INVESTIGADORES
GARCIA BORBOROGLU Jorge Pablo
artículos
Título:
Comparative habitat use by syntopic Kelp Gulls (Larus dominicanus) and Olrogs Gulls (L. atlanticus) in coastal Patagonia
Autor/es:
PABLO GARCIA BORBOROGLU; PABLO YORIO
Revista:
EMU Austral Ornithology
Editorial:
Royal Australasian Ornithologists Union
Referencias:
Lugar: Sydney, Australia; Año: 2007 vol. 107 p. 321 - 326
Resumen:
We studied comparative microhabitat use by breeding Kelp Gull (Larus dominicanus) and the threatened
Olrogs Gull (Larus atlanticus) at six colonies through the distributional range of Olrogs Gull in coastal Patagonia,
Argentina. The ranges of values for most of the 13 microhabitat variables measured (related to vegetation, soil and
topography) were broader for the Kelp Gull than Olrogs Gull, with those of that latter within the range of Kelp Gull,
indicating potential spatial conflict between the two species. There was particular overlap in nest-site characteristics, but
differences were observed between the two species. Multivariate analyses showed that the most important differences in
habitat between the two species related to vegetation cover and distance to the high-tide line. Compared with Kelp Gulls,
Olrogs Gulls placed their nests in sites with lower proportion of vegetation cover, lower percentages of siltclay in the
substrate, and closer to the high-tide line. For both species the patterns of nest-site selection did not vary among colonies,
although the extent of differences between the two species varied with availability of habitat at each colony. Although
Olrogs Gulls started laying 1214 days earlier than the larger Kelp Gulls, the latter occupied breeding colonies earlier and
may, therefore, interfere with settlement of Olrogs Gulls. Considering the increase in the numbers, colony area and nesting
density of Kelp Gulls currently observed in coastal Patagonia, there is an urgent need to implement monitoring programs
for both species and conduct studies to better predict the results of their interactions.