Contents 
Abstract eevee opeueeveeoeoeeaeeeueaeeecaspoeveeeoesp peevsvese 
ee@esp@eoeosvpetepauaespesevaeeepesepeaneeeeea iv 
ENGrOOUCEIGY « < ive ab bs-6 ee ee Ow ee OS 
Procedure @poeooseosvpw@aeosoeeseseeoewetespevaeesveaeaeaeseaes 
The Call-count Method eee@eweesaeeaeveaneee eae nne 
oe ge Le 
Weighting Factor’ ..4 508 cstiseeeae eens ea 
Long-term Trends eeoteeeeseoeeeneeeeeeovnens 
ees owe eepoeoecevp GOeaueuueeeoeveaesveene 
Trends in the breeding population index - 1962 ..ccccccccccenccces 
Rastern Management Unit .cccccsececscscssces 
Central Management Unit .«..sccccscccscvsveces 
Western Management Unit .crseeseeeecessecnes 
Discussion of population index trendS ...ccccccccvcee 
Oo wm WD wo wns wh MV 
TA Gere Ure CAGE xa 5 a ee 4S RAS Oe Se 
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