive Skew In Cooperatively Polygynandrous Acorn Woodpeckers (Melanerpes Formicivorus), Anna C. Brownson

Biological Sciences Theses & Dissertations

Reproductive skew, the degree to which reproduction is shared among same-sex individuals in a social group, is a pattern affected by ecological conditions, sociality, cooperation, and the inter- and intrasexual behavior of individuals in complex animal societies. Transactional and compromise skew models assume that high skew is the product of dominance hierarchies among cobreeders, yet this has rarely been tested. Both model types fail to incorporate the decisions of more than two individuals, generally overlooking the effect of female behavior on male reproductive success in multi-male groups, and are ineffective at predicting skew in larger groups characterized by more than …

Elevational Gradients In Β-Diversity Reflect Variation In The Strength Of Local Community Assembly Mechanisms Across Spatial Scales, J Sebastián Tello, Jonathan A. Myers, Manuel J. Macia, Alfredo F. Fuentes, Leslie Cayola, Gabriel Arellano, M Isabel Loza, Vania Torrez, Maritza Cornejo, Tatiana B. Miranda, Peter M. Jørgensen

Biology Faculty Research

Despite long-standing interest in elevational-diversity gradients, little is known about the processes that cause changes in the compositional variation of communities (β-diversity) across elevations. Recent studies have suggested that β-diversity gradients are driven by variation in species pools, rather than by variation in the strength of local community assembly mechanisms such as dispersal limitation, environmental filtering, or local biotic interactions. However, tests of this hypothesis have been limited to very small spatial scales that limit inferences about how the relative importance of assembly mechanisms may change across spatial scales. Here, we test the hypothesis that scale-dependent community assembly mechanisms shape …

An Individual-Based Model Of Chaparral Vegetation Response To Frequent Wildfire, Timothy Lucas, Dayna Mann, Reanna Dona

Seaver College Research And Scholarly Achievement Symposium

In recent years, the Santa Monica Mountains (SMM) have been plagued by frequent wildfires which threaten the native chaparral species. Nonsprouting chaparral species are completely killed by a fire, but their seeds germinate in response to fire cues. Facultative sprouters both resprout after a wildfire and release seeds that germinate post-fire. This project is based on data collected since 1986 at a biological preserve adjacent to the Malibu campus of Pepperdine University with an average fire return interval of 7.5 years. We present a spatial model that simulates the growth, seed dispersal and resprouting behavior of individual shrubs that compete …

Relatedness, Conflict, And The Evolution Of Eusociality, Xiaoyun Liao, Stephen Rong, David C. Queller

Biology Faculty Research

The evolution of sterile worker castes in eusocial insects was a major problem in evolutionary theory until Hamilton developed a method called inclusive fitness. He used it to show that sterile castes could evolve via kin selection, in which a gene for altruistic sterility is favored when the altruism sufficiently benefits relatives carrying the gene. Inclusive fitness theory is well supported empirically and has been applied to many other areas, but a recent paper argued that the general method of inclusive fitness was wrong and advocated an alternative population genetic method. The claim of these authors was bolstered by a …

Cuban Treefrogs, Osteopilus Septentrionalis (Duméril & Bibron 1841) (Anura: Hylidae), And Other Nonindigenous Herpetofauna Interdicted In Grenada, Lesser Antilles., Louis A. Somma, Paul R. Graham

Papers in Herpetology

The number of introduced nonindigenous species of amphibians and reptiles within the greater Caribbean, including Grenada, is escalating and has become an ever-increasing critical conservation concern (Daudin and de Silva 2011; Powell et al. 2011; Powell and Henderson 2012). The amount of development, tourism, and consequent import commerce is increasing, requiring careful regulation of the pet trade and fauna introduced for biological control as well as diligence in cargo inspection. Herein we document the first records of nonindigenous Cuban Treefrogs, Osteopilus septentrionalis (Duméril and Bibron 1841), interdicted from cargo, along with recent interceptions of two species of nonindigenous lizards already …

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 …

Improving The Efficacy Of Family Planning Policies In Indian, Chinese, Tanzanian Contexts, And Beyond, Jayce O'Shields

Student Scholarship

In this paper, I will first present the problem of global overpopulation and the solution of decreasing populations to replacement level fertility using effective family planning and contraceptive policies. I will then describe the Indian state of Kerala as a model cultural context in which fertility rates have significantly declined in recent history and explain how Kerala can provide insight into efficient family planning and contraceptive strategies. Next, I will examine extant state and non-governmental organization (NGO) family planning and contraceptive policies in in India, China, and Tanzania, and in comparison to the Kerala mode, make general recommendations on how …

Understory Diversity And Composition Drives Carabid Assemblages, Tierney Brosius, Michael Reisner

Biology: Faculty Scholarship & Creative Works

Fire suppression has nearly eliminated fire as a disturbance in temperate deciduous forests. Lack of fire is transforming these ecosystems through a positive feedback loop termed mesophication: cool, damp, shady conditions become continually more favorable for a few mesophytic species, while deteriorating for diverse array of heliophytic ones. Disturbances caused by urbanization fragment and degrade remnant forests. In urban settings, human management (or lack thereof) is often a dominate driver of succession. Carabid diversity, understory vegetation, patch size, patch connectivity, and permeable surface area were all examined in multiple forest plots in Rock Island and Moline. The result of this …

Sea Turtle Hatchling Sex Ratios Determined Via Hormone Assay: Implications Of Climate Change?, William A. Hilton, Matthew Godfrey, Camryn D. Allen

STAR Program Research Presentations

Currently all species of sea turtles are listed as threatened or endangered with extinction under the U.S. Endangered Species Act. Due to their status, sea turtle conservation is a high priority for the U.S. National Marine Fisheries Service and U.S. Fish and Wildlife Service. One major challenge conservationists face is the lack of a noninvasive, cost efficient method for determining the sex of hatchling sea turtles. Because secondary sex characteristics (i.e. males have longer tails) are not evident until turtles start to reach sexual maturity, the sex of hatchlings is not easily determined. The least invasive way to determine the …

Microhabitat Conditions Influence Mesohabitat Associations And Distribution Of Larval Salamanders In Headwater Streams, J. M. Yeiser, Stephen C. Richter

Biological Sciences Faculty and Staff Research

Distribution patterns of stream biota are the result of complex interactions between individuals and their surrounding environment. Determining the spatial scale by which an organism is most influenced is paramount to understanding distribution patterns. Using a multi-scale approach, we investigated factors influencing habitat associations of larval Ambystoma barbouri (streamside salamander) and Eurycea cirrigera (southern two-lined salamander) in three Kentucky headwater streams. We used likelihood ratio G tests to identify associations between species and mesohabitat (i.e., runs, riffles, and pools), and we used microhabitat variables to predict the presence and abundance of salamanders via a priori multiple regression modeling. Ambystoma barbouri …

Updated Marine Mammal Distribution And Abundance Estimates In British Columbia, Benjamin D. Best, Caroline H. Fox, Rob Williams, Patrick H. Halpin, Paul C. Paquet

Population Distribution and Habitat Collection

Information relating to the distribution and abundance of species is critical for effective conservation and management. For many species, including cetacean species of conservation concern, abundance estimates are lacking, out of date and/or highly uncertain. Systematic, line-transect marine mammal surveys were conducted in British Columbia’s (BC) coastal waters over multiple years and seasons (summer 2004, 2005, 2008, and spring/autumn 2007). In total, 10,057km of transects were surveyed in an 83,547km2 study area. Abundance estimates were calculated using two different methods: Conventional Distance Sampling (CDS) and Density Surface Modelling (DSM). CDS generates a single density estimate for each stratum, whereas DSM …

Further Description Of Hybridization In The Sea Stars Asterias Rubens And Asterias Forbesi Through The Application Of Species-Specific Genetic Markers, Callie Bateson

Honors Program Theses

Hybridization occurs when two separate species reproduce to form hybrid offspring. If the hybrid offspring backcross with individuals of their parental species, the subsequent offspring may have varying amounts of the parental genomes, if viable. Following the retreat of the Last Glacial Maxima 20,000 years ago, two sea star species, Asterias forbesi and A. rubens came into secondary contact in the Gulf of Maine where they began to hybridize. Previous research in our lab studied the frequency of hybridization at four locations along the east coast (Quebec, Nova Scotia, New Hampshire, and New York) using morphological identifications as well two …

Asian Carp Population Status And Reproductive Potential In Illinois River Tributaries, Clinton Wesley Morgeson

Masters Theses

Large floodplain rivers are among the most complex natural systems characterized by exchange between the river and its floodplain. Information regarding fishes in main channel habitats is abundant, however much less understanding extends into their tributaries. Tributaries of large rivers provide critical habitats for main channel fishes, important for foraging, spawning, and refuge. In addition to native diversity, large rivers are host to multiple exotic species invasions, threatening biodiversity, ecosystem function, and habitat quality. Two notorious invaders are Silver Carp (Hypophthalmichthys molitrix) and Bighead Carp (H. nobilis), collectively Asian Carp, presenting an imminent threat of invasion …

Behavior Of Pollinators That Share Two Co-Flowering Wetland Plant Species, Joshua R. Morris

Williams Honors College, Honors Research Projects

Abstract:

Intermixed, co-flowering plant species often attract the same pollinators and may therefore compete for pollinator visits. Mimulus ringens and Verbena hastata are sympatric wetland plants that flower in synchrony and share many pollinators, the most common being bumblebees. The possibility of competition between these two plant species led to this observational study tracking pollinator movements in an area intermixed with both M. ringens and V. hastata. We identified pollinator species and tracked them as they visited flowers and moved from plant to plant. Smaller bees seemed to prefer the smaller flowers present on the V. hastata, and …

Influence Of Landscape On Gene Differentiation In The American Pika (Ochotona Princeps) Within The Interstate 90 Snoqualmie Pass Corridor, Craig P. Fergus

All Master's Theses

Understanding the impact of different landscape features on the movement of genes among populations can be helpful in managing wildlife populations. Our study used GIS tools to compare genetic connectivity among 13 American pika (Ochotona princeps) habitat patches across an approximately 77 square km area adjacent to Interstate 90 near Snoqualmie Pass, WA. Tissue samples were collected from 85 individuals and genotyped at six microsatellite loci to determine genetic differentiation among each pair of patches. A variety of models estimating the influence of landscape factors on gene flow were then used to find “resistance scores” between each pair …

Behavioral Response To Uvb Differs In Subalpine Populations Of Daphnia Melanica, Amanda Tompkins

All Master's Theses

Daphnia are a genus of freshwater zooplankton that inhabit ponds and lakes. They are commonly used as a model organism because they can reproduce clonally and are considered a foundation species in pond ecosystems. Daphnia melanica that inhabit the subalpine ponds of the Olympic National Park are exposed to high levels of ultraviolet radiation (UVR). UVR causes DNA damage that can be detrimental to the organism if not fixed. One way to avoid these harmful rays is to migrate to protected areas. In my study, I looked at two behaviors in D. melanica: diel vertical migration (DVM), which involves …

Provisioning And Its Effects On The Social Interactions Of Tibetan Macaques (Macaca Thibetana) At Mt. Huangshan, China, Brianna I. Schnepel

All Master's Theses

The dispersal patterns of food resources has a significant effect on the composition of primate groups and social interactions within those groups. Humans often alter the dispersal of food. Non-humans often use affiliative behaviors to elicit tolerance or support from other group members. I investigated whether provisioned food resources alter the social interactions and group dynamics of Macaca thibetana. All-occurrence sampling and scan sampling were used for data recorded by camera traps. Trail-cameras were placed at six locations that contain natural and human food resources and recorded 60-second videos. Social behavior and proximity of the monkeys were recorded. I …

Assessing The Contributions Of Two Stocked Strains On A Minnesota-Wisconsin Border Water, Douglas Zentner

Journal of Earth and Life Science

Stocking has long been used as a management tool in the United States even though many of its effects remain cryptic. Past comparisons between stocked strains were generally based on the survival and growth rates of physically marked individuals. More recently the use of genetic markers to assess contributions of stocked individuals has been employed by fisheries managers. Using 13 microsatellite markers we assessed the contributions of two muskellunge (Esox masquinongy) strains (Wisconsin and Leech) stocked into the St. Louis River Estuary. Ancestry in the adult samples remained relatively constant with differences only observed between the 2008 and …

Spatial And Temporal Factors Influencing Northern Pike Fry Density Estimates, Nate Stott

Journal of Earth and Life Science

The Tamarac River in northern Minnesota is an important spawning site for northern pike (Esox lucius) in the Red Lake system. However, little is known about fry production in the river. This study investigates migration densities and spatial and temporal factors influencing northern pike fry density estimates. Northern pike fry were collected with drift nets between 28 May and 4 June 2014. Thirty northern pike fry were randomly selected to have total length measured from each sample. Northern pike fry were observed in the first sample day. Northern pike fry density maxima occurred on 29 May at midnight …