Fig. 3
a-c. Naris damage caused by Philornis downsi in Darwin‘s finch beaks is shown for host a nestlings, b fledglings, and c adults. The 1st instar P. downsi larvae feed inside the host’s beak resulting in naris damage. Usually P. downsi in the naris creates enlarged naris size, but in some cases the naris can become smaller if P. downsi larvae become encrusted inside the naris. If nestlings survive, they can have enlarged naris size as fledglings and adults. Photos by Jody O’Connor (a) and Katharina J. Peters (b, c, d, e, f)