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- Immediate early genes (2)
- Age (1)
- Auditory selectivity (1)
- Avian hippocampus (1)
- Balancing selection (1)
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- Bank Swallows (1)
- Bird (1)
- Cardiac function (1)
- Climate change (1)
- Cluster N (1)
- Estradiol (1)
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- Hippocampus (1)
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- Invasive species (1)
- Lake trout (1)
- Magnetic compass (1)
- Magnetoreception (1)
- Major histocompatibility complex (1)
- Melospiza melodia (1)
- Migration Timing (1)
- Motus (1)
- Neural plasticity (1)
- Orientation and navigation (1)
- Positive selection (1)
- Post-breeding (1)
- Radio telemetry (1)
- Serotonin (1)
- Sexual Size Dimorphism (1)
- Sexual selection (1)
Articles 1 - 6 of 6
Full-Text Articles in Life Sciences
Differential Migration Timing And The Form And Function Of Avian Wings, Jessica E. Deakin
Differential Migration Timing And The Form And Function Of Avian Wings, Jessica E. Deakin
Electronic Thesis and Dissertation Repository
A common differential migration strategy in birds is protandry, whereby males arrive earlier than females. The probable causes of protandry are well studied from the perspective of innate and physical environmental cues, but the influence of the social environment and wing morphology are less known. Theoretical models propose that sex ratio influences protandry; male-biased sex ratios are predicted to advance timing in males due to increased intrasexual competition. To empirically test this, I investigated the spring migration traits of male Yellow-rumped Warblers Setophaga coronata under differing sex ratios. An integrated automated telemetry approach was used, where locomotor movement of captive …
Neural Responses To Magnetic Orientation Information In Songbirds, Madeleine Ir Brodbeck
Neural Responses To Magnetic Orientation Information In Songbirds, Madeleine Ir Brodbeck
Electronic Thesis and Dissertation Repository
Effective navigation and orientation is essential for animals to survive. The study of migratory birds provides insights into these processes, particularly through mechanisms like the geomagnetic compass, which uses Earth's magnetic field for directional information. A brain region in songbirds relevant to this is cluster N, known for its potential role in processing geomagnetic information. Notably, cluster N appears exclusive to nocturnally migratory birds, being active solely at night, and lesion studies reveal that an intact cluster N is necessary for geomagnetic compass orientation. However, given the scarcity of empirical data concerning cluster N, substantial questions persist regarding its function. …
Random Mating In The Face Of Balancing Selection At The Major Histocompatibility Complex Class I In Song Sparrows (Melospiza Melodia), Scout R.L Thompson
Random Mating In The Face Of Balancing Selection At The Major Histocompatibility Complex Class I In Song Sparrows (Melospiza Melodia), Scout R.L Thompson
Electronic Thesis and Dissertation Repository
The major histocompatibility complex (MHC) is a large group of genes encoding cell-surface proteins that recognize and bind pathogens to initiate an adaptive immune response. MHC loci experience intense pathogen-mediated selection which may be directional, where specific alleles provide the best disease protection, or balancing, where rare alleles or diverse combinations are most protective. However, balancing selection (specifically heterozygote advantage) is more common and often accompanied by disassortative mating. I sought to use genetic and behavioural information to evaluate whether balancing selection and disassortative mating occur at MHC class I (MHCI) in a population of song sparrows (Melospiza melodia …
The Role Of Serotonin In The Estradiol-Dependent Selectivity Of Auditory Regions In Songbirds, Calista J. Henry
The Role Of Serotonin In The Estradiol-Dependent Selectivity Of Auditory Regions In Songbirds, Calista J. Henry
Electronic Thesis and Dissertation Repository
Breeding-typical levels of estradiol in songbirds has been shown to lead to selective auditory processing and induce a release of serotonin in auditory regions of the forebrain. These findings triggered the question of whether auditory discrimination is driven by estradiol directly, or by the associated release of serotonin. I treated non-breeding female white-throated sparrows (Zonotrichia albicollis) with either blank implants, 17β-estradiol, serotonin enhancer and blank implants, or serotonin antagonist and 17β-estradiol implants. Birds then heard male conspecific songs or control tones, and ZENK-immunoreactivity was quantified in the caudomedial nidopallium (NCM) and caudomedial mesopallium (CMM). While I did not …
The Effect Of Dietary Thiaminase On Cardiac Function And Morphology In Lake Trout (Salvelinus Namaycush), Peter Baker
The Effect Of Dietary Thiaminase On Cardiac Function And Morphology In Lake Trout (Salvelinus Namaycush), Peter Baker
Electronic Thesis and Dissertation Repository
Thiamine deficiency from the consumption of invasive, high-thiaminase prey fishes is considered to be a major barrier for lake trout restoration in the Great Lakes. In fishes, an understudied aspect of thiamine deficiency is its effect on cardiac function. I examined the effects of dietary thiaminase on cardiac function and morphology in lake trout, specifically as they relate to thermal tolerance. Two hatchery strains of lake trout (Seneca and Slate) were raised on a control or thiaminase diet for nine months. The thiaminase diet was associated with significant ventricle enlargement, impaired cardiac function, and reduced thermal tolerance; these effects were …
Post-Breeding Survival Of Adult And Hatch-Year Bank Swallows (Riparia Riparia) In The Great Lakes Region: A Radio Telemetry Study, Christian M.M Buchanan-Fraser
Post-Breeding Survival Of Adult And Hatch-Year Bank Swallows (Riparia Riparia) In The Great Lakes Region: A Radio Telemetry Study, Christian M.M Buchanan-Fraser
Electronic Thesis and Dissertation Repository
The post-breeding period poses significant threats to newly fledged birds due to predation, starvation, exposure to inclement weather, and collision risk prior to their first southward migration. I used automated radio telemetry to track 100 adult and 100 hatch-year Bank Swallows (Riparia riparia) in the Great Lakes ecoregion during the 2021 post-breeding period. Additionally, 74 hatch-year birds tracked in 2018 by Mitchell et al. were included. In 2021, daily apparent survival probability was higher for adults compared to hatch-years; we estimated that ~10% of hatch-year birds die within two weeks post-fledging but high rates of tag loss in …