It takes the better part of two hours of searching this strange, alien landscape, before they find signs of the Jabberwock being near; the landscape seems to heal itself quickly, so despite the passage of the enormous beast, it leaves behind little evidence, and it takes most of that time to even recognize the evidence that is to be found. Eventually, though, they begin to pick up its trail, and begin pursuing it properly. Since it was moving away from them, they'd either have to try to get ahead of it, to set an ambush, or try to lure it into one, which might give them further time to prepare shorter term effects.