Some Responses of a Free Living Community of Rodents to the Odors of Predators

Abstract

When the forces of Natural Selection created mammalian predators which feed upon mammalian prey, they incidentally created a paradox, at least in the nostrils of a human observer. Mammals generally have a very good olfactory sense; small rodents particularly so (Stoddart 1974). Paradoxically their predators are characterized by their ability to produce copious quantities of extraordinarily pungent secretions, as anyone who has ever kept ferrets or encountered a skunk that has been run over on the road will aver. Are rodent prey animals unable to smell their predators? The long term stability and persistence of predator-prey interactions indicates that small mammals, even with their excellent noses, still get caught and eaten in sufficient numbers to support substantial predator populations. Clearly they do not always react to the odor of their predators, but do they ever? In answering this question it would be helpful to know whether there is any odor quality fundamentally associated with predators — a sort of olfactory Leitmotiv harking back to some ancient evolutionary contact between predator and prey. As Marlitt says in her study Das Eulenhaus: “Nichts in der Welt macht Vergangenes so lebendig wie der Geruch”. (‘Nothing on earth brings the past so alive as odor’).