﻿380 
  AXjSTUAL 
  report 
  SMITHSONIAN 
  INSTITUTION, 
  192 
  9 
  

  

  contain 
  more 
  than 
  a 
  single 
  species 
  of 
  weaver, 
  at 
  least 
  in 
  my 
  experience. 
  

   In 
  such 
  cases 
  the 
  individual 
  cuckoos, 
  bj'' 
  restricting 
  their 
  territories 
  to 
  

   single 
  trees, 
  automatically 
  limit 
  their 
  parasitism 
  to 
  single 
  species. 
  

   These 
  weaver 
  colonies 
  are 
  very 
  common 
  all 
  over 
  the 
  African 
  continent 
  

   south 
  of 
  the 
  Sahara 
  and 
  the 
  didric 
  cuckoos 
  are 
  also 
  common 
  and 
  wide- 
  

   spread. 
  Therefore 
  it 
  seems 
  very 
  likely 
  that 
  individual 
  host 
  specific- 
  

   ities 
  are 
  being 
  formed 
  in 
  many 
  individual 
  cuckoos 
  in 
  the 
  way 
  just 
  

   mentioned. 
  

  

  It 
  is 
  impossible 
  to 
  imagine 
  any 
  cuckoo 
  as 
  originally 
  going 
  around 
  

   the 
  countryside, 
  inspecting 
  various 
  kinds 
  of 
  nests, 
  making 
  notes 
  of 
  

   the 
  dietetics 
  of 
  the 
  different 
  species, 
  and 
  then 
  repairing 
  to 
  its 
  favorite 
  

   perch 
  to 
  cogitate 
  upon 
  its 
  researches 
  and 
  finally 
  decide 
  to 
  limit 
  itself 
  

   to 
  any 
  one 
  of 
  them. 
  Specificities 
  must 
  have 
  originated 
  without 
  

   premeditation 
  and 
  survived 
  because 
  they 
  were 
  convenient. 
  The 
  

   fact 
  that 
  not 
  all 
  parasitic 
  cuckoos 
  are 
  specific 
  indicates 
  that 
  some 
  

   never 
  went 
  through 
  any 
  such 
  experience 
  as 
  the 
  didric 
  cuckoo 
  is 
  sub- 
  

   ject 
  to. 
  Host 
  specificity 
  is 
  decidedly 
  convenient 
  to 
  a 
  didric 
  cuckoo 
  

   fortunate 
  enough 
  to 
  have 
  within 
  its 
  territory 
  a 
  whole 
  colony 
  of 
  suit- 
  

   able 
  nests. 
  Their 
  territorial 
  instincts 
  of 
  defense, 
  like 
  those 
  of 
  most 
  

   parasitic 
  species, 
  are 
  faulty 
  and 
  if 
  they 
  had 
  to 
  wander 
  far 
  afield 
  in 
  

   their 
  search 
  for 
  nests 
  the 
  chances 
  are 
  they 
  would 
  not 
  be 
  able 
  to 
  keep 
  

   any 
  territory 
  for 
  themselves. 
  That 
  is 
  what 
  seems 
  to 
  have 
  taken 
  

   place 
  in 
  the 
  Indian 
  koel, 
  Eudynamis 
  honorata. 
  In 
  this 
  species 
  indi- 
  

   vidual 
  territories 
  as 
  such 
  seem 
  nonexistent 
  any 
  more. 
  Baker 
  (5) 
  

   writes 
  that 
  the 
  koel, 
  "* 
  * 
  * 
  sets 
  all 
  cuckoo 
  laws 
  in 
  defiance; 
  

   many 
  birds 
  breed 
  in 
  the 
  same 
  area 
  and 
  even 
  in 
  the 
  same 
  tree; 
  and 
  

   as 
  many 
  as 
  11 
  have 
  been 
  taken 
  together." 
  

  

  The 
  important 
  point 
  in 
  all 
  this 
  for 
  our 
  immediate 
  purpose 
  is 
  that 
  

   the 
  development 
  of 
  host 
  specificities 
  seems 
  to 
  depend 
  on 
  the 
  strict 
  

   adherence 
  to 
  individual 
  breeding 
  areas. 
  This 
  indicates 
  that 
  with 
  

   the 
  development 
  of 
  the 
  parasitic 
  habit 
  in 
  the 
  cuckoos 
  there 
  was 
  no 
  

   coincidental 
  diminution 
  of 
  the 
  reality 
  of 
  the 
  territory 
  such 
  as 
  we 
  

   find 
  in 
  the 
  cowbirds. 
  

  

  The 
  evolution 
  of 
  the 
  habit 
  in 
  different 
  groups 
  of 
  birds 
  in 
  widely 
  

   separated 
  parts 
  of 
  the 
  world 
  is 
  one 
  of 
  the 
  most 
  notable 
  examples 
  

   of 
  parallel 
  development 
  in 
  the 
  great 
  group 
  of 
  birds. 
  

  

  LIST 
  OF 
  LITERATURE 
  

  

  (1) 
  Allen, 
  Glover 
  M. 
  1925. 
  Birds 
  and 
  their 
  attributes. 
  Pp. 
  198-216. 
  

  

  (2) 
  AuDOBON, 
  John 
  James. 
  1842. 
  Birds 
  of 
  America, 
  Vol. 
  4, 
  pp. 
  18-22. 
  

  

  (3) 
  Baker, 
  E. 
  C. 
  Stuart. 
  1907. 
  The 
  oology 
  of 
  Indian 
  parasitic 
  cuckoos, 
  

  

  pts. 
  1, 
  2, 
  3. 
  Journ. 
  Bombay 
  Nat. 
  Hist. 
  Soc, 
  Vol. 
  17, 
  pp. 
  72-83, 
  351-374, 
  

   678-696. 
  

  

  (4) 
  . 
  1913. 
  The 
  evolution 
  of 
  adaptation 
  in 
  parasitic 
  cuckoos' 
  eggs. 
  

  

  Ibis, 
  10th 
  series. 
  Vol. 
  1, 
  No. 
  3, 
  pp. 
  384-398. 
  

  

  