Crested black macaque
Macaca nigra

SOCIAL ORGANIZATION AND BEHAVIOR

Crested black macaques live in large, multi-male/multi-female groups (Kinnaird & O'Brien 2000). The social organization of crested black macaques revolves around female philopatry; females remain in their natal group while males disperse at sexual maturity resulting in female-bonded societies (Reed et al. 1997). Adult males within a group are unlikely to be related and show little affiliative behavior, and social interactions between males are dominated by antagonism (Kinnaird & O'Brien 1999). They are rarely seen grooming one another or sitting near each other and aggressive behavior serves to reinforce the linear dominance hierarchy (Reed et al. 1997). One measure of antagonism among male macaques is frequency of yawning, a signal used most by dominant males to intimidate others (Hadidian 1980). Females exhibit a more egalitarian social structure within the group, but males are generally dominant over females at feeding sites (O'Brien & Kinnaird 1997). Mid-ranking males are quite aggressive toward females and frequently harass, chase, and threaten them. The highest-ranking males attract the most attention from females; females sit closer to them and groom them more often than lower ranking males (Reed et al. 1997). Presumably, higher-ranking males are more attractive social partners because females benefit from these interactions. Females are less likely to be harassed by lower-ranking males if they are in proximity to higher-ranking males, they may enjoy better foraging opportunities because one of the advantages of rank is better access to food resources, and finally females are attracted to higher ranking males because they are better mates (Reed et al. 1997). Grooming is an excellent measure of affiliative behavior and rank in macaques; crested black macaque females groom males almost four times as frequently as they are groomed by males, especially during times of sexual receptivity (Reed et al. 1997). Crested black macaques also exhibit embracing behaviors which signal amicable relations and are seen frequently among females as they approach each other and rub one side of their body against the other and sniff the anogenital region of the other, much like dogs (Thierry et al. 2000).

Group movements are coordinated by either males or females and social groups generally remain at distances greater than 500 m (.311 mi) from each other (Kinnaird & O'Brien 1999; 2000). One of the ways crested black macaques judge intergroup distance is by vocalizing. Fully adult males, especially high-ranking ones, give loud-calls, raspy, repetitive cackles that are loud enough to be heard by neighboring groups (Kinnaird & O'Brien 1999; 2000). When groups come into closer proximity, crested black macaques have been characterized as bold and fearless during encounters with neighbors, and groups often fight or display and continue to use loud-calls throughout the aggressive encounter. Encounters are especially high as food resources decrease during the year; crested black macaque groups are more likely to tolerate each other nearby during periods of high fruit abundance. Intergroup fighting to defend fruit resources can result in serious injury because of the large size of the macaque's canine teeth (Kinnaird & O'Brien 2000).

REPRODUCTION

Living in multi-male/multi-female groups, crested black macaques are promiscuous and both males and females mate multiple times with multiple partners (Soltis 2004). Almost all female macaques exhibit some form of "advertising" their sexual status in the form of obvious swelling and pink or red coloration of the skin surrounding their genitals (Soltis 2004). Females reach sexual maturity at 49 months (Rowe 1996). The ovarian cycle lasts 40 days in crested black macaques and over this time period, swelling around the anogenital area increases to a point of maximum tumescence and then recedes in concert with menstruation. This communicates to males their sexual receptivity and is used in sexual solicitation. Females solicit males by presenting their swollen rumps towards the male, looking back at him, and smacking their lips together (Bernstein & Baker 1988). The period of peak receptivity, ovulation, is not always coordinated with the period of maximum swelling, an adaptation to confuse paternity among males (Thomson et al. 1992). Females who mate with multiple males benefit from confusing paternity in multi-male/multi-female groups because there is less chance that a male will threaten or injure an infant if it is potentially his offspring (Soltis 2004). Mating and births occur throughout the year with no definite birth season and gestation lasts 174 days (Thomson et al. 1992).

PARENTAL CARE

There are no published data about parental care patterns in crested black macaques, but given their social system and taxonomic relationship to other macaque species, a few generalizations can be made. Infant macaques are cared for primarily by their mothers. Juvenile and subadult females often carry infants for brief periods, under supervision of the mother, a behavior known as aunting. By doing this, young macaques gain mothering skills that may increase the survival of their own infants in the future (Maestripieri 2004).

COMMUNICATION

Communication among crested black macaques involves a variety of vocalizations for different situations as well as number of postural displays that serve to enforce group cohesion, mediate social interactions between individuals, and are used in inter-group communication (Thierry et al. 2000). "Coos" are contact vocalizations heard between group members, differing in pitch and frequency depending on the distance between group members. Crested black macaques also have a "bark" which is accompanied by other threat gestures including staring, chasing, and aggression (Thierry et al. 2000). The "loud call" is another frequently heard vocalization given only by adult male crested black macaques and is heard in a variety of situations including in non-specific situations, during times of arousal and social tension, and during inter-group encounters (Kinnaird & O"Brien 1999; Thierry et al. 2000).

Often accompanying vocalizations are facial expressions or postural displays. One affiliative facial expression is the "scalp retraction," when ears flattened against the head give the face a tightened look. This is seen when an approaching animal is initiating play or grooming. "Lipsmacking" is another important facial expression in which the lips are smacked together producing an audible sound while the eyelids are half-lowered and the animal may also be displaying "scalp retraction." This is seen during affiliative interactions and may be used as a sign of appeasement or reconciliation after conflict (Thierry et al. 2000). "Staring," "half-open mouth," "yawn," and "jaw movement" associated with a chattering of the teeth are all threat displays seen among crested black macaques (Hadidian 1980; Thierry et al. 2000).

Content last modified: February 2, 2006

Written by Kristina Cawthon Lang. Reviewed by Margaret Kinnaird.

Cite this page as:
Cawthon Lang KA. 2006 February 2. Primate Factsheets: Crested black macaque (Macaca nigra) Behavior . <http://pin.primate.wisc.edu/factsheets/entry/crested_black_macaque/behav>. Accessed 2010 February 9.