Ornithology Commons^™

High Prevalence Of Leucocytozoon Parasites In Nestling Northern Goshawks (Accipiter Gentilis) In The Northern Great Basin, U.S.A., Michelle I. Jeffries, Robert A. Miller, Michelle D. Laskowski, Jay D. Carlisle

Robert Miller

The Northern Goshawk (Accipiter gentilis) is currently listed as a sensitive species by the U.S.D.A. Forest Service. Previous research in our study area, the South Hills of the Minidoka Ranger District of the Sawtooth National Forest, Idaho, identified possible signs of parasite infections among the banded adult and nestling goshawks, which could influence their survival and breeding success. Therefore, we sought to quantify the prevalence and intensity of Leucocytozoon parasites among a sample of nestling goshawks in the South Hills during the 2012 breeding season. We sampled 27 nestlings from 12 nests for Leucocytozoon parasites by examining blood smears. All …

Annual Variation In Autumn Migration Phenology And Energetic Condition At A Stopover Site In The Western United States, Robert A. Miller, Jay D. Carlisle, Neil Paprocki, Gregory S. Kaltenecker, Julie A. Heath

Robert Miller

Climate change is having a dramatic effect on many migratory species. Changes in climate may lead to changes in food availability or other proximate cues that affect migratory behavior. We used 13 years (2000–2012) of data on songbird banding and raptor migration counts and captures during autumn migration in the intermountain West to evaluate whether regional temperature or precipitation or hemispheric climate indices predicted autumn migratory timing and energetic condition. We examined overall trends and evaluated the effects of diet and migratory distance on phenology and conditional responses. For the 13-year study period, no temperature, precipitation, or climate index trends …

Geographic Segregation And Evidence Of Density-Dependent Changes In Sex Ratios In An Abundant Colonial Waterbird, Brian S. Dorr, Katie C. Hanson-Dorr, Travis L. Devault, Alban Guillaumet, Scott C. Barras

Brian S Dorr

Demographic information, such as geographic segregation of sexes and sex ratio data, is needed to develop, model and evaluate conservation and management strategies for wildlife. A variety of physiological, behavioral and environmental factors can influence segregation of sexes and sex ratios, many of which originate with density- dependent processes. Departure from 50:50 sex ratios of double-crested cormorants (Phalacrocorax auritus) collected during control efforts in breeding and wintering areas across their eastern range of the USA were evaluated using using a Z-test as well as Stouffer’s weighted Z-tests. In addition, a specifically-designed randomization test was used to evaluate density-dependent effects on …

Predicting Nesting Habitat Of Northern Goshawks In Mixed Aspen-Lodgepole Pine Forests In A High-Elevation Shrub-Steppe Dominated Landscape., Robert A. Miller, Jay D. Carlisle, Marc J. Bechard, Dena Santini

Robert Miller

We developed a habitat suitability model for predicting nest locations of breeding Northern Goshawks (Accipiter gentilis) in the high-elevation mixed forest and shrub-steppe habitat of south-central Idaho, USA. We used elevation, slope, aspect, ruggedness, distance-to-water, canopy cover, and individual bands of Landsat imagery as predictors for known nest locations with logistic regression. We found goshawks prefer to nest in gently-sloping, east-facing, non-rugged areas of dense aspen and lodgepole pine forests with low reflectance in green (0.53 - 0.61 μm) wavelengths during the breeding season. We used the model results to classify our 43,169 hectare study area into nesting suitability categories: …

A Study Of Mexican Free-Tailed Bat Chirp Syllables: Bayesian Functional Mixed Modeling Of Nonstationary Time Series Data With Time-Dependent Spectra, Josue G. Martinez, Kirsten M. Bohn, Raymond J. Carroll, Jeffrey S. Morris

Jeffrey S. Morris

We describe a new approach to analyze chirp syllables of free-tailed bats from two regions of Texas in which they are predominant: Austin and College Station. Our goal is to characterize any systematic regional differences in the mating chirps and assess whether individual bats have signature chirps. The data are analyzed by modeling spectrograms of the chirps as responses in a Bayesian functional mixed model. Given the variable chirp lengths, we compute the spectrograms on a relative time scale interpretable as the relative chirp position, using a variable window overlap based on chirp length. We use 2D wavelet transforms to …

Influence Of Latitude On The Winter Abundance Of Red-Tailed Hawks (Buteo Jamaicensis) And American Kestrels (Falco Sparverius) In Illinois, Given Harper, Anna Groves, Vic Berardi, Paul Sweet, Jance Sweet, Angelo P. Capparella

Given Harper

Melanistic Adult Male Northern Harrier Wintering In Idaho, Robert A. Miller, Neil Paprocki, Elizabeth H. Urban

Robert Miller

Field observation of a Northern Harrier with rare aberrant plumage.

The Art And Artistic Legacy Of Louis Agassiz Fuertes, Paul A. Johnsgard

Paul Johnsgard

Perhaps some Nebraska birders will not immediately recognize the name Louis Agassiz Fuertes, as he died almost 80 years ago. Yet he influenced the art of bird painting as much as did John James Audubon, and provided wonderful artwork for many major state bird reference books. He also personally tutored George Miksch Sutton, the Nebraska-born artist and biologist who provided the NOU with its Burrowing Owl logo, and who contributed greatly to American ornithology, especially that of the southern Great Plains. It is interesting that, like John James Audubon, Roger Tory Peterson, and George Miksch Sutton, we would never think …

Review Of 'My Way To Ornithology' By Olin Pettingill, Jr., Paul A, Johnsgard

Paul Johnsgard

Most Nebraskans who recognize this author's name probably will remember him as a cinematographer and lecturer in the Audubon Screen Tour series. The series was a regular part of live entertainment in Lincoln and Omaha until the early 1960s. Other bird-oriented people will know that Pettingill wrote two of the first and still best regional bird-finding books (detailed guidebooks to bird-finding localities in the states east and west of the Mississippi, respectively). Perhaps still others will remember him as a one-time teacher of ornithology at Carleton College and the University of Michigan Biological Station, or as a director of the …

Historic Birds Of Lincoln's Salt Basin Wetlands And Nine-Mile Prairie, Paul A. Johnsgard

Paul Johnsgard

The changes that have occurred in the bird life of the Lincoln area during the past century must certainly be great, but we have little evidence to document this point. There is, however, an annotated bird list from 1900 for the salt basin wetlands of western Lincoln, an area then gradually being developed for recreational use. This list was published by J. S. Hunter in the Proceedings of the First Annual Meeting of the Nebraska Ornithologists' Union (1900, 18-21). At this time, the recently impounded but still saline lake was 2 to 3 feet deep, and it covered about two …

Louis A. Fuertes And The Zoological Art Of The 1926–1927 Abyssinian Expedition Of The Field Museum Of Natural History, Paul A. Johnsgard

Paul Johnsgard

The year 2009 marked the 110th anniversary of the first colored reproduction of a Fuertes painting; a watercolor of two seaside sparrows published in The Auk, when Fuertes was about 25 years old. Although Fuertes' life spanned little more than a half-century, and most living ornithologists were born after his tragic 1927 death, his influence on natural history art has not lessened. This manuscript is a testimony to his enduring artistic legacy. I first looked in awe at the original set of Fuertes paintings in the summer of 1995, during a visit to the Field Museum in conjunction with my …

Thermal Constraints On Foraging Activity Of Adult Starlings, Larry Clark

Larry Clark

The operative temperature of the environment was estimated for starlings using hollow, unheated taxidermic mounts. On average, adults foraging in full sun were characterized by shorter foraging bouts than those adults foraging in full shade. Simultaneous observations of air temperature, operative temperature, and the foraging duration of adults indicated that air temperature was a poor predictor of the maximum length of a foraging bout. The operative temperature of the environment was not correlated to the maximum and mean length of foraging bouts for temperatures below 31.5 ~ C, but was negatively related to maximum and mean foraging duration for values …

Use Of Nest Material As Insecticidal And Anti-Pathogenic Agents By The European Starling, Larry Clark, J Russell Mason

Larry Clark

Passerine birds that reuse nest sites face an increased parasite and pathogen load. They also are more likely to use fresh green vegetation during nest construction. The present results demonstrate that at least one passerine, the European Starling: (a) selects a small subset of available plant species for inclusion in nest material; and (b) chooses plants whose volatiles are more likely to inhibit arthropod hatching and bacterial growth relative to a random subset of available vegetation. The results also show that preferred plants possess greater numbers of mono- and sesqueterpenes at higher concentrations relative to a random subset of available …

Consequences Of Homeothermic Capacity Of Nestlings On Parental Care In The European Starling, Larry Clark

Larry Clark

The homeothermic capacity of chicks varied as a function of brood size, age, and air temperature. Commitment to rooding by parents also varied as a function of brood size, age of the young brooded, and prevailing air temperature. It was experimentally determined that parents altered their brooding commitment in direct response to the achieved mean homeothermic capacity of the brood rather than energy demands of the brood per se. Because larger broods achieved a given level of homeothermic capacity earlier than smaller broods, parents spent less time brooding larger broods. This "freed" time represented an increase in potential foraging time …

Nest Site Selection By The Red-Tailed Tropicbird, Larry Clark, Robert Ricklefs, Ralph Schrieber

Larry Clark

-Red-tailed Tropicbirds (Phaethon rubricauda) nest under shrubs in loosely associated groups on Christmas Island, Central Pacific Ocean. Aggressive interactions among adults at nest sites are high; yet, large areas of superficially similar habitat contain no tropicbird nests at all. We compared physiognomic features of nest sites with those of two sets of randomly generated "nest sites" by discriminant function analysis. Of those variables measured, the number of stems within a nest space and the amount of peripheral cover influenced the tropicbirds' choice of nest sites. Differences among localities existed. Areas where tropicbirds nested had shrubs with few stems and more …