* Humans: Sadly, humans are a major threat to lions and tigers due to poaching, habitat loss, and conflict.
* Other large predators: In rare cases, other large predators like leopards, hyenas, or crocodiles might prey on young, injured, or weak lions or tigers. But this is very uncommon.
* Disease: Diseases like rabies, distemper, and feline immunodeficiency virus (FIV) can also be fatal to lions and tigers.
It's important to remember that lions and tigers are primarily threatened by human activity, not other animals.