Protecting Nonhuman Primates in Peri-Urban Environments: A Case Study of Neotropical Monkeys, Corridor Ecology, and Coastal Economy in the Caribe Sur of Costa Rica

Host specificity of gastrointestinal parasites in free-ranging sloths from Costa Rica

The diversity and host specificity of gastrointestinal parasites infecting free-ranging sloths is poorly known. We compared gastrointestinal parasites of two sloth species from Costa Rica-three-fingered sloths (Bradypus variegatus) and two-fingered sloths (Choloepus hoffmanni)-for the first time in both a primary forest and an urban habitat. We asked whether host-parasite interactions were predominantly structured by host identity, the habitats in which hosts occurred, or both. Coproparasitology revealed protozoa and nematode eggs from both host species, but cestode eggs were recorded only in C. hoffmanni. We found eight parasitic morphotypes in 38 samples, which matches the total number of these parasites described in sloths over the past 100 years. We found no significant difference in overall parasite richness between sloth species or habitats, but the parasite richness of C. hoffmanni was 2-fold greater in the primary forest vs. urban habitat. As no parasite sharing was observed between sloth species, we found strong and significant differences in parasite composition between host species regardless of habitat. In B. variegatus, we observed eggs of four nematode taxa (Spirocercidae, Subuluroidea, Spirurida, Ascaridida) and cysts of Eimeriidae (Apicomplexa). By contrast, in C. hoffmanni, we observed cestodes (Anoplocephalidae), a different nematode from the family Spirocercidae, and also different cysts of Eimeriidae (Apicomplexa). Many rare taxa were recorded only in samples from the primary forest, and these did not match any sloth parasites that had been previously described in the literature, suggesting that at least some could be undescribed species. Together, these results highlight the paucity of comparative parasitology involving tropical wildlife, the importance of characterizing host-parasite transmission networks, and the potential relevance of intermediate hosts that may be relevant to sloth health.

Use of Space by black-and-gold howler monkeys (Alouatta caraya) in an urban environment in Paraguay

As urbanisation continues to reduce the available habitat for wildlife, some species, including the black-and-gold howler monkey (Alouatta caraya) in Pilar, southwest Paraguay, are making their homes in anthropogenic environments. Understanding an animal’s home range is an important step to understanding its ecological needs, and an essential requirement for the creation of robust conservation plans. In this study, we determined the home ranges and core areas of five groups of urban dwelling A. caraya using Minimum Convex Polygon (MCP) and Kernel Density Estimation (KDE) Analysis. We used a Spearman’s Correlation to explore the relationship between home range size and group size. All five groups had home ranges of less than 10 ha and used core areas of less than 1 ha. Group size had no significant relationship to home range size. We provide the first estimates of home range for A. caraya in an urban environment in Paraguay. Though the home ranges of the urban A. caraya in Pilar, Paraguay fall at the smaller end of the spectrum of range sizes in Alouatta, they are not abnormal for a species in this genus.

Forest fragments become farmland: Dietary Response of wild chimpanzees (Pan troglodytes) to fast-changing anthropogenic landscapes

Behavioral flexibility, including an ability to modify feeding behavior, is a key trait enabling primates to survive in forest fragments. In human-dominated landscapes, unprotected forest fragments can become progressively degraded, and may be cleared entirely, challenging the capacity of primates to adjust to the changes. We examined responses of wild chimpanzees (Pan troglodytes schweinfurthii) to major habitat change: that is, clearance of forest fragments for agriculture. Over 7 years, fragments in Bulindi, Uganda, were reduced in size by 80%. We compared the chimpanzees' diet at the start and end of this period of rapid deforestation, using data derived mainly from fecal analysis. Similar to other long-term study populations, chimpanzees in Bulindi have a diverse diet comprising over 169 plant foods. However, extensive deforestation seemed to impact their feeding ecology. Dietary changes after fragment clearance included reduced overall frugivory, reduced intake of figs (Ficus spp.; formerly a dietary "staple" for these chimpanzees), and reduced variety of fruits in fecal samples. Nevertheless, the magnitude of most changes was remarkably minor given the extent of forest loss. Agricultural fruits increased in dietary importance, with crops accounting for a greater proportion of fruits in fecal samples after deforestation. In particular, cultivated jackfruit (Artocarpus heterophyllus) became a "staple" food for the chimpanzees but was scarcely eaten before fragment clearance. Crops offer some nutritional benefits for primates, being high in carbohydrate energy and low in hard-to-digest fiber. Thus, crop feeding may have offset foraging costs associated with loss of wild foods and reduced overall frugivory for the chimpanzees. The adaptability of many primates offers hope for their conservation in fragmented, rural landscapes. However, long-term data are needed to establish whether potential benefits (i.e. energetic, reproductive) of foraging in agricultural matrix habitats outweigh fitness costs from anthropogenic mortality risk for chimpanzees and other adaptable primates.

Electrocutions in free-living black-tufted marmosets (Callithrix penicillata) in anthropogenic environments in the Federal District and surrounding areas, Brazil

Shrinking natural habitats exposes some non-human primates to the risk of accidents associated with electrical transmission lines. We examined dead marmosets (Callithrix penicillata) collected in the region from January 2015 to April 2018 to determine the animals' cause of death and for electrocuted animals we examined the locations the animals had died as well as the configuration of the power lines at these sites. We also recorded the sex of the animal, the body region affected, and characteristics of the injuries. We diagnosed electrocutions in 11% (n = 34) of the marmosets studied. Most of the affected animals were male (n = 22) with single or double sites of injury on the limbs. Animals were injured in urban (n = 26) and peri-urban (n = 8) areas on lower-voltage alternate current lines, and we detected no seasonality or hotspots of electrocution. Our findings suggest that movement along transmission lines composed of bundled conductors is a major factor in electrocutions of marmosets in the Federal District and surrounding areas. The planning of electrical power grid infrastructure should consider arboreal primates to prevent electrocutions.

Surviving in the urban-rural interface: Feeding and ranging behavior of brown howlers (Alouatta guariba clamitans) in an urban fragment in southern Brazil

Wild primates that live in urban areas face extreme threats that are less frequent in nonurban fragments, such as the presence of dangerous matrix elements (e.g., roads, power lines, buildings, and a high density of domestic dogs near food patches), that could influence their movements, feeding behavior, and survival. However, the scarcity of studies addressing this issue hinders our understanding of the behavioral adjustments that favor the survival of primates in urban areas. For 12 months, we studied a six-individual group of brown howlers (Alouatta guariba clamitans) in an urban fragment to determine (i) their diet richness and its relationships with food availability, (ii) their daily path length (DPL) and the matrix elements used during movement, and (iii) the main ecological drivers of the DPL. Sampling effort totaled 72 days, 787 hr, and 3,224 instantaneous scans. We found that the diet of brown howlers contained 35 plant species (including seven cultivated crops) belonging to 33 genera and 21 families. The consumption of fruits and young leaves was directly related to their temporal availability. The average DPL (446 m) was smaller than that reported for groups of howlers inhabiting large nonurban fragments. To move between food patches, animals used three main matrix elements: trees, power lines, and roofs. The number of plant species used during the day was the main driver of DPL. Our findings highlighted that the generalist-opportunistic diet of brown howlers and their ability to move across the anthropogenic matrix using artificial elements such as power lines, roofs, and wildlife crossings represent a remarkable part of their behavioral repertory in Lami. However, there are potential costs associated with these strategies, namely, electrocution and predation by domestic dogs. Thus, it is urgent to further investigate how these behaviors could affect the long-term survival of these animals.