The​ ​effect​ ​of​ ​plumage​ ​coloration​ ​on​ ​nest-box​ ​competition​ ​between mountain​ ​bluebirds​ ​​Sialia​ ​currucoides​ and​ ​tree​ ​swallows​ ​​Tachycineta​ ​bicolor

Sexual selection theory states that male ornamentation may evolve if it helps males obtain more matings by means of male-male competition or female preference. Dominant males can monopolize limited resources to attract mates, increasing variance in male reproductive success and strengthening the effects sexual selection. While there have been several studies examining the function of ornaments in intraspecific contests, less is understood about the role of ornamentation in interspecific competition. In a population of mountain bluebirds near Ronan, MT, tree swallows arrive after mountain bluebirds are nesting, and compete directly for access to nest-boxes. A successful tree swallow intrusion often results in total brood mortality for bluebirds, so the ability of a male mountain bluebird to defend a territory is directly linked to his and his mate’s fitness. Male mountain bluebirds have structural UV-blue plumage and there is evidence that more saturated coloration is associated with increased success in defending territories. We conducted 30 minute observations at active bluebird nests and recorded the parental behavior of bluebirds such as nest attendance and feeding rate. Observations also recorded the length of tree swallow intrusions, number of intruders, and bluebird behavioral response. Through this research, we aim to explore the relationship of male mountain bluebird coloration to his and his mate’s behavior and the characteristics of tree swallow intrusions. Our findings not only provide insight into the effect of ornamentation on interspecific competition, but also serve to support hypotheses regarding status-signal honesty

Review of \u3ci\u3eRaptors of New Mexico\u3c/i\u3e. Edited by Jean-Luc E. Cartron.

As a raptor specialist, I eagerly look forward to the publication of state and regional books on birds of prey, typically rich with hard-to-find locally flavored information on distribution and biology. With the publication of Raptors of New Mexico, my home state has joined the ranks of the handful of states blessed with such volumes, and in fine form. This is an impressive work both in size and content, but the first thing anyone will notice are the photographs-hundreds, most top-notch, many capturing moods, scenes, and places unique to New Mexican raptors. In many ways the book is a showcase for the 109 or so photographers who contributed images, but there is much more here than gorgeous pictures. Raptors of New Mexico includes chapters on the 19 species of Accipitriformes, five species of Falconiformes, and 13 species of Strigiformes that regularly occur in New Mexico, as well as a single chapter covering seven additional raptor species considered casual or accidental. Each species chapter includes sections on distribution (with detailed range maps), habitat associations, nesting, diet and foraging, predation and interspecific interactions, status and management, and references

Age Control for the Buck Tank Draw mammoth site, Big Water, Utah

A site containing Ice Age mammoth, horse, bison and carnivore bones was recently discovered near the town of Big Water, in southernmost Utah. Nearby mammoth remains from Bechan Cave, about 45 km northeast of Big Water, have been dated to 11-13 thousand years old. However, terraces at Lee’s Ferry that are believed to correlate with the mammoth site are between 90-150 thousand years old. To establish age control for the fossil site, five samples were collected in a stratigraphic profile for Optically Stimulated Luminescence (OSL) dating. OSL dating provides an age estimate for the last time the sediment was exposed to light, because light resets a natural “luminescence signal” within mineral grains. Initial analysis of the luminescence signal from the samples collected at Buck Tank Draw demonstrate an age much older than 13 ka (thousand years), but final lab results are still pending. If these mammoth remains are shown to be older than 13 ka, they will fill a gap in the fossil record. Previous work by Pederson et. al on the terrace chronology of the Colorado watershed indicated characteristic cycles of aggradation and incision that correlate strongly with climate patterns. The OSL dates, which will be processed shortly, will show how the mammoth site fits into this greater picture. Sedge seeds within the deposits indicate a marshy habitat, perhaps during a period of wetter regional climate. As results from this study bring clarification to the exact age of the deposits, they can be correlated to the greater Colorado River story and will give insight into understanding the history of the Ice Age in southern Utah

Reddit: Steve Huffman

https://scholarworks.bgsu.edu/mclp/1030/thumbnail.jp

Three Essays on Urban Location Choice and Urban Growth

This dissertation encompasses three papers. My first paper contributes to the larger literature on the effect of individual-level characteristics on urban location choice by examining whether young people aged 25 - 34 with a bachelor\u27s degree or higher are more likely to live in central cities in 2011 than in 1990. In 1990 37% of 25 - 34 year olds (Baby Boomers) living within a metropolitan statistical area (MSA) lived in a central city. By 2011 the percentage of young people (Millennials) living in a MSA that lived in a central city had declined to 33%. However, when 25 - 34 year olds are segmented by education it is clear that this decline was driven by young people with less than a bachelor\u27s degree. Conditional on living in a MSA the percentage of young people with a bachelor\u27s or advanced degree that lived in a central city was approximately 36% in both 1990 and 2011. When I control for individual-level characteristics I find that the effect of education on the probability of living in a central city remains similar in both generations. I estimate that having a bachelor\u27s degree increases the probability that a 25 - 34 year old will locate in a central city by 8.3% in 1990 and 8.2% in 2011. The increases in the probability of living in a central city from having a master\u27s degree or a doctorate in 2011 are also similar in magnitude to their counterparts in 1990. This is evidence that to the extent education plays a role in the larger population of high human capital 25 - 34 year olds in cities it is due to a composition effect rather than cities becoming more attractive to educated people at the margin. While educated young people are not more attracted to cities across generations there have been some intertemporal regional changes. I also analyze individual cities in each region to demonstrate that the regional changes obscure city level heterogeneity. I find that in Cleveland, Chicago, New York and Portland the effect of a bachelor\u27s degree on living in the central city of those MSAs increased from 1990 to 2011. In the Houston MSA the effect of a bachelor\u27s decreased and in the Los Angeles and Atlanta MSAs the effect of a master\u27s decreased

The German Gamble: An Analysis of the Energiewende Policy and its Implications for Energy Security in Europe

This thesis examines energy security in Europe, through a focused case study of the German energy policy known as Energiewende, or “energy transition.” The subject of energy policy and security in Europe has moved to the forefront of debate in recent years. Germany in particular has embraced a radical energy policy that aspires toward a low carbon, fully energy independent industrial economy by 2050. From an analysis of Germany’s Energiewende, this thesis seeks to extrapolate insights that can be applied to the debate of European energy dependency, environmental impacts, and their economic considerations. Understanding the implications of Germany’s energy policy, both economically and defensively, will enable EU member states to consider their own domestic energy policies as well as EU-wide climate and energy initiatives. This thesis concludes with an analysis of the impacts Germany’s energy policy is likely to yield upon fellow EU member states, as well as the future of energy security in Europe