Bacteria, Anaerobic - metabolism, Methane - isolation \& purification, Methane - metabolism, Lignin - metabolism, Biofuels - microbiology, Poaceae - metabolism, Poaceae - microbiology, Refuse Disposal - methods
Lignin - metabolism, Methane - biosynthesis
Birds, Life Sciences, Evolutionary biology, Animal behavior, Winter, Acclimatization, Zoology, Animal Ecology, Comparative analysis, Pectoralis, House Sparrow, Phenotypic flexibility, Ultrasonography