Table 2 The subject areas and description of the contents

Macroscopic ecology

This category mainly included the studies about habitat use (selection/preference), home range and movement, population size and population dynamic, breeding ecology, and the possible influence of human disturbance on Galliformes

Molecular ecology

This category mainly included the studies concerned with population genetics, genetic variability, genetic diversity, genomics, etc., but the articles on molecular taxonomy and phylogenetics were excluded, as they were categorized into Taxonomy and phylogenetics

Taxonomy and phylogenetics

This category mainly included the studies regarding taxonomy and those investigating the evolutionary relationship between species, of which genetic and morphological methods were commonly used

Physiology and biochemistry

This category mainly included physiology, biochemistry, cell biology, endocrinology, morphology and anatomy

Conservation

This category mainly included the studies specialized in assessment of the conservation status of the species of Galliformes, reintroduction of endangered species, and maintaining genetic diversity. Although most articles in relation to macroscopic ecology also discussed the conservation implications of their results, they were not included in this category because of their primary objectives

Others

This category was split into two themes:

Ethology (behavioral studies of Galliformes, but the articles discussing territorial behavior, flocking behavior, and foraging behavior were categorized into Macroscopic ecology as they were often combined with ecological pressures)

Research overview (review studies, such as trends in grouse research)