, ▁and ▁when ▁territory ▁quality ▁was ▁und ist urbed ▁due ▁to ▁increased ▁far ming ▁or ▁development . ▁P erman ent ▁removal ▁of ▁pairs ▁from ▁the ▁population ▁due ▁to ▁development al ▁activities ▁caused ▁reduced ▁population ▁vi ability , ▁and ▁was ▁a ▁far ▁more ▁important ▁factor ▁impact ing ▁bre eding ▁success ▁relative ▁to ▁total ▁annual ▁ra inf all . ▁ ▁Bre eding ▁success ▁in ▁Australia ▁has ▁been ▁estimated ▁by ▁counting ▁the ▁proportion ▁of ▁young - of - the - year ▁in ▁winter ing ▁f lock s ▁in ▁the ▁c rop ▁fields ▁of ▁A ther ton ▁Table lands ▁in ▁north - e astern ▁Queensland . ▁Young ▁birds ▁constit uted ▁ 5 . 3 2 % ▁to ▁ 7 . 3 6 % ▁of ▁the ▁winter ing ▁population ▁between ▁ 1 9 9 7 ▁and ▁ 2 0 0 2 . ▁It ▁is ▁not ▁known ▁if ▁this ▁variation ▁represents ▁annual ▁differences ▁in ▁conditions ▁in ▁the ▁bre eding ▁areas ▁or ▁if ▁it ▁included ▁bi ases ▁such ▁as ▁different ▁proport ions ▁of ▁bre eding ▁pairs ▁travel ing ▁to ▁A ther ton ▁to ▁over - w inter . ▁It ▁is ▁also ▁not ▁known ▁how ▁these ▁proport ions ▁equ ate ▁to ▁more ▁standard ▁metrics ▁of ▁bre eding ▁success ▁such ▁as ▁proport ions ▁of ▁bre eding ▁pairs ▁succeed ing ▁in ▁raising ▁young ▁birds . ▁One ▁multi - f lo od plain ▁survey ▁in ▁Australia ▁found ▁ 6 0 % ▁of ▁all ▁bre eding ▁pairs ▁to ▁have ▁raised ▁at ▁least ▁one ▁ch ick , ▁with ▁ 3 4 % ▁of ▁successful ▁pairs ▁fled