INVESTIGADORES
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artículos
Título:
Latitude does not influence cavity entrance orientation of South American avian excavators
Autor/es:
VALERIA OJEDA; ALEJANDRO SCHAAF; TOMÁS A. ALTAMIRANO; BIANCA BONAPARTE; LAURA BRAGAGNOLO; LAURA CHAZARRETA; KRISTINA COCKLE; RAPHAEL DIAS; FACUNDO DI SALLO; TOMÁS IBARRA; SILVINA IPPI; ADRIÁN JAUREGUI; JAIME E. JIMÉNEZ; MARTJAN LAMMERTINK; FERNANDO LÓPEZ; GABRIELA NÚÑEZ MONTELLANO; MARTÍN DE LA PEÑA; LUIS RIVERA; CONSTANZA VIVANCO; MIGUEL SANTILLÁN; GERARDO E. SOTO; PABLO M. VERGARA; AMY WYNIA; NATALIA POLITI
Revista:
Ornithology
Editorial:
Oxford Academic
Referencias:
Lugar: London; Año: 2021 vol. 138
Resumen:
In the Northern Hemisphere, several avian cavity excavators (e.g., woodpeckers) orient their cavities increasingly toward the equator as latitude increases (i.e. farther north), and it is proposed that they do so to take advantage of incident solar radiation at their nests. If latitude is a key driver of cavity orientations globally, this pattern should extend to the Southern Hemisphere. Here, we test the prediction that cavities are oriented increasingly northward at higher (i.e. colder) latitudes in the Southern Hemisphere and describe the preferred entrance direction(s) of 1,501 cavities excavated by 25 avian species (n = 22 Picidae, 2 Trogonidae, 1 Furnariidae) across 12 terrestrial ecoregions (15°S to 55°S) in South America. We used Bayesian projected normal mixed-effects models for circular data to examine the influenceof latitude, and potential confounding factors, on cavity orientation. Also, a probability model-selection procedure was used to simultaneously examine multiple orientation hypotheses in each ecoregion to explore underlying cavityorientation patterns. Contrary to predictions, and patterns from the Northern Hemisphere, birds did not orient their cavities more toward the equator with increasing latitude, suggesting that latitude may not be an important underlying selective force shaping excavation behavior in South America. Moreover, unimodal cavity-entrance orientations were not frequent among the ecoregions analyzed (only in 4 ecoregions), whereas bimodal (in 5 ecoregions) or uniform (in 3 ecoregions) orientations were also present, although many of these patterns were not very clear. Our results highlight the need to include data from under-studied biotas and regions to improve inferences at macroecological scales. Furthermore, we suggest a re-analysis of Northern Hemisphere cavity orientation patterns using a multi-model approach, and a more comprehensive assessment of the role of environmental factors as drivers of cavity  orientation at different spatial scales in both hemispheres