In March 2010, I blogged about aging and sexing Dark-eyed Juncos. Eye color is one key to age. Birds with reddish-brown eyes are adults. Those with grayish-brown eyes are in their first year. This junco, the first of this fall (30 September 2011), is an hatching-year bird. In the photo below, note the grayish-brown eye. Telling junco sex is much more difficult. Check out McGill Bird Observatory's photographic key. I have always relied on wing measurements, with birds with wing chords over 77 mm being male, and those under 73 mm, female. This individual measured 78 mm--thus a male.