When multiple victim species (eg prey, host) are attacked by one or more shared enemy
species (eg predator, pathogen), the potential exists for apparent competition between victim
populations. We review ideas on apparent com petition (also called" competition for enemy-
free space") and sketch illustrative examples. One puzzling aspect of this indirect interaction
is the repeated rediscovery of the essential ideas. Apparent competition arises between
focal and alternative prey populations because, in the long term, enemy abundance …