bird birds sparrow sparrow's sparrows Adaptation beak Chipping Sparrow house sparrow Perching bird Plant community wildlife finch bids bush clean rest sleep wash eat hungry plant twig twigs background breadcrumbs brown buff Camouflage camouflaged climate-tolerant common common-pest contrast dark ever-expanding populations fauna gray grey house sparrows insect-eaters introduced-species Matthew 10:29 mottled Old-World-sparrows passer domesticus passerine-birds pest plump powerful-beaks prolific seed-eaters small social textures true-sparrows two-a-penny worldwide-distribution Brambling songbird climate tolerant feeding pavement paving