FORAGING BEHAVIOR OF PLAIN-MANTLED TIT-SPINETAIL (LEPTASTHENURA AEGITHALOIDES) IN SEMIARID MATORRAL, NORTH-CENTRAL CHILE

We studied foraging behavior of Plain-mantled Tit-spinetail (Leptasthenura aegithaloides) in matorral (scrubland) habitat of north-central Chile. Our findings show this species is an insectivorous, perch-gleaning specialist. It frequents most dominant shrubs and searches for prey and food primarily in foliage, flower clusters, small twigs and lichen masses. Preferred shrubs include Porlieria and Bacchatis. They forage from near the ground to shrubs exceeding two meters. in height. They are most often encountered in pairs or in small, presumably family groups, of three to five birds. Mean densities in matorral habitats (1.49-1.69 birds per hectare) are higher than reported elsewhere. Tit-spinetails readily form mixed-species assemblages in matorral scrub, particularly in the Austral winter. Its foraging strategy and behavior are similar to North American Bushtit (Psaltnparus minimus) and Long-tailed Tit (Aegithalos caudatus), both of the family Aegithalidae, suggesting convergent ecological strategies in structurally similar environments. Accepted 18 April 2011.