Parental feeding behavior in Southern House Wren (Troglodytes musculus): Effects of brood size and nestling age on the delivery of potential pest prey within an agroecological orchard

Insectivorous birds can play an important role in regulating arthropod populations in agroecosystems, including species considered agricultural pests. The Southern House Wren ( Troglodytes musculus ) is a common, cavity-nesting insectivore that frequently uses nest boxes and may contribute to natural pest control. We studied parental feeding behavior in Southern House Wrens breeding in an agroecological cherry orchard in Buenos Aires Province, Argentina, to assess feeding rates and prey composition during the nestling period. Over two breeding seasons, 276 h of video recordings were analyzed from nest boxes installed throughout the orchard. Additionally, fecal remains in nest boxes were collected from and examined under a stereoscopic magnifying glass to identify prey items that could not be detected through the camera recordings. Parents delivered an average of 15.58 feeding visits per hour, and 747 prey items were identified. The most frequently delivered prey included Lepidoptera larvae (31.2%), Araneae (26.5%), Orthoptera (17.0%), Isopoda (8.3%), and adult Lepidoptera (8.2%). Feeding rates and prey size increased with brood size and nestling age. Some prey taxa (e.g., Lepidoptera, Orthoptera, Isopoda, and Hemiptera identified in fecal samples) are known to include important pest species in regional crops. Our results suggest that the Southern House Wrens may contribute to pest suppression in agroecological settings during the breeding season, and that promoting larger broods through appropriate nest box placement could enhance this service. This study highlights the potential of native insectivorous birds as allies in sustainable agriculture and provides novel behavioral data for a widespread species in South America.