Importance of Algarrobo trees (Prosopis flexuosa) for territory establishment of three seed-eating passerine species in the central Monte desert

M. CECILIA SAGARIO; VICTOR R. CUETO

ARDEA

NEDERLANDSE ORNITHOLOGISCHE UNIE

Año: 2021

0373-2266

The study of habitat selection by birds is crucial to understand their requirements and promote their conservation. In the central Monte desert, Argentina, feeding site selection by seed-eating birds and their greater abundance in association with the presence of trees (particularly Algarrobos Prosopis flexuosa) are notorious patterns during the breeding season, but these associations disappear during autumn and winter. In order to understand habitat selection by these bird species we assessed the importance of Algarrobos during the defence and establishment of breeding territories in the open Algarrobo woodland of the central Monte for the three most common resident seed-eating birds (Ringed Warbling- Finch Microspingus torquatus, Many-coloured Chaco-Finch Saltatricula multicolor, and Rufous-collared Sparrow Zonotrichia capensis). Despite some ecological differences between the species (e.g., nest site selection, feeding behaviour) all of them selected Algarrobo trees (Prosopis flexuosa) as song posts, and also the height, density and spatial configuration of these trees were features associated with the selection of territories. The patterns of selection we found at previously unexplored spatial scales (territory and within-territory) and behaviours (territorial defence) provided plausible explanations to seasonal shifts in the space use reported for central Monte seed-eating birds, and highlight the close link between central Monte desert avifauna and Algarrobo trees. As in many arid regions, tall scattered trees are keystone features of the central Monte, and management plans should be implemented in order to prevent the current degradation and loss of these arid woodlands.