﻿INVESTIGATIONS 
  INTO 
  THE 
  BIONOMICS 
  OF 
  GLOSSINA 
  PALPALIS. 
  395 
  

  

  On 
  these 
  islands 
  it 
  has 
  forsaken 
  the 
  unnecessary 
  protection 
  of 
  the 
  marshes, 
  and 
  

   assumed 
  habits 
  much 
  more 
  like 
  those 
  of 
  the 
  bush-buck 
  on 
  the 
  mainland. 
  It 
  is 
  

   most 
  common 
  in 
  the 
  jungles 
  which 
  have 
  sprung 
  up 
  in 
  the 
  abandoned 
  plantations 
  

   and 
  village 
  sites, 
  and 
  is 
  generally 
  more 
  common 
  on 
  the 
  highlands 
  than 
  in 
  its 
  original 
  

   habitat. 
  At 
  points 
  it 
  has 
  browsed 
  on 
  shrubbery 
  growing 
  on 
  precipitous 
  rocky 
  slopes 
  

   which 
  would 
  seem 
  to 
  afford 
  it 
  the 
  scantiest 
  foothold. 
  Its 
  elongate 
  hoofs 
  spread 
  so 
  

   easily 
  as 
  not 
  to 
  impede 
  rapid 
  flight, 
  if 
  alarmed, 
  even 
  on 
  rocky 
  soil, 
  and 
  they 
  are 
  also 
  

   worn 
  away 
  nearly 
  to 
  the 
  length 
  that 
  is 
  normal 
  for 
  animals 
  that 
  frequent 
  rocky 
  places. 
  

  

  It 
  has 
  developed 
  into 
  a 
  most 
  destructive 
  enemy 
  of 
  many 
  species 
  of 
  plants. 
  Some 
  

   of 
  its 
  most 
  favoured 
  food-plants, 
  formerly 
  very 
  common, 
  have 
  been 
  virtually 
  

   exterminated 
  over 
  wide 
  areas. 
  There 
  is 
  one 
  plant, 
  allied 
  to 
  the 
  cultivated 
  canna, 
  

   which 
  was 
  perhaps 
  the 
  most 
  common 
  and 
  conspicuous 
  of 
  any 
  forest 
  herb. 
  It 
  formerly 
  

   covered 
  the 
  forest 
  floor 
  over 
  extensive 
  areas 
  on 
  Sesse 
  Island, 
  growing 
  to 
  a 
  height 
  

   of 
  2 
  to 
  7 
  feet, 
  and 
  effectually 
  concealing 
  and 
  protecting 
  (in 
  a 
  crouching 
  position) 
  

   the 
  antelope 
  that 
  fed 
  upon 
  it. 
  Hundreds 
  of 
  acres 
  were 
  covered 
  with 
  this 
  plant 
  

   to 
  this 
  degree 
  of 
  density 
  in 
  the 
  autumn 
  of 
  1914, 
  but 
  a 
  year 
  later 
  the 
  plants 
  had 
  been 
  

   browsed 
  to 
  the 
  roots 
  nearly 
  everywhere. 
  Of 
  one 
  species 
  of 
  woodland 
  shrub, 
  formerly 
  

   very 
  common, 
  not 
  a 
  living 
  shoot 
  could 
  be 
  found 
  in 
  1915. 
  Of 
  many 
  species 
  of 
  trees, 
  

   vines 
  and 
  large 
  shrubs 
  not 
  a 
  living 
  seedling, 
  leaf 
  or 
  young 
  shoot 
  within 
  reach 
  of 
  the 
  

   animals 
  could 
  be 
  found. 
  Areas 
  formerly 
  thickly 
  massed 
  with 
  fern 
  had 
  been 
  browsed 
  

   to 
  the 
  bare 
  earth 
  and 
  roots. 
  And 
  when 
  trees 
  fell 
  in 
  the 
  forest 
  it 
  happened 
  repeatedly 
  

   that 
  the 
  animals 
  prevented 
  other 
  trees 
  from 
  springing 
  up, 
  and 
  the 
  spaces 
  thus 
  became 
  

   open 
  glades. 
  

  

  The 
  animals 
  on 
  Sesse 
  Island 
  were 
  rather 
  badly 
  afflicted 
  as 
  they 
  grew 
  older 
  with 
  a 
  

   mange 
  or 
  " 
  scab 
  " 
  parasite, 
  which 
  seemed 
  to 
  be 
  causing 
  more 
  trouble 
  in 
  1915 
  than 
  in 
  

   1914. 
  On 
  Damba 
  Island 
  this 
  parasite 
  did 
  not 
  occur. 
  It 
  appeared 
  possible 
  that 
  it 
  

   might 
  prevent 
  much 
  further 
  increase 
  on 
  Sesse. 
  If 
  not, 
  and 
  if 
  nothing 
  else 
  disastrous 
  

   supervenes, 
  the 
  animal 
  must 
  speedily 
  adapt 
  itself 
  to 
  the 
  grazing 
  habit, 
  for 
  it 
  had 
  

   reached 
  and 
  passed 
  far 
  beyond 
  the 
  maximum 
  density 
  which 
  the 
  island 
  would 
  sustain 
  

   if 
  it 
  retained 
  its 
  woodland 
  habit 
  of 
  browsing. 
  

  

  This 
  " 
  outbreak 
  " 
  of 
  situtunga 
  presents 
  so 
  many 
  points 
  of 
  interest 
  that 
  it 
  was 
  

   carefully 
  studied 
  as 
  a 
  legitimate 
  phase 
  of 
  these 
  investigations, 
  and 
  much 
  more 
  was 
  

   learned 
  of 
  it 
  than 
  can 
  well 
  be 
  included 
  here. 
  

  

  The 
  effect 
  on 
  the 
  range 
  of 
  Glossina 
  of 
  the 
  increasing 
  numbers 
  of 
  situtunga 
  has 
  been 
  

   already 
  described 
  in 
  Sect. 
  V 
  (c). 
  The 
  further 
  effects 
  are 
  bound 
  to 
  be 
  profound 
  if 
  

   increase 
  continues. 
  There 
  are 
  certain 
  islands 
  (notably 
  Bunyama) 
  where 
  density 
  

   of 
  fly 
  was 
  well 
  below 
  the 
  average 
  in 
  1914-15, 
  but 
  where 
  conditions 
  are 
  very 
  favourable 
  

   to 
  rapid 
  increase 
  of 
  the 
  very 
  small 
  herds 
  of 
  situtunga 
  then 
  domiciled 
  upon 
  them, 
  

   and 
  also 
  such 
  as 
  to 
  make 
  spectacular 
  increase 
  in 
  density 
  of 
  fly 
  almost 
  a 
  certainty 
  

   if 
  the 
  antelope 
  increases. 
  

  

  The 
  animal 
  is 
  assiduously 
  hunted 
  by 
  the 
  natives 
  for 
  flesh, 
  skin 
  and 
  horns. 
  As 
  

   already 
  noted, 
  they 
  had 
  either 
  exterminated 
  or 
  prevented 
  establishment 
  of 
  the 
  species 
  

   on 
  islands 
  devoid 
  of 
  the 
  specific 
  protection 
  afforded 
  it 
  by 
  marshy 
  tracts, 
  and, 
  in 
  

   time, 
  they 
  would 
  pretty 
  certainly 
  exterminate 
  it 
  again 
  if 
  the 
  islands 
  were 
  repopulated. 
  

   To 
  exterminate 
  it 
  from 
  the 
  great 
  fields 
  of 
  sudd 
  which 
  are 
  permanently 
  anchored 
  

  

  (659) 
  D 
  

  

  