vesper sparrow pooecetes gramineus perched on the ground on the grasslands and plains

adaptation alpestris animal anthropogenic avian biology bird birding birds birdwatching carbon change climate climatic closeup colorado conservation conservatism dwelling ecology emissions environment eremophila extinction gases global gramineus grasslands greenhouse ground habitat indicator microevolution migration natural nature niche ornithology outside perched phenology plains pooecetes richness science sparrow species temperatures threatened vesper warm warming wild wildlife