Yaama John,

In short some folk have a crocodile as their totem. With this is the obligation to protect and a restriction on eating same. (while the rest of the mob can)
Otherwise some crocs are associated with stories/cautionary tales to a particular place and in particular large males are sacrosanct as some believe they harbour the spirits of the dead.

capiche?

In Arnhem Land species are divided into two; Duuwha and Yirritja. This is in short a pre Linnean classification of species as each has defined relationships to those in immediate ecosystemic and cultural relationships, thus denoting not only them but an obligation to protect and conserve the entire ecosystem. A precise system that predates euro musings by several millenia (Aldo Leuoplod et al are certainly not the originators of practical conservation)

Similar systems and obligations operate all over this way.

Yiyaalu

K