학술논문

How feathered are birds? Environment predicts both the mass and density of body feathers
Document Type
Source
Functional Ecology. 32(3):701-712
Subject
comparative analysis
feather density
feather mass
thermoinsulation
waterproofing
Naturvetenskap
Biologi
Zoologi
Natural Sciences
Biological Sciences
Zoology
Evolutionsbiologi
Evolutionary Biology
Language
English
ISSN
1365-2435
Abstract
1.Studies modelling heat transfer of bird plumage design suggest that insulative properties can be attributed to the density and structure of the downy layer, whereas waterproofing is the result of the outer layer, comprised of contour feathers. In this study, we test how habitat and thermal condition affect feather mass and density of body feathers (contour, semiplume and downy feathers) measured on the ventral and dorsal sides of the body, using a phylogenetic comparative analysis of 152 bird species.2.Our results demonstrate that feather mass and the density of downy feathers are higher in species that inhabit colder environments, whereas total feather density is higher of species breeding under intermediate temperatures compared to the ones breeding under more extreme conditions. The density of contour feathers, depending on the body region, is either quadratically related or negatively correlated with minimum winter temperature.3.The density of contour and downy feathers, measured on both sides of the body, is higher in aquatic than in terrestrial birds. However, among the former, diving behaviour does not select for further increases in body feather mass or density.4.The results of this study provides key insights into how the plumage of birds is adapted to different environments and lifestyles and provides a basis for understanding the diverse range and the evolution of variation in these characteristics.
1. Studies modelling heat transfer of bird plumage design suggest that insulative properties can be attributed to the density and structure of the downy layer, whereas waterproofing is the result of the outer layer, comprised of contour feathers. In this study, we test how habitat and thermal condition affect feather mass and density of body feathers (contour, semiplume and downy feathers) measured on the ventral and dorsal sides of the body, using a phylogenetic comparative analysis of 152 bird species.2. Our results demonstrate that feather mass and the density of downy feathers are higher in species that inhabit colder environments, whereas total feather density is higher of species breeding under intermediate temperatures compared to the ones breeding under more extreme conditions. The density of contour feathers, depending on the body region, is either quadratically related or negatively correlated with minimum winter temperature.3. The density of contour and downy feathers, measured on both sides of the body, is higher in aquatic than in terrestrial birds. However, among the former, diving behaviour does not select for further increases in body feather mass or density.4. The results of this study provides key insights into how the plumage of birds is adapted to different environments and lifestyles and provides a basis for understanding the diverse range and the evolution of variation in these characteristics.