One rainforest tree's seeds can only spread with help from a giant flightless bird

The southern cassowary swallows rainforest fruit whole, including seeds up to 6cm across that almost no other animal in the forest can process. For some tree species, passing through a cassowary's gut changes whether and how fast their seeds germinate at all, so losing the bird can strand a tree with no way left to disperse.

— M. G. Bradford and D. A. Westcott, Consequences of southern cassowary (Casuarius casuarius, L.) gut passage and deposition pattern on the germination of rainforest seeds — Austral Ecology, 2010