I’ve been grading midterm exams so learning is on my mind. A lot
of learning goes on in the bird world, too.  The ability to sing
has a strong component of learning in most birds. Although a
bird raised in isolation will attempt to sing, its song will be
a poor rendition of the song its father sang to attract its
mother.  A number of birds are able mimics. A parrot can be
taught to say “Polly want a cracker” and any number of other
phrases. A northern mockingbird can mimic as many as 30 other
species of birds. The marsh warbler in Britain mimics 99
European species and 133 African species that it coexists with
on its wintering grounds.  A lyrebird in Australia over 19 years
learned to imitate barnyard sounds, including pig squeals, a
chain rattling, a cross-cut saw and a howling dog, along with
most calls and songs of the local birds.  A crested lark in
Germany learned the whistled commands given sheep dogs (“Run
ahead,” “Fast,” “Halt” and “Come here”). When taped and played
back to sheep dogs, these calls we