Because the robin loses nearly all the characteristic colour from its breast in the summer, when it moults, and only recovers it on the approach of autumn. - Knapp.
Because in spring and summer their voices are drowned and lost in the general chorus ; in autumn their song becomes distinguishable. - G. White.
Because its fine, large eyes are fitted to receive all, even the weakest, rays of light that appear. The worm is its food too, and few that move upon the surface escape its notice.
Because they may there find spiders and flies, that have laid themselves up during the cold season. - G. White.