﻿206 
  On 
  Birds 
  observed 
  in 
  the 
  Canary 
  Islands. 
  

  

  arrive 
  in 
  August, 
  and 
  they 
  may 
  be 
  seen 
  in 
  pairs 
  at 
  the 
  begin- 
  

   ning 
  of 
  June. 
  

  

  130. 
  Sterna 
  HiRUNDo. 
  Common 
  Tern. 
  [Garajdoy 
  

  

  A 
  summer 
  visitor 
  to 
  all 
  the 
  islands. 
  In 
  Tenerife 
  they 
  lay 
  

   their 
  eggs 
  on 
  the 
  tops 
  of 
  high 
  isolated 
  rocks. 
  They 
  winter 
  

   in 
  the 
  eastern 
  islands. 
  

  

  131. 
  Sterna 
  cantiaca. 
  Sandwich 
  Tern. 
  

   Seen 
  in 
  flocks 
  off 
  Fuerteventura. 
  

  

  132. 
  Larus 
  cachinnans. 
  Mediterranean 
  Herring-Gull. 
  

   {Gaviota.) 
  

  

  This 
  is 
  the 
  common 
  resident 
  Gull. 
  It 
  breeds 
  in 
  all 
  the 
  

   islands. 
  We 
  never 
  saw 
  the 
  true 
  Larus 
  argentatus. 
  

  

  133. 
  Larus 
  fuscus. 
  Lesser 
  Black-backed 
  Gull. 
  

   There 
  are 
  generally 
  a 
  few 
  of 
  these 
  Gulls 
  about 
  in 
  winter. 
  

  

  134. 
  Larus 
  marinus. 
  Great 
  Black-backed 
  Gull. 
  

   Much 
  scarcer 
  than 
  the 
  last. 
  

  

  135. 
  Larus 
  canus. 
  Common 
  Gull. 
  

  

  Uncommon 
  here. 
  I 
  have 
  seen 
  but 
  two 
  of 
  this 
  species. 
  

  

  136. 
  RissA 
  tridactyla. 
  Kittiwake 
  Gull. 
  

   I 
  have 
  seen 
  very 
  few 
  of 
  these 
  Gulls. 
  

  

  137. 
  Procellaria 
  pelagica. 
  Storm-Petrel. 
  {Perrito.) 
  

   This 
  Petrel 
  is 
  always 
  to 
  be 
  seen 
  about 
  the 
  islands, 
  but 
  I 
  

  

  have 
  not 
  found 
  it 
  breeding. 
  

  

  138. 
  Procellaria 
  leucorrhoa. 
  Leach's 
  Petrel. 
  

   Occasional 
  in 
  winter 
  ; 
  at 
  least 
  I 
  have 
  not 
  seen 
  them 
  at 
  any 
  

  

  other 
  season. 
  

  

  139. 
  Oceanites 
  oceanicus. 
  Wilson's 
  Petrel. 
  

  

  I 
  have 
  seen 
  this 
  Petrel 
  occasionally 
  at 
  all 
  seasons, 
  but 
  do 
  

   not 
  think 
  they 
  nest 
  here. 
  

  

  140. 
  Puffinus 
  anglorum. 
  Manx 
  Shearwater. 
  {Pardela.) 
  

   This 
  species 
  is 
  sometimes 
  common 
  on 
  the 
  water 
  in 
  winter. 
  

  

  It 
  does 
  not 
  seem 
  to 
  come 
  to 
  laud. 
  

  

  