Guidelines and considerations for capturing and collaring wild primates: a case study with capuchin monkeys (Sapajus nigritus cucullatus).

Many aspects of the ecology, evolution and social behavior of wild-living primates remain un-explored and require further investigation. While long-term field studies are crucial for addressing conservation concerns for many primates' species, acquiring the necessary data is often challenging, often due to difficulties in locating study groups. Radio-telemetry has significantly facilitated the study of primates and other animals living in tropical forests. However, there are important practical challenges in the process of capturing and releasing animals after placement of telemetry collars. In this study, we report guidelines and considerations for capturing and collaring wild capuchin monkeys, Sapajus nigritus cucullatus, in the Atlantic Forest of Argentina. Our ultimate goal is to contribute to making captures safer, preventing harm and stress to animals when using radio-telemetry in monitoring strategies for conservation of this primate species. These methods can be useful for researchers using field capture and radio-telemetry for monitoring groups or populations of wild primates, specifically wild Sapajus.

Fragmented forest affects the southern black-horned capuchin (Sapajus nigritus cucullatus) in the Argentinean Atlantic Forest.

The southern black-horned capuchin, Sapajus nigritus cucullatus, is considered Near Threatened on the IUCN Red List and Vulnerable in Argentina. The species is mainly threatened by habitat loss and fragmentation. The aim of this study was to compare range size, group size, and density in S. n. cucullatus groups between areas of continuous and fragmented habitat in the Atlantic Forest in Argentina. The study was carried out in two areas in northern Misiones province, one continuous and one anthropogenic fragment. Fieldwork was carried out for 5 days each month from November 2019 to March 2020 and from November 2020 to March 2021. SARS-CoV-2 restrictions meant we could not survey in the intervening period. Group counts were made on existing trails and subsequent group follows. We georeferenced encounters and follows to estimate home range sizes. We calculated density based on home range modeling using 100% minimum convex polygons (MCP), and compared these using generalized linear models (GLM). Smaller groups and lower density of S. n. cucullatus were found in continuous forest, with group sizes between 12 and 23 individuals, and density of 0.14 ind/ha, whereas in the fragmented forest, group sizes were between 32 and 36, with density of 0.62 ind/ha (n = 107; zero-inflated negative binomial regression [ZINB], p < 0.05). The higher density in forest fragments may be due to reduced dispersal ability. This work highlights data on species plasticity that could contribute to the development of conservation management strategies for S. n. cucullatus and its habitat.

Human and Non-Human Primate Coexistence in Argentina: Conflicts and Solutions.

There are five different primate species inhabiting widely distinct ecoregions in Argentina. Each of them faces various threats in terms of conservation and conflicts that hamper their ability to coexist with human populations. We present here some of the drivers known to be the causes of conflicts between humans and primates in the southernmost area of distribution of Latin American primates. We focus our synthesis on two of the biggest sources of conflict: the effects of different anthropogenic disturbances, and human misconceptions concerning the role of primates in the ecosystem. In each section, we briefly characterize the conflicts worldwide and then provide specific cases and examples from Argentina. In the last part of the manuscript, we further describe some ongoing national and regional educational, research, and conservation approaches to mitigate those effects.

Road Infrastructure and Primate Conservation: Introducing the Global Primate Roadkill Database.

As road infrastructure networks rapidly expand globally, especially in the tropics, previously continuous habitats are being fragmented, resulting in more frequent wildlife-vehicle collisions (WVC). Primates are widespread throughout many sub-/tropical countries, and as their habitats are fragmented, they are increasingly at risk of WVC. We created the Global Primate Roadkill Database (GPRD), the largest available standardized database of primate roadkill incidents. We obtained data from published papers, un-published and citizen science databases, anecdotal reports, news reports, and social media posts. Here, we describe the collection methods for the GPRD and present the most up-to-date version of the database in full. For each primate roadkill incident, we recorded the species killed, the exact location, and the year and month the roadkill was observed. At the time of publication, the GPRD includes 2862 individual primate roadkill records from 41 countries. As primates range in more than twice as many countries, the absence of data from these countries is not necessarily indicative of a lack of primate vehicular collisions. Given the value of these data for addressing both local and global research questions, we encourage conservationists and citizen scientists to contribute to the GPRD so that, together, we can better understand the impact road infrastructure has on primates and evaluate measures which may help mitigate risk-prone areas or species.

Parasites and Other Infectious Agents in Non-human Primates of Argentina.

Purpose of Review: In Argentina, there are five non-human primate (NHP) species: Sapajus nigritus cucullatus, Sapajus cay, Alouatta caraya, Alouatta guariba clamitans, and Aotus azarae. All of them inhabit protected and non-protected areas and face severe threats due anthropization. We aim to summarize the information available about parasites and infectious diseases of these NHPs and suggest further research on primate diseases in Argentina. Recent Findings: NHPs of Argentina are hosts of several parasites and pathogens important for conservation as well as public health. Alouatta species are lethally susceptible to yellow fever virus, which makes them suitable health sentinels of possible outbreaks. For other primate species, few parasite surveys have been carried out. Summary: Assessing the presence of infectious diseases and long-term surveillance on NHP allow the development of strategies to help in the early detection of pathogens that may threat public health. Increasing the knowledge about parasites and infectious diseases and their consequences in NHP of Argentina is needed, considering a One Health approach.

Use of genetic tools to assess predation on reintroduced howler monkeys (Alouatta caraya) in Northeastern Argentina.

Despite strong support from the media, the reintroduction of animals into natural environments does not always achieve its goal. Alouatta caraya is the primate species facing the greatest hunting pressure due to the illegal pet trade in Argentina. Confiscations of this species are common, as is the voluntary surrender of animals by owners no longer able or willing to care for them. These animals ultimately arrive at rehabilitation centers and, in many cases, are released into natural environments that may differ from the original sites where they were captured. Until recently, the lack of genetic analysis of the individuals involved led to biased relocation decisions. We followed the reintroduction of 12 A. caraya individuals in a protected area (Isla Palacio, Misiones, Argentina). The presence of potential predators such as pumas (Puma concolor) and jaguars (Panthera onca) in this area was confirmed by camera traps, footprints and feces. After the disappearance of four A. caraya at the reintroduction site, we investigated the applicability of genetic assignment tests based on genotypic data to accurately identify predated individuals. Genetic analyses allowed us to determine the predator species (P. onca) and to identify the predated individuals as two of the reintroduced animals. This procedure is promising for identifying the remains of predated individuals, and can contribute to the design of reintroduction policies based on scientific evidence.

Genetic assignment of illegally trafficked neotropical primates and implications for reintroduction programs.

The black and gold howler monkey (Alouatta caraya) is a neotropical primate threatened by habitat loss and capture for illegal trade in Argentina. Using multilocus microsatellite genotypes from 178 A. caraya individuals sampled from 15 localities in Argentina, we built a genotype reference database (GRDB). Bayesian assignment methods applied to the GRDB allowed us to correctly re-assign 73% of individuals to their true location of origin and 93.3% to their cluster of origin. We used the GRDB to assign 22 confiscated individuals (17 of which were reintroduced), and 3 corpses to both localities and clusters of origin. We assigned with a probability >70% the locality of origin of 14 individuals and the cluster of origin of 21. We found that most of the confiscated individuals were assigned to one cluster (F-Ch-C) and two localities included in the GRDB, suggesting that trafficked A. caraya primarily originated in this area. Our results reveal that only 4 of 17 reintroduced individuals were released in sites corresponding to their cluster of origin. Our findings illustrate the applicability of genotype databases for inferring hotspots of illegal capture and for guiding future reintroduction efforts, both of which are essential elements of species protection and recovery programs.

Genetic structure in the southernmost populations of black-and-gold howler monkeys (Alouatta caraya) and its conservation implications.

Black-and-gold howler monkeys Alouatta caraya, are arboreal primates, inhabitants of Neotropical forests, highly susceptible to the yellow fever virus, considered early 'sentinels' of outbreaks, and thus, of major epidemiological importance. Currently, anthropogenic habitat loss and modifications threatens their survival. Habitat modification can prevent, reduce or change dispersal behavior, which, in turn, may influence patterns of gene flow. We explored past and contemporary levels of genetic diversity, elucidated genetic structure and identified its possible drivers, in ten populations (n = 138) located in the southernmost distribution range of the species in South America, in Argentina and Paraguay. Overall, genetic variability was moderate (ten microsatellites: 3.16 ± 0.18 alleles per locus, allelic richness of 2.93 ± 0.81, 0.443±0.025 unbiased expected heterozygosity; 22 haplotypes of 491-bp mitochondrial Control Region, haplotypic diversity of 0.930 ± 0.11, and nucleotide diversity of0.01± 0.007). Significant evidence of inbreeding was found in a population that was, later, decimated by yellow fever. Population-based gene flow measures (FST = 0.13; θST = 018), hierarchical analysis of molecular variance and Bayesian clustering methods revealed significant genetic structure, grouping individuals into four clusters. Shared haplotypes and lack of mitochondrial differentiation (non-significant θST) among some populations seem to support the hypothesis of historical dispersal via riparian forests. Current resistance analyses revealed a significant role of landscape features in modeling contemporary gene flow: continuous forest and riparian forests could promote genetic exchange, whereas disturbed forests or crop/grassland fields may restrict it. Estimates of effective population size allow anticipating that the studied populations will lose 75% of heterozygosity in less than 50 generations. Our findings suggest that anthropogenic modifications on native forests, increasingly ongoing in Northeastern Argentina, Southern Paraguay and Southeastern Brazil, might prevent the dispersal of howlers, leading to population isolation. To ensure long-term viability and maintain genetic connectivity of A. caraya remnant populations, we recommend preserving and restoring habitat continuity. To conserve the species genetic pool, as well, the four genetic clusters identified here should be considered separate Management Units and given high conservation priority. In light of our findings and considering complementary non-genetic information, we suggest upgrading the international conservation status of A. caraya to "Vulnerable".

Yellow fever impact on brown howler monkeys (Alouatta guariba clamitans) in Argentina: a metamodelling approach based on population viability analysis and epidemiological dynamics

In South America, yellow fever (YF) is an established infectious disease that has been identified outside of its traditional endemic areas, affecting human and nonhuman primate (NHP) populations. In the epidemics that occurred in Argentina between 2007-2009, several outbreaks affecting humans and howler monkeys (Alouatta spp) were reported, highlighting the importance of this disease in the context of conservation medicine and public health policies. Considering the lack of information about YF dynamics in New World NHP, our main goal was to apply modelling tools to better understand YF transmission dynamics among endangered brown howler monkey (Alouatta guariba clamitans) populations in northeastern Argentina. Two complementary modelling tools were used to evaluate brown howler population dynamics in the presence of the disease: Vortex, a stochastic demographic simulation model, and Outbreak, a stochastic disease epidemiology simulation. The baseline model of YF disease epidemiology predicted a very high probability of population decline over the next 100 years. We believe the modelling approach discussed here is a reasonable description of the disease and its effects on the howler monkey population and can be useful to support evidence-based decision-making to guide actions at a regional level.

Yellow fever impact on brown howler monkeys (Alouatta guariba clamitans) in Argentina: a metamodelling approach based on population viability analysis and epidemiological dynamics.

In South America, yellow fever (YF) is an established infectious disease that has been identified outside of its traditional endemic areas, affecting human and nonhuman primate (NHP) populations. In the epidemics that occurred in Argentina between 2007-2009, several outbreaks affecting humans and howler monkeys (Alouatta spp) were reported, highlighting the importance of this disease in the context of conservation medicine and public health policies. Considering the lack of information about YF dynamics in New World NHP, our main goal was to apply modelling tools to better understand YF transmission dynamics among endangered brown howler monkey (Alouatta guariba clamitans) populations in northeastern Argentina. Two complementary modelling tools were used to evaluate brown howler population dynamics in the presence of the disease: Vortex, a stochastic demographic simulation model, and Outbreak, a stochastic disease epidemiology simulation. The baseline model of YF disease epidemiology predicted a very high probability of population decline over the next 100 years. We believe the modelling approach discussed here is a reasonable description of the disease and its effects on the howler monkey population and can be useful to support evidence-based decision-making to guide actions at a regional level.

Male reproductive strategies in black and gold howler monkeys (Alouatta caraya).

Behavioral and demographic factors such as group size, social structure, dispersal patterns, and mating systems affect male reproductive success. In the present study, we analyze the relationship between social structure, genetic relatedness of adult males and offspring paternity in one population of Alouatta caraya inhabiting a continuous forest in Northern Argentina. After 14 months of behavioral studies and genotyping 11 microsatellites, we found that dominant or central males achieved greater mating success and fathered all the offspring conceived during our study in two multimale-multifemale groups (both including three adult males). Although skewed toward the dominant males, females copulated with almost all resident males and with extra group males. We found significantly fewer agonistic interactions between adult males in the group with fewer females and where males were more genetically related to each other (average relatedness r = 0.237; 0.015 int/ind/hr vs. r = 0.02; 0.029 int/ind/hr). Paternity was also analyzed in two other neighboring groups which also showed strong skew to one male over a 2-year period. These results reveal that even though female black and gold howlers mate with many males, infants are typically fathered by one dominant male.

A new world moneey microsatellite (ap74) highly conserved in primates / AP74, un microsatélite de Monos del Nuevo Mundo altamente conservado en Primates

Given their great variability, microsatellites or STRs became the most commonly used genetic markers over the last 15 years. The analysis of these markers requires minimum quantities of DNA, allowing the use of non invasive samples, such as feces or hair. We amplified the microsatellite Ap74 in blood and hair samples in order to analyze the levels of genomic conservation among a wide range of primates including: Lemur catta, Alouatta caraya, Ateles belzebuth, Ateles chamek, Pan troglodytes, Papio sp., and Homo sapiens. In all cases we obtained amplification products that exhibited similar size both in monkeys and human (oscillating between 126 and 176 bp), except in the lemur where the detected fragment presented a size of approximately 1000 bp. The analysis of the nucleotide sequences permitted the evaluation of the molecular modifications experienced during the evolutionary process in primates.

Dado su alta variabilidad, los microsatélites o STR se convirtieron en los marcadores genéticos más ampliamente utilizados en los últimos 15 años. El análisis de estos marcadores requiere una mínima cantidad de ADN, permitiendo el uso de muestras no invasivas, tales como pelos o heces. Con el objetivo de analizar niveles de conservación genómica, amplificamos el microsatélite Ap74 en muestras de pelo y sangre de un amplio rango de primates incluyendo: Lemur catta, Alouatta caraya, Ateles belzebuth, Ateles chamek, Pan troglodytes, Papio sp., y Homo sapiens. En todos los casos obtuvimos productos de amplificación que exhibieron un tamaño similar (oscilando entre 126 y 176 pb), con excepción del lémur, donde el fragmento detectado presentó un tamaño de aproximadamente 1000 pb. El análisis de las secuencias nucleotídicas nos permitió evaluar las modificaciones moleculares ocurridas durante el proceso evolutivo en primates.

Habitat fragmentation and population size of the black and gold howler monkey (Alouatta caraya) in a semideciduous forest in Northern Argentina.

A population of black and gold howler monkeys (Alouatta caraya) living near the southern limit of its distribution in a semideciduous forest located in northern Argentina was studied in 2003 to evaluate the possible effects of habitat fragmentation - owing to logging - on its density and social organization within it. Aerial photographs taken in 1982, 1992, and 2001 were used to compare maps of vegetation. These maps were used to evaluate changes in the area covered by forest fragments. From March to June 2003, 10-day monthly surveys of howlers were made in each fragment. A total of 232 individual howlers were counted, belonging to 34 groups plus a solitary adult female. Groups ranged from 2 to 19 individuals (mean = 6.82, SD = 4.23), and 21% of the groups contained more than one adult male. Adults accounted for 55% of the individuals, immatures for 45%, and infants represented 13% of the total. Data obtained were compared with information available for the same population for 1982 and 1995. Results revealed no significant changes in the area of fragments, the crude and ecological density of howlers, and group composition. Group sizes and group composition of howlers suggest that the population remained stable over the past 22 years. The density, number of groups, and individuals appears not to be affected by fragmentation and logging, but crude density was low compared with other less-disturbed habitats. The status of the population remains uncertain owing to isolation, and because there are no protected areas to ensure its stability for the future.