Lessons  Learned  from  a  Literal  Migrant  Trap:  Bird  Collisions  on  a  University  Campus  

Timothy  O’Connell,  Monika  Burche@e,  and  Emily  Clark  Natural  Resource  Ecology  and  Management,  Oklahoma  State  University  

Most  carcasses  are  photographed  in  situ  and  then  photographed  again  when  ready  to  be  frozen   for   later  use.  Age,   sex,   fat   content,  and  other  a;ributes   (e.g.,  brood  patch)  and  measurements  are  recorded  prior  to  freezing.  

Background  and  ObjecGves  

Birds  frequently  collide  with  windows  in  buildings  of  educaAonal  and  corporate   campuses.     This   is   a   subtly   different   phenomenon   from  window   collisions   around   homes   and   at   skyscrapers   along   major  migraAon  corridors.  

Much  research  into  collisions  has  focused  on  the  physical  features  of  buildings   that   influence   collisions   and   the   careful   sampling   of  carcasses   to   quanAfy   rates   of   observer   detecAon   and   removal   by  scavengers  or  other  agents.  The  ostensible  purpose  of  this  sampling  is   to   increase   the  accuracy  and  precision  of  numerical   esAmates  of  collision   mortality.   We   illustrate   here   that   there   are   addiAonal  reasons  to  collect  such  data,  including  the  carcasses  themselves.  

Right:  SpaAal  distribuAon  of  trapped  and  dead  birds  at    the  NRC,  Aug.–Nov.  2012.  

Methods  

From  2009–2012,   I   conducted  near  daily   searches   for  window-­‐killed  birds  at  the  Noble  Research  Center  (NRC)  on  the  campus  of  Oklahoma  State  University  in  SAllwater.    The  NRC  is  located  in  a  wide  open  area  of  parking   lots  and  lawns,  but   its  complex  shape  draws  birds  toward  both  reflecAve  and  “pass-­‐through”  expanses  of  glass.  

Le[:  Such  a  waste  -­‐  Lincoln’s  Sparrow.  We  cannot  eliminate  window  collisions  enArely,  but  we  can  try  to  put  the  bodies  of  these  unfortunate  vicAms  to  be;er  use.  

The  Noble  Research  Center  on  the  campus  of  Oklahoma  State  University  in  SAllwater,  OK.    There  are  206  separate  glass  facades  >  1.5  m  wide  on  this  building.    

Most  “trapped”  birds  are  unable  to  be  caught  by  hand,  and  have  an  excellent  chance  of  recovery.   I  have  “saved”  approximately  36  birds  this  way.  

Above  le[:  This  Carolina  Chickadee  has  been  measured  and  its  a;ributes  recorded.  Above  right:  the  same  chickadee  ready  for  temporary  internment  in  the  freezer.    

Results  of  every  survey   (posiAve  and  negaAve  data)  are  posted  to  a  website,  along  with  photographs,   analysis,   commentary,   and   links   to   key   advances   in   window   collision  research  and  conservaAon:  birdsmack.wordpress.com:  

I   leave  some  carcasses   in  situ  to  gather  data  on  removal  rates.    The  best  specimens  and  those   under-­‐represented   in   our   holdings   are   prepared   as   museum   skins   for   the   OSU  CollecAon  of  Vertebrates.    Other  specimens  of  species  not  needed  for  our  collecAons  are  used  for  dissecAons  in  Ornithology.  

Above,   from   le[:   Specimens   awaiAng   curaAon   in   the   CollecAon   of   Vertebrates   (COV);   this   Sprague’s   Pipit   and   molAng   Indigo  BunAng  were  valuable  addiAons  to  the  COV;  students  much  prefer  dissecAon  of  wild  birds  of  mulAple  species,  such  as  this  Yellow-­‐billed  Cuckoo,  to  dissecAon  of  Rock  Pigeons  prepared  in  formalin.    

Results,  Discussion,  Lessons  Learned  

From  2009–2012,   I  confirmed  collision  mortality  of  122   individuals  of  42   species.     Almost   all   were  migrants   that   would   otherwise   not   be  recorded   near   the   NRC   due   to   the   lack   of   appropriate   habitat,   e.g.,  Whip-­‐Poor-­‐Will   (eastern),   Sora,   Canada   Warbler,   and   Black-­‐throated  Green  Warbler.  Most  frequently  found  were  Lincoln’s  Sparrow  (18)  and  Grasshopper   Sparrow   (15).   Compared   to   data   from   eBird,   Lincoln’s  Sparrow   encountered   21%   of   the   Ame   it   occurred   in   the   county   in  spring;  58%  of  the  Ame  in  autumn.  

Le[:   Moving   this   Orange-­‐crowned  Warbler   to   a   secure  locaAon  away  from  the  NRC  gave  it  the  chance  to  recover  and   conAnue   on   its   journey.     Anecdotal   evidence  suggests   that   some   birds   die   from   the   exhausAon   and  stress   of   being   “trapped”   by   the   building’s   shape   as  opposed  to  simply  hikng  a  window  at  high  speed.