Population densities of Sulawesi crested black macaques (Macaca nigra) on Bacan and Sulawesi,Indonesia: Effects of habitat disturbance and hunting

Population surveys of Sulawesi crested black macaques (Macaca nigra) were conducted on the Indonesian islands of Sulawesi and Bacan in 1992–1994 to assess the status of natural populations and determine habitat and anthropogenic factors affecting their population densities. We surveyed five sites for primates, including undisturbed and disturbed habitats. Data were collected on habitat structure and composition at two undisturbed and one disturbed forest site in which the primates were surveyed. The highest density of macaques was found in primary forest at Gunung Sibela Nature Reserve on Bacan (170.3 individuals/km²). Population density in logged forest on Bacan was high but significantly less than primary forest (133.4 individuals/km²). The high density of crested black macaques in primary forest on Bacan is best explained by the high carrying capacity found in primary forest. The lower food quantity and quality of food resources found in logged forest correlated with lower primate densities compared to primary forest. However, the large population of macaques in logged forest demonstrates the conservation value of such forest. Densities on Sulawesi at Tangkoko-Batuangas-DuaSudara Nature Reserve (TBDS) showed a continuing decline since earlier surveys. Primate densities were highest near the protected center of Tangkoko Reserve (66.7 individuals/km²). The peripheral areas of Batuangas and DuaSudara, even though adjacent and continuous, showed lower population densities of 46.4 and 23.5 individuals/km², respectively. The best explanation for the continued decline of Macaca nigra populations at TBDS is hunting. Unless conservation measures are implemented immediately, M. nigra on Sulawesi risks extinction in the near future. Am. J. Primatol. 44:89–106, 1998. © 1998 Wiley-Liss, Inc.     

Long‐Term Population Survey of the Sulawesi Black Macaques (Macaca nigra) at Tangkoko Nature Reserve,North Sulawesi,Indonesia

The Sulawesi black macaque (Macaca nigra) population at Tangkoko Nature Reserve in North Sulawesi, Indonesia has been the focus of periodic study for over 30 years. The population has shown considerable decline during much of that time. Here we present the results of a long‐term population survey of the Tangkoko M. nigra, conducted over the past decade, to provide updated information and on‐going assessment of the population. Line‐transect sampling was conducted annually from 1999 to 2002 and 2005 to 2011 along the same transect during a 2‐ to 3‐week survey period. Although further decline in the population was observed at the outset of the survey, over the subsequent 12‐year period we have seen stability in the population parameters with evidence of modest increases in both group and population density. During the 1999–2002 survey periods, there was a mean group density of 3.6 groups/km² and a mean population density of 39.8 individuals/km². During 2005–2011, mean group density increased to 3.8 groups/km² and mean population density was 51.4 individuals/km². The 2011 survey data indicated an estimated group density of 4.3 groups/km² and a population density of 61.5 individuals/km². Given that our transect was located in the core of the Tangkoko reserve, our density estimates should be limited to that area of the reserve. One explanation for the apparent stabilization of the population may be tied to the increasing and sustained number of training and research programs being conducted at the reserve. This collective effort by local and international groups may be helping to reduce illegal activity in the reserve (i.e., hunting and habitat destruction) and generate greater awareness of this critically endangered species. Without the continued vigilance afforded by the existing research and training programs and the support and involvement of the local people, the M. nigra at the Tangkoko Nature Reserve will likely face further decline. Am. J. Primatol. 75:88‐94, 2013. © 2012 Wiley Periodicals, Inc.     

The borderlands and possible hybrids between three species of macaques,M. nigra,M. nigrescens,andM. hecki,in the northern peninsula of Sulawesi

The borderlands between three species of macaques,Macaca nigra, M. nigrescens, andM. hecki, which live on the northern peninsula of Sulawesi were surveyed mainly via observations of pet monkeys kept by local people. The borderlands between these species could be delineated. Some monkeys of peculiar appearance and/or with mixtures of the external characteristics of two species were found in the borderlands between the respective pairs of species. However, such possibly hybrid monkeys were seen or originated only in the very limited areas where the species might come into contact with each other.     

Origin and evolution of the sulawesi macaques 1. Electrophoretic analysis of hemoglobins

The monkeys on the island of Sulawesi (Celebes), Indonesia, comprise seven species ofMacaca, that isM. maura, M. tonkeana, M. hecki, M. nigrescens, M. nigra, M. ochreata, andM. brunnescens. Hemoglobins from 248 individuals of these seven species were analyzed by isoelectric focusing electrophoresis (IEFE) and by starch gel electrophoresis in the presence of urea (USGE). Eighteen phenotypes consisting of eight molecular types were identified by IEFE analysis. The speciestonkeana inhabiting the central part of the island revealed 11 phenotypes, while peripheral species such asnigrescens andbrunnescens carried only 3 and 2 phenotypes, respectively. On USGE, three α chains and three β chains were identified and named α1, α2, and α6, and β1, β3, and β5, respectively. The α1 chain has the same mobility as the α chains of other macaques, while the α2 chain is less positively charged than α1, and α6 is the least positive among these α chains. The α2 chain is widely distributed in the Sulawesi macaques as the major component. Four species,ochreata, tonkeana, maura, andnigrescens, carried the α1 and α6 chains as minor components. The electrophoretic mobility of β1 was the same as that of other macaques, while β3 and β5 were more positively charged and less positively charged than β1, respectively. All of the Sulawesi species had β3 in high or low gene frequencies and inmaura, tonkeana, andbrunnescens, this type was most abundant. β5 chain existed in the species of the northern peninsula, as the major type. The subordinate type was β3 innigra andnigrescens and β1 inhecki. On the other hand, β1 was most frequently observed inochreata.     

Evidence of gene flow between Sulawesi macaques

A pilot field study was conducted in Sulawesi (Indonesia) to assess the status of macaque populations on the island. Wild and captive animals were sampled, mainly in border areas between presumed different species. The five species investigated were Macaca maurus, M. tonkeana, M. hecki, M. nigrescens, and M. nigra, for which morphological and gene frequency data suggested the presence of hybridization zones. Some individuals within these zones showed intermediate or mosaic morphology between parental forms. These individuals also had intermediate gene frequencies for most of the polymorphic systems investigated. Karyotypes were identical in all species, and no cytogenetic barrier to hybridization existed between species. A review of the recent literature also provided evidence for hybridization between Sulawesi macaques. Clinical frequencies in both morphological and biomolecular traits perhaps can be best explained by the operation of gene flow between the various forms of macaques on the island. However, additional data are necessary before current classification schemes are revised. The unique opportunity and need of further study of Sulawesi macaques for a range of evolutionary questions is emphasized.     

Morphological studies on the Sulawesi macaques I: Phyletic analysis of body color

The body color of Sulawesi macaques was measured quantitatively and compared among the different monkeys. As a result, divergence models for extant Sulawesi macaques, withtonkeana as the starting point and fading as the sole direction of color change, were inferred as follows: (1) fading slightly on the upper half of the body—nigra, fading more on the proximal part of the body—nigrescens; (2) fading over the whole body—maura; (3) fading greatly on the legs—hecki; and (4) fading on the distal part of the body—ochreata, fading more over the whole body, including the proximal part of the body—brunnescens. The color changed progressively in the order of (1) through (4). The divergence model, excluding the position ofhecki (3), supports the speciation model ofFooden (1969). If the proto-Sulawesi macaques had a body color pattern similar to the livingnemestrina, darkening would have been necessary for the evolution of the Sulawesi macaques after their immigration, and it may have been acquired as an adaptation to the ground (forest floor) living nature of the Sulawesi macaques, together with influences deriving from the insularity and/or from the absence of predators.     

Species differences of male loud calls and their perception in sulawesi macaques

Playback experiments were conducted to investigate interspecific discrimination of male loud calls in Sulawesi macaques. Loud calls of four macaque species living in Sulawesi (Macaca tonkeana, M. maurus, M. hecki, andM. nigrescens) and a control stimulus (an 8-sec frequency modulated sound) were played back to semi-free-ranging Tonkean macaques (M. tonkeana). A preliminary acoustic analysis indicated that the calls of these four species differ in some spectral and temporal features. In the playback experiments, Tonkean macaques responded in a similar manner to conspecific calls and calls of two other species,M. maurus andM. hecki. In contrast, animals responded more weakly to the call ofM. nigrescens and the control stimulus. Males responded more strongly than females to all stimuli, while females appeared to be more discriminating for species differences than males. Analyses on the acoustic features of loud calls suggested that high frequency, wide frequency range, and repetition of sound units at a high rate elicit quick responses from animals.     

Focusing Conservation Efforts for the Critically Endangered Brown-headed Spider Monkey (<Emphasis Type="Italic">Ateles fusciceps</Emphasis>) Using Remote Sensing,Modeling, and Playback Survey Methods

Brown-headed spider monkeys (Ateles fusciceps), endemic to the Choco-Darien forests and lower Andean forests of NW Ecuador, are considered critically endangered. Unfortunately, scientific data regarding the actual status of populations is lacking. We combined satellite image analysis, species-specific habitat assessment, and a field survey technique using playback to focus conservation efforts for this species. First, we identified remaining forest via a LANDSAT mosaic and then applied species-specific criteria to delineate remaining forest with potential to hold populations. By combining this with the historical distribution from ecological niche modeling and predicted hunting intensity we generated a species-specific landscape map. Within our study area, forest capable of sustaining Ateles fusciceps covers 5872 km², of which 2172 km² (40%) is protected. Unprotected forest considered suitable for Ateles fusciceps extends to 3700 km² but within this only 989 km² (23%) is under low hunting pressure and likely to maintain healthy populations of Ateles fusciceps. To overcome problems of sampling at low primate density and in difficult mountain terrain we developed a field survey technique to determine presence and estimate abundance using acoustic sampling. For sites under low hunting pressure density of primates varied with altitude. Densities decreased from 7.49 individuals/km² at 332 masl to 0.9 individuals/km² at 1570 masl. Based on combining data sets in a gap analysis, we recommend conservation action focus on unprotected lowland forest to the south and west of the Cotacachi-Cayapas Ecological Reserve where hunting pressure is low and population densities of Ateles fusciceps are greatest.     

Macaca nigra on Bacan Island,Indonesia: Its morphology,distribution, and present habitat

We studied the monkeys inhabiting Bacan Island on the Maluku Archipelago, Indonesia. We compared them morphologically with Sulawesi black macaques (Macaca nigra).We also assessed their distribution on the island and on neighboring islands and the influence of human activity on them. We found that the Bacan black macaques are essentially similar to Sulawesi macaques; the variations in each locality are comparable. The monkeys probably inhabit the whole island or, at least, the lower forest thereon. Human activities — cultivation, logging, catching and killing monkeys — have not much affected their population. Thus they constitute a good stock of Macaca nigra,though the main population in Sulawesi is endangered.     

Maned Wolf Density in a Central Brazilian Grassland Reserve

ABSTRACT The maned wolf (Chrysocyon brachyurus) inhabits the savannah-like Cerrado of Brazil. Although 80% of this biome has already been affected by human activity, little is known about maned wolf abundance. Using mark—recapture models, we obtained the first density estimate from central Brazil, the core of maned wolf distribution. With 5.19 individuals/100 km², even large reserves support only small maned wolf populations. Therefore, long-term conservation of the maned wolf depends on land management outside of reserves.     

Population Structure and Ranging Patterns of <Emphasis Type="Italic">Rhinopithecus roxellana</Emphasis> in Zhouzhi National Nature Reserve,Shaanxi, China

We describe the population structure and ranging patterns of a troop of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) based on a study conducted between November 2002 and November 2003 in Zhouzhi National Nature Reserve, Shaanxi Province, China. The troop comprised several 1-male units and an all-male unit. Opportunistic censuses revealed that there were ≥112 individuals in the troop. The adult sex ratio (male vs. female) was 1:3.7. The ratios of adults to immatures and infants to adult females were 1:0.7 and 1:2, respectively. Via a grid system, we estimated the home range of the troop to be 18.3 km², of which 7.4 km² was the core area. The subjects exhibited distinct seasonal ranging patterns. Their movement across the home range was extensive in spring and restricted in autumn. In addition, reuse of quadrats was highest in winter and lowest in spring in comparison with other seasons. The daily path length (DPL) varied from .75 to 5 km, with a mean of 2.1 km. Seasonal analysis showed that DPL is significantly shorter in winter than in spring or summer; however, there is no significant difference between the DPLs of spring and summer or those of spring and autumn. The monkeys occupied elevations 1500–2600 m above sea level; the annual mean of altitudinal range is 2137 m. Contrary to early studies that reported Rhinopithecus roxellana migrates to lower elevations in winter, we found no evidence supporting a seasonal altitudinal shift. Using the highest troop count and home range estimate, and considering the extent of range overlap between neighboring troops, we calculated the population density and biomass of Rhinopithecus roxellana to be 7.2 individuals/km² and 68.3 kg/km², respectively. The temporal and spatial distribution of food resources may be the most important determinant of ranging behavior in Rhinopithecus roxellana, though understanding the relationship between resource distribution and seasonal range use may require further investigation.     

Vertical distribution of wild Yakushima macaques (Macaca fuscata yakui) in the western area of Yakushima Island, Japan: Preliminary report

A census of wild Yakushima macaques (Macaca fuscata yakui) was carried out in a 23-km² area of the western coast of Yakushima Island, Japan. We analyzed the census data to investigate changes in monkey distribution associated with the vertical distribution of vegetation. In the lowland coastal zone of 0–300 m above sea level (a.s.l.), 4.8 troops and 62.4–99.8 monkeys are estimated to have existed per km². In the mountainside zones of 300–900 m a.s.l., the troop density decreased to 1.3–1.6 troops/km². Since there was no difference in size between the coastal and mountainside troops, population density should decrease with altitude to about 30–36 monkeys per km². On the other hand, 2.4 troops and about 36 monkeys were estimated to have inhabited per km² in the mountain summit zone of 900–1,323 m a.s.l. Nature Conservation College     

Genetic mark–recapture population estimation in black bears and issues of scale

Abundance estimates for black bears (Ursus americanus) are important for effective management. Recently, DNA technology has resulted in widespread use of noninvasive, genetic capture–mark–recapture (CMR) approaches to estimate populations. Few studies have compared the genetic CMR methods to other estimation methods. We used genetic CMR to estimate the bear population at 2 study sites in northern New Hampshire (Pittsburg and Milan) in 2 consecutive years. We compared these estimates to those derived from traditional methods used by the New Hampshire Fish and Game Department (NHFG) using hunter harvest and mortality data. Density estimates produced with genetic CMR methods were similar both years and were comparable to those derived from traditional methods. In 2006, the estimated number of bears in Pittsburg was 79 (95% CI = 60–98) corresponding to a density of 15–24 (95% CI) bears/100 km²; the 2007 estimate was 83 (95% CI = 67–99; density = 16–24 bears/100 km²). In 2006, the estimated number of bears in Milan was 95 (95% CI = 74–117; density = 16–25 bears/100 km²); the 2007 estimate was 96 (95% CI = 77–114; density = 17–25 bears/100 km²). We found that genetic CMR methods were able to identify demographic variation at a local scale, including a strongly skewed sex ratio (2 M:1 F) in the Milan population. Genetic CMR is a useful tool for wildlife managers to monitor populations of local concern, where abundance or demographic characteristics may deviate from regional estimates. Future monitoring of the Milan population with genetic CMR is recommended to determine if the sex ratio bias continues, possibly warranting a change in local harvest regimes. © 2011 The Wildlife Society.     

Status of the Arabian Gazelle,Gazella arabica (Mammalia: Bovidae), in Dhofar,Oman

The Arabian Gazelle, Gazella arabica, was once widely distributed in Oman, but its population decreased through illegal hunting and capture of the species. It is now found in small, isolated populations in the country, but little is known about the size and dynamics of these populations. In November 2014 we conducted a survey to estimate the density and size of two populations in the Dhofar region, one in the foot-hills of Jabal Samhan and the other in the Nejd. Population densities were found to be 0.33 animals/km² at Jabal Samhan and 0.28 animals/km² in Nejd. The total population size for the two areas combined was extrapolated to be 1,737 animals.     

Habitat Degradation of Rhinopithecus bieti in Yunnan, China

Black-and-white snub-nosed monkeys (Rhinopithecus bieti) are endemic to the Trans-Himalayas in Northwest Yunnan and Southeast Tibet between the upper Yangtze and Mekong Rivers. Based on field surveys and previous reports, we identified the dark-coniferous forest, the mixed coniferous and broadleaf forest, and oak patches as suitable habitats (SH) for the monkeys. Summer grazing lands (SGL), which were made by local people cutting and burning the dark-coniferous forest at the high altitude belt, replaced SH. To have a general view of the status of the SH in Yunnan, we estimated the areas of SH and SGL from satellite images in 1997, and compared with areas estimated from aerial photo-based maps (ca. 1958). The work resulted in: 1) the area of SH was 4,169 km² in 1997; 2) SGL was 1,923 km²; 3) during the past 40 years, the area of SH decreased by 31% (1,887 km²), and SGL increased by 204% (1,291 km²); and 4) the mean size of forest patches decreased from 15.6 to 5.4 km². In addition, the area of SGL is positively correlated to local human population (R² 0.53), implying that the reduction and fragmentation of habitat for Rhinopithecus bieti is a result of population growth of humans, who mostly employ traditional modes of production. Only 11 monkey groups remained in the changing habitat. Considering that forests at lower elevation were also encroached upon by farmlands in a similar way, the forest ecosystem is highly threatened. The destruction will continue unless there is a change in the mode of production in the region.     

Home Range,Population Density,and Food Resources of Agouti paca (Rodentia: Agoutidae) in Costa Rica: A Study Using Alternative Methods1

Field studies of elusive mammals such as Agouti paca are difficult, and results are often biased and incomplete because the animals are nocturnal and avoid traps. By studying an A. paca population in a Pacific lowland forest of Costa Rica, we developed indirect observational methods to estimate population density and food resource utilization. To estimate population density, we divided the number of A. paca burrows found in a 12-ha census area by the average number of burrows utilized per individual from radiotelemetry data. We compared this estimate to independent population estimates obtained using two transect methods. Agouti paca density was estimated at 93 individuals/km² based on burrow number, and between 67 to 70 individuals/km² using transect methods. This discrepancy corroborates previous studies suggesting that transect methods underestimate population density. To identify food resources consumed by the species, we collected fruits and seeds with unambiguous A. paca teeth marks. The only animal in Central America with an incisor width similar to A. paca. is Dasyprocta variegata; in a comparison of both species, however, we found that A. paca had a significantly larger incisor width and that teeth marks of 4 mm or wider unambiguously indicated handling by this species. By applying this technique, food resources utilized by A. paca can be identified more easily than by direct observation. At our study site, we identified 33 plant species consumed by A. paca; 61 percent are new records for this animal. Our results suggest that A. paca plays a major, although not fully understood, ecological role in seed predation and dispersal.     

Estimating brocket deer (<Emphasis Type="Italic">Mazama gouazoubira</Emphasis> and <Emphasis Type="Italic">M. americana</Emphasis>) abundance by dung pellet counts and other indices in seasonal Chiquitano forest habitats of Santa Cruz,Bolivia

We assessed dung and track counts for indexing brocket deer abundance in seasonal habitats on a ranch where hunting is not practiced in the Bolivian lowlands. Surveys were replicated along four 10-km trails (totaling 180 km in the wet season and 90 km in the dry season) through four semideciduous forest habitats. Dung pellets and tracks were identified as belonging to Mazama gouazoubira or M. americana by size and shape. Pellet groups lasted more than 1 month during the dry season, but decayed within 1–2 weeks in the wet season. Mean density estimates based on dung counts varied widely between seasons for gray brockets (from 6.77±4.0 to 30.57±23.5 ind/km²; mean±SD) but not for reds (from 3.52±4.6 to 6.98±7.2 ind/km²). These values were probably too high due to underestimation of daily deposition rate, and were reduced during the wet season because of dung decay. We found consistently more dung in the dry season and more tracks in the wet season. Sightings of red brockets were too few for line-transect analysis (n=6), but those of gray brockets (n=42) produced an overall estimate of 5.6 ind/km² (95% CI=3.5–9.0 ind/km²). Different estimates indicated that gray brockets were more abundant than reds in all situations, except perhaps in the riverine forest. Environmental factors affected these indices of abundance differently, and while we recommend the use of dung counts in dry-season scenarios, we think that index reliability should be assessed locally before conducting population comparisons.     

Hematological values and parasite fauna in free-rangingMacaca hecki and theM. hecki/M. tonkeana hybrid group of Sulawesi Island, Indonesia

Hematological values and parasitological fauna of free-rangingMacaca hecki and the hybrid group betweenM. hecki/M. tonkeana of Sulawesi Island, Indonesia, were investigated. The hematological values, especially the red cell number (RBC), were lower than those of other macaque species, indicating that Sulawesi macaques are slightly anemic. Several parasites including Plasmodium sp., trombiculid mites, andTrichuris trichiura were identified. Although infection by Plasmodium was observed with considerable frequency, no clear relationship between its infection and the occurrence of anemia was found. Trombiculid mites and eggs ofAnatrichosoma sp. were detected in foci of the ears of most monkeys. The infection with a trombiculid mite is the first recorded occurrence in free-ranging wild Sulawesi macaques. Gastrointestinal parasites were identified from their eggs in fecal samples, where five species of nematoda and one trematoda species were found.