interesting. I thought maybe it was a Wikipedia sort of thing (where websites just take dodgy Wikipedia facts and it creates a self-sustaining circle) - but some looking elsewhere showed KIngdon saying that during the lying-up period calves are vulnerable to pythons, leopards and hyaenas. I am surprised at that, simply because I never associated hyaenas with dense forest.
But here's even some camera-trap footage of a spotted hyaena in old-growth rainforest.