Feline canines: community-wide character displacement among the small cats of Israel

Each of the 3 sympatric, syntopic small cat species of Israel (wildcat Felis silvestris, caracal F. caracal and jungle cat F. chaus) is strongly sexually dimorphic. Thus, if each sex is veiwed as morphologically distinct, as a "morphospecies', there are 6 morphospecies potentially competing with one another. The mean canine diameters of these morphospecies are remarkably evenly spaced on a log-scaled line (the size ratios between adjacent morphospecies in a size ranking are suprisingly equal). Condylobasal lengths show no such pattern. The same 3 species occupy a narrow band from the Nile delta to NW India. It is a tenable hypothesis that intra- and interspecific competition for food has selected for equal canine size ratios and also for a decrease in the sizes of Sind animals relative to Israeli conspecifics. By such a hypothesis, larger teeth are used to kill larger prey, on average. An alternative hypothesis would entail ethological interactions mediated by canine display or use in fighting, both intra- and interspecifically. Such interactions are plausible and could contribute to a pattern of displacement. -from Authors