﻿art, 
  19 
  CONCERNING 
  BIRDS 
  ' 
  TONGUES 
  GARDNER 
  7 
  

  

  Hawks, 
  owls, 
  and 
  vultures 
  have 
  powerful 
  rasping 
  tongues, 
  a 
  

   structure 
  that 
  does 
  not 
  seem 
  to 
  be 
  based 
  primarily 
  on 
  the 
  funda- 
  

   mental 
  pattern. 
  For 
  in 
  most 
  of 
  these 
  birds 
  the 
  ceratohyals, 
  accord- 
  

   ing 
  to 
  Giebel, 
  6 
  are 
  fused 
  the 
  greater 
  part 
  of 
  their 
  length 
  except 
  at 
  

   about 
  the 
  mid 
  point, 
  where 
  by 
  reason 
  of 
  failure 
  of 
  fusion 
  a 
  hole 
  

   is 
  left. 
  

  

  Parrots 
  display 
  an 
  individuality 
  of 
  their 
  own. 
  In 
  many 
  of 
  these 
  

   birds 
  the 
  tongue 
  is 
  broader 
  at 
  the 
  tip 
  than 
  at 
  the 
  base, 
  forming 
  

   almost 
  a 
  finger, 
  with 
  the 
  anterior 
  margin 
  convex. 
  It 
  may 
  be 
  flat, 
  

   cupped, 
  grooved, 
  rolled 
  into 
  a 
  tube, 
  or 
  even 
  brush-tipped 
  (figs. 
  

   70-73). 
  

  

  Finally, 
  without 
  considering 
  the 
  various 
  rudimentary 
  tongues 
  

   there 
  are 
  a 
  host 
  of 
  odd 
  types 
  scattered 
  throughout 
  the 
  class 
  Aves, 
  

   such 
  as 
  the 
  curious 
  feathered 
  tongues 
  of 
  the 
  toucans 
  (fig. 
  87) 
  ; 
  that 
  

   organ 
  as 
  found 
  in 
  the 
  puff-birds 
  (fig. 
  83), 
  the 
  cuckoos, 
  the 
  flamingoes, 
  

   and 
  the 
  like. 
  One 
  is 
  constantly 
  impressed 
  with 
  the 
  fact 
  that 
  no 
  

   reliable 
  guess 
  as 
  to 
  the 
  tongue 
  form 
  can 
  be 
  made 
  by 
  the 
  appearance 
  

   or 
  function 
  of 
  the 
  bill 
  and 
  that 
  any 
  generalization 
  is 
  a 
  very 
  un- 
  

   certain 
  procedure. 
  

  

  The 
  color 
  of 
  the 
  tongue 
  is 
  interesting 
  only 
  in 
  passing. 
  Usually 
  

   flesh 
  colored, 
  it 
  may 
  not 
  be 
  so, 
  however, 
  often 
  taking 
  the 
  color 
  of 
  the 
  

   bill 
  or 
  assuming 
  a 
  color 
  of 
  its 
  own. 
  Thus 
  it 
  is 
  black 
  in 
  the 
  crow 
  and 
  

   its 
  allies 
  ; 
  has 
  brown 
  spots 
  in 
  some 
  swallows 
  ; 
  may 
  be 
  entirely 
  black 
  

   with 
  white 
  spines 
  in 
  that 
  odd 
  cuckoo, 
  the 
  road-runner 
  (Geococcyx 
  

   calif 
  'ornianus) 
  , 
  or 
  be 
  almost 
  entirely 
  flesh-colored, 
  mottled 
  with 
  

   black, 
  in 
  other 
  members 
  of 
  the 
  same 
  species. 
  It 
  is 
  pink 
  in 
  the 
  red- 
  

   billed 
  Heermann 
  gull 
  (Larus 
  heermanni). 
  It 
  is 
  said 
  to 
  be 
  scarlet 
  

   in 
  the 
  black 
  cockatoo. 
  Still 
  again 
  a 
  light 
  blue 
  is 
  seen. 
  Some 
  of 
  

   the 
  hawks, 
  as 
  the 
  marsh 
  hawk 
  (Circus 
  hudsonius) 
  , 
  have 
  the 
  posterior 
  

   end 
  and 
  the 
  spines 
  this 
  color. 
  

  

  Out 
  of 
  this 
  confusing 
  multiplicity 
  of 
  form 
  it 
  seems 
  possible 
  to 
  

   make 
  certain 
  groupings 
  as 
  to 
  function 
  and 
  adaptation. 
  And 
  if 
  

   this 
  is 
  done 
  one 
  finds 
  approximately 
  eight 
  natural 
  groups 
  are 
  

   formed 
  : 
  

  

  1. 
  An 
  omnivorous 
  diet 
  is 
  productive 
  of 
  a 
  rather 
  generalized 
  pat- 
  

   tern. 
  This 
  includes 
  the 
  great 
  majority 
  of 
  tongues 
  found 
  in 
  the 
  

   Passeri 
  formes, 
  as 
  has 
  been 
  described. 
  The 
  chief 
  adaptive 
  feature 
  

   lies 
  in 
  the 
  presence 
  of 
  the 
  posterior 
  marginal 
  spines. 
  The 
  tongue 
  is 
  

   capable 
  of 
  being 
  depressed 
  at 
  the 
  tip 
  and 
  elevated 
  posteriorly. 
  

   When 
  worked 
  rapidly 
  backward 
  and 
  forward 
  it 
  can 
  be 
  used 
  to 
  

   force 
  resistant 
  food 
  down 
  the 
  throat. 
  The 
  efficacy 
  of 
  this 
  is 
  most 
  

   astonishingly 
  manifest 
  if, 
  for 
  instance, 
  a 
  bit 
  of 
  cloth 
  be 
  fed 
  to 
  a 
  

   nestling. 
  In 
  such 
  an 
  instance 
  it 
  is 
  only 
  with 
  difficulty 
  that 
  the 
  

   cloth 
  can 
  be 
  withdrawn 
  from 
  the 
  throat 
  without 
  injury 
  to 
  the 
  bird, 
  

   so 
  eagerly 
  is 
  the 
  tongue 
  with 
  its 
  spines 
  used 
  to 
  resist 
  the 
  effort. 
  

  

  