▁the ▁found ing ▁f athers ▁of ▁the ▁field ▁of ▁eth ology , ▁the ▁study ▁of ▁animal ▁behavior . ▁He ▁is ▁best ▁known ▁for ▁his ▁discovery ▁of ▁the ▁principle ▁of ▁attachment , ▁or ▁im print ing , ▁through ▁which ▁in ▁some ▁species ▁a ▁bond ▁is ▁formed ▁between ▁a ▁new ▁born ▁animal ▁and ▁its ▁care g iver . ▁This ▁principle ▁had ▁been ▁discovered ▁by ▁Douglas ▁Sp ald ing ▁in ▁the ▁ 1 9 th ▁century , ▁and ▁Lor enz ' s ▁ment or ▁O sk ar ▁Hein ro th ▁had ▁also ▁worked ▁on ▁the ▁topic , ▁but ▁Lor enz ' s ▁description ▁of ▁Pr äg ung , ▁im print ing , ▁in ▁n id if ug ous ▁birds ▁such ▁as ▁gre yl ag ▁ge ese ▁in ▁his ▁ 1 9 3 5 ▁book ▁Der ▁K ump an ▁in ▁der ▁Um welt ▁des ▁Vog els ▁(" The ▁Comp an ion ▁in ▁the ▁Environment ▁of ▁Bird s ") ▁became ▁the ▁found ational ▁description ▁of ▁the ▁phenomen on . ▁ ▁Here , ▁Lor enz ▁used ▁Jakob ▁von ▁U ex k üll ' s ▁concept ▁of ▁Um welt ▁to ▁understand ▁how ▁the ▁limited ▁per ception ▁of ▁animals ▁filtered ▁out ▁certain ▁phen omena ▁with ▁which ▁they ▁interact ed ▁instinct ively . ▁For ▁example , ▁a ▁young ▁go ose ▁instinct ively ▁b onds ▁with ▁the ▁first ▁moving ▁stim ulus ▁it ▁perce ives , ▁whether ▁it ▁be ▁its ▁mother , ▁or ▁a ▁person . ▁Lor enz ▁showed ▁that ▁this ▁behavior ▁of ▁im print ing ▁is ▁what ▁allows ▁the ▁go ose ▁to ▁learn