Birding fever hit a high this past weekend in natural areas throughout northern Illinois. Birders flocked in throngs with binoculars strung on their necks like potential Olympic medals and a hope of spotting some of the most coveted migratory birds— wood-warblers. Members of the family Parulidae, wood-warblers are the colorful jewels of migration from the sapphire blue of a cerulean warbler (Setophaga cerulea) to the amber orange of a Blackburnian warbler (Setophaga fusca). Yet, as these birds flit about in the treetops, no color is as visually striking as the lemony-yellow citrine that adorns so many warblers as they pass through our area on a flyway. Once these impish birds reach their destinations (as far as northern Canada for some species) and breed, they will molt their flamboyant plumage and become far less conspicuous, which is why seeing them in the spring is considered such a prize for birders.  Continue reading →