The fruits drop to the rainforest floor, and this is where the cassowary enters the story. Southern Cassowaries (Casuarius casuarius johnsonii) eat fruits, like that of the Fan Palm, that are too large to be eaten by other species. By dispersing seeds they’re essential in the longevity of Fan Palm populations.
The wet season is a time of food scarcity for cassowaries because not many plants fruit at that time. Fan Palms however do fruit throughout the wet season so they’re a particularly important food source for cassowaries.
Australian Fan Palms have low seedling numbers, typically only 50 to 500 per hectare.4 Even in good conditions it’s known to be a slow-growing plant.
Threats to Fan Palms
The biggest threat to remnant Fan Palm forests is large-scale clearing.
Large areas of north Queensland’s coastal rainforest have been cleared, and wetlands drained, to make way for agricultural and housing developments.
This also means that edge effects in fragmented remnants is a serious management challenge. Feral pigs also pose a problem: they plough up the ground underneath Fan Palms, disturbing the forest floor and damaging seedlings.
Finally, weed invasion threatens to outcompete native plants such as the Fan Palm, in particular weed species such as Pond Apple (Annona glabra) and Harungana (Harungana madagascariensis).