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
Invasive species which were brought to control insects upon the introduced grain crops, have displaced native birds as have rainbow lorikeets and cockatoos (both from Australia) which fly free around areas west of Auckland City such as the Waitakere Ranges. In much of New Zealand, the Australian black swan has effectively eliminated the existence of the previously introduced mute swan. Two notable varieties of spiders have also been introduced: the white tail spider and the redback spider. Both may have arrived inside shipments of fruit. Until then, the only spider (and the only venomous animal) dangerous to humans was the native katipo,