The fast life of a dwarfed giant

In the first half of the 1960s, a rich paleontological site was discovered at Spinagallo caves (Eastern Sicily, Southern Italy). A very abundant fossil population (at least 104 specimens) of the dwarf elephant Elephas falconeri, the smallest elephant that ever lived, was recovered. We computed the survivorship curve for this fossil population in order to investigate both the great juvenile abundance and high calf mortality which it shows. Through the analysis of E. falconeri survivorship, of some reconstructed life-history traits, and of its ecology, and taking into account the Island rule (Foster, 1964), we concluded that E. falconeri moved somewhat toward the 'fast' extreme of the slow-fast continuum in life-history traits in regards to its mainland ancestor E. antiquus, that is, it was somehow r-selected. In keeping with our findings, we propose a new explanation for the common occurrence of dwarfism in large mammals living on islands. We suggest the interplay of competition, resource allocation shift and feeding niche width could successfully explain this pattern.