Diet of the vulnerable White-browed guan Penelope jacucaca (Galliformes Cracidae) in two contrasting Caatinga fragments in Northeastern Brazil

Abstract

Diet studies of cracids have highlighted the group’s significance as seed dispersers and the impact of their disappearance from natural environments. However, the diet of Penelope jacucaca remains largely unknown, limiting our understanding of its natural history and potential ecosystem services. In this study, we investigated the diet of P. jacucaca in two Caatinga fragments with varying levels of preservation using fecal material analysis. The diet of the species consisted primarily of fruits, flowers, and leaves, comprising a total of 22 food items. The number of seeds found in individual fecal samples exhibited a negative correlation with individual seed masses. The species demonstrated a preference for zoocoric fruits of different sizes from the local vegetation. The diet varied between the sampled areas, suggesting that P. jacucaca exhibits dietary flexibility based on local vegetation. However, it is also possible that fragmentation affects the nutritional value of the species’ diet. Due to its large body size, the White-browed guan can ingest a wide variety of fruits, including larger ones, incorporating seeds that are rarely explored by other birds. We propose that plant species with “large” seeds (> 15 mm), such as Ziziphus joazeiro, Brosimum gaudichaudii, and Ximenia americana, would be mainly negatively affected by the absence of P. jacucaca in the studied areas. The decline in the population of this important seed disperser in the region is likely to have negative implications for the viability of many zoocoric plants, thereby posing a threat to the vegetation of the studied fragments.