I8


DESCRIPTIONS  OF  SPECIES

In  the  descriptions  in  this  book,  since  they
have  been  prepared  especially  to  aid  those
observing  the  birds  while  living  and  usually
therefore  at  some  distance,  details  and  char-
acters not  likely  to  be  noticed  by  the  ob-
server have  often  been  disregarded.  Such
adjectives  as  large,  short,  dark,  etc.,  are
necessarily  used  in  senses  more  or  less  rela-
tive, so  that  they  must  be  construed  with
regard  to  the  usual  characters  of  the  birds
of  the  family  to  which  the  species  belongs.
The  dimensions,  length  (total  length  from
tip  of  bill  to  tip  of  tail  feathers)  and  tail
(length  of  longest  tail  feathers),  that  are  given
are  those  which  will  be  of  most  service  in
giving  an  idea  of  the  size  of  a  bird.  Even  if
the  total  length  is  known,  only  an  indefinite
idea  is  obtained  of  the  real  size  unless  it  is
also  known  how  much  of  this  is  taken  up  by
the  tail.  In  this  connection  the  reader  should
be  cautioned  that  as  the  basal  portion  of  the
tail  feathers  is  covered  for  some  distance  by
the  short  feathers  of  the  posterior  part  of  the
body  called  the  tail  coverts,  the  tail  actually
appears  proportionately  shorter,  relative  to
the  body  and  the  total  length,  than  its  dimen-
sions in  inches  or  millimeters  indicate.
