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Body size increase in insular rodent populations: a role for predators?
Author(s) -
Michaux Johan R.,
De Bellocq Joëlle Goüy,
Sarà Maurizio,
Morand Serge
Publication year - 2002
Publication title -
global ecology and biogeography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.164
H-Index - 152
eISSN - 1466-8238
pISSN - 1466-822X
DOI - 10.1046/j.1466-822x.2002.00301.x
Subject(s) - biology , predation , apodemus , ecology , predator , rodent , mediterranean islands , mediterranean climate , ecomorphology , mediterranean sea , zoology , habitat
Insular mammalian populations living in areas of small size are often characterized by a drastic change in body mass compared to related continental populations or species. Generally, small mammals (less than 100 g) evolve into giant forms while large mammals (up to 100 g) evolve into dwarf forms. These changes, coupled with changes in other life, behavioural, physiological or demographic traits are referred to generally as the insular syndrome. We tested in this study the relative contribution of three factors — area of island, numbers of competitor species and number of predator species — to changes in body size of the woodmouse ( Apodemus sylvaticus ) in the Western Mediterranean Sea. Our results, based on a comparative analysis using the phylogenetic independent contrasts method, indicate that the increase in body size is related both to the decrease of island size and to the lower number of predator species. A decrease of competitor species does not seem to have an important effect.