To the delight of many local birders, Dave Tracy has once again kicked-off spring by leading the weekly bird walk, Birding by Ear, in Sawyer Park. Learn to identify the birds you hear, practice your ear-birding skills, or share your talents with others during this weekly walk in the riverside park. Beginners and seasoned birders are welcomed. The Tuesday morning event begins at 8 a.m. and lasts for a couple of hours; stay as long as you like. Come prepared for a mile-or-so walk on flat but uneven ground. This drop-in walk will be held through early June.