Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 21 for “"brown-headed cowbird"”.
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Assessing the Imprint of Geography, Host Species, Land Cover and Space on the Local Abundance of a Generalist Nest Parasite, the Brown-headed Cowbird
The Brown-headed Cowbird is an obligate nest parasite suspected of causing local population declines in several threatened and endangered passerine species. Much attention has been directed towards uncovering the fundamental factors that affect cowbird abundance; however, no study has evaluated …
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Nesting ecology and conservation of shrubland birds in a fragmented urbanized landscape in northeastern Illinois
… other bird species, and abandonment due to Brown-headed Cowbird (Molothrus ater) parasitism were also documented. All nests experiencing Brown-headed Cowbird parasitism failed (n=5). Red-winged Blackbird (Agelaius phoeniceus) was one of the most successful species; Willow Flycatcher …
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Mechanisms underlying population dynamics of a migratory songbird in a fragmented forest
… considered edge effects (nest predation and cowbird brood parasitism), whereas others are attributed to fragment size and isolation (low pairing success, area sensitivity, unstable population sizes). I studied the impact of Brown-headed Cowbird (Molothrus ater) brood parasitism and of nest …
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Population Dynamics of the Endangered Black-capped Vireo (Vireo atricapilla)
… suffers from high rates of parasitism by the brown-headed cowbird (Molothrus ater) across its breeding range from northeastern Mexico to southern Oklahoma. The largest population located on the Fort Hood Military Reservation in central Texas is well-studied, but its role in landscape-level …
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Age-specific mortality, pre- to post-fledging carryover effects, and the timing of fledging in altricial songbirds
… if carryover effects occur in brood parasitic cowbirds. I found evidence for pre- to post-fledging carryover effects of wing development in all species I examined, with individuals with less developed wings exhibiting poorer flight ability and experiencing higher rates of mortality after …
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Testing proximate causes and ultimate explanations of social cue use for habitat selection by songbirds
… occurs. Results from an experiment with Brown-headed Cowbird models (Molothrus ater; a brood parasite that reduces reproductive success) revealed that Yellow Warblers behaved more aggressively towards cowbirds when apparent conspecific density was high. Results from these studies provide …
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Nest Predation by brown-headed cowbirds (Molothrus ater)
… predictions of this ‘farming’ hypothesis for the brown-headed cowbird (Molothrus ater). I found evidence that cowbird attacks are not uncommon, a basic requirement of the hypothesis. Furthermore, I found multiple lines of evidence that cowbird attacks are not indiscriminate, but directed at …
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Effects of Grazing on Nongame Breeding brids, Insects, and Vegetation in Conservation Reserve Program Grasslands in North Dakota
… Grasshopper Sparrow, Red-winged Blackbird, and Brown-headed Cowbird composed a majority of the species composition in 1992 and 1993. Mean density of male birds (all species combined) exhibited a downward trend from 1992 to 1993 which was most likely due to colder temperatures and greater …
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Survey of Nasal Mites (Acari: Rhinonyssidae, Ereynetidae, Turbinoptidae) in Birds from Three States in the United States
… nasal mites collected from the brood parasite, brown-headed cowbird (Molothrus ater), in specimens from Texas and Arkansas. For this survey, 126 individuals were analyzed, and 84 (66.6 %) were found to be infested with nasal mites, which included new host records for the cowbirds. I addressed …
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Landscape Fragmentation and Grassland Patch Size Effects on Non-game Grassland Birds in Xeric Mixed-grass Prairies of Western South Dakota
… were: grasshopper sparrows, western meadowlarks, brown-headed cowbirds, chestnut-collared longspurs, bobolinks and red-winged blackbirds. Grasshopper sparrows and western meadowlarks were observed in >99% of grassland patches. Avian community composition was affected by landscape fragmentation and …
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Using Occupancy Models to Predict Grassland Bird Distributions in Southeastern Alberta
… for: Baird's Sparrow (Ammodramus bairdii), Brown-headed Cowbird (Molothrus ater), Chestnut-collared Longspur (Calcarius ornatus), Clay-colored Sparrow (Spizella pallida), Horned Lark (Eremophila alpestris), Long-billed Curlew (Numenius americanus), Marbled Godwit (Limosa fedoa), McCown's …
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Wildlife Use of Wastewater Ponds at the Idaho National Engineering Laboratory
… swallow, barn swallow, European starling, yellow-headed blackbird, Brewer's blackbird, and brown-headed cowbird. Most of the common species nested at or near the ponds. Species richness was greatest in May and September. Waterfowl had highest use in April, May, August, and September. Shorebirds …
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The role of individual variation in auditory and visual processing: implications for mate choice
… several specific research questions using the brown headed cowbird (Molothrus ater) as a model species: (i) how does male signaling behavior differ with the sex of the receiver? (ii) how do components within a signal combine to generate a response by the female, (iii) how is female sensory …
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Evaluation of Mixed-Vegetation Plantings As Avian Nesting Habitat in Eastern South Dakota
… that of 2006, being 21 and 10%, respectively. Brown-headed cowbird parasitism caused the failure of 38 and 24% of all passerine nests in 2005 and 2006, respectively. My results suggest avian nest density and nest success within MVPs are similar to those found in previous studies evaluating DNC …
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An integrative approach to testing density effects in a migratory songbird, the Prothonotary Warbler (Protonotaria citrea)
… removed the eggs of a common brood parasite, the Brown-headed Cowbird (Molothrus ater), to improve warbler nesting success and increase their densities. The resultant range of densities (1-27 neighbors/pair) were at or beyond that seen under natural conditions in this system. Each year, I …
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Behavioral characteristics and hormonal mechanisms of egg ejection in the American robin (Turdus migratorius)
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2024-03-01 without embargo terms
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Reproductive success of a generalist brood parasite predicts the rate of parasitism in the subsequent year
Brown-headed cowbirds (Molothrus ater) rely solely on hosts to raise their young. Although cowbirds parasitize 200+ species, recent evidence suggests that females avoid unsuitable hosts that either reject parasitic eggs or provide incompatible parental care. Female cowbirds may be able to improve …
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Development of new methods to investigate the role of the avian hippocampus in memory formation in brown-headed cowbirds
The hippocampus is known to participate in a variety of cognitive functions in humans, non-human primates, rodents, and birds. A great deal of previous research on the avian hippocampus has examined its role in spatial memory. A question regarding avian hippocampal function that remains unanswered …
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Host recognition and fitness costs of avian brood parasitism
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2023-09-01 without embargo terms
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