﻿51G 
  Mr. 
  W. 
  W. 
  Smith 
  on 
  New-Zealand 
  Birds. 
  

  

  chrysalises 
  obtained 
  in 
  the 
  decaying 
  limbs 
  of 
  trees 
  and 
  in 
  

   moss-covered 
  trunks, 
  everywhere 
  abundant 
  in 
  the 
  bush. 
  A 
  

   comparatively 
  bloomless 
  season 
  of 
  the 
  forest-flora 
  would 
  also 
  

   materially 
  affect 
  the 
  more 
  strictly 
  insectivorous 
  birds 
  by 
  in- 
  

   ducing 
  the 
  Lepidoptera 
  to 
  migrate 
  to 
  other 
  districts 
  in 
  search 
  

   of 
  flowers, 
  and 
  thus 
  cause 
  a 
  scarcity 
  of 
  food 
  the 
  following 
  season. 
  

   I 
  cannot 
  entertain 
  the 
  theory 
  of 
  favourable 
  breeding-seasons 
  

   producing 
  more 
  individuals 
  than 
  the 
  food-supply 
  will 
  support. 
  

   It 
  is 
  unquestionably 
  the 
  reverse 
  cause 
  that 
  produces 
  the 
  

   irruptions 
  of 
  certain 
  species 
  of 
  birds 
  and 
  insects 
  into 
  Britain 
  

   from 
  European 
  and 
  Asiatic 
  countries 
  at 
  varying 
  intervals 
  of 
  

   years. 
  In 
  New 
  Zealand 
  birds 
  of 
  all 
  species 
  thus 
  afl'ected 
  are 
  

   invariably 
  in 
  an 
  extremely 
  emaciated 
  and 
  starving 
  condition. 
  

   Several 
  native 
  insectivorous 
  birds 
  are 
  chiefly 
  ground- 
  

   feeders 
  ; 
  the 
  latter 
  do 
  not 
  suff'er 
  so 
  much 
  from 
  lack 
  of 
  insect- 
  

   food 
  as 
  others 
  do, 
  as 
  they 
  are 
  able 
  to 
  subsist 
  on 
  earthworms 
  

   and 
  coleopterous 
  larvae 
  common 
  in 
  the 
  layer 
  of 
  humus 
  

   covering 
  the 
  bottom 
  o£ 
  the 
  bush. 
  

  

  As 
  the 
  irruptions 
  of 
  native 
  birds 
  and 
  the 
  total 
  or 
  gradual 
  

   disappearance 
  of 
  certain 
  species 
  were 
  unknown 
  to 
  the 
  Maoris 
  

   before 
  the 
  European 
  colonization 
  of 
  New 
  Zealand, 
  we 
  may 
  

   safely 
  infer 
  that 
  they 
  are 
  due 
  to 
  certain 
  causes 
  operating 
  

   with 
  greater 
  eff"ect 
  as 
  colonization 
  proceeded. 
  The 
  older 
  

   colonists 
  are 
  fully 
  aware 
  that 
  the 
  seasons 
  in 
  the 
  early 
  days 
  of 
  

   Canterbury 
  settlement 
  were 
  much 
  more 
  genial 
  and 
  equable 
  

   than 
  they 
  have 
  been 
  of 
  late, 
  the 
  summers 
  were 
  hotter, 
  and 
  

   the 
  winter 
  rains 
  were 
  much 
  heavier 
  and 
  more 
  periodical 
  with 
  

   fewer 
  frosts. 
  When 
  the 
  Canterbury 
  plains 
  were 
  thickly 
  clothed 
  

   in 
  tussock 
  -grass, 
  the 
  latter 
  absorbed 
  and 
  retained 
  the 
  sun's 
  

   heat 
  until 
  cooled 
  by 
  showers 
  of 
  rain. 
  In 
  the 
  spring 
  months 
  

   when 
  the 
  north-west 
  or 
  snow-melting 
  winds 
  blew 
  across 
  the 
  

   plains, 
  they 
  took 
  up 
  the 
  dry 
  heat 
  from 
  the 
  tussocks 
  and 
  

   became 
  the 
  "hot 
  nor'-wester.^' 
  These 
  winds 
  in 
  blowing 
  across 
  

   the 
  alpine 
  snow-fields 
  frequently 
  became 
  charged 
  with 
  mois- 
  

   ture, 
  which 
  fell 
  in 
  copious 
  showers 
  along 
  the 
  base 
  of 
  the 
  

   ranges 
  and 
  on 
  the 
  western 
  portions 
  of 
  the 
  plains. 
  The 
  latter 
  

   are 
  now 
  almost 
  cleared 
  of 
  native 
  tussock, 
  and 
  as 
  a 
  result 
  

   the 
  north-west 
  winds 
  blow 
  much 
  cooler, 
  while 
  the 
  north-west 
  

  

  