Aggressive Signalling
After the feeding phase male solider crabs begin to respond
and react to other male solider crabs. This aggressive signalling occurs when
two rival males meet, females do not engage in this behaviour (Cameron, 1966).
Both males raise their first walking legs and balances on either the third or
fourth walking legs or the fourth legs alone.
The two males extend their raised legs and chelipeds as far as possible,
in an attempt to make themselves look as large and as possible (Cameron, 1966).
Whilst this is occurring the crabs also vibrate their stretched out walking
legs and raise their chelipeds from a horizontal stretch out position to a more
vertical one, this is also to enhance their intimidation and a demonstration of
their strength (Cameron, 1966). The two crabs never touch and eventually the
loser will back down first.
This threat display in males is found to be triggered by 4
scenarios (Cameron, 1966):
-
When a male walks over the top of another male’s
burrow, which causes the second male to emerge from his burrow and challenge
the other male
-
A physical collision by two male crabs, in a
location close to one of their burrows
-
A male occupant of a burrow will threat display
to another male close to its burrow
-
Digging/intrusion of a burrow occupied by a male
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