Golden lion tamarin
Leontopithecus rosalia

SOCIAL ORGANIZATION AND BEHAVIOR

Because golden lion tamarins were studied extensively in captivity before data from long-term studies had accumulated, there are some discrepancies about wild tamarin behavior and considerable conflict about their true social structure and mating behaviors. Additionally, the only habituated population of wild golden lion tamarins that has been studied over extended periods is found at Poço das Antas, and therefore represents most of the conclusions made about wild tamarin social structure (Baker et al. 2002). Further research in the field may lead to new understanding about wild golden lion tamarin behavior.

In the wild, golden lion tamarins have been observed living in groups of two to 11 individuals (Dietz & Baker 1993). Historically, most groups had, on average, about five members, but average group size has decreased in recent years because of the effects of predators (Bales pers. comm.). In these small groups, they exhibit cooperative rearing of offspring; all members of the group help a mother tamarin carry, care for, and provide solid food for her infants (Dietz & Baker 1993). The social structure of groups varies and includes either one adult male and one female (about 50% of the groups), two to three males and one female (about 40% of the groups), or one male and two females (about 10% of the groups) (Baker et al. 1993; Dietz & Baker 1993). In addition to these dominant, breeding adults, there are subadults, juveniles, and infants of both sexes which are usually the offspring of the breeding pair(s). If there are more than two adult males within the group, one maintains dominance over the other by physical fighting, lunging and displacing the subordinate animal, and displays such as "arch-walking" where the dominant male arches his back as he walks quadrupedally along a branch (Baker et al. 1993). Dominance relationships between adult males and females are determined by which animal has been on the group territory the longest period of time. For example, a newly immigrated male has not been on the territory as long as a female who inherited her mother's breeding position and she will therefore be dominant over him, displacing him at feeding sites (Bales 2000). In captivity, golden lion tamarins are usually housed in family groups with just one breeding pair and their offspring of various ages. At around two years old, offspring may be removed from the social group and paired with an unrelated member of the opposite sex to begin their own family group (Cohn 1997).

Females within the wild group are generally related to each other, usually as mother-daughter or as sisters, while adult males may be non-natal. This configuration exists because of the dispersal patterns of young golden lion tamarins; both males and females disperse by the age of four, but if the breeding female within a group dies or disappears before a young female has dispersed, she will inherit her mother's breeding position in the group and the adult breeding male in the group, presumably her father, will leave (Baker & Dietz 1996). Young male golden lion tamarins, however, usually do not inherit their father's breeding position and disperse, forming roaming, single-sex groups looking for immigration opportunities. These roaming bands do not have specific territories and usually move between groups in home ranges that overlap multiple groups (Kleiman et al. 1988; Baker & Dietz 1996). Young males have been recorded inheriting their natal territories, but they are more likely to disperse and find a new territory (Bales per. comm.). Males have significantly higher success of joining a group after dispersing from their natal groups compared to females. More than 70% of females that leave their natal groups die or disappear before joining another group and becoming the breeding female (Dietz & Baker 1993).

Patterns of immigration are highly sex-biased, with males representing 85% of the immigration events (Baker & Dietz 1996). Adult males immigrate into a neighboring group from a roaming band if the dominant breeding male of a group dies or disappears, leaving a "vacancy," or immigrant males may hostilely take over the breeding position and eject a resident breeding male from his group (Baker & Dietz 1996). When there is a hostile takeover, often two immigrant males (usually brothers) will move into a group and only one of them will become the breeding male and behaviorally suppress the other through dominance interactions (Baker et al. 2002). Another reason a breeding "vacancy" may become available is if the breeding female in a group dies or disappears and her daughter subsequently becomes the dominant breeder. Rather than the dominant male mating with his probable daughter, he leaves the group and an immigrant, unrelated male takes his place (Baker et al. 2002).

In general, the dominant male and female within the group behaviorally restrict mating opportunities between other adult group members (Baker et al. 2002). In groups with two breeding females, they are usually mother and daughter and both will mate with the dominant male (Dietz & Baker 1993). If intruders from a roaming band attempt to move into the territory, the dominant male and female are quite aggressive towards them. Breeding males in an established wild group generally chase male intruders away, while both females and males will chase female intruders away (Baker & Dietz 1996; Baker et al. 2002). This severe aggression toward female intruders may be what limits their success in dispersing from their natal groups (Cohn 1997). In captivity, males rarely show aggression toward intruders of either sex while dominant females are highly intolerant of female intruders and agonistically display at, chase, charge, grab, and attack them (French & Inglett 1989).

Golden lion tamarins exhibit territorial behavior not only as a form of mate defense, restricting access to the breeding female or male within the group, but also as home range defense. They are highly territorial and act to distinguish home range boundaries and keep other groups from exploiting food resources within their territory (Peres 2000). Most encounters between neighboring golden lion tamarin groups occurs during the first few hours of the morning as the monkeys emerge from their sleeping sites and begin to vocalize and wait for responses from other groups (Peres 1991; 2000). Long-range calling to one another increases in frequency as groups move closer to each other, but if groups do encounter each other face-to-face, usually the type of vocalizations change and increase in frequency and intensity and eventually escalate to fighting between the adult males of each group (Peres 1991). Aggressive interactions between males include posturing, chasing, displays, and fights. These encounters occur over an invisible territory boundary and usually end as the groups lose interest (Peres 1991).

REPRODUCTION

Golden lion tamarins have a monogamous mating system both in captivity and in the wild. Even when there are multiple males and one female, only one male and one female reproduce. On some occasions, golden lion tamarins are polygynous, where one male mates with two females, usually a mother-daughter pair (Baker et al. 1993; Dietz & Baker 1993; French et al. 2002). In this case, both females can produce offspring, though it is quite rare when it occurs (Dietz & Baker 1993).

Wild lion tamarins are seasonal breeders and they time reproduction and parturition with seasonal variation in rainfall (French et al. 2002). The peak period of reproductive activity occurs from late March through mid-June (the end of the rainy season) and the majority of births occur between September and February (the rainy season) (Kleiman et al. 1988; French et al. 2002). This pattern corresponds to the period of highest fruit availability and foraging opportunities for insects and other vertebrate prey (Dietz et al. 1994a). Because nursing is extremely energetically expensive, female golden lion tamarins have adapted a system of birth and nursing during the time of year with the lowest amount of nutritional stress (French et al. 2002). In captivity, golden lion tamarins do not exhibit seasonal birth patterns like their wild counterparts, but births are not distributed evenly throughout the year, either. The breeding season lasts from about March to September and no litters are produced during the winter months (French et al. 2002).

Female golden lion tamarins reach sexual maturity between 15 and 20 months of age, though because of their social structure, usually do not reproduce until they are 30 months old (Kleiman et al. 1988; Dietz et al. 1994a). In the wild, female golden lion tamarins first reproduce between two and six years of age, but the average age of first reproduction is 3.6 (Bales et al. 2001). The ovarian cycle lasts about 19 days and there is neither menstruation nor any external signs of estrus. Golden lion tamarins are anovulatory during the non-breeding season and therefore will not conceive except during the breeding season (French et al. 2003). Like many callitrichids that are cooperative breeders, the dominant female physiologically suppresses ovulation in subordinate group members, and a female in the group will not reproduce unless she occupies the social status of breeding female (French et al. 2003). With only one breeding male per group, younger females may not have the opportunity to mate with him because their mother, the dominant breeding female, acts aggressively to prevent mating or, if the male is likely the father of the younger female, she may avoid mating with him as an adaptation to avoid incest (French et al. 2002). Compared to females, little is known about male reproductive development, but male puberty is thought to occur around 28 months of age (Kleiman et al. 1988; French et al. 2002).

Copulations occur throughout the ovarian cycle, with the peak number of copulations occurring during the highest period of fertility (Kleiman 1977). Males solicit females by approaching and sniffing them more frequently, grooming more often, and displaying by tongue-flicking to entice the receptive female. The female also increases the number of approaches towards and sniffing of the male in the days just before peak receptivity (Kleiman 1977; Kleiman et al. 1988). Gestation lasts about four months (125 days), and within a month after parturition females begin to cycle normally, though they will not conceive until the following breeding season (French et al. 2002). If a female gives birth early enough in the season and the infants die, she is able to conceive again that year, but generally, wild golden lion tamarins only give birth to one litter per year unless food resources are extremely abundant, and even then second litters are born only about 20% of the time. The average interbirth interval is 311 days (Dietz et al. 1994a). In captivity, about one-third of females produce two litters per year and there has been a report of three litters being born to one female in a year (Dietz et al. 1994a).

PARENTAL CARE

As cooperative breeders, callitrichid mothers are not the only ones that care for infants and juveniles in the group. All members of the group take turns carrying and providing solid food for the infants (Kleiman et al. 1988; Bales et al. 2002; Tardif et al. 2002). Though they forgo breeding opportunities by remaining in the group and not breeding, younger group members benefit from cooperative rearing of infants because they gain valuable parental experience and invest in the survival of their younger brothers and sisters, thereby increasing their inclusive fitness (Kinzey 1997; Bales et al. 2000; Tardif et al. 2002). One of the reasons this system of cooperative breeding may have evolved is the tendency for callitrichids to give birth to twins. A golden lion tamarin mother would not be able to successfully carry and feed two or three infants on her own without sacrificing the infants' well-being. By enlisting the help of other group members, she is able to raise the infants with assistance as all members of her family take turns carrying and caring for her offspring (Tardif et al. 2002). Other infant care behaviors exhibited by group members include foraging tutoring, huddling with young at night and during periods of rest to reduce heat loss, protection against predators through increased vigilance, grooming, and playing to increase socialization (Rapaport & Ruiz Miranda 2002; Tardif et al. 2002; de Oliveira et al. 2003). The role of helpers and the experience level of the mother are crucial in the survival of infants (French et al 1996; Santos et al. 1997). Infants are most vulnerable during the first week of life and survival is particularly related to the parental and helping experience of the mother. A female that is nulliparous has lower offspring survivorship than one that is multiparous and a female with previous helping experience has higher offspring survivorship than one that has never carried or cared for an infant (French et al. 1996).

Data on infant development from captive studies provides information about parent/offspring interactions in golden lion tamarins. The dependent infant phase in golden lion tamarins lasts from one to four weeks and is characterized by relying on the mother for transport and nursing. Infants in this stage are dorsally carried almost constantly by the mother while other group members intensely interested in the infants touch, sniff, and mouth them (Hoage 1982). Infants lean or reach off their mother during this time and are interested in other group members and their environments. They are able to vocalize and do so if they are dislodged from their mothers or are rejected by other potential carriers. After week three, mothers rapidly decrease the amount of time spent carrying the infants and the father and other group members over the age of one become the primary transporters. As they grow, infants begin to spend more time off of carriers, moving independently. By week four, about 10% of their time is spent off carriers (Hoage 1982).

Weeks five through 16 are the advanced infant stage and infants spend increasingly less time being carried and more time moving independently and exploring their environment. By week 11 they spend about 80% of their time off of carriers (Tardif et al. 2002). Mothers and other group members reject the infants' attempts at being carried starting at week five, though fathers are generally more tolerant than other group members and will carry infants into week 12 (Tardif et al. 2002). It is during the advanced infant phase that weaning begins (around week five), and by week 12, they cease nursing. Infants begin to try solid food before they are weaned, but during the weaning period, intake of solid food increases because they beg group members or are given food by their caretakers (Hoage 1982). Food transfer to young golden lion tamarins lasts throughout their development, until about 21 months of age, though the amount and frequency of food shared by older group members significantly decreases after nine months of age (Tardif et al. 2002). Infants and juveniles receive fruit, insects, and animal prey from older members of the group and are sometimes taught where and how to catch prey by older group members (Rapaport & Ruiz-Miranda 2002).

The young juvenile phase lasts from weeks 17 through 28 and it is during this time that young golden lion tamarins play with and groom other group members. By the time they reach the advanced juvenile phase, weeks 29 through 40, the mother has probably given birth to a new set of twins and the juveniles begin to exhibit great interest in their younger siblings (Hoage 1982). The young subadult phase lasts from about 41 to 52 weeks and tamarins exhibit almost the full suite of adult behaviors, including first sexual behaviors. This stage lasts until sexual maturity at which point the golden lion tamarins will be true adults (Hoage 1982).

COMMUNICATION

Golden lion tamarins use visual, vocal, and chemical systems to communicate to other members of their group and conspecifics. The repertoire of visual signals is limited compared to the other communication forms, but includes both postural and facial expressions that act as signals to nearby individuals (Kleiman et al. 1988; Kinzey 1997). Visual signals are not very efficient means of communication for small-bodied animals that live in dense forests, nonetheless they exhibit tongue flicking, arch-walking, tail thrashing, rump displays and piloerection in sexual and social contexts (Kinzey 1997; Ruiz-Miranda & Kleiman 2002). Most visual signals are used during territorial encounters, social interactions, and reproductive events (Ruiz-Miranda & Kleiman 2002).

Often accompanying visual signals but more importantly serving as long-distance communication are vocal signals. There are six discrete categories of vocalizations in golden lion tamarin communication: tonal, clucks, trills, atonal, multisyllable, and combination (Ruiz-Miranda & Kleiman 2002). Tonal vocalizations include the "whine" and "peep" calls and serve as alarm and affiliation calls. "Whines" are given in reaction to the presence of predators while "peeps" are sounded by solitary young after being reunited with the group or by any group member upon finding food (Kleiman et al. 1988; Boinski et al. 1994; Ruiz-Miranda & Kleiman 2002). "Clucks" signal reaction to the presence of a novel item or are giving during foraging bouts. They also can signal aggression when golden lion tamarins encounter neighbors or intruders and are given while chasing or mobbing predators (Kleiman et al. 1988; Boinski et al. 1994). "Trills" have multiple purposes but mainly serve to indicate the location of the caller to other individuals over long distances. Atonal calls such as "rasps" or "screeches" are heard mostly during playing or as playing escalates to fighting (Kleiman et al. 1988; Boinski et al. 1994). Multisyllable calls include the most important vocalizations for group cohesion, the "short" and "long calls." These are typically heard as golden lion tamarins leave their sleeping sites in the morning to localize their neighbors and are heard throughout the day as individuals keep in vocal contact with other group members (Peres 1991; Ruiz-Miranda & Kleiman 2002). Combination calls also serve multiple purposes and include "trill-rasps," "trill-whines," and "cluck-whines." These are used by juveniles begging for attention, protection, or food or by group members as they defend their territory against intruders or predators (Ruiz-Miranda & Kleiman 2002).

The most specialized form of communication exhibited by golden lion tamarins is the chemical communication system relayed by scent marking surfaces throughout their territories. Scent glands on their chest and around their genitals are activated as they are rubbed along a surface, leaving behind chemical signals to other group members and conspecifics (Ruiz-Miranda & Kleiman 2002; Miller et al. 2003). Some of the purposes of scent marking include conveying reproductive status and individual identification, social regulation, location of food resources, and parent-offspring interactions. Reproductive males and females do most of the scent marking among golden lion tamarins and the behavior is rarely seen among juveniles or nonreproductive individuals still in their natal group (Hoage 1982; Ruiz-Miranda & Kleiman 2002). Dominant males within a group scent mark to signify social status and reinforce dominance to other group members; this behavior may be linked to behavioral suppression of reproduction seen among subordinate males. Both males and females mark specific sites on their way to food areas within their home ranges and on the edges of their territories probably to facilitate relocation of food resources among members of the group (Miller et al. 2003). Marking fruit trees and the paths to food resources is much higher during the wet season and could be due to seasonal rain abundance washing away scent marks more frequently than during the dry season (Miller et al. 2003).

Content last modified: December 1, 2010

Written by Kristina Cawthon Lang. Reviewed by Karen Bales and Lisa G. Rapaport.

Cite this page as:
Cawthon Lang KA. 2010 December 1. Primate Factsheets: Golden lion tamarin (Leontopithecus rosalia) Behavior . <http://pin.primate.wisc.edu/factsheets/entry/golden_lion_tamarin/behav>. Accessed 2013 May 20.