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Ornithology Commons™

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2025

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Articles 61 - 69 of 69

Full-Text Articles in Ornithology

Habitat Loss And Its Behavioral Effects On A Female Gray Hawk In The Lower Rio Grande Valley Of Texas, Usa, Michael T. Stewart, Ashley M. Tanner, Brian A. Millsap, William S. Clark Jan 2025

Habitat Loss And Its Behavioral Effects On A Female Gray Hawk In The Lower Rio Grande Valley Of Texas, Usa, Michael T. Stewart, Ashley M. Tanner, Brian A. Millsap, William S. Clark

Human–Wildlife Interactions

Habitat loss is a major threat to wildlife worldwide. While habitat loss is commonly associated with the fragmentation, degradation, or destruction of large tracts of suitable space, habitat loss in urban environments can be much more incremental and nuanced. We tracked an adult female gray hawk (Buteo plagiatus) in the Lower Rio Grande Valley of Texas, USA, before and after 70% of the trees (7.6 ha) were cleared from the core of the nesting territory. While the hawk’s overall activity budget between within-patch and exploratory movements was unchanged, the hawk undertook substantially longer exploratory movements after the trees …

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Investigating Relatedness Within Breeding Units Of The Highly Social Bushtit (Psaltriparus Minimus), Fiona Skye Connelly Jan 2025

Investigating Relatedness Within Breeding Units Of The Highly Social Bushtit (Psaltriparus Minimus), Fiona Skye Connelly

Theses and Dissertations--Biology

Cooperative breeding systems represent an array of varied reproductive strategies and remain a topic of interest in behavioral ecology (i.e., Riehl 2013, Cornwallis et al. 2017). Different manifestations of cooperative breeding, such as cooperative polyandry, no doubt have unique evolutionary pressures tied to local ecologies which have led to their proliferation. Of particular interest are species that show flexibility in their use of reproductive strategies, wherein individuals may choose one strategy over another given a specific circumstance. Here, I used double-digest restriction site-associated DNA sequencing (i.e., ddRAD-seq) to investigate bushtit (Psaltriparus minimus) reproductive strategies and the relatedness between …

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Shrubsteppe Birds Under Fire: Guiding Post-Wildfire Habitat Restoration In The Whiskey Dick And Quilomene Units, Washington, Kevin Clements Jan 2025

Shrubsteppe Birds Under Fire: Guiding Post-Wildfire Habitat Restoration In The Whiskey Dick And Quilomene Units, Washington, Kevin Clements

All Master's Theses

Bird species, globally, are declining at an alarming rate. Birds of the shrubsteppe are particularly vulnerable to habitat loss caused by agricultural development, invasive vegetation, and heightened wildfire frequency and severity. Fire and invasive vegetation create a positive feedback cycle that threatens complete conversion of shrubsteppe to grasslands. Restoring habitat following wildfire is a top priority for land managers. As bioindicators of ecosystem health, bird populations reflect landscape changes and restoration efficacy. I analyzed bird populations in the Whiskey Dick and Quilomene units of the L.T. Murray Wildlife Area in Kittitas County, Washington following the 2022 Vantage Highway fire. Using …

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Evaluating And Mapping Habitat Suitability And Effects Of Woodland Treatment On Breeding Pinyon Jays In Colorado, Emily Diane Macklin Jan 2025

Evaluating And Mapping Habitat Suitability And Effects Of Woodland Treatment On Breeding Pinyon Jays In Colorado, Emily Diane Macklin

Electronic Theses and Dissertations

The pinyon jay (Gymnorhinus cyanocephalus) is a highly social, colonially nesting corvid endemic to the interior western United States whose populations have declined by ~72% since 1966, prompting the species’ current review for listing under the Endangered Species Act. Pinyon jays inhabit pinyon pine (Pinus subsect. Cembroides) and juniper (Juniperus spp.) woodlands and other dry conifer woodlands, portions of which are treated through tree thinning and removal for fuels reduction, ecological restoration, and habitat improvement for wildlife. As a result there is pressing need to better understand how woodland treatment and other potential drivers impact pinyon jay habitat suitability and …

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Binoculars To Bytes: Development And Field Validation Of An Ai-Driven System For Avian Monitoring, Christian J. Dupree Jan 2025

Binoculars To Bytes: Development And Field Validation Of An Ai-Driven System For Avian Monitoring, Christian J. Dupree

Graduate Student Theses, Dissertations, & Professional Papers

Autonomous camera-trap arrays coupled with artificial-intelligence (AI) vision can lift bird monitoring beyond the spatial, temporal, and labor limits of traditional field surveys. We present Binoculars to Bytes (B2B), an open-source pipeline that turns 180–360° time-lapse imagery into analysis-ready avian data. At Freezout Lake Wildlife Management Area (Montana, USA) the system ran four-hour morning deployments during spring and fall migrations (2023–2024). A YOLO-NAS detector, incrementally refined with a “Specialized Localized Iterative Model” workflow, quadrupled local accuracy and, after confidence-based species-binning, cut false-positive rates in half. Daily AI species lists were benchmarked against contemporaneous eBird citizen-science checklists and recovered ≥ …

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Food Finding Ability Does Not Predict Annual Survival In Winter Resident Birds, Aidan Hand Jan 2025

Food Finding Ability Does Not Predict Annual Survival In Winter Resident Birds, Aidan Hand

Honors Program: Senior Projects (Public)

Small non-migratory birds in temperate locations face many challenges to survive the winter. They must be able to find enough food, which is in decreased supply, to fuel the energetic demands of staying warm. Prior work has demonstrated that birds show individual variation in their foraging behaviors that could contribute to the discovery of new foraging patches, such as novel environment exploration. A better ability to discover new food sources could increase a bird’s chance of surviving the winter by increasing its access to new food patches. To test this hypothesis, we used radio frequency identification (RFID)-enabled bird feeders to …

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Severe Aggression Among Zoo-Housed Coconut (Trichoglossus Haematodus) And Rainbow (Trichoglossus Moluccanus) Lorikeets: Wellbeing Considerations For Free-Flight Aviaries, Emily Simkins Jan 2025

Severe Aggression Among Zoo-Housed Coconut (Trichoglossus Haematodus) And Rainbow (Trichoglossus Moluccanus) Lorikeets: Wellbeing Considerations For Free-Flight Aviaries, Emily Simkins

UNF Graduate Theses and Dissertations

As conservation and education institutions, modern zoos balance the needs of animals with the interests of visitors through several strategies which can increase animal wellbeing and improve visitor experience. Environmental enrichment is frequently employed to increase the suitability of anthropogenic environments for zoo-housed animals, such as through walkthrough habitats and free-flight aviaries. While habitats such as these are important for visitor experience and can be enriching to animals, there are also wellbeing considerations for these spaces. Walkthrough habitats can be a potential source of fear and stress for animals, as shown by increased frequencies of vigilance, undesirable behavior, and aggression. …

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Identifying Patterns In Avian Plasma Metabolites For Use In Comparing Between-Site Differences In Habitat Quality, Katherine A. Brouwer Jan 2025

Identifying Patterns In Avian Plasma Metabolites For Use In Comparing Between-Site Differences In Habitat Quality, Katherine A. Brouwer

Dissertations, Master's Theses and Master's Reports

Habitat loss and degradation are especially important considerations for migratory songbirds, since they depend on a variety of distinct habitats within different life phases (such as breeding, wintering, and migration) that are widely dispersed across a spatial scale. Additionally, abundance of migratory songbirds has been in severe decline, making habitat maintenance and recovery of particular interest as a research avenue. Identifying high quality habitats across a bird’s annual range is therefore of increasing importance and represents fundamental information for guiding management decision making. Free-floating metabolites found in blood are frequently used to determine short-term mass changes in birds and have …

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Home Range, Habitat Use, And Fall Migration Of Lewis’S Woodpeckers In The Eastern Cascade Range, Oregon, Cameron Piper Jan 2025

Home Range, Habitat Use, And Fall Migration Of Lewis’S Woodpeckers In The Eastern Cascade Range, Oregon, Cameron Piper

Cal Poly Humboldt theses and projects

Lewis’s woodpecker (Melanerpes lewis), a burn specialist, is experiencing range-wide population declines despite increasing fire activity in the western U.S. The White River Wildlife Area in Oregon hosts the state's only year-round population, raising questions about their breeding, habitat use, and migration. In summer 2024, we tracked nine woodpeckers using telemetry to estimate home range size and overlap. Full home ranges averaged 428 ha, with 66 ha core areas, and showed evidence of growing after nesting. Home ranges overlapped extensively (Full: 91 ± 13%; Core: 63 ± 29%), though individuals had distinct areas of intense use. Males had …

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