The Collaborative International Dictionary of English v.0.48:

Piculet \Pic"u*let\, n. [Dim. of Picus.] (Zool.)
   Any species of very small woodpeckers of the genus Picumnus
   and allied genera. Their tail feathers are not stiff and
   sharp at the tips, as in ordinary woodpeckers.
   [1913 Webster]

WordNet (r) 3.0 (2006):

piculet
    n 1: small woodpeckers of South America and Africa and East
         Indies having soft rounded tail feathers