NoDictionaries   Text notes for  
... nantem sequeretur, traxisse gregem, ut quemque timentem altitudinem destitueret...

Not introducing a purpose or result clause despite the subjunctive, but meaning "as" in a frequentive clause with the subjunctive. So, "each fearing the deep (water) as it (each elephant left/forsook the shallows." Nouns are accusative in o. o. introduced by "tradunt."