Aspectos da ecologia básica do Guigó-da-caatinga (Callicebus Barbarabrownae Hershkovitz, 1990) em fragmentos de Caatinga, Nordeste do Brasil

Abstract

The blond titi monkey (C. barbarabrownae), classified as Critically Endangered (CR) by the International Union for Conservation of Nature (IUCN), is the only primate endemic to the Caatinga biome. Despite its high threat status and endemism, there are still significant knowledge gaps regarding the species. With this in mind, this study was developed to expand knowledge about its biology and ecology. The first chapter addresses acoustic ecology, with the main objective of describing the species’ vocalization patterns and their daily, seasonal, and annual variations, in association with resource availability. Over two years (10 days per month), we collected acoustic data using autonomous recorders in two forest fragments of different sizes. We recorded 242 independent vocalization events in 193 samples, 28 in the smaller fragment (7 ha) and 214 in the larger fragment (70 ha). Of these, 81% were recorded in the morning period, with the highest frequency at 08:00. The month with the lowest number of records was October 2021 and the highest was June 2022. Vocalization frequency showed significant differences between morning and afternoon periods, times of day, months of the year, fragments, and seasons. No significant relationship was found between vocalization frequency and the availability of ripe fruits, suggesting that ripe fruits may influence vocalization frequency. The second chapter investigates the structure and composition of trees in fragments where the species occurs, with the main objective of characterizing the habitat in five fragments and examining its relationship with species density in these locations. Data were collected at five sites in the municipalities of Euclides da Cunha, Jacobina, Jeremoabo, and Lamarão (Bahia State), and Monte Alegre de Sergipe (Sergipe State). We sampled 200 trees in five transects per fragment (point-centered quarter method), selecting individuals with diameter at breast height (DBH) > 10 cm. For each tree, we identified the species and measured DBH, tree height (TH), distance to the previous tree (DPT), and crown cover (CC). Fabaceae was the most abundant family in all areas, except in Jacobina, where Myrtaceae predominated. The areas differed in diversity (H’), ranging from 2.27 to 3.35. Significant differences among areas were also found for TH, DPT, and CC, but not for DBH. This study represents the first approach to identifying habitat factors and their relationship with ecological aspects of C. barbarabrownae, highlighting its response to fruit availability as well as its occurrence in structurally heterogeneous yet compositionally more homogeneous areas.