Efecto de la fragmentación del bosque sobre las fuentes potenciales de alimento para aves en Córdoba

Abstract

Forest loss and fragmentation can affect food resources consumed by different avian groups. A better knowledge on the relationships between different proxies of forest fragmentation and food resources consumed by a wide diversity of avian species can help us understand the indirect effects of forest fragmentation on bird populations. We worked in forest patches in the Chaco forest of Córdoba, Argentina. We estimated the relative abundance of arthropods, flowers, fruits and seeds (food items for different bird feeding guilds) in a fragmentation gradient during summer and winter. During the summer season, Celtis ehrenbergiana and Lycium cestroides offered >90% of the total fruits and flowers estimated abundance, respectively. Solanum argentinum offered most of the estimated fruit abundance during the winter season. Arthropod abundance (in winter) and seed abundance (in both seasons) increased with patch size reduction; moreover, we observed higher abundance in the forest edge than in the interior. We only found a negative effect of forest fragmentation on fruit and flower abundance for individual species. Regarding to seasonality, relative abundance of arthropods was significantly reduced in winter, whereas relative abundance of fruit and seeds was similar between seasons. Relative abundance of flowers was drastically reduced in winter; therefore, we could not perform statistical comparisons between seasons. This work offers a first approach to the food abundance resources for birds and their response to fragmentation in an area of the Chaco forests.