Why are long-beaked echidnas encountered less frequently by researchers compared to their Australian counterparts?

Answer

They inhabit montane forests harder for human observers to survey extensively

The scarcity reported for the New Guinea species may relate to their remote habitat and dense forest cover, as they are specialized inhabitants of montane forests that are inherently harder for human observers to survey extensively.

Why are long-beaked echidnas encountered less frequently by researchers compared to their Australian counterparts?
GeographyfaunamammalAustraliaechidna