Structural support, not insulation, is the primary driver for avian cup-shaped nest design
Structural support, not insulation, is the primary driver for avian cup-shaped nest design
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DOI：
10.1098/rspb.2010.2798
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发表时间：
2011-10-07
影响因子：
4.7
通讯作者：
Seymour, Roger S.
中科院分区：
文献类型：
--
作者：
Heenan, Caragh B.;Seymour, Roger S.
巢微环境是鸟类生物学中一个被广泛研究的领域，然而，巢电导(绝缘体的相反)对孵化成虫和后代的能量学的贡献在很大程度上被忽视了。地表比热导(W-C-1厘米(-2))与巢的尺寸、墙壁孔隙率、离地高度和海拔有关，但最相关的衡量标准是总电导(G，W-C-1)。本研究首次将电导与成人体重(M，g)按Gam(B)形式进行异速测量分析。我们提出了三种不同的假设来解释电导的标度。指数可能来自：热损失标度(M-0.48)，其中G与成年鸟的热导具有相同的指数；等距标度(M-0.33)，其中巢形状随着母体质量的增加而保持不变；以及结构标度(M-0.25)，其中巢被设计为支持给定的成鸟质量。来自36种澳大利亚物种的213个杯状鸟巢的数据显示，电导与M-0.25成正比。这一异速生长指数与热量损失和等长伸缩的预期有显着不同，证实了对卵和孵化的亲本的结构支持是推动巢穴设计的主要因素的假设。
The nest micro-environment is a widely studied area of avian biology, however, the contribution of nest conductance (the inverse of insulation) to the energetics of the incubating adult and offspring has largely been overlooked. Surface-specific thermal conductance (W degrees C-1 cm(-2)) has been related to nest dimensions, wall porosity, height above-ground and altitude, but the most relevant measure is total conductance (G, W degrees C-1). This study is the first to analyse conductance allometrically with adult body mass (M, g), according to the form G aM(b). We propose three alternative hypotheses to explain the scaling of conductance. The exponent may emerge from: heat loss scaling (M-0.48) in which G scales with the same exponent as thermal conductance of the adult bird, isometric scaling (M-0.33) in which nest shape is held constant as parent mass increases, and structural scaling (M-0.25) in which nests are designed to support a given adult mass. Data from 213 cup-shaped nests, from 36 Australian species weighing 8-360 g, show conductance is proportional to M-0.25. This allometric exponent is significantly different from those expected for heat loss and isometric scaling and confirms the hypothesis that structural support for the eggs and incubating parent is the primary factor driving nest design.