They need snakes (that bike with poison effects)
Large animals (that can trample you).
Predators (Lions, etc that wouldn't mind attacking you)
While I think this game would be interesting without the above (never played pokemon snap), it would be FUN it there were a sense of danger.
Things that will make it stand out:
Stealth mechanics to sneak up on animals
Cover mechanics to hide from predators
Continuous night and day with weather events
Quirky (voice acted) remarks
"Natural Motion"
If it had all these things (or just most), I would be SOLD!