Crabs constantly monitor the
area surrounding their burrow and respond by rushing
home when other crabs approach the burrow too closely
(Hemmi & Zeil 2003a). Burrow defence can accidentally
be triggered by other crabs rushing home in response to
a bird dummy. Such contaminating effects will tend to
increase the response distance selectively in those cases
where the dummy approaches from beyond a crab’s
burrow. The Kramer & Bonen fant model does clearly not
apply to the antipredator responses of fiddler crabs.