Supercolonies, nests, and societies: distinguishing the forests from the trees

Moffett (this issue) defines supercolony as ‘‘a colony with a capacity to grow without bounds.’’ By this and many past definitions, even a founding group of Argentine ant queens is a ‘‘supercolony,’’ but the word is used in practice only when colonies reach an exceptional size. Three commentators did not like the suggestion to employ supercolony after such colonies reach populations of over a million individuals— admittedly an arbitrary number. Still, no particular size has previously been specified, and colony growth is continuous and seems to follow the same rules at every stage: as I emphasize (Moffett, this issue), to use Pedersen’s phrase (this issue), there is ‘‘no tipping point’’ at which a colony ‘‘becomes’’ a supercolony. Thus, supercolony has always been applied arbitrarily. Some experts describe Argentina’s smaller Argentine ant colonies as supercolonies,forinstance,whereasothers pointedlydo not.I suggested a minimum size of about a million ants (‘‘well over a million’’ is a better wording: see the glossary in Moffett, this issue) because that is about the largest population for colonies in ant species without supercolonies, whether monodomous or polydomous—one interpretation of ‘‘exceptionally large.’’ The intent is to provide a guideline for usage, not to require a precise count of ants. ‘‘Supercolony’’ can of course continue to be used, not just arbitrarily but inconsistently, for any very large colony, albeit only if it shows the defining character, which, again, is a colony’s boundless capacity for growth under suitable conditions. First and foremost, a supercolony is a colony or equivalently a society: A social group able to distinguish and reject conspecific outsiders (Moffett, this issue). Lester and Gordon (both in this issue) instead characterize ant colonies (societies) in terms of ‘‘functionality.’’ This, Gordon defines as a sharing of resources and reproduction(i.e.,bynestclumpslocally:Helleretal.2008).Even