Survival and winter site fidelity of Sooty Fox Sparrows on southern Vancouver Island, British Columbia

Michael Simmons 

Rocky Point Bird Observatory, #170­1581­H Hillside Ave, Victoria, B.C. V8T 2C1; email: rpbo@rpbo.or

Abstract:  In  the  winter  of  2012­13,  115  Sooty  Fox  Sparrows  (Passerella  iliaca)  were  trapped  and  banded  in  southern Vancouver  Island,  B.C.  Intensive  searches  were  made  to  locate  those  birds  in  the  winter  of  2013­14  and  incidental observations of banded birds were made in each of the next four winters. All re­captures and re­sightings were either at the original  capture  site  or  in  very  close  proximity  indicating  strong  wintering  area  site  fidelity.  The  banded  birds  were  46% adults, a very large difference from the 16% found during fall migration banding at Rocky Point Bird Observatory in Victoria. This  suggests  that  fall  migrants  are  a  different  population  than  winter  residents  of  southern  Vancouver  Island. Adjusted recovery  rates  over  one  year  were  51%  for  adult  birds,  30%  for  young,  and  40%  overall.  Because  of  the  intensity  of observation and high site fidelity, it is suggested that these be considered estimates of true survival.

Key Words: Sooty Fox Sparrow, Passerella iliaca, Vancouver Island, true survival, winter site fidelity, age ratio, banding, geolocators.

PDFiconSimmons, M. 2020. Survival and winter site fidelity of Sooty Fox Sparrows on southern Vancouver Island, British Columbia. British Columbia Birds 30:2–6.

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