Bill and plumage evolution in Spartonoica maluroides (Aves: Furnariidae) between coastal and interior marshes in South America.

CARDONI, D. A.; GREENBERG, R.; MALDONADO, J.; ISACCH, J. P.

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2013 p. 1 - 39

0024-4066

Tidal marshes present profound adaptive challenges to terrestrial vertebrates. For example, North American sparrows have relatively longer and thinner bills and darker dorsal plumage in coastal saltmarshes than interior marshes. Bay-capped Wren-Spinetail (Furnariidae; Spartonoica maluroides) show a strong association with South American saltmarshes. We hypothesized that Bay-capped Wren-Spinetail have similar adaptations as North American sparrows to the saltmarsh environment, which would be indicative of the selection force on traits in the coastal saltmarsh ecosystem. We captured individuals of S. maluroides from coastal saltmarshes and interior marshes. Populations were compared based on morphology and molecular markers. We found significant phenotypic differences in bill shape and plumage coloration (melanism) between S. maluroides populations from coastal and inland marshes. The low levels of genetic variation, weak geographic structure, and shallow divergences, based on mitochondrial DNA and microsatellite data, suggest that coastal populations had a recent demographic expansion. Our results are consistent with the pattern of morphological divergence found between North American Emberizids. The convergent evolutionary adaptations between saltmarsh North American Emberizids and South American Furnariids suggests that there are strong selective pressures associated with saltmarsh environments on beak shape morphological adaptations for food acquisition and on plumage coloration for better camouflage for predator avoidance (melanism).