, ▁foc using ▁on ▁research ing ▁the ▁local ▁Le ach ' s ▁storm ▁pet rel s . ▁Thus , ▁ ▁some ▁hope ▁remained ▁for ▁the ▁present ▁species ' ▁surv ival , ▁or ▁rather , ▁its ▁ext inction ▁could ▁not ▁be ▁definitely ▁confirmed . ▁ ▁From ▁June ▁ 4 ▁to ▁June ▁ 1 0 , ▁ 2 0 0 0 , ▁the ▁Gu ad alu pe ▁storm ▁pet rel ' s ▁bre eding ▁grounds ▁were ▁finally ▁survey ed ▁at ▁the ▁correct ▁time . ▁Had ▁the ▁species ▁surv ived , ▁not ▁only ▁would ▁recently ▁fled ged ▁imm ature ▁birds ▁have ▁been ▁present , ▁but ▁also ▁all ▁signs ▁of ▁a ▁recently ▁ended ▁bre eding ▁season , ▁such ▁as ▁egg sh ells ▁and ▁fresh ly ▁used ▁bur rows ▁retain ing ▁the ▁mus ky ▁sm ell ▁of ▁these ▁birds . ▁In ▁the ▁words ▁of ▁the ▁expedition ' s ▁primary ▁research er , ▁Ex equ iel ▁Ez cur ra ▁of ▁the ▁San ▁Diego ▁Natural ▁History ▁Museum , ▁ ▁We ▁searched ▁thoroughly ▁for ▁the ▁Gu ad alu pe ▁storm ▁pet rel , ▁and ▁failed ▁to ▁find ▁it . ▁Sad ly , ▁we ▁are ▁now ▁more ▁ready ▁to ▁admit ▁that ▁the ▁species ▁is ▁indeed ▁ext inct . ▁Never , ▁since ▁the ▁ 1 9 2 0 s , ▁had ▁so ▁much ▁search ▁effort ▁been ▁devoted ▁to ▁this ▁species . ▁At ▁different ▁times , ▁more ▁than ▁ 1 0 ▁research ers ▁looked ▁for ▁the ▁el us ive ▁creature . ▁It ▁simply ▁was ▁not ▁there . ▁ ▁The ▁official ▁classification ▁by ▁the ▁IU