Fiddler crab two weeks. Fiddler crabs such as "Uca mjoebergi" have been shown to bluff about their fighting ability. Upon regrowing a lost claw, a crab will occasionally regrow a weaker claw that nevertheless intimidates crabs with smaller but stronger claws. This is an example of dishonest signalling. The dual functionality of the major claw of fiddler crabs has presented an evolutionary conundrum in that the claw mechanics best suited for fighting do not match up with the mechanics best suited for a waving display. The internal classification of the genus "Uca" is unstable, but it contains around 100 species arranged among
Tapajós hermit little hermit, and the Tapajós hermit was believed to be most closely related to the black-throated hermit. In 1996 it was suggested that the Tapajós hermit was entirely invalid, and actually represented hybrids between the reddish and streak-throated hermits. In 2009 this hypothesis was shown to be incorrect, and the Tapajós hermit was instated as a valid species. Tapajós hermit The Tapajós hermit ("Phaethornis aethopygus") is a species of hummingbird in the family Trochilidae. It is found in the south-eastern Amazon in Brazil, and its common name refers to the Tapajós River, which forms the western border of its distribution.