The brown rat, in particular, appears especially able to develop local traditions, more so perhaps than other more-closely examined mammals, possibly including the anthropoids.
Steiniger, 1950, p. 368Introduction
Imagine, if you will, an energetic, young graduate student who has established a study site near Para, Brazil, where she spends 3 years observing a geographically isolated population of capuchin monkeys that no other primatologist has looked at. Imagine further that our graduate student soon finds, to her great surprise and pleasure, that all of the members of one troop of capuchins at Para, unlike any previously studied capuchins, regularly hunt and eat small lizards. Many months of demanding field work show that the lizards are the source of more than 20% of the calories and 36% of the protein ingested by troop members.
Discovering a complex, biologically meaningful pattern of behavior that is unique to a particular population of monkeys would be a significant event in the career of any behavioral scientist. Surely, before very long, our imaginary graduate student is going to want to tell her colleagues, and quite possibly members of the media as well, about her discovery. To do so, she is going to have to decide how to refer to the unusual behavior that her field studies have documented.
If our imaginary graduate student were to make the conventional choice, and there is little reason to doubt that she would, she would soon be referring to the lizard hunting she has observed as “cultural”, as a “tradition” of the capuchins at Para.