Taxonomy and Classification of Long-tailed Macaque and Con Son Long-tailed Macaque:
Adult Long-tailed macaques vary in body length across subspecies, with males generally larger than females. Their upper body is dark brown with light golden brown tips, while the underparts are light grey, complemented by a dark grey/brown tail. Notably, they have backward-directed crown hairs that can create short crests on the midline.
The skin on their feet and ears is black, while the muzzle exhibits a light grayish-pink hue. White markings often adorn the eyelids, and occasional white spots may appear on the ears. Males sport distinctive mustaches and cheek whiskers, whereas females only have cheek whiskers. Long-tailed macaques possess cheek pouches for food storage during foraging. In 15-30 years, their weight ranges from 3 to 9 kg, and their length measures between 38 and 55 cm.
The Con Son Long-tailed Macaque exhibits a unique feature in its eyebrow, featuring a distinctive white line absent in other macaque species in the region.
Habitat and Distribution of Long-tailed Macaque and Con Son Long-tailed Macaque:
The Long-tailed Macaque, scientifically known as Macaca fascicularis, is a highly adaptable species with a distribution ranging from sea level up to an impressive altitude of 2250 meters. Thriving across diverse environments such as forests, savannas, shrublands, grasslands, wetlands (inland), caves, subterranean habitats (non-aquatic), marine intertidal zones, and artificial/terrestrial areas, including introduced vegetation. Found in the south-central to the southernmost regions of Vietnam, this macaque species exhibits a broad range, extending from the southeastern tip of Bangladesh to Malaysia and various islands in Southeast Asia.
Encountering this species is most convenient at three notable locations in Vietnam. The first is Monkey Island within Can Gio Biosphere Reserve, followed by Monkey Pagoda in Vung Tau City, and finally, Cat Tien National Park.
Con Son Long-tailed Macaque:
In contrast, the Con Son Long-tailed Macaque, a distinctive subspecies of Macaca fascicularis, is exclusive to Con Dao National Park on Con Son Island. It is specifically located in Hon Ba Island, Bay Canh Island, and Hon Troc Island within the Con Dao Archipelago, situated off the southern coast of Vietnam.
However, this subspecies has a more limited distribution, reaching up to 100 meters in altitude. With an extent of occurrence (EOO) measuring less than 200 km² and an area of occupancy (AOO) of 72 km², this subspecies is geographically limited but ecologically important in its unique island habitat. Just have an easy place to encounter this one is in Con Son island the main island of Con Dao National Park.
Behavior and Social Structure:
Both the Long-tailed Macaque and the Con Son Long-tailed Macaque exhibit similar behavior and social structures, displaying adaptability and opportunism in various habitats. These generalist and opportunistic species have successfully adjusted to living in a diverse range of environments, including forests, coasts, hills, and mountains (Fooden 1995).
While they are commonly found in mangroves and swamp forests, especially in riverine habitats, they also thrive in human-altered landscapes such as temples, roadsides, agricultural areas, and rural/urban settlements (Gumert 2011). There is a possibility that a significant portion of their population has become synanthropic, having inhabited human environments for millennia. Consequently, anthropogenic ecologies play a crucial role in their historical natural ecology (Gumert et al. 2011, Fuentes et al. 2005, Marty et al. 2020).
Both species of macaques are diurnal and highly social, forming groups consisting of one or more males and 3-20 females with their young. Mature individuals in these groups are predominantly females, with males dispersing upon reaching maturity to establish new groups or join bachelor herds. The males adhere to a well-defined linear hierarchy based on age, size, and fighting skills. Young females typically remain with their natal group, forming the core of the social unit. Related females maintain close relationships, engaging in mutual grooming as a common practice. This behavior helps lower-ranking individuals avoid intimidation, receive support during conflicts, and gain access to limited resources within the group.
As omnivores, both Long-tailed Macaques and Con Son Long-tailed Macaques have varied diets encompassing fruits, crabs, flowers, leaves, fungi, grasses, and clay. Additionally, they supplement their diet with various insects, showcasing their adaptability and opportunistic feeding habits.
Employ both polygynous (one male mates with multiple females) and polygynandrous (promiscuous) (multiple males mate indiscriminately with multiple females) mating systems. The prime birthing season for these macaques spans from May to July, coinciding with the rainy season. The gestation period lasts between 162 and 193 days, culminating in the birth of a single offspring by high-ranking females at approximately 390-day intervals, while others follow a two-year reproductive cycle. The newborn is nursed until reaching 420 days of age. Reproductive maturity is attained at 6 years for males and 4 years for females.
The population faces a concerning decline, with estimates suggesting a 40% decrease in the last three generations and a projected increase to at least 50% in the next three generations. Past assessments indicated a decline from around 5 million individuals in the 1980s to approximately 3 million by the early 2000s. The species encounters diverse threats, including local declines, disappearances, and high-density areas with negative human-macaque interactions. The synanthropic nature of the species and habitat degradation contribute to challenges in estimating population trends accurately. In regions like Malaysia, significant culling has occurred, impacting both the population and the behavior of remaining groups.
In Vietnam, the Long-tailed Macaque population is experiencing a growth in numbers, attributed to successful conservation efforts. Despite their adaptation to human feeding practices, the population is steadily increasing.
Con Son Long-tailed Macaque:
In contrast, the Con Son Long-tailed Macaque, residing in Vietnam’s Con Dao National Park, presents a more positive conservation scenario. With an estimated population of 1,500 to 2,000 individuals, conservation efforts have proven successful. The 2012 survey recorded four groups on Con Son Island, with an encounter rate of 0.25 individuals/km. Fauna and Flora International surveys in 2014 identified populations across Con Son, Hon Ba, Bay Cach, and Hon Troc, totaling 407 individuals.
Conservation strategies involve addressing potential threats, such as coastal development and human-macaque conflict. National Park authorities aim to carefully plan future developments, ensuring the protection of vital populations and implementing measures like a no-feeding policy for Con Son Long-tailed Macaques. Additionally, genetic research is underway to inform tailored conservation actions for this distinct subspecies.
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In conclusion, Long-tailed macaques exhibit diverse traits, adaptability to various habitats, and share similar social structures. Conservation challenges include a 40% population decline, yet successful efforts in Vietnam showcase population growth. Con Son Long-tailed Macaques, endemic to Con Dao National Park, show positive conservation outcomes with 1,500-2,000 individuals. Ongoing genetic research informs tailored strategies for preserving these unique primate populations.