An urgent call-to-action to protect the nonhuman primates and Indigenous Peoples of the Brazilian Amazon.

Primates are facing an impending extinction crisis. Here, we examine the set of conservation challenges faced by the 100 primate species that inhabit the Brazilian Amazon, the largest remaining area of primary tropical rainforest in the world. The vast majority (86%) of Brazil's Amazonian primate species have declining populations. Primate population decline in Amazonia has been driven principally by deforestation related to the production of forest-risk commodities including soy and cattle ranching, the illegal logging and setting of fires, dam building, road and rail construction, hunting, mining, and the confiscation and conversion of Indigenous Peoples' traditional lands. In a spatial analysis of the Brazilian Amazon, we found that 75% of Indigenous Peoples' lands (IPLs) remained forested compared with 64% of Conservation Units (CUs) and 56% of other lands (OLs). In addition, primate species richness was significantly higher on IPLs than on CUs and OLs. Thus, safeguarding Indigenous Peoples' land rights, systems of knowledge, and human rights is one of the most effective ways to protect Amazonian primates and the conservation value of the ecosystems they inhabit. Intense public and political pressure is required and a global call-to-action is needed to encourage all Amazonian countries, especially Brazil, as well as citizens of consumer nations, to actively commit to changing business as usual, living more sustainably, and doing all they can to protect the Amazon. We end with a set of actions one can take to promote primate conservation in the Brazilian Amazon.

Influence of landscape structure on previous exposure to Leptospira spp. and Brucella abortus in free-living neotropical primates from southern Brazil.

The environments in which neotropical primates live have been undergoing an intense fragmentation process, constituting a major threat to the species' survival and causing resource scarcity, social isolation, and difficulty in dispersal, leaving populations increasingly vulnerable. Moreover, the proximity of wild environments to anthropized landscapes can change the dynamics of pathogens and the parasite-host-environment relationship, creating conditions that favor exposure to different pathogens. To investigate the previous exposure of free-living primates in Rio Grande do Sul State (RS), southern Brazil, to the bacterial agents Leptospira spp. and Brucella abortus, we investigated agglutinating antibodies against 23 serovars of Leptospira spp. using the microscopic agglutination test and B. abortus acidified antigen test in primate serum samples; 101 samples from primates captured between 2002 and 2016 in different forest fragments were used: 63 Alouatta caraya, 36 Alouatta guariba clamitans, and 02 Sapajus nigritus cucullatus. In addition, the forest remnants where the primates were sampled were characterized in a multiscale approach in radii ranging from 200 to 1400 m to investigate the potential relationship of previous exposure to the agent with the elements that make up the landscape structure. The serological investigation indicated the presence of antibodies for at least one of the 23 serovars of Leptospira spp. in 36.6% (37/101) of the samples analyzed, with titers ranging from 100 to 1600. The most observed serovars were Panama (17.8%), Ballum (5.9%), Butembo (5.9%), Canicola (5.9%), Hardjo (4.9%), and Tarassovi (3.9%); no samples were seropositive for Brucella abortus. Decreased forest cover and edge density were the landscape factors that had a significant relationship with Leptospira spp. exposure, indicating that habitat fragmentation may influence contact with the pathogen. The data generated in this study demonstrate the importance of understanding how changes in landscape structure affect exposure to pathogenic microorganisms of zoonotic relevance. Hence, improving epidemiological research and understanding primates' ecological role in these settings can help improve environmental surveillance and conservation strategies for primate populations in different landscapes.

The Influence of Landscape Structure on the Occurrence of Neospora caninum, Toxoplasma gondii, and Sarcocystis spp. in Free-Living Neotropical Primates.

PURPOSE: Habitat fragmentation is the main threat to primate survival in the world. Additionally, changes in the environments in which they live can also contribute to exposure to pathogens. To investigate some pathogens that free-living primates may be exposed to in Rio Grande do Sul State (RS; southern Brazil) and characterize the forest remnants in which they live, we investigated anti-Neospora caninum, Toxoplasma gondii, and Sarcocystis spp. antibodies in the serum of the animals. METHODS: We analyzed 105 serum samples from 63 black howler monkeys (Alouatta caraya), 39 southern brown howler monkeys (Alouatta guariba clamitans), and 03 capuchin monkeys (Sapajus nigritus cucullatus), which were captured in forest fragments of RS. Indirect fluorescence antibody test (IFAT) and indirect hemagglutination assay (IHA) were used to detect antibodies to the agents. We then characterized the landscapes in a multiscale approach in radii from 200 to 1400 m to investigate the relationship of the presence of the agents with landscape elements. RESULTS: In the IFAT-IgG, 13.3% (14/105) of the samples were seropositive for N. caninum, 4.8% (5/105) for T. gondii, and 5.7% (6/105) for Sarcocystis spp. In the IHA-IgM/IgG, 24.8% (26/105) were seropositive for T. gondii. The metrics that best explained exposure to agents were edge and patch density, forest cover, urban cover, and average Euclidean distance to the nearest patch. CONCLUSIONS: This study indicated that the primates were exposed to the agents studied, demonstrating that some landscape features are associated with exposures to the investigated pathogens.

Necropsies disclose a low helminth parasite diversity in periurban howler monkeys.

Primate-parasite interactions are often investigated via coprological studies given ethical and conservation restrictions of collecting primate hosts. Yet, these studies are inadequate to recover adult helminths for taxonomic identification and to accurately assess their prevalence, intensity, abundance, and site of infection. Fresh carcasses found in anthropogenic landscapes come as informative and reliable alternatives. In this study, we identified the helminths of brown howler monkeys (Alouatta guariba clamitans) and their sites of infection, and measured their prevalence, intensity, and abundance of infection. We necropsied 18 adult males, 11 adult females, and 7 juvenile males that died in conflicts with the anthropogenic environment (domestic dog attacks, n = 11; electrocutions and road-kills, n = 10 each; unknown, n = 5) in periurban landscapes of southern Brazil between 2013 and 2019. We found three nematodes (Trypanoxyuris minutus, Dipetalonema gracile, and Parabronema bonnei) and one cestode (Bertiella cf. studeri), a diversity estimated to account for a sampling completeness of 99%. Prevalence ranged from 3% for P. bonnei to 100% for T. minutus. Mean abundance ranged from 2 (D. gracile and B. cf. studeri) to 55,116 (T. minutus) and mean intensity of infection ranged from 4 (B. cf. studeri) to 55,116 (T. minutus). Trypanoxyuris minutus sex ratio was strongly male-biased. The intensity of infection with T. minutus was higher in juvenile males and adult females than in adult males. The low parasite diversity and the helminths' mode of transmission are compatible with howlers' arboreality and folivorous-frugivorous diet. The howlers were not infected with soil-transmitted helminth parasites of humans and domestic animals on the ground and probably did not eat invertebrates to complement the diet. Given the lack of evidence of howler health problems, we suggest that the causes of death of the necropsied howlers are the major threats to the long-term conservation of the species at the study periurban landscapes.