Animals that are known/said to eat fiddler crabs include ibis, terns, possibly the giant mudskipper and the mangrove kingfisher. At high tide, fish and rays will also eat any fiddler crab they can find. Mangrove kingfishers certainly eat crabs and recently I spotted one that appeared to be hunting fiddler crabs. Being short of time, I could not sit and watch, however you can see several sets of fiddler crab eyes watching the kingfisher – look along the ridge line behind the kingfisher. Mangrove kingfishers (Todiramphus chloris) are are much larger than other kingfishers and make a loud kak kak sound.
|Mangrove kingfisher hunting crabs on the mudflats of Tingalpa Creek|
Of all the birds, the Great -billed Heron (Ardea sumartrana) would seem to be the ultimate fiddler crab catcher. It is a massive and powerful bird which stands around 1.15 m tall and is only slightly smaller than a Jabiru. They usually hunt the mangrove waterways near river mouths.
|Great-billed heron hunting along waters edge|
|Fiddler crabs behind a great-billed heron.|