Evolutionary perspective
The fast life of a dwarfed giant
PASQUALE RAIA1,*, CARMELA BARBERA2 and MAURIZIO CONTE2
1Universita`
degli Studi del Molise, Dip. STAT, Via Mazzini 8, 86170 Isernia; 2Universita` Federico II
di Napoli, Dip. Scienza della Terra, L.go San Marcellino 10, 80138 Napoli, Italy
(*author for correspondence, e-mail: pasquale.raia@libero.it)
Received 26 July 2002; accepted 10 June 2003
Co-ordinating editor: N.Chr. Stenseth
Abstract.
In the .rst 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 .ndings, we propose a new
explanation for the common occurrence of dwar.sm in large mammals living on islands. We
suggest the interplay of competition, resource allocation shift and feeding niche width could successfully
explain this pattern.
Key words: dwar.sm, elephants, island rule, life history, resource allocation
Evolutionary Ecology 17: 293–312, 2003.
_ 2003 Kluwer Academic Publishers. Printed in the Netherlands.