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首页> 外文学位 >The effects of forest management and food availability on the ecophysiology of pre-breeding and breeding hermit thrushes (Catharus guttatus).
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The effects of forest management and food availability on the ecophysiology of pre-breeding and breeding hermit thrushes (Catharus guttatus).

机译：森林管理和粮食供应对隐居鹅口鹅（Catharus guttatus）的生态生理的影响。

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摘要

I investigated the physiology of Hermit Thrushes during the pre-breeding and breeding periods from 2002 through 2005 at the Penobscot Experimental Forest in Bradley, Maine. The objective was to understand how breeding birds meet their energetic requirements throughout breeding, and to evaluate impacts of forest management and food availability on energetics. Using hormonal, metabolic, and physical measures, I sampled the energetic condition of males during pre-breeding (Chapter 2), both sexes during breeding (Chapter 3), and both sexes provided supplemental food during breeding (Chapter 5). I also measured food availability within habitats under three forest management regimes (Chapter 4).; Fat metabolism in adults and mass of fledglings suggested that the regenerating even-age habitats were of poorer quality for Hermit Thrushes than either shelterwood or selection cut plots. However, availability of the ground-dwelling invertebrates eaten by Hermit Thrushes was not found to vary markedly by forest management type, but there was higher abundance of most invertebrates in less shaded microhabitats, regardless of habitat type. Substantial seasonal decline in spiders may contribute to an overall decline in food availability through the breeding season.; Variation in physiological condition suggested that fat metabolism is important to birds of both sexes during breeding stages in which individuals face food limitation. Pre-breeding males carried fat stores that are hypothesized to aid in territorial defense and to assist in the transition to reproductive readiness. Incubating females also carried more fat than provisioning females, suggesting that food limitation associated with reproductive effort promotes prior fat storage.; To experimentally test the hypothesis that food limitation influences energy balance in breeding birds, mealworms were supplemented to birds during the provisioning stage. Body mass and fat declined for both sexes over the provisioning stage and females carried more fat than males, but there was no effect of food supplementation on mass or fat. However, triglycerides were higher in females than males and higher in supplemented birds regardless of sex. This suggests that birds provided supplemental food were not fattening as much as control birds, since triglycerides are the primary pre-cursor of fat production. Corticosterone concentrations were higher in supplemented birds. Since this finding was contradictory to other studies, future studies should examine the relationship between food availability, corticosterone, and provisioning rates.
机译：我调查了2002年至2005年期间在缅因州布拉德利的Penobscot实验林的繁殖期和繁殖期隐士鹅口疮的生理。目的是了解种禽在整个繁殖过程中如何满足其能量需求，并评估森林管理和食物供应对能量的影响。通过激素，代谢和身体测量，我在繁殖前（第2章），繁殖期间（第3章）的性别对男性的活力状况进行了采样，并在繁殖期间（第5章）对性别进行了补充。我还根据三种森林管理制度（第4章）对生境内的食物供应量进行了测量。成年人的脂肪代谢和幼雏的数量表明，隐居鹅口疮的再生均匀年龄栖息地的质量要比防护林或选择砍伐的地块差。但是，并未发现隐居画眉鸟食用的地面无脊椎动物的可用性随森林经营类型的变化而显着变化，但是阴影少的微生境中大多数无脊椎动物的丰度较高，无论其栖息地类型如何。蜘蛛的季节性大幅下降可能导致整个繁殖季节食物供应的总体下降。生理条件的变化表明，在个体面临食物限制的繁殖阶段，脂肪代谢对于两性鸟类都很重要。繁殖前的雄性携带的脂肪被认为可以帮助领土防御并有助于向生殖准备过渡。孵化的雌性也比提供雌性的雌性携带更多的脂肪，这表明与生殖力有关的食物限制促进了先前的脂肪储存。为了通过实验检验食物限制会影响种鸡能量平衡的假设，在准备阶段向家禽中添加了粉虫。在预备阶段，男女的体重和脂肪均下降，女性的脂肪比男性多，但补充食物对体重或脂肪没有影响。然而，无论性别，雌性中的甘油三酸酯均高于雄性，补充鸟类中的甘油三酸酯更高。这表明提供补充食物的禽类没有像对照禽类那样增肥，因为甘油三酸酯是脂肪产生的主要前兆。补充鸟类的皮质酮浓度较高。由于这一发现与其他研究相矛盾，因此未来的研究应检查食物供应量，皮质酮和供应率之间的关系。

著录项

  • 作者

    Johnston, Jason Clarence.;

  • 作者单位

    The University of Maine.;

  • 授予单位 The University of Maine.;
  • 学科 Biology Ecology.; Biology Physiology.
  • 学位 Ph.D.
  • 年度 2007
  • 页码 166 p.
  • 总页数 166
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 生态学（生物生态学）;
  • 关键词

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