▁in ▁a ▁mon og am ous ▁system , ▁and ▁such ▁variation ▁in ▁growth ▁rate ▁could ▁lead ▁to ▁higher ▁ch ances ▁of ▁ext inction . ▁The ▁optimal ▁balance ▁in ▁sex ▁ratio ▁is ▁an ▁important ▁component ▁of ▁the ▁re int roduction ▁of ▁the ▁Pers ian ▁fall ow ▁de er . ▁ ▁The ▁re int roduction ▁process ▁also ▁depends ▁on ▁the ▁avail ability ▁of ▁bre eding ▁sources , ▁which ▁are ▁capt ive ▁populations ▁that ▁are ▁permitted ▁to ▁bre ed ▁in ▁a ▁safe ▁environment , ▁and ▁the ▁number ▁of ▁animals ▁that ▁can ▁be ▁period ically ▁removed ▁from ▁these ▁sources ▁for ▁re int roduction . ▁Because ▁poor ▁sex ▁r ati os ▁and ▁low ▁proport ions ▁of ▁bre eding ▁individuals ▁are ▁a ▁major ▁cause ▁of ▁ext inction ▁in ▁very ▁small ▁populations , ▁the ▁size ▁of ▁each ▁group ▁removed ▁should ▁be ▁large ▁enough ▁to ▁maintain ▁a ▁low ▁ext inction ▁probability , ▁but ▁small ▁enough ▁to ▁maintain ▁the ▁core ▁bre eding ▁population . ▁Monte ▁Carlo ▁Les lie ▁matrix ▁growth ▁models ▁were ▁used ▁to ▁determine ▁the ▁maximum ▁sust ain able ▁yield , ▁the ▁greatest ▁number ▁of ▁individuals ▁that ▁can ▁be ▁removed ▁from ▁the ▁bre eding ▁pool ▁to ▁maxim ize ▁the ▁re int rodu ced ▁population ' s ▁size ▁while ▁allowing ▁the ▁bre eding ▁core ▁to ▁recover ▁between ▁each ▁re int roduction ▁event , ▁and ▁the ▁project ed ▁population ▁growth ▁after ▁re int roduction . ▁The ▁removal ▁of ▁ 2 8 % ▁of ▁female ▁de er ▁from ▁the ▁bre eding ▁source ▁in ▁the ▁first ▁year ▁of ▁re int roduction ▁and ▁then ▁the ▁removal