Applied Biological Sciences. In the article “Multilocus DNA fingerprinting reveals high rate of heritable genetic mutation in herring gulls nesting in an industrialized urban site” by Carole L. Yauk and James S. Quinn, which appeared in number 22, October 29, 1996, of Proc. Natl. Acad. Sci. USA (93, 12137–12141), the following correction should be noted. The equation on p. 12138, which calculates the probability that a randomly selected adult would share 10 or more of the bands, should be changed to

for a probability of 1.6 × 10⁻⁶. We apologize for this error.