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Rozprawy doktorskie na temat „Songbirds”

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Autor: Grafiati
Data publikacji: 4 czerwca 2021
Data aktualizacji: 4 marca 2023

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1

Smith, Susan B. "Patterns of fuel use and storage in songbirds in relation to diet composition and food availability during migration /". View online ; access limited to URI, 2007. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3277015.

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2

Pierce, Barbara Jean. "The nutritional ecology of songbirds : how food quality, diet preferences, and food limitation influence nutrient storage and use during migration /". View online ; access limited to URI, 2003. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3112123.

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3

Podlesak, David William. "Metabolic routing of macronutrients in migratory songbirds : effects of diet quality and macronutrient composition revealed using stable isotopes /". View online ; access limited to URI, 2004. http://wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3160036.

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4

Weakland, Cathy Ann. "Effects of diameter-limit and two-age timber harvesting on songbird populations on an industrial forest in central West Virginia". Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1353.

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Thesis (Ph. D.)--West Virginia University, 2000.
Title from document title page. Document formatted into pages; contains xv, 150 p. : ill. (some col.); maps (some col.) Vita. Includes abstract. Includes bibliographical references.
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5

Long, Jennifer A. "Hormonal and Cellular Mechanisms of Fattening in Migratory Songbirds". Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/LongJA2007.pdf.

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6

Condon, Anne Moire. "Mercury Levels in Newly Independent Songbirds". W&M ScholarWorks, 2008. https://scholarworks.wm.edu/etd/1539626870.

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7

Reeves, Brendan J. "Neural basis of song perception in songbirds /". Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/9127.

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8

Newman, Amy Elida Margaret. "Neurosteroids and stress physiology in adult songbirds". Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/7532.

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Stress increases adrenal glucocorticoid secretion, and chronic elevation of glucocorticoids can have detrimental effects on the brain. Dehydroepiandrosterone (DHEA) is an androgen precursor synthesized in the adrenal glands, gonads or the brain and has anti-glucocorticoid properties. However, little is known about the role of DHEA in the stress response, particularly in the brain. In Chapter 2, I validated a solid phase extraction technique for extracting steroids from lipid-rich brain tissue and plasma of songbirds. In Chapter 3, I demonstrated that acute stress had statistically significant effects on plasma corticosterone and DHEA in wild adult male song sparrows that were season and vein specific. For corticosterone, acute stress increased jugular levels more than brachial levels during the molt. For DHEA, acute stress did not affect brachial DHEA but decreased jugular DHEA during the breeding season and increased jugular DHEA during the molt. These results suggest that corticosterone and DHEA are locally synthesized in the brain during molt. In Chapter 4, I measured the effects of acute stress and season on corticosterone and DHEA in brain tissue and jugular plasma. Compared to jugular plasma, corticosterone levels were up to 10× lower in brain, whereas DHEA levels were up to 5× higher in brain and were highest in the hippocampus. Acute stress increased corticosterone levels in jugular plasma and brain, except during molt, when stress decreased corticosterone levels in the hippocampus. In Chapter 5, I tested the effects of corticosterone and DHEA treatments on the brain. Corticosterone and DHEA had additive effects on the volume, neuron number and recruitment of new cells into HVC. Elsewhere in the brain, DHEA increased BrdU+ cells only in the absence of corticosterone suggesting that corticosterone can interfere with the action of DHEA. Together, these studies demonstrate that acute stress and season have distinct effects on corticosterone and DHEA in plasma and brain. Furthermore, I demonstrate that corticosterone and DHEA can have additive effects on cell survival and recruitment in the adult brain and that, in some cases, corticosterone can inhibit the actions of DHEA in the brain.
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9

Perlut, Noah G. "Effects of Hayfield Management on Grassland Songbirds:". ScholarWorks @ UVM, 2007. http://scholarworks.uvm.edu/graddis/178.

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Over the last 40 years North American grassland bird populations have declined more than any other bird guild. This trend is especially evident in Vermont, where species experiencing precipitous declines include the Savannah Sparrow (Passerculus sandwichensis) and Bobolink (Dolichonyx oryzivorus). These declines are linked to habitat loss due to reforestation and suburbanization as well as the intensification of grassland management. Modern grassland management includes earlier first-haying dates (late-May) and shorter intervals between haying events (35 days). These management practices have severe repercussions for songbird populations because 1) early-haying results in complete nest failure (99% Savannah Sparrow and 100% Bobolink nests), 2) the interval between the first and second haying is too short for birds to renest, and 3) intensively managed fields comprise a significant portion of the total available habitat (as much as 40%). In 2002-2006, I examined how hayfield and pasture management affected grassland songbird ecological and evolutionary behavior in the agricultural landscape of the Champlain Valley, Vermont and New York. I studied songbirds in four grassland management types: early-hayed fields harvested in late-May or early-June and again in mid-July; middle-hayed fields harvested in late-June or early-July; late-hayed fields harvested after 1 August; rotationally-grazed pastures, a matrix of small paddocks where cows are moved after the grass in a paddock is eaten to a low point. I addressed the following objectives: 1. Determined the annual productivity, survival, and recruitment of Bobolinks and Savannah Sparrows in the four treatment types. 2. Identified the effects of early-haying on the social and genetic mating systems of Savannah Sparrows. 3. Conducted a population viability analysis for Bobolinks and Savannah Sparrows nesting in the Champlain Valley, assessing sensitivities of life-history parameters and identifying effective management alternatives. This study provides information on how agricultural management affects the ecology, evolution, and viability of grassland birds. It will help inform landowners, managers, and law-makers about management practices and habitat requirements needed to sustain populations.
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10

Foss, Carol Rolfe. "Nesting Success as an Indicator of Habitat Quality for Forest Songbirds". Fogler Library, University of Maine, 2004. http://www.library.umaine.edu/theses/pdf/FossCR2004.pdf.

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11

Lichstein, Jeremy William. "Landscape effects on breeding songbird abundance in managed southern Appalachian forests". NCSU, 2000. http://www.lib.ncsu.edu/theses/available/etd-20001010-181554.

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Lichstein, Jeremy William. Landscape effects on breeding songbird abundance in managed southern Appalachian forests. Chair of advisory committee: Theodore R. Simons.Many studies have demonstrated adverse effects of forest fragmentation on breeding forest songbirds in North America, and the viability of regional populations is thought to depend on large, unfragmented forests. However, we know relatively little about the landscape scale consequences of management in the forested landscapes that are presumed to be important to maintaining songbird metapopulations. The southern Appalachians, a mostly forested region, contains the largest network of public lands in the eastern U.S. Most of these public lands are managed by the U.S. Forest Service. To begin to understand the landscape scale effects of forest management in the southern Appalachians, I examined the relationship between the relative abundance of different species of breeding songbirds and local and landscape scale habitat variables in two predominately mid- to late-successional National Forests in the southern Appalachian Mountains, USA: the French Broad Ranger District of Pisgah National Forest (North Carolina) and the Nolichucky Ranger District of Cherokee National Forest (Tennessee). As part of the study, I explored two statistical problems frequently encountered in species-environment analysis: count data and spatial autocorrelation. Results from classical normal-errors regression models were similar to results from Poisson and negative binomial models that explicitly model counts. Normal-errors regression models were then modified to account for spatial autocorrelation using a conditional gaussian autoregressive model. Most species, especially Neotropical migrants, were significantly correlated with at least one landscape variable. These correlations included both landscape composition (i.e., the proportion of different landcover types) and landscape pattern (i.e., the spatial arrangement of landcover types) variables at 500 m to 2 km landscape scales. However, these landscape effects explained only a small fraction of the variation in bird relative abundance, and most species appear to respond primarily to elevation and local habitat factors in my study area. My results are consistent with other studies that have reported only weak to moderate landscape effects on songbird abundance in large managed forests. These results should not be interpreted as being inconsistent with results from studies in highly fragmented forests that have reported strong effects of patch size, patch isolation, and landscape scale forest cover on breeding songbirds.

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12

McFarlane, Dorothy Mary. "Post-fledging movements and territoriality of forest songbirds". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0033/MQ65507.pdf.

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13

Burdge, Ryan Brennan. "Songbirds, Pesticides, and Golf Courses: Exposure and Effects". W&M ScholarWorks, 2009. https://scholarworks.wm.edu/etd/1539626888.

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14

Dossman, Bryant C. "Stopover Departure and Movement Behaviors of Migratory Songbirds". The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1428055119.

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15

Whittaker, Xanthe. "The use of song in territory defence by the wren, Troglodytes troglodytes". Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319616.

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16

Butcher, Jerrod Anthony. "Minimum patch size thresholds of reproductive success of songbirds". Thesis, [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2842.

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17

Milbern, Lana Cecile. "Habitat usage of breeding songbirds in urban Columbus, Ohio". The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587476090513815.

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18

Reed, Veronica Arlene. "Natural and Experimental Noise Affects Acoustic Communication in Songbirds". DigitalCommons@CalPoly, 2021. https://digitalcommons.calpoly.edu/theses/2279.

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Background noise is ubiquitous and can impair acoustic communication and influence signaling behavior in animals. Despite evidence demonstrating myriad effects of anthropogenic noise on animal communication, precisely how natural background noise influences communication and behavior remains unclear. Yet, natural sources of background noise, such as rushing rivers or crashing ocean surf, share similar power spectra to sources of anthropogenic noise and can occur at high amplitudes, potentially masking acoustic signals. To investigate the effects of water-generated noise on songbird behavior, we experimentally broadcast landscape-level playbacks of ocean surf and river noise in coastal California, USA, and riparian habitat in Idaho, USA, respectively. In Chapter 1, we conducted a conspecific playback experiment examining how territorial defense behaviors of lazuli buntings (Passerina amoena) and spotted towhees (Pipilo maculatus) vary in response to broadcast water noise. We also incorporated cicada noise from a serendipitous Okanagana spp. emergence as a biotic source influencing lazuli bunting behavior. Both species produce songs that share substantial spectral overlap with low-frequency, water-generated noise, and lazuli bunting song shares an additional high-frequency overlap with cicada calls. Thus, there is potential for background acoustic conditions to mask conspecific signals. We found that detection and discrimination of conspecific playback occurred more slowly for both species as sound level increased. Lazuli buntings also exhibited divergent flight behaviors in response to high- and low-frequency acoustic sources, both dependent and independent of sound level. In Chapter 2, we investigated how amplitude and frequency of water-generated noise influences spectral and temporal song characteristics in six songbird species. We recorded individuals defending territories across 37 sites, with each site representing one of four acoustic environments: naturally quiet ‘controls’, naturally noisy ‘positive controls’ adjacent to the ocean or a whitewater river, ‘phantom’ playback sites with continuous broadcast of low-frequency water noise, and ‘shifted’ playback sites with continuous broadcast of high-frequency water noise. We predicted that all individuals exposed to ‘positive control’, ‘phantom’, or ‘shifted’ noise would adjust song structure, but the magnitude of signal modification would be larger in noisier locations and the type of modification would depend on the spectral profile of the acoustic environment. No two species altered songs in precisely the same way. However, song structure of all six species varied with amplitude and/or frequency of background noise. Together our results demonstrate that natural noise can impair agonistic behaviors and influence vocal structure. These findings suggest that the natural acoustic environment shapes acoustic communication, highlighting natural soundscapes as an under-appreciated axis of the environment.
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19

Kuhlman, Joshua Ryan. "Immune Redistribution to Skin in Wild and Domesticated Songbirds". Scholar Commons, 2010. https://scholarcommons.usf.edu/etd/1690.

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Implantation of dental sponges under the skin of lab rodents has been used to evaluate whether acute stress enhances leukocyte infiltration to a surgical site. First, I replicated this technique in house sparrows to test whether transient stressors cause similar immunoredistribution (i.e., movement of immune cells out of circulation and to the periphery) in a wild animal. As placement into captivity alone may serve as a stressor to wild animals, I compared sponge infiltration over different periods of captivity. Second, I compared how domestication affects immunoredistribution by comparing results of wild sparrows to domesticated zebra finches. Zebra finches were chosen because they are widely used for evolutionary ecology research, and they share a similar diet and comparable body size and lifestyle to house sparrows. Birds were randomly assigned to treatment groups of either a restraint stressor or no restraint stressor treatment prior to implantation. In the first chapter birds were also divided into one of three groups: sponge implantation at capture, after short duration captivity (1 or 2 days), or long duration captivity (1 month). Total leukocyte infiltration into the sponge varied among captive groups. Birds implanted at capture had greater leukocyte infiltration to the sponge compared to birds kept in captivity 1 or 2 days before implantation. Birds placed into captivity for 1 month before implantation showed similar sponge infiltration relative to the immediate implant group. However, time in captivity altered the dominant type of leukocytes present in the sponge at explant with lymphocytes decreasing with time in captivity and granulocytes increasing. Domestication affected cell infiltrates with domesticated species exhibiting more infiltration of heterophils and monocytes while wild house sparrows exhibited more infiltration of lymphocytes and basophils. My data indicates that in house sparrows, time in captivity affects the magnitude and character of immune responses to surgery and more importantly data are suggestive of immunoredistribution. My data also indicate that domestication has an impact on infiltrating cell types.
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20

Whittaker, Kara Ayn. "Dispersal, habitat use, and survival of native forest songbirds in an urban landscape /". Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/5483.

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21

Carle, Robin Jean. "Factors affecting nest survival of three species of migrant songbirds in the Greater Yellowstone Ecosystem". Thesis, Montana State University, 2006. http://etd.lib.montana.edu/etd/2006/carle/CarleR0506.pdf.

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22

Lehmann, Marina [Verfasser]. "Circadian biology of songbirds : endogenous and environmental components / Marina Lehmann". Konstanz : Bibliothek der Universität Konstanz, 2015. http://d-nb.info/1110771819/34.

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23

Johnson, Patrick Lyon. "Migratory Stopover of Songbirds in the Western Lake Erie Basin". The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1357314398.

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24

Withey, John C. "Interactions among American crows, breeding songbirds, and forest function, and their responses to urbanization /". Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/5555.

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25

Fry, Christopher Lee. "A source-filter model of birdsong production /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9913150.

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26

Jackson, Brandon Edward. "The allometry of bird flight performance". Diss., [Missoula, Mont.] : University of Montana, 2009. http://etd.lib.umt.edu/theses/available/etd-03102010-100229.

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27

Villain, Avelyne. "Acoustic communication in female songbirds : functions, flexibility and plasticity in calls". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSES069/document.

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La théorie de la sélection sexuelle a drastiquement orienté l’effort de recherche sur la communication acoustique chez les oiseaux : les mâles apprennent et produisent des chants élaborés et les femelles choisissent. Par conséquent (1) la production vocale chez les femelles a été négligée, (2) les cris (la majorité de la communication sociale) ont été peu étudiés. Contrairement aux chants, les cris ont été considérés comme innés et aucun effet de l’environnement sur leur structure n’était attendu. J’ai donc posé la question de la flexibilité vocale (court-terme) et de la plasticité vocale (au cours du développement) chez les femelles, en étudiant les cris majoritairement. J’ai étudié deux contextes où les deux sexes vocalisent: la communication dans le couple au nid et la communication parent-jeunes. Les vocalisations produites au nid par les couples montrent-elles de la flexibilité en réponse au bruit? Le développement des cris est-il influencé par l’environnement social ? J’ai travaillé sur deux espèces: le cincle plongeur, Cinclus cinclus et le diamant mandarin, Taeniopygia guttata. Chez les deux espèces, en réponse au bruit, les couples augmentent l’amplitude de leurs vocalisations. Chez le cincle une variation de la structure spectrale est observée dans les notes de chant mais pas dans les cris. Chez le diamant mandarin, les cris montrent des changements de leur structure spectrale: ils peuvent donc être flexibles en réponse au bruit. Les changements sont similaires chez les femelles et les mâles : la flexibilité n’est pas spécifique du sexe. Enfin, j’ai montré que l’environnement social précoce influence le développement des cris de quémande alimentaire chez le diamant mandarin : il existe une plasticité précoce des cris chez les mâles. J’ai montré que les femelles expriment des degrés de flexibilité similaires aux mâles mais que leur développement vocal peut prendre des trajectoires différentes. Les cris sont de bons objets de recherche pour étudier des variations de comportement vocal liées au sexe
The theory of sexual selection has drastically oriented research on acoustic communication in birds: males learn and sing conspicuous songs and females choose. Consequently, (1) female vocal production has been neglected, (2) birdcalls (most bird social communication) have been understudied. Birdcalls were supposed to be non-learned and no effect of the environment was expected on their structure (no flexibility, no learning). I thus focused my thesis on vocal flexibility (short-term) and vocal plasticity (developmental) of female vocalizations (mainly calls). I studied two contexts in which both sexes produce vocalizations: intrapair communication at the nest and parent-offspring communication. Do pairs express vocal flexibility in their calls in response to environmental noise? Is call development influenced by social environment? I studied two species: the white-throated dippers, Cinclus cinclus. (in which both sexes produce calls and songs) and the zebra finch, Taeniopygia guttata, (in which only males sing but both sexes use the same calls). I showed in both species, that in response to environmental noise, pairs increased the amplitude of their calls or song notes. In dippers, spectral flexibility was observed in song notes but not in calls. However, zebra finch calls showed spectral flexibility in response to noise. Both sexes showed similar changes in their calls: call spectral flexibility is not sex specific. Last, I showed that the structure of male begging calls changed in response to the early social environment, bringing evidence of early vocal plasticity in males. No change was found in females, showing that they either differ in their plasticity abilities or do not express plasticity because they receive different social feedbacks. My work showed that females and males show vocal flexibility but their vocal developmental trajectories may differ. Calls are thus good study objects to investigate sexual dimorphism in vocal behaviour
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28

Heaton, William Cory. "Evaluation of conservation management practices for Northern Bobwhites and shrub-scrub songbirds". Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1202409211/.

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29

Schmidt, Kimberly L. "Cortisol and corticosterone in the immune system and brain of developing songbirds". Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/5373.

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Glucocorticoids (GCs) are primarily produced by the adrenal glands, however GCs can also be synthesized in extra-adrenal tissues. For example, immune and brain tissues contain all the enzymes necessary to synthesize GCs in vitro suggesting local GC synthesis. However, few studies have measured endogenous GC levels in neural or immune tissues. The primary objectives of this thesis were: (1) to determine if GCs are synthesized in immune and brain tissue of developing songbirds by measuring endogenous GC levels, (2) to determine how plasma and tissue GC levels change with age and (3) to determine how plasma and tissue GC levels are affected by restraint stress. In Chapter 2, baseline corticosterone and cortisol levels were measured in plasma, immune and brain tissue of zebra finches on the day of hatch (P0), P3, and P30. Cortisol levels in immune organs were higher than cortisol levels in plasma at all ages, suggesting local cortisol synthesis. Interestingly, corticosterone was the predominant plasma GC but cortisol was the predominant GC in immune tissues. In Chapter 3.1 corticosterone and cortisol levels were measured in wild European starlings on P0 and P10 (at baseline and after restraint). At P0, neither GC increased with restraint in plasma or any of the tissues studied. At P10, restraint increased corticosterone in plasma and all tissues, and cortisol in plasma, diencephalon and thymus. In contrast to Chapter 2, local GC levels were low at both ages suggesting that there may be a difference in local GC levels between starlings and zebra finches. To test this hypothesis, in Chapter 3.2, local GC levels in P4 zebra finches and starlings were compared. Again, in zebra finches, cortisol levels in the immune system were higher than cortisol levels in plasma. In starlings, cortisol levels in the immune system were similar to cortisol levels in plasma. These data suggest a difference in immunosteroid synthesis between zebra finches and starlings. These studies suggest that circulating GC levels are not always representative of tissue GC levels. Measuring GC levels in tissues can provide important insights into how GCs are regulated in age-specific, tissue-specific, and species-specific manners.
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30

Duran, Lucy. "Stars and songbirds : Mande female singers in urban music, Mali 1980-99". Thesis, SOAS, University of London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340348.

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31

Scott, Benjamin Barnett. "The design and assembly of neural circuits for vocal communication in songbirds". Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/62984.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Brain and Cognitive Sciences, 2009.
"June 2009." Cataloged from PDF version of thesis.
Includes bibliographical references.
Unlike the human brain, which produces few neurons in adulthood, the brains of songbirds continue to produce new neurons throughout life. The function of these new neurons is not know, although it has been suggested that they endow the avian brain with a remarkable regenerative capacity that does not exist in mammals. It has also been proposed that the addition of new neurons in adulthood underlies behavioral plasticity, such as song learning. A better understanding of the cellular mechanisms that control the addition of new neurons to the postnatal brain may help clarify its biological function. This thesis is an investigation of the cell biology of postnatal neurogenesis in the songbird forebrain, with special emphasis on the High Vocal Center. Neuronal progenitors in the juvenile zebra finch brain were identified by fate mapping using engineered retroviruses. Multiple populations of neural progenitors appear to exist in the juvenile zebra finch brain, and each produces different types of neurons. At least three cell types appear to be added to the postnatal finch brain. Homology between neurogenesis in the postnatal finch and embryonic mammalian forebrain was also assessed. To characterize the mechanism of cell addition, videos were made, documenting the migration and integration of new neurons into the High Vocal Center. Neural progenitors were labeled using retroviruses, carrying the gene for the green fluorescent protein, allowing new neurons to be observed in the intact brain, with a powerful infrared laser. By replacing a small hole in the skull with a piece of optical glass, one could observe labeled neurons periodically over many days as they were born until they wired up to the existing circuitry. New neurons engaged in a previously undescribed form of migration. Further study of this form of neuron migration as well as other aspects of postnatal neurogenesis may lead to the development of strategies for replacing neurons in the human brain lost to death or disease.
by Benjamin Barnett Scott.
Ph.D.
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32

Verheijen, Bram Hendrik Ferdinand. "Demographic responses of grassland songbirds to rangeland management in the tallgrass prairie". Diss., Kansas State University, 2017. http://hdl.handle.net/2097/35800.

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Streszczenie:
Doctor of Philosophy
Department of Biology
Brett K. Sandercock
Grasslands are among the most rapidly declining ecosystems in the world. The Flint Hills ecoregion contains one of the largest remaining tracts of tallgrass prairie, but most of the area is managed with high densities of grazing animals and frequent prescribed burns, thereby reducing variation in vegetative structure. A homogeneous landscape leads to lower diversity and abundance of wildlife species, including grassland songbirds. Patch-burn grazing management has been proposed to more closely match the historical interaction between fire and selective grazing by native ungulates. Pastures managed with patch-burn grazing have a greater variety of vegetative structure and plant species composition, and as a result, higher species diversity, abundance, and reproductive success of grassland birds. However, past work has not considered potential effects of regional variation in predation risk and rates of brood parasitism by Brown-headed Cowbirds (Molothrus ater), or annual variation in climatic conditions on the effects of patch-burn grazing management on the reproductive success of grassland songbirds. Over a six year period and at two tallgrass prairie sites, I tested the effects of patch-burn grazing on the reproductive success of three native grassland songbird species, Dickcissels (Spiza americana), Eastern Meadowlarks (Sturnella magna), and Grasshopper Sparrows (Ammodramus savannarum), as well as subsequent effects on the space use, movements, and survival of fledgling Dickcissels. I found only minor effects of patch-burn grazing on the reproductive success of grassland songbirds, supporting previous studies that show that patch-burn grazing does not have negative effects on demographic rates of grassland songbirds. Management regime did not affect densities or territory size of male Dickcissels, but bird densities tended to be higher and territories tended to be smaller on patches within the patch-burn grazing treatment that were burned in the previous year. Thus, patch-burn grazing management might benefit Dickcissel populations by providing higher quality breeding habitat in unburned patches. Last, I found evidence for a potential tradeoff between habitat selection for nests vs. fledglings of Dickcissels in some rangeland management strategies. Parents that realized high reproductive success by nesting in pastures with lower cowbird densities, produced fledglings that faced high rates of depredation by snakes and showed greater movements away from those pastures. Survival rates and movements of Dickcissel fledglings were low, especially during the first week after leaving the nest, which stresses the importance of local habitat conditions. At a larger spatial scale, I tested whether regional differences in habitat structure could drive variation in apparent survival of grassland songbirds. I found that grassland- and shrubland-breeding species had higher estimates of apparent survival than forest-breeding species, contrary to the prevailing viewpoint that birds breeding in dynamic landscapes, such as frequently burned grasslands, should show lower apparent survival than species that breed in woody habitats. The results of my field study show that restoring the historical interaction between fire and grazing on the landscape via patch-burn grazing management could benefit grassland songbirds. Moreover, my dissertation is the first study that tests the effects of patch-burn grazing management on the survival and movements of fledgling Dickcissels, and shows that high cowbird densities can cause a tradeoff between different life-stages. Future conservation efforts should take into account regional variation in species abundance, predator community composition and abundance of Brown-headed Cowbirds when assessing the effects of rangeland management on the demography of grassland songbirds.
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33

Durán, Lucy. "Stars and songbirds Mande female singers in urban music, Mali 1980-99 /". Boston Spa, U.K. : British Library Document Supply Centre, 1999. http://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.340348.

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34

Dougall, Thomas William. "Characteristics of breeding passerine communities at Earlshallmuir and Tentsmuir, North-East Fife". Thesis, University of St Andrews, 1986. http://hdl.handle.net/10023/2700.

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The literature pertaining to a variety of methods for estimating the abundances of songbirds is reviewed, and the use of two of the main methods - mapping and transects - is described and discussed. The mapping method is found to be the most efficient and reliable in the context of the present study, and work elsewhere in the British Isles suggests that the method has wide applicability in the region. Various methods for describing the habitats in which birds occur are discussed. In the present study the method chosen involved measuring various parameters of the vegetation within a limited area at each of several sampling points in five study plots in North-east Fife. It proved a useful method in the habitats studied - dune grassland, commercial and semi-natural coniferous woodlands, and deciduous scrub and mature woodland - and results of the vegetation sampling are discussed in terms of habitat structure and succession, and in the relationship of this structure to the breeding bird communities. The composition of these communities in the study plots is described, as are the changes over the three breeding seasons 1979-1981, which followed on from a meteorologically "hard" winter. Over the study period there was an overall increase in the populations of all five study plots, and this increase was greatest in the poorest habitat - the dune grassland - and least in the richest habitat - the mature deciduous woodland. Using indices to compare the study plots a major difference was found between the grassland plot and all four woodland plots, amongst which the two coniferous ones were most similar. Of the more abundant bird species, Robin, Song Thrush and Coal Tit were more prevalent in coniferous habitats; Willow Warbler and Blue Tit were more prevalent in the deciduous habitats. In relation to habitat structure, the more diverse bird communities were found in the more complex habitats, and there was evidence of succession in the bird communities concomitant with habitat succession. The present study is one of very few in Europe involving woodland habitats especially of a commercial nature near sea-level, and it was found that the four woodland study plots were rich in terms of the diversities and densities of their passerine breeding populations when compared with other European studies.
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35

Fink, Mark Lewis. "Post-fledging ecology of juvenile wood thrush in fragmented and contiguous landscapes /". free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p3115545.

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Okubo, Tatsuo. "Neural mechanisms underlying the emergence of rhythmic and stereotyped vocalizations in juvenile songbirds". Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/103213.

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Thesis: Ph. D. in Neuroscience, Massachusetts Institute of Technology, Department of Brain and Cognitive Sciences, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 243-252).
Complex motor behaviors in humans, such as speech, are not innate, but instead are learned. How does the brain construct neural circuits that generate these motor behaviors during learning? To understand the neural mechanisms underlying learned motor skills, I use vocal learning in songbirds as a model. While previous studies have shown that a premotor area in the songbird brain, HVC, is important for stereotyped adult song, the role of HVC in juvenile song is less known. This thesis characterizes how activity in HVC develops during song learning in juvenile birds. Early in song learning, temporal structure emerged in HVC. During the earliest vocalization of juvenile birds (subsong), HVC neurons exhibit bursts of action potentials. However, only half of the neurons show bursts that are temporally aligned to syllables, and most of these bursts are clustered around onsets of subsong syllables. Over several days, as the bird starts producing the earliest stereotyped vocalization called protosyllables, HVC neurons start exhibiting rhythmic bursts at 5-10 Hz. These rhythmic bursts are aligned to protosyllables, and bursts from different neurons are active at different latencies relative to protosyllables. Thus, as a population, HVC neurons start forming a rhythmic neural sequence. As the bird matures, multiple distinct syllable types emerge from a protosyllable. During this process, some neurons are active only during a specific syllable type ('specific neurons') while others are active during both syllable types ('shared neurons'). These shared neurons are active at similar latencies for both syllable types, and therefore form a shared neural sequence. Over development, fraction of shared neurons decrease and more neurons become specific. These results demonstrate that splitting of a neural sequence into multiple sequences underlies the emergence of a multiple syllable types. Moreover, this sequence splitting is observed during different song learning strategies, suggesting that this is a fundamental neural mechanism for song learning. This work demonstrates how the growth of a rhythmic neural sequence and its subsequence splitting gives rise to complex vocalization in songbirds. This may be a general neural mechanism in which the brain constructs neural circuits during learning of a complex motor behavior.
by Tatsuo Okubo.
Ph. D. in Neuroscience
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Andalman, Aaron Samuel. "The role of basal ganglia-forebrain circuitry in the vocal learning of songbirds". Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/54631.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Brain and Cognitive Sciences, 2009.
Cataloged from PDF version of thesis.
Includes bibliographical references.
The basal ganglia form the largest sub-cortical structure in the human brain and are implicated in numerous human diseases. In songbirds, as in mammals, basal ganglia-forebrain circuits are necessary for the learning and production of complex motor behaviors; however, the precise role of this circuitry remains unknown. This thesis is an investigation into how the anterior forebrain pathway (AFP), an avian basal ganglia-forebrain circuit, supports vocal learning in the songbird. This investigation reveals two previously undiscovered functions of the AFP - both related to reinforcement, or trial-and-error, learning. One necessary component of reinforcement learning is the generation of variable behavior. The songs of learning juvenile birds are naturally highly variable. Rapid pharmacological inactivation of the AFP output nucleus causes an immediate and dramatic reduction in this variability. In addition, the first single-unit recordings of AFP output neurons in singing juvenile birds reveal little correlation with plastic song and a premotor correlation with the most variable form of singing, subsong. These results suggest a novel function for basal ganglia-forebrain circuitry in the production of exploratory behavior. A second component of reinforcement learning is the evaluation of performance-based feedback - auditory feedback in the case of singing. Conditional disruptive auditory feedback is a novel behavioral paradigm capable of causing rapid experimentally-controlled vocal learning. Inactivating the AFP while using this new paradigm to induce learning reveals that the AFP biases motor output to improve auditory feedback. This result suggests that basal gangliaforebrain circuits are involved in the evaluation of performance-based feedback. It also suggests for the first time that these circuits are capable of producing temporally precise premotor drive that incrementally improves a motor skill. In summary, this investigation significantly furthers the view that basal ganglia-forebrain circuitry is involved in reinforcement learning. It ascribes two functions to the anterior forebrain pathway: to drive variable behavior; and to bias future behavior incrementally towards better performance. By analogy, basal ganglia-thalamocortical loops may perform similar functions in mammals.
by Aaron Samuel Andalman.
Ph.D.
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Aronov, Dmitriy. "Neural mechanisms of early motor control in the vocal behavior of juvenile songbirds". Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61875.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Brain and Cognitive Sciences, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 201-211).
An infant reaches out for her new toy, struggling day after day to simply grasp her fingers around it. A few years later, she hits a tennis serve, perfect in the timing of its intricately choreographed movements. How does a young brain learn to use the muscles it controls, to properly coordinate motor gestures into complex behavioral sequences? To a surprising extent, for many advanced vertebrate behaviors this knowledge is neither innately programmed nor acquired via deterministic developmental rules, but must be learned through trial-and-error exploration. This thesis is an investigation of the neural mechanisms that underlie the production and maturation of one exploratory behavior - the babbling, or subsong, of a juvenile zebra finch. Using lesions and inactivations of brain areas in the song system, I identified neural circuits involved in the production of subsong. Remarkably, subsong did not require the high vocal center (HVC) - a premotor structure long known as the key region for controlling singing in adult birds - but did require the lateral magnocellular nucleus of the nidopallium (LMAN) - the output region of basal ganglia-forebrain circuitry previously considered a modulatory area. Recordings in LMAN during subsong revealed premotor activity related to the vocal output on a fast timescale. These results show, for the first time, the existence of a specialized circuit for driving exploratory motor control, distinct from the one that produces the adult behavior. The existence of two neural pathways for singing has raised the question of how motor control is transferred from one pathway to another and, in particular, how the control of song timing develops in these pathways. I found that early singing can be decomposed into mechanistically distinct "modes" of syllable and silent gap timing - randomly-timed modes that are LMAN-dependent and developmentally-acquired, consistently-timed modes that are HVCdependent. Combining acoustic analysis with respiratory measurements, I found that the consistently-timed mode in gap durations is formed by brief inspiratory pressure pulses, indicating an early involvement of HVC in coordinating singing with respiration. Using mild localized cooling - a manipulation that slows down biophysical processes in a targeted brain area - I found that the circuit dynamics intrinsic to HVC and LMAN are actively involved in controlling the timescales of distinct behavioral modes. In summary, this work demonstrates the existence of two motor circuits in the song system. These circuits are specialized for the generation of distinct types of neural dynamics - random exploratory dynamics, which are dominant early in life, and stereotyped sequential dynamics, which become dominant during development. Characterization of behaviorally-relevant dynamics produced by neural circuits may be a general framework for understanding motor control and learning.
by Dmitriy Aronov.
Ph.D.
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39

Needham, Katie Beth. "Examination of the Period of Preparation for Breeding in Male and Female Songbirds". Diss., North Dakota State University, 2017. https://hdl.handle.net/10365/28504.

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In virtually all species, reproduction must be precisely timed to coordinate breeding and rearing of offspring with favorable conditions. It is imperative for individuals to time the highest energetic cost to themselves or highest needs by offspring with greatest food availability in either abundance or nutrient make-up. To accomplish this, individuals must integrate signals conveying both internal and external status and accordingly alter the activity of the reproductive axis. To date most efforts to identify variation in control mechanisms for reproduction in seasonally breeding animals have focused on the brain as the initiator for reproduction. However, recent studies have re-directed attention to two other potential tissues, the pituitary and ovary, where variation in brake sensitivity may be important. To this end, a series of experiments were performed in two songbird species to elucidate the hormonal role in timing of breeding and the interaction of an energetic trade-off on the decision to breed in both males and females. I used two species, the wild dark-eyed junco (Junco hyemalis) and the wild-caught captive house sparrow (Passer domesticus) as model systems to address the following questions: 1) What physiological mechanisms explain individual variation in onset of gametogenesis? And 2) How are mechanisms of energy integrated with the reproductive axis? control of reproduction and timing of breeding to regulate energetic trade-offs? Specifically, we focused the role of testosterone in males (Chapter 2), and mechanisms downstream of the hypothalamus in females (Chapter 3). Next, in Chapter 4, the question of whether an energetic demand would reduce sperm quality was addressed. Lastly, in Chapter 5, we asked if an energetically costly immune challenge would result in the delay of clutch initiation. The results of these studies demonstrate the significant differences between sexes in the signals conveying an individual?s internal and external status in order to alter activity of the reproductive axis, and therefore timing of breeding. Collectively, these findings provide further evidence that females are ?in the driver?s seat? for onset of breeding and should be the focus of future research.
National Science Foundation (NSF)
Sigma Xi
North American Society for Comparative Endocrinology
North Dakota State University. Department of Biological Sciences
North Dakota State University. Environmental and Conservation Sciences Program
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40

Huggins, Kristal Alissa Mendonça Mary T. "The physiological effects of bright plumage coloration". Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Biological_Sciences/Thesis/Huggins_Kristal_6.pdf.

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41

Shah, Amit Harendra. "Dehydroepiandrosterone and 17beta-Estradiol in plasma and brain of developing and adult zebra finches". Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1980.

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The classical model of sexual differentiation states that genes influence gonadal differentiation, and gonadal hormones then drive sexual differentiation throughout development. This model has been called into question by research, especially in songbirds, providing evidence for alternative mechanisms like direct effect of genes and local production of steroids via de novo synthesis or local metabolism of steroid precursors like DHEA, which can be metabolized to testosterone and E₂. In order to assess the role of local steroid production on sexual differentiation in songbirds, levels of DHEA and E₂ were measured in brachial and jugular plasma, as well as brain and peripheral tissues in zebra finches at critical ages during development and in adulthood. DHEA levels in brachial and jugular plasma peaked at P30 and higher DHEA levels in jugular plasma were found in males relative to females at P30. Also, at P30, higher DHEA levels were found in rostral telencephalon in females relative to males. The findings of this study indicate that DHEA may play a role in sexual differentiation of songbirds. Surprisingly, E₂ was non-detectable in many plasma and tissue samples. Higher E₂ was found in the diencephalon in females relative to males at P3/P4 and higher E₂ was found in gonads in adult females relative to males. There was little evidence to suggest that E₂ is synthesized de novo in the brain, although perhaps E₂ is being rapidly metabolized into another estrogen or E₂ synthesis is more localized in the synapse. The findings of this study support the role of alternative mechanisms like de novo steroid synthesis and local metabolism of steroid precursors and challenge the role of classical mechanisms of sexual differentiation in songbirds. Also, these findings may have important implications for sex differences, which develop independently of gonadal hormones, in other animal species.
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42

DeMeo, Thomas E. "Forest songbird abundance and viability at multiple scales on the Monongahela National Forest, West Virginia". Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=1059.

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Thesis (Ph. D.)--West Virginia University, 1999.
Title from document title page. Document formatted into pages; contains xi, 149 p. : ill. (some col.), map. Vita. Includes abstract. Includes bibliographical references.
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43

Tittler, Rebecca. "Effects of residual tree retention of breeding songbirds in Alberta's boreal mixed-wood forest". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ34428.pdf.

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44

McMartin, Donald William. "Landscape and vegetation effects on breeding songbirds in the mixedwood forests of southern Ontario". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0017/NQ53739.pdf.

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Baxter, Thomas S. H. "A foraging time-activity study of breeding songbirds in a successional white spruce community". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0027/MQ52040.pdf.

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Berg, Mathew Leslie. "Sexual selection and reproductive strategies in songbirds territoriality, mate attraction, parentage and parental care /". [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2007. http://irs.ub.rug.nl/ppn/300721439.

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Dellinger, Tim A. "Post-fledging ecology and survival of neotropical migratory songbirds on a managed Appalachian forest". Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5312.

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Thesis (M.S.)--West Virginia University, 2007.
Title from document title page. Document formatted into pages; contains xii, 122 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references.
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48

MacDade, Lauren S. "DIETARY CONTRIBUTION OF EMERGENT AQUATIC INSECTS AND CONSEQUENCES FOR REFUELING IN SPRING MIGRANT SONGBIRDS". The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1236799366.

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Newell, Felicity L. "A Bird’s Eye View of the Forest: How Does Canopy Openness Affect Canopy Songbirds?" The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1276875484.

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Kishkinev, Dmitry [Verfasser], i Henrik [Akademischer Betreuer] Mouritsen. "Long-distance navigation and magnetosensory mechanisms in migratory songbirds / Dmitry Kishkinev. Betreuer: Henrik Mouritsen". Oldenburg : IBIT - Universitätsbibliothek, 2011. http://d-nb.info/1018233563/34.

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