• April 6: Project FeederWatch ends • April 15: New Moon; April 29: Full Moon • April 23 - 29: National Environmental Education Weekdd • April 22 - 23: Lyrids Meteor Shower peaks • April 22: Earth Day • April 27: Arbor Day •Spring Arrivals: Caspian Terns, Barn Swallows, Purple Martins, Wilson’s and other warblers, Common Yellowthroats, Rufous Hummingbirds, Western Tanagers and Black-headed Grosbeaks • Red-Breasted Nuthatch courtship behavior begins • Killdeer eggs are laid and incubated for 24-26 days • Great Blue Heron egg-laying begins in April with incubation lasting 28 days • One of the first native butterflies to emerge from its overwintering chrysalis is the Sara Orangetip • Listen for Ruffed Grouse drumming in the lower-elevation mixed woodlands • Cliff Swallows come from southern South America to build their mud nests under eaves and bridges In an irruptive year, Snowy Owls depart for their northern breeding grounds
