Ornithology Commons^™

Forest Characteristics And Avian Community Differences Among Cerulean Warblers (Setophaga Cerulea) Use Types, Dustin Kohler

ATU Scholars Symposium

Avian species are often used to measure the health of an ecosystem, in part because the specific forest structure can significantly impact the avian community. A heterogeneous landscape can support a more diverse avian community and benefit specialist species like the Cerulean Warbler (Setophaga cerulea), a rapidly declining, neotropical migrant that can be found in large deciduous forests. The Ozark Mountains of northwestern Arkansas represent a small core area for the species, but at all sites in the upland Ozarks where Cerulean Warbler research has been conducted, there are fewer individuals than there were twenty years ago; some …

Population Loss And Site Abandonment Of Cerulean Warblers (Setophaga Cerulea) In The Ozarks, Brayden D. Johnson, Dustin Kohler

ATU Scholars Symposium

Cerulean Warblers (Setophaga cerulea) have declined across their breeding range, including the Ozark Mountains of Arkansas, where historically occupied sites have experienced reduced populations or abandonment. Understanding population trends and habitat structure is important for informing forest management and conservation. This study compares historic and current Cerulean Warbler counts at selected upland sites within the Ozark-St. Francis National Forest and evaluates whether differences in canopy composition between abandoned historic sites and foraging sites currently used by Cerulean Warblers can explain site abandonment. Population trajectories varied among sites. Cherry Bend remained consistently occupied from 1998-2004 with 16-24 individuals and supported 17 …

Grassland Bird Community Responses To Fire Management, Mason H. Dillard

ATU Scholars Symposium

Vegetation structure plays a major role in determining avian community makeup. Controlled burn frequency changes vegetation structure and consequently the makeup of avian communities. To examine this relationship, I surveyed breeding birds in grasslands and savannahs of the Ozark Mountains, Arkansas River Valley, and Northwest Arkansas. I created models to outline the relationship between these three factors (avian community, fire management, and vegetation structure.) I also examined surrounding land cover and patch size as potential variables that may impact avian community structures.

I will outline the role fire management plays in determining the makeup of breeding bird communities in grasslands, …

Bluebird Bait: Quantifying The Attraction Of Ectoparasites To Nestling Eastern Bluebirds (Sialia Sialis), Ella Grace Bollinger

ATU Scholars Symposium

Ectoparasites, such as mosquitoes (Culicidae), blackflies (Simuliidae), and biting midges (Ceratopogonidae), have been shown to reduce population viability by lowering post-fledging survival and decreasing the lifetime reproductive success of adult birds. This issue is particularly concerning for songbirds such as the Eastern Bluebird (Sialia sialis) because their nestlings are relatively naked and have limited mobility, making them highly vulnerable to attacks by biting flies. However, the specific mechanisms attracting ectoparasites to nests remain understudied. We hypothesized that biting fly and mosquito abundance would be significantly higher at active Eastern Bluebird nests than that of empty boxes and would increase with …

Reproductive Success And Post-Fledging Ecology Of The American Robin (Turdus Migratorius) In Suburban Areas Of The Arkansas River Valley, Brandon Maiersperger

ATU Theses and Dissertations 2021 - Present

Study of the nesting and post-fledging periods is necessary to properly evaluate avian reproductive success. Birds breeding in suburban areas are threatened by a high abundance of predators and limited habitat availability. American Robins (Turdus migratorius) are common birds in suburban areas across North America, but their breeding ecology is understudied. The goals of my study were to: assess robin nest survival and its relationships with nest characteristics, evaluate fledgling survival, movement, and behavior, and determine the fledging sex ratio and sex-based plumage characteristics of fledglings. I found that robin daily nest survival (0.920) was lower than previous …

Evaluation Of Interior Least Tern (Sterna Antillarum Anthalassos) Colony Success Rate And Distance Upstream On The Arkansas River, Coley Turner, Nathan Mansor, Shelby Hunter

ATU Scholars Symposium

The previously endangered Interior Least Terns (or LETEs) are currently being monitored to ensure their populations are increasing. The purpose of this study was to provide current data to inform management decisions that must be made during their migration season. Sandbars where LETEs colonized were assigned a number corresponding to river mile. Fledglings per Breeding pair Rate (FBR) was calculated by dividing peak fledgling count by half of the adult count. A total of 798 adult LETEs and 228 fledglings were observed on sandbars. A colony was considered ‘failed’ if it had an FBR of 0, and ‘successful’ for anything …

Changes In Animal Vocalizations In Response To A Total Solar Eclipse, Colton W. Morris

ATU Scholars Symposium

My proposed research project will study the changes in animal vocalizations in response to the total solar eclipse that will take place in Russellville, Arkansas, on April 8, 2024. I will use audio recordings before, during, and after the eclipse to quantify changes in animal vocalizations. Most recordings will be in the range of normal hearing, and will primarily detect birds, frogs, and insects. Additionally, I will deploy one ultrasonic recorder capable of detecting bats. From these recordings I will be able to quantify overall and species-specific call rates. Audio recordings will be paired with continuous measurements of light intensity …

Interior Least Terns (Sternula Antillarum Athalassos) In A Landscape Of Fear: Explaining Predator Frequency On Sandbars Using Habitat Features, Carice N. Kimbrell

ATU Theses and Dissertations 2021 - Present

Causes of colony failure in interior least terns (Sternula antillarum athalassos) have been a prevalent topic for researchers investigating this previously endangered species. In Arkansas, these colonies are primarily located on sandbars formed along the McClellan-Kerr Arkansas River Navigation System. Reduction in nesting site quality may put this sensitive species at a greater risk for predator encounters. In my first chapter, I identified which sandbar characteristics resulted in higher frequencies of predator encounters at interior least tern colonies. In my second chapter, I investigated how those predators influenced colony production and whether interior least tern colonies exhibited similar …

Nesting Success Of American Robins (Turdus Migratorius) In Suburban Areas Of The Arkansas River Valley, Brandon Maiersperger

ATU Scholars Symposium

The American Robin (Turdus migratorius) is an abundant North American songbird species that thrives in suburban areas. Estimates of robin nesting success in suburban areas range from 31% to 90%. Robin nest site selection and success have not received much attention in the past few decades. Most passerines have a balanced sex ratio at fledging, but little is known about the fledgling sex ratio of robins. We located 44 robin nests in six public parks around Russellville, AR and on the Arkansas Tech University campus. Nest success was low; 27% (12/44) of nests fledged at least one young. Robins nested …

Overwinter Ecology Of Rusty Blackbirds (Euphagus Carolinus) In Arkansas, Araks Ohanyan

ATU Theses and Dissertations 2021 - Present

Rusty Blackbirds are one of the most rapidly declining songbirds in North America. They have lost an estimated 85-95% of their population since the 1960s. Unfortunately, we currently do not know what is causing their decline. However, since habitat alteration and loss in their nonbreeding range has been much more severe than in their breeding range, many think the decline is associated with winter habitat loss. Consequently, knowledge of winter ecology, with a focus on habitat use and selection, may provide management insights useful for reversing the decline. My field assistants and I (hereafter we) used radio telemetry to collect …

Effects Of Management Efforts On Fledging Success Of Endangered Interior Least Terns (Sternula Antillarum Athalassos) On The Mcclellan-Kerr Arkansas River Navigation System In Arkansas, Trevor N. Jensen

Theses and Dissertations from 2020

The Interior Least Tern (Sternula antillarum athalassos) is an endangered shorebird that primarily nests in colonies on barren riverine sandbars on many major river systems throughout the central United States. Water resource development projects such as damming and channelization have altered the natural flow regimes of these systems leading to a decrease in sandbar quality and quantity, and as a result this species is dependent on management to ensure their recovery. Managers within Arkansas have been applying a variety of management approaches to improve sandbar nesting habitat and success of this population intermittently since 2002, with increased intensity since 2015. …

Examination Of Photographic Evidence Of Disturbance On Interior Least Tern Breeding Behavior And Reproductive Success, Stephanie M. Nefas

Theses and Dissertations from 2018

The colonial ground nesting interior Least Tern (Sternula antillarum athalassos,) is an example of a species that requires frequent monitoring in order to estimate population size and determine long-term trends. Modifications in nesting habitat such as flooding, predation, and disturbances to colonies severely reduce reproductive success each year. I continued long-term monitoring efforts by identifying colonies and recording breeding activity along the Arkansas River. To improve the way that we understand factors that contribute to survival rates of nests and chicks, I examined survival at several colonies during the 2017 breeding season. Then to improve current monitoring techniques I tested …