﻿CANVASBACK. 
  43 
  

  

  about 
  as 
  far 
  north 
  as 
  the 
  species 
  occurs 
  regularly 
  in 
  large 
  numbers, 
  

   the 
  course 
  is 
  almost 
  at 
  right 
  angles 
  to 
  the 
  general 
  trend 
  of 
  the 
  

   Atlantic 
  coast 
  line. 
  In 
  other 
  words, 
  this 
  is 
  the 
  course 
  the 
  redhead 
  

   should 
  take 
  to 
  reach 
  salt 
  water 
  by 
  the 
  shortest 
  route. 
  This 
  route 
  

   from 
  Manitoba 
  to 
  Long 
  Island 
  is 
  through 
  a 
  district 
  abounding 
  in 
  

   shallow 
  lakes 
  and 
  marshes, 
  which 
  furnish 
  abundant 
  food. 
  After 
  

   reaching 
  the 
  coast, 
  most 
  of 
  the 
  redheads 
  pass 
  southward 
  and 
  winter 
  

   from 
  Chesapeake 
  Bay 
  to 
  Florida 
  and 
  the 
  Bahamas. 
  Only 
  a 
  portion 
  of 
  

   the 
  species, 
  however, 
  takes 
  this 
  east 
  and 
  west 
  course. 
  Many 
  flocks 
  pass 
  

   directly 
  south 
  and 
  are 
  common 
  all 
  through 
  the 
  Mississippi 
  Valley 
  to 
  

   the 
  Gulf 
  coast 
  and 
  through 
  Texas 
  to 
  central 
  Mexico. 
  The 
  average 
  

   date 
  when 
  the 
  first 
  migrants 
  appear 
  in 
  southern 
  Ontario 
  is 
  September 
  

   19 
  (earliest 
  September 
  10, 
  1896); 
  at 
  Erie, 
  Pa., 
  the 
  average 
  date 
  is 
  

   October 
  7, 
  while 
  at 
  Alexandria, 
  Va., 
  a 
  long 
  series 
  of 
  careful 
  records 
  

   fixes 
  October 
  12 
  as 
  the 
  average 
  date 
  of 
  arrival 
  — 
  October 
  5 
  (1901) 
  the 
  

   earliest— 
  and 
  October 
  29 
  as 
  the 
  average 
  date 
  when 
  the 
  species 
  becomes 
  

   common. 
  In 
  general 
  it 
  may 
  be 
  said 
  that 
  the 
  large 
  flocks 
  cross 
  into 
  

   North 
  Dakota 
  about 
  the 
  1st 
  of 
  October, 
  are 
  common 
  in 
  the 
  central 
  

   Mississippi 
  Valley 
  about 
  the 
  middle 
  of 
  the 
  month, 
  and 
  reach 
  the 
  Gulf 
  

   coast, 
  from 
  Texas 
  to 
  Florida, 
  early 
  in 
  November, 
  when 
  the 
  last 
  are 
  

   deserting 
  the 
  northern 
  breeding 
  grounds. 
  

  

  A 
  single 
  individual 
  was 
  seen 
  in 
  southeastern 
  Labrador, 
  September 
  

   23, 
  and 
  this 
  bird 
  must 
  have 
  journeyed 
  nearly 
  2,000 
  miles 
  in 
  a 
  due 
  

   easterly 
  direction. 
  

  

  Aythya 
  vallisneria 
  (Wils. 
  ). 
  Canvasback. 
  

  

  Breeding 
  range. 
  — 
  The 
  district 
  just 
  east 
  of 
  the 
  Rocky 
  Mountains 
  in 
  

   Alberta 
  seems 
  to 
  be 
  a 
  center 
  of 
  abundance 
  of 
  this 
  species 
  in 
  the 
  

   breeding 
  season. 
  East 
  of 
  this 
  district 
  it 
  breeds 
  commonly 
  to 
  about 
  

   the 
  one 
  hundredth 
  meridian; 
  south 
  to 
  the 
  southern 
  boundary 
  of 
  

   Canada, 
  west 
  to 
  central 
  British 
  Columbia 
  and 
  Sitka, 
  north 
  to 
  Great 
  

   Slave 
  Lake, 
  and 
  northwest 
  to 
  Gens 
  de 
  large 
  Mountains 
  and 
  Fort 
  

   Yukon. 
  It 
  does 
  not 
  commonly 
  breed 
  in 
  the 
  United 
  States, 
  but 
  a 
  few 
  

   nest 
  in 
  northern 
  North 
  Dakota 
  and 
  in 
  diminishing 
  numbers 
  southward 
  

   to 
  Nebraska 
  (Cody, 
  Irwin, 
  Hackberry 
  Lake); 
  it 
  is 
  rare 
  as 
  a 
  breeder 
  in 
  

   Minnesota 
  (Madison, 
  Heron 
  Lake), 
  and 
  a 
  few 
  crippled 
  birds 
  have 
  been 
  

   known 
  to 
  breed 
  on 
  Lake 
  Koshkonong, 
  Wisconsin. 
  In 
  1900 
  it 
  bred 
  

   casually 
  at 
  Barr 
  Lake, 
  near 
  Denver, 
  Colo., 
  and 
  it 
  has 
  been 
  known 
  to 
  

   breed 
  at 
  Pyramid 
  Lake, 
  Nevada, 
  and 
  in 
  a 
  few 
  places 
  in 
  Oregon. 
  

  

  Winter 
  range. 
  — 
  The 
  statements 
  of 
  the 
  breeding 
  range 
  just 
  made 
  

   show 
  that 
  the 
  eastern 
  edge 
  of 
  the 
  regular 
  summer 
  home 
  is 
  more 
  than 
  

   a 
  thousand 
  miles 
  west 
  of 
  Chesapeake 
  Bay, 
  which, 
  until 
  a 
  comparatively 
  

   recent 
  period, 
  was 
  a 
  favorite 
  winter 
  home 
  for 
  the 
  canvasback. 
  The 
  

   line 
  of 
  the 
  Great 
  Lakes 
  seems 
  to 
  be 
  the 
  general 
  route 
  followed 
  in 
  this 
  

   southeastward 
  migration, 
  and 
  a 
  few 
  canvasbaeks 
  stop. 
  for 
  the 
  winter 
  

  

  