Some people think of American Robins as the first sign of spring, despite the fact that at this latitude robins can happily survive through the winter and often hang out in flocks numbering into the thousands. I have several species that I like to use as signs of spring. My first clue that the seasons are changing in Pennsylvania are the small flocks of Red-winged Blackbirds and Common Grackles that start arriving in early March. The thing that really alerts me to the fact that spring is coming is the sound of the early migrant- the Eastern Phoebe. This year my first phoebe was right outside my door on March 15th. What do you use as your signs of spring?