Life Sciences Commons^™

Comparative Pollination Biology Of Sympatric And Allopatric Andean Iochroma (Solanaceae)1, Steven J. Hall, Stacy Dewitt Smith, Pablo R. Izquierdo, David A. Baum

Steven J. Hall

Field studies were conducted for 15 species of Iochroma Benth. and the nested genus Acnistus Schott to quantify the diversity of pollination systems and to assess the potential contribution of pollinator behavior to the persistence of closely related species in sympatry. We combined measures of pollinator visitation and pollen deposition to estimate the importance of major groups of pollinators for each species, and we calculated proportional similarity in the pollinator assemblage among species. We found that 12 species of Iochroma, encompassing a range of flower colors and sizes, were principally pollinated by hummingbirds and, in many cases, by the same …

Distribution Patterns Of Sciurus Niger (Eastern Fox Squirrel) Leaf Nests Within Woodlots Across A Suburban/Urban Landscape, Carmen M. Salsbury

Carmen M. Salsbury

To determine habitat characteristics that influence Sciurus niger (Eastern Fox Squirrel) abundance and distribution within a suburban/urban landscape in the midwestern United States, I documented the density and placement of fox squirrel leaf nests in 20 woodlots in the Indianapolis metropolitan area. Marion County, IN. The woodlots varied in size (0.94 to 19.5 ha), approximate age, shape, and degree of isolation from other woodlots and suitable squirrel habitat in the surrounding area. Only 8.0% of nests were located in a tree with another nest, and nests were randomly distributed in all but one woodlot, where they were uniformly dispersed. Nest …

Reflections On Recycling, Pollution And History Or, How To Beat The High Cost Of Living, Richard B. Philp

Richard B. Philp

Lessons learned during the Great Depression and World War II may have to be relearned. The three Rs (reduce, reuse and recycle) were essential then to individual and national survival. A fourth R, repair, was practised as well. These lessons, if relearned, will stand us in good stead when dealing with the current economic climate as well as with problems of pollution and global warming.

Demographic Parameters Of Yellowfin Croaker, Umbrina Roncador (Perciformes: Sciaenidae), From The Southern California Bight, Daniel Pondella, John Froeschke, Lynne Wetmore, Eric Miller, Charles Valle, Lea Medeiros

Daniel Pondella

The yellowfin croaker, Umbrina roncador Jordan & Gilbert, 1882, is a common nearshore and surf-zone species in the southern California bight. Age was determined for individuals (n = 1,209) using annual increments in otoliths, and size at age was modeled using the von Bertalanffy growth curve (L∞ = 307.754 mm, k = 0.278 yr−1, t0 = −0.995 yr; maximum age = 15 yr). Females (L∞= 313.173 mm, k = 0.307 yr−1, t0 = −0.771 yr) grew significantly faster and larger than males (L∞= 298.886, k = 0.269 yr−1, t0 = −1.072 yr). Age and growth modeling based upon otolith length …

Mexican Jay (Aphelocoma Ultramarina), John Mccormack, L. Brown

John E. McCormack

No abstract provided.

Niche Expansion Leads To Small-Scale Adaptive Divergence Along An Elevation Gradient In A Medium-Sized Passerine Bird, John Mccormack, Thomas Smith

John E. McCormack

Niche expansion can lead to adaptive differentiation and speciation, but there are few examples from contemporary niche expansions about how this process is initiated. We assess the consequences of a niche expansion by Mexican jays (Aphelocoma ultramarina) along an elevation gradient. We predicted that jays at high elevation would have straighter bills adapted to feeding on pine cones, whereas jays at low elevation would have hooked bills adapted to feeding on acorns. We measured morphological and genetic variation of 95 adult jays and found significant differences in hook length between elevations in accordance with predictions, a pattern corroborated by analysis …

Leave Film Tax Credits On Cutting-Room Floor, Sheldon H. Laskin

Sheldon H. Laskin

No abstract provided.

Polar Bear Population Forecasts: A Public-Policy Forecasting Audit, J. Scott Armstrong, Kesten C. Green, Willie Soon

J. Scott Armstrong

Calls to list polar bears as a threatened species under the United States Endangered Species Act are based on forecasts of substantial long-term declines in their population. Nine government reports were written to help U.S. Fish and Wildlife Service managers decide whether or not to list polar bears as a threatened species. We assessed these reports based on evidence-based (scientific) forecasting principles. None of the reports referred to sources of scientific forecasting methodology. Of the nine, Amstrup, Marcot, and Douglas (2007) and Hunter et al. (2007) were the most relevant to the listing decision, and we devoted our attention to …

Brazilian Free-Tailed Bats (Tadarida Brasiliensis) As Insect Pest Regulators In Transgenic And Conventional Cotton Crops, P. Federocp, T. G. Hallam, Gary F. Mccracken, S. T. Purucker, W. E. Grant, A. N. Correa-Sandoval, J. K. Westbrook, R. A. Medellin, C. J. Cleveland, C. G. Sansone, J. D. Lopez Jr., M. Betke, A. Moreno-Valdez, T. H. Kunz

Gary F. McCracken

During the past 12 000 years agricultural systems have transitioned from natural habitats to conventional agricultural regions and recently to large areas of genetically engineered (GE) croplands. This GE revolution occurred for cotton in a span of slightly more than a decade during which a switch occurred in major cotton production areas from growing 100% conventional cotton to an environment in which 95% transgenics are grown. Ecological interactions between GE targeted insects and other insectivorous insects have been investigated. However, the relationships between ecological functions (such as herbivory and ecosystem transport) and agronomic benefits of avian or mammalian insectivores in …

Integrating Paleoecology And Genetics Of Bird Populations In Two Sky Island Archipelagos, John Mccormack, Bonnie Bowen, Thomas Smith

John E. McCormack

Background: Genetic tests of paleoecological hypotheses have been rare, partly because recent genetic divergence is difficult to detect and time. According to fossil plant data, continuous woodland in the southwestern USA and northern Mexico became fragmented during the last 10,000 years, as warming caused cool-adapted species to retreat to high elevations. Most genetic studies of resulting 'sky islands' have either failed to detect recent divergence or have found discordant evidence for ancient divergence. We test this paleoecological hypothesis for the region with intraspecific mitochondrial DNA and microsatellite data from sky-island populations of a sedentary bird, the Mexican jay (Aphelocoma ultramarina). …

Writing Research Proposal: Literature Review And Database Search, Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

Repellent Properties Of Δ-Octalactone Against The Tsetse Fly, Glossina Morsitans Morsitans, Martin T. Mwangi, Nicholas K. Gikonyo, Isaiah O. Ndiege

Martin M. Thuo

δ-octalactone, produced by several Bovidae, has been suggested as a potential repellant of tsetse fly attack. Racemic δ-octalactone was synthesized via an abbreviated route. The product was assayed against 3-day old starved teneral female tsetse flies, Glossina morsitans morsitans Wiedemann (Diptera: Glossinidae), in a choice wind tunnel and found to be a potent tsetse repellent at doses ≥0.05 mg in 200 μl of paraffin oil (0.05 >p >0.01).

Speciation In The Highlands Of Mexico: Genetic And Phenotypic Divergence In The Mexican Jay (Aphelocoma Ultramarina), John Mccormack, A. Peterson, E. Bonaccorso, Thomas Smith

John E. McCormack

The pine-oak woodlands of the Mexican highlands harbour significant biological diversity, yet little is known about the evolutionary history of organisms inhabiting this region. We assessed genetic and phenotypic differentiation in 482 individuals representing 27 populations of the Mexican jay (Aphelocoma ultramarina) — a widespread bird species of the Mexican highlands — to test whether populations in the central and northern Mexican sierras display discrete breaks between groups, which would be consistent with a role for the different mountain chains in divergence and speciation. We found abrupt breaks in mitochondrial DNA (mtDNA; ND2 and control region) delineating four major genetic …

Beyond The Liability Wall: Strengthening Tort Remedies In International Environmental Law, Noah Sachs

Noah Sachs

Despite decades of effort, the international community has stumbled in attempts to craft tort remedies for victims of transboundary environmental damage. More than a dozen civil liability treaties have been negotiated that create causes of action and prescribe liability rules, but few have entered into force, and most remain unadopted orphans in international environmental law. In this Article, I explain the problematic record of tort liability regimes by developing a theoretical model of liability negotiations, grounded in regime theory from political science. Based on the model, I conclude that negotiated liability regimes have foundered because of three main roadblocks: 1) …

Why Are Incubation Periods Longer In The Tropics? A Common-Garden Experiment With House Wrens Reveals It Is All In The Egg, Given Harper, W. Douglas Robinson, John D. Styrsky, Brian J. Payne, Charles F. Thompson

Given Harper

Environmental Conditions Affect Sperm Competition Risk In Japanese Beetles (Coleoptera: Scarabaeidae), Paul V. Switzer, Carissa A. Schoenick, Patrick C. Enstrom

Paul V. Switzer

Males of many species guard their mates to prevent rivals from usurping paternity of the potential offspring. Environmental conditions, such as temperature, may affect a male’s ability to guard a female effectively and consequently the amount of sperm competition that occurs. We tested whether temperature and light affected mating behavior in laboratory experiments on the Japanese beetle, Popillia japonica Newman, a species in which males guard females for minutes to many hours after mating. When tested in groups, under conditions of high temperature and high light, males guarded females for shorter periods of time and males and females both mated …

Scale-Dependent Habitat Use By Fall Migratory Birds: Vegetation Architecture, Floristics, And Geographic Consistency, Jill L. Deppe, John T. Rotenberry

Jill L Deppe

Animal habitat selection is a central focus of ecology and conservation biology. Understanding habitat associations in migratory animals is particularly complicated because individuals have variable habitat requirements during the annual cycle, across their geographic range, along migratory routes, and at multiple spatial scales. We studied habitat associations of 16 fall Nearctic–Neotropical migratory land birds at two spatial scales at a stopover site along the northern Yucatan coast to examine scale-dependent habitat use, identify proximate cues shaping birds' distributions, and evaluate similarities in habitat use between our tropical stopover site and temperate sites. We addressed scale-dependent habitat associations in two ways, …

Microsatellite Analysis Of Mating And Kinship In Beavers (Castor Canadensis)., J C. Cawford, Zhiwei Liu, T A. Nelson, C K. Nielsen, C K. Bloomquist

Zhiwei Liu

No abstract provided.

Sustainable Management, David A. Bainbridge

David A Bainbridge

Management for the future must include a broader and more complex view of the world. Sustainable management of business can be profitable and provide benefits for workers, shareholders as well as communities, nations and the planet.

The Fire Next Time: Land Use Planning In The Wildland/Urban Interface, Jamison E. Colburn

Jamison E. Colburn

Wildfire is a growing threat to suburban and exurban communities, in part because fires have grown more severe and frequent as a result of land use and climatic influences and in part because more people are living in fire prone areas. The so-called Healthy Forest Restoration Act (HFRA), the federal government’s response to this crisis, is a deeply flawed statute that will likely exacerbate wildfire risks at the same time it makes real ecological restoration even harder. While HFRA took halting, partial steps toward the integration of broad and small scale land use planning, it was clearly still the outgrowth …

Climate Change And Freshwater Resources, Noah D. Hall, Bret B. Stuntz, Robert H. Abrams

Noah D Hall

The Earth’s climate is warming. This is the unequivocal conclusion of climate scientists. Despite the complexities of climatology, certain consistent trends emerge with implications for water availability: as the world gets warmer, it will experience increased regional variability in precipitation, with more frequent heavy precipitation events and more susceptibility to drought. These simple facts will have a profound impact on freshwater resources throughout the United States, as the warmer climate will reduce available water supplies and increase water demand. Unfortunately, current water law and policy are not up to the new challenges of climate change and resulting pressures on freshwater …

Occupancy Of Mountain Plover And Burrowing Owl In Colorado, Heather Tipton, Victoria Dreitz, Paul Doherty

Victoria Dreitz

No abstract provided.

Response Of Mountain Plovers To Plague-Driven Dynamics Of Black-Tailed Prairie Dog Colonies, David Augustine, Stephen Dinsmore, Michael Wunder, Victoria Dreitz, Fritz Knopf

Victoria Dreitz

No abstract provided.

When Fairness Bends Rationality: Ernst Fehr Meets John Nash, Alessandro Tavoni

Alessandro Tavoni

No abstract provided.

An Update On The Diversity Of Wolbachia In Spalangia Spp. (Hymneoptera: Pteromalidae)., David B. Taylor

David B Taylor

Results from 13 additional host populations improves resolution on the diversity of Wolbachia bacteria in Spalangia spp. (Hymenoptera: Pteromalidae). These bacteria are of interest because they can profoundly affect their host’s reproduction. Manipulating Wolbachia infections may provide a method to improve the efficacy of biocontrol agents including Spalangia spp.

Climate Change And Carbon Sequestration: Assessing A Liability Regime For Long-Term Storage Of Carbon Dioxide, Alexandra B. Klass, Elizabeth J. Wilson

Alexandra B. Klass

As the nation struggles with how to address climate change, one of the most significant questions is how to reduce increasing levels of carbon dioxide in the atmosphere. One promising technology is carbon capture and sequestration (“CCS”), which consists of capturing carbon dioxide emissions from power plants and industrial sources and sequestering them in deep geologic formations for long periods of time. Areas for potential CO2 sequestration include oil and gas fields, saline aquifers, and coal seams. As Congress and the private sector begin to spend billions of dollars to research and deploy this technology, there has been insufficient attention …

Behavioral Effects Of Contraception Management: The Use Of Porcine Zona Pellucida On Wild Horses, Cassandra M.V. Nuñez

Cassandra M.V. Nuñez

The advent of immunocontraception with porcine zona pellucida (PZP) has all but revolutionized wild horse management, providing a more humane method of population control than earlier strategies. Early studies on Assateague Island National Seashore have described it as an ideal form of fertility control in that it reduces the chance of conception to below 10%, can be delivered remotely, is reversible (after short-term use), lacks debilitating physiological side effects, cannot pass through the food chain, and shows minimal effects on social behaviors. However, recent research in other populations has revealed behavioral and physiological side effects of long-term PZP use. These …

Important, But Odd And Obscure, Reasons To Use The Library, Maxine G. Schmidt

Maxine G Schmidt

No abstract provided.

Shading Facilitates Sessile Invertebrate Dominance In The Rocky Subtidal Gulf Of Maine, Ron J. Etter, Robert J. Miller

Ron Etter

Dramatic shifts in community composition occur between vertical and horizontal rocky surfaces in subtidal environments worldwide, yet the forces mediating this transition are poorly understood. Vertical rock walls are often covered by lush, diverse communities of sessile suspension-feeding invertebrates, while adjacent horizontal substrates are dominated by algae, or corals in the tropics. Multiple factors, including light, sedimentation, water flow, and predation have been proposed to explain this pattern, but experimental tests of these hypotheses are lacking. We manipulated light level and predation to test whether variation in these mechanisms could be responsible for the shift in composition of sessile communities …

Sex And The Single Weed: Connecting Floral And Genetic Diversity In Purple Loosestrife, Lythrum Salicaria, Maia F. Bailey

Maia F. Bailey

No abstract provided.