HABITAT USE OF ROAD BORDERS BY BIRDS IN THE FLOODING PAMPA AND ITS RELATION WITH ENVIRONMENTAL VARIABLES AND RESOURCE AVAILABILITY

MERMOZ, M. E.; LORENZO, GASTÓN; DEPALMA, DANIELA M; DEL CASTILLO, MARÍA; PICCA, PABLO

Puerto Iguazú

Congreso; Ornithological Congress of the Americas; 2017

AFO-Aves Argentinas-Sociedad Brasileira de Ornitología

Given the increasing habitat fragmentation within the Pampean Region, road borders could complement resource availability for birds, although its use depends on the characteristics of these patches. Our objective was to determine which characteristics of borders influence its use. During breeding season of 2016 we randomly selected 87 road border fragments of the Flooding Pampa. In each fragment we performed bird and food (invertebrates and/or fruits) surveys and estimated vegetation cover at local scale and within a 400 m radius. We recorded 94 species using these borders. We analyzed the relation between the abundance of the 21 most frequent species and measured variables with Generalized Lineal Models. The most influencing variables were grassland, wetland and native woodland (mainly Celtis ehrenbergiana) extension within borders. Birds could use these environments with different aims, nesting among them. In general, insectivores which nest in wetlands correlated with wetland (for example Pseudocolopterix flavirostris) and those nesting in trees (granivores and/or insectivores, for example Phacellodomus striaticollis) with native woodland. Almost none of the species correlated with its main food resource, probably because birds use borders as nesting places and obtain food in and outside them. We highlight the importance of vegetation structure of borders for birds. Conserving the diversity of environments present in borders would thus favor the abundance and richness of the bird assemblage that uses them.