a house wren troglodytes aedon perched in a budding aspen tree with a blue sky background

adaptation aedon alpestris animal anthropogenic aspen avian biology bird birding birds birdwatching budding carbon change climate climatic closeup colorado conservation conservatism distribution ecology emissions environment eremophila extinction gases global greenhouse habitat house indicator microevolution migration modeling natural nature niche ornithology outside perched richness science species temperatures threatened tree troglodytes warmdwellin warming wild wildlife wren