Dieta e manejo alimentar de Penelope jacucaca (Galliformes: Cracidae) de vida livre e seu potencial como dispersor de sementes da Caatinga

Abstract

Cracids are medium and large birds capable of dispersing a wide variety of seeds that cannot be consumed by smaller birds. Penelope jacucaca is an endemic of Caatinga and endangered species (VU). This work aims to describe the diet composition of P. jacucaca in the dry and rainy seasons; to evaluate whether the use of maize as a food reinforcement (feeder) for P. jacucaca interferes either positively or negatively in its ecological functions as seed disperser in Caatinga; and ascertain its potential as a seed disperser from Caatinga. We seek to evaluate whether the use of corn as food reinforcement (feeder) for P. jacucaca interferes either positively or negatively in its ecological functions as seed disperser in Caatinga. Two areas in Quixadá (CE) were chosen for this research. Trails were established in each area and walked in both seasons. At the Hotel Pedra dos Ventos, a corn feeder was provided every day of the research campaigns in both dry and rainy seasons. The diet was analyzed based on feces samples. The samples were marked, numbered, georeferenced, washed, dried, and separated into categories of feeding items. We analyzed the variation in the composition and frequency of feeding items in both dry and rainy season, as well as calculated the niche width for the species and compared the effects of seasonality. We collected 61 feces samples, of which 32 (52.5%) contained at least one seed. In total, 774 seeds were found distributed in 12 species/morphotypes. There was a seasonal variation in the composition and frequency of feeding items: in the dry season only 7 samples contained seeds, and we perceived the consumption of molluscs, invertebrates, and vertebrates, as well as plant debris; whereas in the rainy season 25 samples contained seeds and the diet was composed almost exclusively of plant-based items. Corn was perceived exclusively in 16 of the 25 samples found at the Hotel in the dry season, not being perceived at all during the rainy season even with the constant presence of the feeder. The use of a corn feeder as a food supplement during the dry season was positive for the population of Penelope jacucaca at the Hotel Pedra dos Ventos, helping to maintain a greater number of individuals of that population in the area. We did not identify negative effects on seed dispersal during periods when plant resources, especially fruits, were available in abundance. Furthermore, niche width analysis indicated a tendency towards a generalist behavior in the dry season (LPNW = 0.597). Isolating the seed’s data, there was a tendency towards specialization in the rainy season (LPNW = 0.343), where P. jacucaca preferentially consumed some fruits, according to availability. P. jacucaca has a diet composed basically of fruits, when they are abundant in the rainy season, fulfilling its ecological function as an important seed disperser in Caatinga.