﻿28 
  HORNED 
  LAEKS 
  IN 
  RELATION 
  TO 
  AGRICULTURE. 
  

  

  MINERAL 
  MATTER. 
  

  

  Horned 
  larks 
  use 
  a 
  very 
  large 
  amount 
  of 
  gravel 
  to 
  assist 
  in 
  grinding 
  

   their 
  food, 
  and, 
  strange 
  as 
  it 
  may 
  seem, 
  nestlings 
  have 
  more 
  of 
  it 
  in 
  

   their 
  stomachs 
  than 
  adults. 
  Five 
  stomachs 
  of 
  nestlings 
  which 
  con- 
  

   tained 
  no 
  food 
  material 
  except 
  of 
  an 
  animal 
  nature 
  held 
  an 
  average 
  of 
  

   21 
  percent 
  of 
  gravel. 
  Now, 
  it 
  has 
  been 
  supposed, 
  since 
  granivorous 
  

   birds 
  usually 
  eat 
  much 
  gravel, 
  and 
  since 
  exclusively 
  insectivorous 
  

   birds, 
  such 
  as 
  cuckoos, 
  take 
  almost 
  none, 
  that 
  its 
  function 
  is 
  the 
  crush- 
  

   ing 
  and 
  grinding 
  of 
  seeds 
  to 
  aid 
  in 
  their 
  digestion. 
  But 
  why 
  the 
  thin- 
  

   walled 
  stomach 
  of 
  fledglings 
  which 
  are 
  fed 
  almost 
  exclusively 
  on 
  soft 
  

   animal 
  foods 
  should 
  contain 
  so 
  much 
  gravel 
  is 
  a 
  question 
  for 
  which 
  no 
  

   satisfactory 
  answer 
  has 
  yet 
  been 
  found. 
  The 
  percentage 
  for 
  the 
  nest- 
  

   lings 
  is 
  21.8, 
  for 
  the 
  adults 
  18.4, 
  and 
  for 
  the 
  birds 
  in 
  first 
  plumage 
  

   14.9. 
  The 
  last 
  group 
  is 
  the 
  most 
  vegetarian 
  of 
  the 
  three, 
  but, 
  oddly 
  

   enough, 
  takes 
  the 
  least 
  grinding 
  material. 
  The 
  mineral 
  matter 
  con- 
  

   sists 
  principally 
  of 
  coarse 
  and 
  fine 
  sand, 
  sandstone, 
  quartz, 
  and 
  cinders. 
  

   Many 
  bits 
  of 
  fossils 
  were 
  found, 
  among 
  which 
  were 
  fragments 
  of 
  

   foraminifera, 
  brachipods, 
  sea 
  urchins, 
  corals, 
  bryozoans, 
  and 
  crinoids. 
  

  

  NESTLING 
  AND 
  OTHER 
  YOUNG 
  HORNED 
  LARKS. 
  

  

  As 
  with 
  most 
  of 
  our 
  common 
  birds, 
  nestlings 
  of 
  the 
  horned 
  larks 
  are 
  

   more 
  insectivorous 
  than 
  older 
  individuals, 
  although 
  while 
  still 
  in 
  the 
  

   nest 
  they 
  are 
  sometimes 
  fed 
  considerable 
  vegetable 
  matter. 
  From 
  the 
  

   present 
  investigation 
  the 
  ratio 
  of 
  vegetable 
  to 
  animal 
  food 
  is 
  found 
  to 
  

   be 
  16.3 
  to 
  83.7. 
  

  

  A 
  thorough 
  study 
  of 
  the 
  diet 
  of 
  the 
  nestling 
  larks 
  requires 
  a 
  larger 
  

   amount 
  of 
  material 
  than 
  is 
  available. 
  Ten 
  stomachs 
  have 
  been 
  exam- 
  

   ined, 
  which 
  were 
  taken 
  in 
  three 
  States, 
  from 
  April 
  to 
  July, 
  inclusive. 
  

   Those 
  obtained 
  early 
  in 
  the 
  season, 
  and 
  from 
  northern 
  States, 
  contained 
  

   the 
  largest 
  amounts 
  of 
  vegetable 
  matter. 
  Of 
  these, 
  three 
  contained 
  1, 
  

   8, 
  and 
  40 
  percent, 
  respectively, 
  and 
  two 
  50 
  percent, 
  of 
  vegetable 
  sub- 
  

   stances. 
  A 
  nestling 
  taken 
  in 
  April 
  in 
  New 
  York 
  had 
  been 
  fed 
  45 
  per- 
  

   cent 
  of 
  wheat. 
  This 
  consisted 
  of 
  whole 
  grains, 
  which 
  would 
  seem 
  to 
  

   be 
  rather 
  unsuitable 
  food 
  for 
  a 
  fledgling. 
  The 
  other 
  vegetable 
  matter 
  

   found 
  in 
  the 
  stomachs 
  of 
  nestling 
  larks 
  was 
  mainly 
  weed 
  seeds. 
  Among 
  

   them 
  were 
  green 
  foxtail 
  {Chdetochloa 
  viridis), 
  tumbleweed 
  (Amaran- 
  

   thus), 
  and 
  yellow 
  sorrel 
  (Oxalis 
  striata). 
  

  

  In 
  the 
  animal 
  matter 
  were 
  wireworms 
  (Elateridse), 
  other 
  beetle 
  larvae, 
  

   mainly 
  white 
  grubs 
  (Scarabaeidde), 
  adult 
  beetles, 
  such 
  as 
  scarabseids, 
  leaf 
  

   beetles 
  {Chrysomelidde), 
  pill 
  beetles 
  {Byrrhidde), 
  and 
  weevils 
  (Ehyn- 
  

   chophora). 
  The 
  latter 
  were 
  found 
  in 
  all 
  but 
  three 
  of 
  the 
  stomachs 
  and 
  

   formed 
  16.3 
  percent 
  of 
  the 
  total 
  food 
  of 
  the 
  nestlings. 
  Of 
  the 
  chrys- 
  

   omelids, 
  one 
  stomach 
  contained 
  fragments 
  of 
  at 
  least 
  50 
  individuals 
  

  

  