Territorial marking in the desert ant Cataglyphis niger: Does it pay to play bourgeois?

Here we report on territorial behavior in the desert ant Cataglyphis niger. We show that, similar to the "bourgeois strategy," contests are settled quickly through nonescalating fights, with the owner of the territory usually being placed in the winning role. The chemical cue that advertises ownership is shown to come from pheromones secreted by the cloacal gland. Differences in size did not influence the outcome of the experimental contests, but resource value did. The observed results fit in well with the biology of Cataglyphis, where, due to the harsh semidesert environment, fighting costs (C) are expected to be high relative to the value of the contested resources (V). A situation where V < C is exactly that in which bourgeois behavior is expected to be seen.