Habitat determinants of golden‐headed lion tamarin (Leontopithecus chrysomelas) occupancy of cacao agroforests: Gloomy conservation prospects for management intensification

Abstract

Organismal distributions in human‐modified landscapes largely depend on the capacity of any given species to adapt to changes in habitat structure and quality. The golden‐headed lion tamarin (GHLT; Leontopithecus chrysomelas) is an Endangered primate from the Brazilian Atlantic Forest whose remaining populations occupy heterogeneous landscapes consisting primarily of shade cacao (Theobroma cacao) agroforestry, locally known as cabrucas. This cash crop can coexist with high densities of native tree species and holds a significant proportion of the native fauna, but its widely extolled wildlife‐friendly status is increasingly threatened by management intensification. Although this potentially threatens to reduce the distribution of GHLTs, the main determinants of tamarin's occupancy of cabrucas remain unknown, thereby limiting our ability to design and implement appropriate conservation practices. We surveyed 16 cabruca patches in southern Bahia, Brazil, and used occupancy modeling to identify the best predictors of GHLT patch occupancy. Key explanatory variables included vegetation structure, critical resources, landscape context, human disturbance, and predation pressure. We found a negative relationship between GHLT occupancy and the prevalence of jackfruit trees (Artocarpus heterophylus), which is likely associated with the low representation of other key food species for GHLTs. Conversely, cabrucas retaining large‐diameter canopy trees have a higher probability of GHLT occupancy, likely because these trees provide preferred sleeping sites. Thus, key large tree resources (food and shelter) are currently the main drivers of GHLT occupancy within cabruca agroecosystems. Since both factors can be directly affected by crop management practices, intensification of cabrucas may induce significant habitat impacts on GHLT populations over much of their remaining range‐wide distribution.

The role of hunting on Sapajus xanthosternos' landscape of fear in the Atlantic Forest, Brazil

“…Within areas of high perceived predation risk and high evidence of primate hunting, traveling in silence may show a behavioral change strategy used by the capuchins. The same strategy has been observed in goldenheaded lion tamarins (Leontopithecus chrysomelas) living in cabruca forests (Almeida-Rocha et al, 2020). Because cabruca lacks understory (Sambuichi, 2006), capuchins were frequently up in the canopy, exposed to aerial predators, and consequently to an aerial attack (e.g., L. C. .…”

“…As found in other primate species, capuchin monkeys living in contact with humans might be affected by the perception of predation risk due to hunting activity and the presence of domestic animals (Bonnot et al, 2013;Frid & Dill, 2002;Torre et al, 2000;Valeix et al, 2012). Indeed, contact with humans was more likely to occur in the cabruca, as revealed by greater evidence of hunting in that area, and that was the area where capuchins were silent the most (see also Almeida-Rocha et al, 2020). The capuchin monkeys spent only 7% of their time within cabruca despite the high availability of fruit resources (Table S1).…”

“…The harpy eagle (H. harpyja), a key predator of Neotropical primates (Boinski et al, 2003), is considered rare throughout the Atlantic Forest but has been observed more recently in this region (Soares et al, 2008;Suscke et al, 2017). In cabruca, predation risk is presumed to be high due to the frequent signs of hunting by humans and the presence of domestic dogs (Almeida-Rocha et al, 2020;ICMBio, 2011;V. B. Oliveira et al, 2008).…”

Pairing a user‐friendly machine‐learning animal sound detector with passive acoustic surveys for occupancy modeling of an endangered primate

“…Combining PAM and occupancy modeling has substantial potential to advance primatology (Piel et al, 2022), and global primate population declines (Estrada et al, 2017) suggest that monitoring efforts capable of informing conservation are urgently needed. Though the use of occupancy modeling in primatology lags behind other disciplines of wildlife ecology (Piel et al, 2022), it is gaining traction (e.g., Almeida‐Rocha et al, 2020; Keane et al, 2012; Vu et al, 2020). Combined PAM and occupancy studies are more scarce (e.g., Crunchant et al, 2020), though we are not the first to propose the PAM to machine learning to occupancy workflow (Kalan et al, 2015).…”

Effect of landscape attributes on the occurrence of the endangered golden‐headed lion tamarin in southern Bahia, Brazil

“…We performed playbacks between 05:00 and 11:00 a.m., the period in which L. chrysomelas is most active and likely to be awake (Almeida-Rocha et al, 2020;Raboy et al, 2010).…”