干旱区生态环境知识资源中心

Nest orientation patterns of Passeriformes in an and area of central-western Argentina. - Nest orientation determines the microenvironment for incubation and chick growth. In this study, patterns of nest orientation in Passeriforms and their influence on hatching success are analyzed in a locality of the central Monte desert, Mendoza province, Argentina. Orientation of the complex closed nests of Furnariidae species was not significantly different from random, and this pattern did not vary through the breeding season. The globular closed nests of Rhinocryptidae and the open-cup nests of Tyrannidae and Emberizidae were preferentially oriented toward the north-northeast. Early nests of Rhinocryptidae were oriented toward the north-northeast, while average orientation for late nests was north-northwest. Mean orientation of the nests of Tyrannidae and Emberizidae were always toward the north-northeast, although was non-significant for late nests in Tyrannidae. The entrances to the closed nests of Furnariidae and Rhinocryptidae were oriented toward a similar direction than nests (i.e., facing towards the periphery of the plant). Hatching success did not differ for nests placed in the preferred orientations compared to those placed in the non-preferred ones, although observations of hatching failure were scarce due to the high rate of predation. The data suggest that the direction of prevailing winds during the nesting season and, to a lesser extent, solar radiation were the main factors conditioning nest orientation in this area.