Ecogeographical Variation in Skull Shape of South-American Canids: Abiotic or Biotic Processes?

摘要: Species morphological changes can be mutually influenced by environmental or biotic factors, such as competition. South American canids represent a quite recent radiation of taxa that evolved forms very disparate in phenotype, ecology and behaviour. Today, the central part America there is one dominant large species (the maned wolf, Chrysocyon brachyurus) directly influence sympatric smaller via interspecific killing. Further south, three similar sized foxes (Lycalopex spp.) share same habitats. Such unique combination geographic distribution makes dogs an ideal group to test for simultaneous impact climate competition on phenotypic variation. Using geometric morphometrics, we quantified skull size shape 431 specimens belonging eight extant canid species: Atelocynus microtis, Cerdocyon thous, Ch. brachyurus, Lycalopex culpaeus, L. griseus, gymnocercus, vetulus Speothos venaticus. are significantly different both shape. The hypercarnivorous bush dog mostly distinct from all other while degree overlap shape—but not size—occurs between genus Lycalopex. Both impacts We identified climatic adaptations main driving force diversification canids. Competition has lower their morphology although it might have played role past, when community was richer morphotypes.