﻿A 
  Migration 
  of 
  Yellow 
  Butterflies 
  in 
  Trinidad. 
  79 
  

  

  By 
  the 
  22nd 
  September 
  the 
  migration 
  across 
  the 
  northern 
  

   district 
  had 
  begun 
  in 
  earnest, 
  and 
  in 
  one 
  locahty 
  a 
  motor- 
  

   car 
  had 
  to 
  stop 
  and 
  put 
  down 
  its 
  side 
  curtains 
  owing 
  to 
  the 
  

   enormous 
  numbers 
  of 
  butterflies 
  which 
  interfered 
  with 
  the 
  

   view 
  of 
  the 
  driver. 
  

  

  On 
  the 
  23rd 
  they 
  were 
  reported 
  in 
  smaller 
  numbers 
  from 
  

   the 
  same 
  district, 
  and 
  on 
  the 
  24th 
  they 
  had 
  reached 
  the 
  

   eastern 
  coast 
  in 
  small 
  numbers 
  at 
  Port 
  of 
  Spain 
  (see 
  Plate 
  X 
  

   for 
  localities). 
  

  

  The 
  movement 
  continued 
  in 
  increasing 
  intensity 
  past 
  

   Port 
  of 
  Spain, 
  and 
  on 
  the 
  27th 
  September 
  had 
  become 
  a 
  

   striking 
  phenomenon. 
  On 
  this 
  day 
  they 
  were 
  crossing 
  the 
  

   open 
  Savannah 
  in 
  Port 
  of 
  Spain 
  about 
  mid-day 
  at 
  a 
  density 
  

   of 
  up 
  to 
  two 
  or 
  three 
  hundred 
  per 
  minute 
  across 
  a 
  distance 
  

   .of 
  one 
  hundred 
  yards. 
  On 
  the 
  same 
  day 
  and 
  on 
  the 
  follow- 
  

   ing 
  they 
  were 
  seen 
  crossing 
  the 
  sea 
  over 
  the 
  Island 
  of 
  Patos 
  

   near 
  the 
  Venezuelan 
  coast, 
  and 
  undoubtedly 
  were 
  reaching 
  

   the 
  mainland 
  of 
  Venezuela. 
  

  

  The 
  28th 
  and 
  29th 
  September 
  were 
  marked 
  by 
  rains 
  in 
  

   the 
  northern 
  district, 
  and 
  the 
  migration 
  fell 
  off 
  suddenly 
  and 
  

   became 
  apparently 
  much 
  confused. 
  On 
  both 
  these 
  days 
  a 
  

   few 
  were 
  recorded 
  in 
  the 
  fine 
  intervals, 
  flying 
  in 
  an 
  opposite 
  

   direction 
  (eastward), 
  but 
  not 
  in 
  any 
  large 
  numbers, 
  and 
  from 
  

   the 
  30th 
  to 
  the 
  4th 
  October 
  small 
  numbers 
  were 
  seen 
  flying 
  

   in 
  various 
  directions 
  chiefly 
  west 
  or 
  south-west. 
  Between 
  

   the 
  5th 
  and 
  7th 
  none 
  were 
  recorded, 
  on 
  the 
  8th, 
  9th, 
  and 
  

   10th 
  a 
  few 
  were 
  recorded 
  flying 
  in 
  a 
  southerly 
  direction, 
  

   and 
  on 
  the 
  12th 
  October 
  a 
  number 
  were 
  seen 
  flying 
  over 
  the 
  

   sea 
  in 
  a 
  south-westerly 
  direction. 
  Attention 
  should 
  also 
  be 
  

   drawn 
  to 
  the 
  offshoot 
  migration, 
  in 
  a 
  southerly 
  direction, 
  

   from 
  the 
  main 
  stream 
  just 
  east 
  of 
  Port 
  of 
  Spain 
  from 
  the 
  

   27th 
  September 
  to 
  1st 
  October. 
  On 
  the 
  first 
  of 
  these 
  days 
  

   they 
  were 
  reported 
  as 
  appearing 
  suddenly 
  in 
  unprecedented 
  

   numbers 
  in 
  the 
  cocoa 
  groves 
  a 
  httle 
  to 
  the 
  south 
  of 
  this. 
  

  

  While 
  this 
  migration 
  was 
  passing 
  across 
  the 
  northern 
  half 
  

   of 
  the 
  Island, 
  chiefly 
  at 
  the 
  southern 
  edge 
  of 
  the 
  northern 
  

   range 
  of 
  hills, 
  a 
  similar 
  stream 
  was 
  also 
  moving 
  across 
  the 
  

   southern 
  district 
  in 
  the 
  same 
  direction. 
  There 
  is, 
  however, 
  

   no 
  record 
  of 
  movement 
  here 
  until 
  the 
  26th 
  September, 
  

   which 
  is 
  four 
  days 
  after 
  the 
  start 
  of 
  the 
  migration 
  in 
  the 
  

   north. 
  Migrating 
  butterflies 
  were 
  recorded 
  in 
  great 
  num- 
  

   bers, 
  particularly 
  in 
  the 
  western 
  half 
  of 
  the 
  south 
  coast, 
  at 
  

   Palo-Seco 
  and 
  Erin, 
  and 
  in 
  a 
  few 
  days 
  the 
  flight 
  had 
  become 
  

   general 
  across 
  the 
  south-eastern 
  district 
  of 
  the 
  Island, 
  

  

  