Vocal learning in birds is typically restricted to a sensitive period early in life, with the few exceptions to this rule reported in songbirds and parrots. Here we present evidence of open-ended vocal learning in a hummingbird, the third avian group with vocal learning. We studied vocalizations at four display leks of the long-billed hermit Phaethornis longirostris during a four-year period. Individuals produce a single song repertoire, although several song-types can coexist at a single lek. We found that nine of 49 birds recorded on multiple days (18%) changed their song-type between consecutive recordings. Three of these birds replaced song-types twice. Moreover, the earliest estimated age when song replacement occurred ranged from 186 to 547 days (mean= 307 days) and all nine birds who replaced song-types produced a crystallized song before replacement. The findings indicate that song-type replacement is distinct from an initial early learning sensitive period. As half of lekking males do not survive past the first year of life in this species, song learning may well be extended throughout the lifespan. This behavior would be convergent to vocal learning programs found in parrots and some songbirds.