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Meyer | 0 The Ecological Impacts of Removing the Gray Wolf (Canis Lupus) from the Endangered Species List in the Yellowstone/ Idaho Area. Adam Meyer ENVS 190 13 May 2014 Canis lupus Credit: Gary Kramer / USFWS

TheEcological$Impactsof$Removingthe$Gray$Wolf$(CanisLupus ... 2014/800.gray wolf in the...Analysis ... Map’of’Yellowstone.’Lonely’Planet ... competitive!interactions!when!attempting!to

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Page 1: TheEcological$Impactsof$Removingthe$Gray$Wolf$(CanisLupus ... 2014/800.gray wolf in the...Analysis ... Map’of’Yellowstone.’Lonely’Planet ... competitive!interactions!when!attempting!to

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The  Ecological  Impacts  of  Removing  the  Gray  Wolf  (Canis  Lupus)  from  the  Endangered  Species  List  in  the  Yellowstone/  Idaho  Area.  

 

 

 

Adam  Meyer  

ENVS  190  

13  May  2014  

 

 

 

 

 

 

 

 

 

 

 

 

 

Canis  lupus  Credit:  Gary  Kramer  /  USFWS  

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Table  of  Contents:  

 

Acronym  list:……………………………………………………………………………………………………………2  

Abstract:…………………………………………………………………………………………………………………..3  

Introduction:…………………………………………………………………………………………………………….3  

Methods:…………………………………………………………………………………………………………………..9  

Analysis:…………………………………………………………………………………………………………………...10  

Discussion:……………………………………………………………………………………………………………….17  

References:………………………………………………………………………………………………………………19  

 

 

 

 

 

 

 

 

 

 

 

 

 

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Acronym  list:  

ESA:  Endangered  Species  Act  

NPS:  National  Park  Service  

USFWS:  United  States  Fish  &  Wildlife  

YNP:  Yellowstone  National  Park  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Abstract:  

  The  goal  of  this  project  is  to  evaluate  the  ecological  impacts  of  removing  the  gray  

wolf  (Canis  lupus)  from  the  endangered  species  list  in  the  Yellowstone/  Idaho  area.  

Removing  a  keystone  species  has  proven  detrimental  to  ecosystems.  In  June  2013,  the  

United  States  Fish  &  Wildlife  [USFWS]  has  proposed  to  remove  the  gray  wolf  off  the  

endangered  species  list.  This  decision  is  backed  with  scientific  research  that  has  proven  

that  the  gray  wolf  has  grown  outside  their  historic  range  and  the  reintroduction  has  proven  

successful.  As  of  now,  the  gray  wolf  is  preying  on  a  lot  of  livestock  which  is  causing  issues  

with  many  livestock  ranchers.  Because  of  these  reasons,  the  ranchers  also  want  the  gray  

wolves  delisted.  

Introduction:    

  Gray  wolves  were  eradicated  from  the  Yellowstone/  Idaho  area  in  the  1940-­‐1970’s  

(http://www.nps.gov/yell/naturescience/wolfrest.htm).  After  the  recognition  of  the  wolf  

as  a  keystone  species  in  the  1970’s,  the  United  States  added  the  gray  wolf  to  the  federal  

endangered  species  list.  Following  the  listing  of  the  gray  wolf,  Yellowstone  National  Park  

was  in  desperate  need  of  a  top  predator  to  restore  its  ecosystem,  and  in  the  spring  of  1995  

the  gray  wolf  was  reintroduced  to  the  park  

(http://www.nps.gov/yell/naturescience/wolfrest.htm).  After  close  to  20  years  of  careful  

conservation  practices,  the  gray  wolf  is  now  flourishing  in  the  Yellowstone/  Idaho  area.  

Currently,  the  gray  wolf  is  still  protected  under  the  federal  Endangered  Species  Act.  This  

act  protects  the  wolf  from  hunting  and  trapping;  however,  there  are  people  that  want  the  

gray  wolf  delisted  in  North  America.  After  several  comprehensive  studies,  it  has  been  

determined  that  the  gray  wolf  has  outgrown  its  historic  range  and  has  proven  the  recovery  

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methods  effective.  The  USFWS  has  proposed  to  have  the  gray  wolf  delisted  from  the  

endangered  species  list  because  of  these  reasons.  

  The  gray  wolf  is  a  member  of  the  dog  family.  Gray  wolves  are  the  ancient  ancestors  

to  our  domesticated  dogs  and  are  related  to  the  coyote  (Canis  latrans)  and  several  other  

wild  dog  species.  Like  many  other  dog  species  the  gray  wolf  is  a  pack  hunter;  however,  it  is  

not  uncommon  for  an  individual  wolf  to  break  from  a  pack  and  form  its  own  pack  

(http://www.nps.gov/yell/naturescience/wolfinfo.htm).  These  individual  wolves  may  

remain  alone  from  days  to  years  before  they  can  find  a  mate.  Although  wolves  are  pack  

hunters,  an  individual  is  still  a  highly  efficient  hunter.  The  gray  wolf  in  most  ecosystems  is  

the  top  predator.  There  are  several  populations  of  gray  wolf;  however  this  study  focuses  on  

the  Idaho/  Yellowstone  population.  The  Yellowstone/  Idaho  population  of  wolves  is  a  

larger  than  average  wolf;  males  weigh  between  100-­‐130  pounds  and  females  weigh  

between  80-­‐110  pounds  (http://www.nps.gov/yell/naturescience/wolves.htm).  The  

average  life  span  of  these  wolves  is  5  years;  however,  they  can  live  up  to  12  years  in  the  

wild  (http://www.nps.gov/yell/naturescience/wolves.htm).  The  average  pack  size  in  this  

area  is  2-­‐11  individuals.  The  pack  size  varies  under  a  number  of  conditions  including  food  

availability,  disease,  wolf  mortality  from  other  packs,  and  poaching  

(http://www.nps.gov/yell/naturescience/wolfinfo.htm).  They  mate  in  February  and  give  

birth  to  average  of  five  pups  in  April.  Each  pack  has  its  own  unique  structure,  with  some  

individuals  being  an  alpha  male  or  female  and  some  members  being  subordinate  

(http://www.nps.gov/yell/naturescience/wolves.htm).  Each  member  has  its  role  in  the  

pack.  Packs  mark  their  territory  by  urinating  around  the  boundary  and  howling.  A  wolf  

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caught  crossing  another  wolf’s  territory  is  most  likely  to  be  greeted  with  a  fight  

(http://www.nps.gov/yell/naturescience/wolves.htm).    

The  reason  why  the  gray  wolf  is  considered  a  keystone  species  is  because  of  its  role  

as  a  top  predator.  In  most  ecosystems,  a  top  predator  is  needed  for  the  ecosystem  to  

function  properly.  Although  the  Yellowstone/  Idaho  area  does  contain  grizzly  and  black  

bears,  these  bears  cannot  kill  large  prey  such  as  elk  or  deer  on  a  regular  basis.  The  gray  

wolf  primarily  feeds  on  ungulates  where  as  a  bear’s  diet  might  contain  berries  and  other  

plants.  By  feeding  on  these  ungulates,  the  gray  wolf  effectively  controls  these  species  from  

over  grazing  an  area.  After  making  a  kill,  the  wolves  also  contribute  to  several  other  species  

that  prey  on  the  carcass  (http://www.nps.gov/yell/naturescience/wolfinfo.htm).  Unlike  

mountain  lions  and  grizzly  bears,  wolves  abandon  their  prey  after  feeding  on  the  carcass.  

Abandoning  the  carcass  leaves  much  needed  meat  for  scavengers,  which  include  the  

coyote,  bald  eagle,  golden  eagle,  grizzly  bear,  black  bear,  raven,  magpie,  and  red  fox  

(http://www.nps.gov/yell/naturescience/wolfinfo.htm).  This  extra  food  source  for  

scavengers  is  essential  in  hard  winters  when  other  food  sources  are  unavailable.    

During  the  early  1800’s,  the  native  people  worshipped  and  idolized  the  wolf;  man  

and  wolf  lived  harmoniously.  That  story  would  change  however,  westward  expansion  

brought  settlers  from  the  east.  Many  settlers  staked  out  a  claim  in  what  is  now  Idaho,  

Montana,  and  Wyoming  (http://www.nps.gov/yell/naturescience/wolfrest.htm).  These  

settlers  made  a  living  however  they  could,  and  many  of  them  chose  livestock  ranching  as  a  

means  to  get  ahead.  Their  livestock  overgrazed  many  areas  causing  local  wildlife  to  have  a  

shortage  on  food.  This  shortage  would  cause  a  ripple  effect,  local  wildlife  would  soon  starve  

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and  populations  would  drop.  The  wolves  that  would  prey  on  the  local  wildlife  would  also  

need  to  find  a  way  to  eat.  It  is  believed  that  because  the  wolf  is  such  an  efficient  hunter  that  

it  invokes  fear  in  us.  This  meant  preying  on  the  livestock  that  replaced  the  local  wildlife.  

Losing  livestock  to  a  predator  was  not  

something  taken  lightly,  and  men  would  poison,  

trap,  and  shoot  any  wolf  that  was  viewed  as  a  

threat  (Zmyj  1996).  “Between  1914  and  1926,  

at  least  136  wolves  were  killed  in  the  park;  by  

the  1940s,  wolf  packs  were  rarely  reported.  By  the  mid-­‐1900s,  wolves  had  been  almost  

entirely  eliminated  from  the  48  states  

(http://www.nps.gov/yell/naturescience/wolfrest.htm)”.  It  was  not  only  the  wolf  being  

poisoned  and  trapped,  any  predator  viewed  as  a  threat  to  livestock  or  “more  desirable”  

wildlife  like  elk  or  deer  were  also  hunted.  This  meant  the  death  of  many  bears,  coyotes,  

foxes,  and  cougars  (Wilmers  2003).    

The  1950’s  &  1960’s  marked  a  harsh  time  for  the  wolves;  more  accurate  rifles,  

"In those days we had never heard of passing up a chance to kill a wolf. In a second we were pumping lead into the pack, but with more excitement than accuracy…" ~Aldo Leopold

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stronger  poisons,  and  more  lethal  traps  were  available  to  hunters  and  ranchers9  (Zmyj  

1996).  [Figure  1,  shows  some  of  inhumane  methods  some  of  the  ranchers  used  to  capture/  

eradicate  the  wolves].  During  this  time,  white  men  set  out  on  a  mission  to  eradicate  the  

wolf  and  create  a  predator  free  ecosystem.  The  U.S.  government  even  implemented  a  

nationwide  wolf  control  policy.  This  wolf  control  policy  was  highly  effective;  an  intensive  

survey  conducted  in  the  1970s  found  no  evidence  of  a  wolf  population  in  Yellowstone  

(http://www.nps.gov/yell/naturescience/wolfrest.htm).    

This  hunting  free-­‐  for-­‐  all  would  soon  come  to  a  halt  in  1973  when  the  Endangered  

Species  Act  [ESA]  was  passed  (Perry  2012).  The  ESA  would  protect  any  plant  or  animal  

facing  extinction.  Under  the  Act  a  “threated”  or  “endangered”  species  will  have  a  significant  

amount  of  its  habitat  protected  in  order  for  the  species  to  fully  recover.  Because  of  the  gray  

wolves  low  numbers,  they  were  listed  as  an  endangered  species,  and  any  person  caught  

poisoning,  trapping,  or  shooting  the  wolves  for  no  reason  would  have  been  penalized  

heavily.  Two  decades  after  the  passing  of  the  ESA  marked  a  controversial  time  in  U.S.  

history,  and  on  March  21,  1995,  gray  wolves  were  reintroduced  back  into  Yellowstone  

National  Park  (http://www.nps.gov/yell/naturescience/wolfrest.htm).  This  decision  

would  prove  to  be  a  heavily  debated  one  through  the  years.  Today,  many  farmers  and  

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ranchers  still  do  not  agree  with  the  reintroduction  of  the  wolves.

 

Figure  2:  http://www.fws.gov/mountain-­‐prairie/species/mammals/wolf/annualrpt13/figures/FINAL_Fig7a_Num-­‐BP-­‐State_2013.pdf  

[Figure  2,  shows  the  population  trend  of  the  gray  wolf  from  1982-­‐2013.  This  graph  

emphasizes  the  dramatic  population  growth  following  the  reintroduction  of  the  wolves.]  

Yellowstone  

National  Park  [YNP]  

was  created  as  the  

first  national  park  in  

1872.  YNP  expands  

over  3,472  square  

miles.  The  park  

resides  96%  in  

Figure  3:  Map  of  Yellowstone.  Lonely  Planet.  (2009)  

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Wyoming,  3%  in  Montana,  and  1%  in  Idaho  

(http://www.nps.gov/yell/planyourvisit/factsheet.htm).  Yellowstone  is  home  to  many  

species  including  threatened  Canada  lynx  and  grizzly  bear,  and  the  endangered  gray  wolf  

(http://www.nps.gov/yell/planyourvisit/factsheet.htm).  The  history  of  the  park  states  that  

the  gray  wolves  were  in  the  park  when  it  was  created  

(http://www.nps.gov/yell/naturescience/wolfrest.htm).  United  States  created  a  

Yellowstone  National  Park  Act  of  1872.  It  states  the  Secretary  of  the  Interior  "shall  provide  

against  the  wanton  destruction  of  the  fish  and  game  found  within  said  Park  

(http://www.nps.gov/yell/naturescience/wolfrest.htm)"  Although  the  wolves  resided  in  

the  park,  people  viewed  them  as  a  “wanton  destruction  of  the  fish  and  game”,  and  the  

eradication  methods  followed.  These  eradication  methods  would  continue  for  nearly  200  

years  until  the  passing  of  ESA  in  1973.    During  1995  to  1997,  Yellowstone  was  designated  

as  one  of  three  recovery  sites  for  the  gray  wolves  and  41  wild  wolves  from  Canada  and  

northwest  Montana  were  released  in  YNP  

(http://www.nps.gov/yell/naturescience/wolfrest.htm).    

Methods:  

  The  gray  wolf  is  one  of  the  most  researched  species  in  the  world.  I  focused  on  the  

research  pertaining  to  the  gray  wolf  as  an  important  species  to  ecosystems.  Many  of  these  

studies  compare  what  the  Yellowstone/  Idaho  area  was  like  before  the  reintroduction  of  

the  wolf  to  what  the  ecosystem  is  now,  and  how  the  gray  wolf  has  enhanced  the  area.  I  will  

be  utilizing  a  meta-­‐approach  style  to  conduct  this  study.  I  will  review  the  current  studies  

and  literature  on  this  topic.    

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Analysis:  

There  have  been  several  studies  pertaining  to  the  listing  of  the  gray  wolf  as  an  

endangered  species,  one  of  which  is  an  analysis  conducted  by  Chris  Woolston  (2013).  He  

reviewed  the  decision  of  USFWS  to  delist  the  gray  wolf  from  the  endangered  species  list.  

The  USFWS  argues  that  the  gray  wolf  has  outgrown  its  historic  range  and  that  the  agency  

needs  to  focus  on  the  recovery  of  the  Mexican  gray  wolf  now  (Woolston  2013).  However,  

many  scientists  and  organizations  believe  that  USFWS  did  not  use  proper  researching  

methods  for  their  studies.  Without  proper  research  methods,  these  studies  would  be  

incorrect.  This  was  of  particular  interest  because  it  shows  the  misconnection  between  

scientists  and  general  public.  The  general  public  believes  that  all  studies  conducted  by  a  

federal  branch  i.e.  USFWS  should  be  truthful  and  correct.  Still  many  scientists  speculate  on  

the  correct  population  of  Canis  lupus.  Another  study  conducted  by  Creel  and  Rotella  (2010)  

reviews  the  scientific  justification  of  the  2009  delisting  of  the  Rocky  mountain  population  

of  the  gray  wolf.  The  researchers  believe  that  USFWS  based  their  justification  on  many  

social  attitudes  toward  the  wolves  (Bruskotter  et.  al  2010).  “In  general,  stakeholders  calling  

for  reductions  in  wolf  numbers  are  concerned  about  three  issues:  livestock  losses,  effects  

on  ungulates  (particularly  elk)  and  human  safety.  In  2008  and  2009,  Northern  Rocky  

Mountain  wolves  were  responsible  for  an  average  of  203  confirmed  kills  of  cattle  (from  a  

population  of  approximately  5.9  million  cattle)  and  538  confirmed  kills  of  sheep  (Creel  and  

Rotella  2010)”.  These  stakeholders  have  a  huge  influence  in  the  law  making  in  the  

endangered  species  list.  Creel  and  Rotella  (2010)  conclude  that  the  USFWS  should  

reevaluate  their  decision  and  use  accurate  population  surveys  to  determine  if  the  gray  wolf  

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is  in  need  of  delisting.  This  study  is  of  particular  interest  because  it  solidifies  the  

importance  of  “good  science”  when  determining  the  need  for  a  delisting  of  a  species.  Not  

only  is  “good  science”  a  necessity  when  it  comes  to  delisting  an  endangered  species,  it  is  

severely  important  to  be  accurate  in  population  estimates  when  the  species  that  is  in  

consideration  for  delisting  is  also  one  of  the  keystone  species  of  the  ecosystem.  Another  

study  conducted  in  2009-­‐2010  researchers  (Ausband,  Rich,  and  Glenn)  used  surveys  from  

hunters,  howling  and  sign  surveys  to  help  predict  wolf  population  in  Idaho.  The  authors  

emphasize  the  importance  of  using  more  than  one  survey  method  to  improve  the  accuracy  

of  the  study.  The  difficulties  in  

estimating  a  wolf  population  is  

highlighted  in  this  study,  “Methods  for  

estimating  the  size  of  large  carnivore  

populations  are  financially  and  

logistically  challenging  (Ausband  etal.  

2014)”.  These  difficulties  could  lead  to  

inaccuracy  which  could  misconstrue  

population  estimates  (Ausband  et  al.  

2014).  Since  the  gray  wolf  population  

is  being  evaluated  for  delisting,  it  is  

essential  that  population  estimate  surveys  are  accurate.  [Figure  4,  shows  a  team  of  

researchers  taking  measurements  and  fitting  a  wolf  for  a  radio  collar.  A  lot  of  data  

regarding  the  species  is  gathered  this  way  (Smith  et.  al  2010)]  .  

Figure  4:  Radio-­‐collaring  a  wolf.  http://www.nps.gov/yell/naturescience/upload/Wolf_AR_2011.pdf  

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Many  other  studies  have  been  conducted  regarding  the  wolf’s  impacts  on  other  

species.  Researches  Ripple,  Beschta,  and  Fortin  (2014)  analyzed  the  secondary  effects  of  

reintroducing  wolves  back  into  YNP.  The  researchers  theorized  that  the  threatened  grizzly  

bear  would  benefit  from  a  lower  elk  population.  Lower  elk  populations  would  decrease  

forging  from  these  ungulates  and  in  turn  have  more  berry-­‐producing  shrubs  for  the  grizzly  

bear  to  eat  (Ripple  et.  al  2014).  Their  study  on  the  impacts  of  ungulates  on  the  threated  

grizzly  bear  population  was  the  first  of  its  kind.  Their  research  and  finding  were  significant  

to  the  importance  of  the  gray  wolf  in  the  ecosystem.  “We  suggest  researchers  and  policy  

makers  consider  wolves,  trophic  interactions  and  competition  from  wild  and  domestic  

ungulates  when  addressing  research  and  management  of  grizzly  bears  (Ripple  et.  al  2014)”.  

This  study  signifies  the  importance  of  the  gray  wolf  on  the  threatened  grizzly  bear  

population  in  the  YNP.  The  grizzly  bear  and  the  elk  are  not  the  only  species  that  the  wolf  

has  had  a  major  impact  on.  The  coyote,  one  of  the  parks  other  canine  species  had  a  huge  

population  change  after  the  reintroduction  of  the  wolf.  Before  the  wolf  was  reintroduced,  

the  coyote  was  largest  canine  species  in  the  area  (Merkle  et.  al  2009).  The  study  conducted  

by  Merkle,  Stahler,  and  Smith  (2009)  investigated  the  environmental  impacts  of  the  wolf  on  

the  coyote.  Before  the  reintroduction  of  the  wolves,  the  coyotes  were  over  populated.  

Coyotes  in  that  area  preyed  heavily  on  small  mammals  and  birds  (Merkle  et.  al  2009).  This  

created  an  imbalance  on  the  ecosystem.  The  wolves  were  documented  to  kill  25  coyotes  

and  in  275  interactions  wolves  chased  the  coyotes  (Merkle  et.  al  2009).  This  study  suggests  

the  importance  of  the  wolf  to  moderate  the  coyote’s  population.  By  moderating  the  coyote’s  

population,  the  wolves  partially  restored  the  ecosystem  back  to  a  natural  state.  Once  again,  

this  study  highlights  the  importance  of  the  wolf  as  a  keystone  species.  Not  only  are  coyotes  

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and  grizzly  bears  affected  by  the  wolf’s  presence,  but  the  endangered  Canadian  lynx  as  well.  

Ripple,  Wirsing,  and  Beschta  (2011)  studied  the  effects  of  the  reintroduction  of  the  wolves  

on  the  endangered  Canadian  lynx  population.  The  results  of  their  study  theorize  that  the  

reintroduction  of  wolves  will  do  two  things,  1)  bring  the  coyote  population  back  to  a  

healthy  population,  which  will  in  turn  increase  the  snowshoe  hare  population.  The  

snowshoe  hare  is  a  primary  food  source  for  the  lynx.  And  2)  bring  the  elk  population  back  

to  a  healthy  population,  which  will  in  turn  increase  the  forging  sites  for  the  snowshoe  hare  

(Ripple  et.  al  2011).  They  emphasize  the  importance  of  little-­‐considered  trophic  and  

competitive  interactions  when  attempting  to  recover  an  endangered  carnivore  such  as  the  

lynx  (Ripple  et.  al  2011).  This  means  if  more  wolves  equals  less  coyotes,  then  less  coyotes  

equals  less  competitive  interactions,  which  in  turn  would  lead  to  a  rebounding  lynx  

population.  This  is  another  study  affirming  the  importance  of  the  wolf  to  the  Yellowstone/  

Idaho  area.  The  data  from  this  study  helps  solidify  the  need  for  the  wolf  in  this  ecosystem.  

Not  only  do  wolves  create  more  prey  for  lynxes  by  reducing  the  number  of  coyotes,  they  

also  create  more  carrion  for  other  scavengers.  Researchers  Wilmers,  C.C.,  and  Crabtree  

(2003)  create  an  experiment  looking  at  the  carrion  available  to  scavengers  after  the  wolves  

have  made  a  kill.  They  conclude  that  in  the  presence  of  the  wolf,  more  large  animals  are  

killed  and  thus  providing  more  carrion  for  scavengers.  “By  partially  consuming  their  prey,  

wolves  subsidize  scavengers  with  a  high  calorie  resource  that  may  be  essential  for  

metabolic  maintenance,  growth  and/or  reproductive  success  (Wilmers  et.  al  2003)”.This  

carrion  is  particularly  important  during  winter  months  when  food  is  scarce  for  scavengers,  

thus  creating  a  need  for  wolves.  For  example  “Female  grizzly  bears  with  reliable  high-­‐

energy  foods,  for  instance,  have  been  shown  to  attain  larger  body  size  and  have  bigger  litter  

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sizes  than  their  counterparts  with  less  reliable  and/or  lower-­‐calorie  foods  (Wilmers  et.  al  

2003)”.  As  indicated  above,  the  wolves  have  provided  an  essential  resource  for  the  threated  

grizzly  bear;  however,  not  only  the  grizzly  bear  benefits  from  this  resource,  “increasing  the  

time  over  which  carcasses  are  available  during  the  winter,  this  carrion  subsidy  may  

contribute  significantly  to  the  biodiversity  of  the  region  (Wilmers  et.  al  2003)”.    

Many  studies  provided  thus  far  have  shown  only  the  importance  of  the  wolf  to  other  

fauna.  There  have  been  significant  amounts  of  studies  conducted  pertaining  to  the  wolf  and  

its  effects  on  plants.  Scientists  Beschta,  R.L.  and  Ripple  (2012)  conducted  several  studies  on  

the  berry-­‐producing  shrubs  within  

YNP’s  northern  ungulate  winter  

range.  These  studies  were  conducted  

15  years  after  the  gray  wolves  

reintroduction  into  the  park,  which  

gave  the  plants  ample  time  to  

regrow.  The  studies  have  provided  

evidence  that  the  gray  wolves  

predation  on  the  ungulates  has  

helped  to  restore  berry-­‐producing  

shrubs  stands  to  recover  (Beschta  et.  

al  2012).  The  berry-­‐producing  

shrubs  are  not  only  beneficial  to  

ungulates  but  other  species  as  well,  

Figure  5:  (Beschta  et.  al  2012)  

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and  a  fully  recovered  ecosystem  is  beneficial  to  all  species.  The  importance  and  role  of  the  

gray  wolf  in  this  ecosystem  is  highlighted  in  this  study,  and  in  figure  5  [the  images  show  the  

differences  between  the  absence  of  ungulates  in  area  (a)  and  the  presence  of  ungulates  in  

an  area  (b).  “Contrasting  aspen  sites  in  the  northern  range  of  Yellowstone  (September  

2010):  (a)  A  riparian  site  that  has  experienced  reduced  ungulate  browsing  pressure  in  

recent  years  with  resultant  increases  in  the  heights  of  serviceberry  and  chokecherry  

(foreground)  as  well  as  increased  aspen  and  mountain  alder  (Alnus  incana)  recruitment  

(i.e.,  growth  above  browse  level  of  elk;  background)  and  (b)  an  upland  site  experiencing  

continued  high  levels  of  ungulate  browsing,  no  increased  heights  of  berry-­‐producing  

shrubs,  and  no  aspen  recruitment.  Note  the  two-­‐tiered  aspen  stand  structure  comprising  an  

overstory  of  mature  trees  and  an  understory  of  young  aspen;  the  missing  intermediate  

size/age  classes  occurred  over  multiple  decades  when  elk  herbivory,  in  the  absence  of  

wolves,  prevented  aspen  recruitment  (Beschta  et.  al  2012)”].  Another  study  conducted  by  

Eisenber,  Seager,  and  Hibbs  (2013)  evaluates  the  gray  wolf  and  its  importance  to  forest  

ecology.  This  study  and  Beschta’s  2012  study  show  the  importance  of  the  wolf  to  forest  

ecology.  “Trophic  cascades  driven  by  apex  predators  via  top-­‐down  effects  have  been  

identified  in  ecosystems  worldwide  (Eisenberg  et.  al  2013)”.  In  this  study  it  shows  the  

effects  of  the  gray  wolf  on  aspen  communities.  They  conclude  that  the  wolves  have  helped  

the  aspen  groves  back  to  a  more  natural  state.  They  suggest  “applying  the  precautionary  

principle  to  create  healthier,  more  resilient  aspen  forests  would  suggest  conserving  apex  

predators,  as  feasible,  where  their  ranges  coincide  with  aspen  (Eisenberg  et.  al  2013)”.  In  

conclusion,  the  wolves  have  helped  the  ecosystem  rebound  to  a  more  natural  state,  thus  

proving  the  importance  of  the  wolf  as  a  keystone  species.  

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If  the  gray  wolf  were  to  be  delisted  nationwide,  many  states  would  open  a  hunting  

season  for  the  species.  Many  states  that  already  have  a  recovered  population  have  already  

chosen  to  use  a  hunting  season  as  a  means  of  population  control.  There  have  already  been  

some  studies  on  the  effects  of  hunting  on  wolf  populations.  One  of  which,  is  the  study  

conducted  by  Creel  and  Rotella  (2010).  Their  study  shows  some  of  the  possible  effects  of  

the  delisting  of  the  species.  Creel  and  Rotella  (2010)  evaluate  the  impacts  of  an  immediate  

hunting  season  following  the  delisting  of  a  population  of  gray  wolves  in  2009.  Idaho  and  

Montana  had  a  set  20%  quota  on  population  elimination,  after  the  season  a  population  

estimate  determined  that  37%  of  the  population  was  killed  during  the  year  of  the  delisting.  

This  evidence  is  useful  when  determining  the  delisting  of  other  wolf  populations.  If  the  

entire  gray  wolf  population  were  to  decrease  by  37%  that  could  prove  detrimental  to  the  

population.  If  wolves  are  to  be  kept  on  the  endangered  species  list,  alternative  methods  are  

available  for  nuisance  control  of  the  wolf.  Researches  Hawley,  Rossler,  and  Gehring  (2013)  

studied  the  likelihood  of  using  electronic  shock  collars  as  a  management  tool  for  reducing  

livestock  losses  caused  by  gray  wolves.  Electronic  shock  collars  could  help  reduce  

negativity  towards  wolves  as  well  as  livestock  loss.  This  device  would  be  an  excellent  non-­‐

lethal  management  tool.  These  shock  collars  are  expensive,  but  these  collars  would  help  

ranchers  keep  wolves  off  their  property  (Hawley  et.  al  2013).    

A  lot  of  money  and  effort  has  gone  into  the  research  of  the  gray  wolves  (Way  and  

Bruskotter  2012).  USFWS  now  wants  to  shift  their  efforts  to  the  recovery  of  the  Mexican  

wolf  population  in  the  Southwest.  (http://www.fws.gov/home/wolfrecovery/).  “The  

Mexican  wolf  is  the  rarest  subspecies  of  gray  wolf  in  North  America.  Once  common  

throughout  portions  of  the  southwestern  United  States,  the  Mexican  wolf  was  all  but  

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eliminated  from  the  wild  by  the  1970s  

(http://www.fws.gov/southwest/es/mexicanwolf/)”.  A  mere  83  Mexican  wolves  roam  the  

wild  today.  This  number  is  drastically  less  than  the  historic  population  number.  This  

subspecies  is  also  an  essential  species  to  an  ecosystem,  and  it  has  shared  a  similar  story  to  

the  gray  wolf’s  tragic  history.  

A  higher  Mexican  wolf  

population  would  be  needed  

for  the  ecosystem  to  regain  

its  natural  state.  [Figure  6,  

shows  the  home  range  of  the  

Mexican  gray  wolf].    

   

Discussion:  

  As  a  top  predator  and  a  keystone  species,  the  gray  wolf  is  an  important  asset  to  an  

area.  The  results  of  this  discussion  should  assess  the  implications  of  removing  the  gray  wolf  

from  the  endangered  species  list.  I  am  hoping  this  research  will  help  students  become  

familiar  with  the  current  issues  associated  with  removing  gray  wolves  from  the  

endangered  species  list.  Aldo  Leopold  was  an  author  and  leading  environmentalist.  His  

work  has  inspired  many  conservationists.  Many  of  his  ideas  were  formed  from  his  work  

with  the  wolf.  Aldo  was  a  ranger  for  USFWS  and  his  job  was  to  increase  the  deer  population  

for  the  hunters.  USFWS  believed  that  the  best  way  to  increase  the  population  was  to  

eliminate  the  wolf  and  make  a  predator-­‐free  ecosystem.  "I  was  young  then,  and  full  of  

Figure  6:  http://www.azgfd.gov/w_c/es/mexican_wolf.shtml  

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trigger-­‐itch;  I  thought  that  because  fewer  wolves  meant  more  deer,  that  no  wolves  would  

mean  hunters’  paradise."  This  belief  held  true  to  many  scientists  and  hunters  at  the  time.  

This  belief  has  carried  on  to  many  hunters  and  ranchers  today.  After  his  realization  of  his  

impacts  of  removal  of  the  wolf  from  the  mountains  he  worked,  he  changed  his  beliefs  and  

redirected  his  career  to  obtain  a  more  natural  ecosystem.  "I  now  suspect  that  just  as  a  deer  

herd  lives  in  mortal  fear  of  its  wolves,  so  does  a  mountain  live  in  mortal  fear  of  its  deer."  

Just  as  Aldo  once  believed  that  a  predator-­‐free  landscape  was  the  solution  to  a  flourishing  

game  population,  we  too  have  to  change  our  misconceptions  and  negativity  towards  the  

wolf.  I  believe  the  wolf  is  an  essential  species  to  the  Yellowstone/  Idaho  ecosystem  because  

of  its  impact  in  helping  restore  the  ecosystem  back  its  natural  state.  This  quality  makes  the  

gray  wolf  a  keystone  species  to  this  area.    Although  there  have  been  many  studies  

indicating  the  benefits  of  the  wolf  to  this  ecosystem,  there  have  also  been  many  biased  

studies  that  have  proven  the  wolf’s  population  higher  than  what  it  actually  is.  This  higher  

population  estimate  would  lead  to  a  higher  hunting  quota.  An  incorrect  population  

estimate  could  be  detrimental  to  the  wolf’s  population  (Ausband  et  al.  2014).  I  hope  USFWS  

will  reevaluate  their  studies  and  methods  they  used  to  conduct  their  population  estimates.    

 

 

 

 

 

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 2) Beschta,  R.L.,  and  Ripple,  W.J.  (2012).  Berry-­‐producing  shrub  characteristics  

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 8) Perry,  S.  (2012).  The  Gray  Wolf  Delisting  Rider  and  State  Management  Under  the  

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