Allogrooming, partner choice, and dominance in male anubis baboons

This study was designed to test the hypothesis that among unrelated male baboons (Papio cynocephalus anubis) in single-gender social groups there is no significant association between dominance status and allogrooming performance. The hypothesis was tested using behavioral measures obtained by focal animal sampling techniques. The results indicate that unrelated male baboons established well-defined linear dominance hierarchies, formed allogrooming relationships with one another, and exhibited a nonrandom distribution of allogrooming; however, there were no significant relationships between dominance rank and the frequency of allogrooming. We further tested our results by grouping individuals into three dominance status classes (high, middle, and low) and comparing the classes. Analysis of variance demonstrated no significant differences in rates of allogrooming by dominance class. These results suggest that dominance did not account for the variation in observed allogrooming behavior: Dominance status did not appear to determine the frequency with which animals groomed others, the number of grooming partners, or frequency of grooming that any individual received in comparison to that performed. High-ranking animals did not have significantly more grooming partners than low-ranking animals, and there appeared to be little competition within the groups for subordinates to groom high-ranking animals. When age, kinship, and group tenure are controlled, performance and reception of allogrooming are not strongly associated with dominance in single-gender social groups of male anubis baboons.     

Correlates of Self-Directed Behaviour in Wild White-Faced Capuchins

Elevated rates of self‐directed behaviour (SDB) such as self‐scratching and autogrooming have been widely used in recent years as an indicator of anxiety in catarrhine primates. This study presents the first examination of correlates of SDB rates in a platyrrhine primate. Subjects were 8 wild female white‐faced capuchins at Lomas Barbudal, Costa Rica, who were observed for 119 h of focal individual follows. The subjects performed significantly more self‐scratching and autogrooming while in close proximity to conspecifics than while alone, irrespective of whether the neighbour was dominant or subordinate to them. This result was attributable to elevated SDB rates during the 30 s preceding and following allogrooming bouts. Furthermore, subjects engaged in more SDB while in proximity to females (a) that were closer to them in dominance rank and (b) with whom they spent a larger proportion of their time in proximity. Self‐directed behaviour rates after conflicts did not differ from non‐postconflict rates. Nor were SDB rates above baseline levels during the 30 s before subjects descended to the ground. These results may provide support for the view that SDB rates index anxiety in this species, if grooming decisions signal individuals' current allegiances and are therefore a source of anxiety, even if being groomed is, itself, relaxing. Postconflict preparation for further aggression may mitigate against scratching and autogrooming in a fast‐moving arboreal species.     

笼养川金丝猴理毛行为功能

<正>理毛行为(Grooming behavior)的定义是动物个体对自身或其同类个体体表(皮肤、毛发或羽毛等)进行的多种形式护理,包括对体表进行有规律的梳理,以及用舌头或嘴唇舔皮肤和毛发等(Veà et al., 1999)。在灵长类动物中,理毛行为大多表现为个体接触和探查自身或另一个体体表被毛,将毛发分开后从中拣出盐粒或皮肤寄生物放入口中咀嚼或直接用嘴咬食被毛下的盐粒或皮肤寄生物(李银华和李保国, 2002)。依据理毛接收对象的不同,可将     

Allogrooming Behavior and Grooming Site Preferences in Captive Bonobos (Pan paniscus): Association with Female Dominance

I tested the utility of Seyfarth's (1977) model of rank-related attractiveness to explain the distribution of allogrooming behavior among captive bonobos (Pan paniscus). Adult female bonobos generally have high social status and may be dominant over males. As predicted by the model, I found that high-ranking adult females received most allogrooming within each of the four investigated groups. Among adult female-adult female dyads, however, allogrooming was not clearly associated with dominance rank. Contradictory to predictions of the model, the highest-ranking females were responsible for most displacements over allogrooming, and grooming competition is positively correlated with dominance rank. In the second part of this study, I investigated the social significance of allogrooming body site preferences. Bonobos direct significantly most allogrooming to the face of conspecifics, and high- and low-ranking individuals, as well as males and females, differ significantly in their preferences for certain allogrooming sites. Subordinates and males tended to avoid facial grooming and preferred the back and anogenital region, while high-ranking individuals and females directed most allogrooming to the face and head of grooming partners. Data from this study support the hypothesis that high-ranking females are the most attractive grooming partners within a female-centered bonobo society. Many other aspects of allogrooming behavior, however, are not consistent with the model of rank-related attractiveness.     

灵长类相互理毛的影响因素、功能及其利益分析

理毛行为是动物行为学研究的主要内容之一,根据理毛的对象可分为自我理毛(Autogrooming)和相互理毛(Allogrooming),其中相互理毛是灵长类重要的社会行为。现在认为相互理毛可能与社会参量(亲缘关系、性别、年龄、等级制度、繁殖状况等)有联系,并且有一定的社会功能。本文论述了理毛行为的分类、影响相互理毛的因素、相互理毛功能假说及其相互理毛的投入-收益分析,以便人们对相互理毛的行为进行更深入的研究。     

Experimental analysis of causal relationships between grooming behavior and inter-individual proximity in the stumptailed macaque (Macaca arctoides): a preliminary report

Some causal relationships between allogrooming, autogrooming, locomotion and close proximity in the behavior of one (adult female) Macaca arctoides while in the presence of another (adult male) monkey of the same species are reported. Allogrooming reduces the probability of walking away in the groomer, and thus increases the time spent close to the other monkey; autogrooming seems to have a similar effect. The duration of autogrooming is increased in a non-proportional manner by reduction of locomotion, but the duration of autogrooming seems to directly reduce the amount of locomotion. Up to a certain optimal value, the duration of autogrooming increases accordingly as the time spent close to the other monkey increases. The duration of allogrooming may be influenced in the same way as the duration of autogrooming.     

Differential effects of ambient temperature and humidity on allogrooming, self-grooming, and scratching in wild Japanese macaques

This study presents data on the effects of variations in ambient temperature and humidity on behaviors related to the care of the pelage (allogrooming, self-grooming, and scratching) in wild Japanese macaques (Macaca fuscata yakui). The amount of time monkeys spent allogrooming was essentially unaffected by variations in ambient temperature and relative humidity. Frequency of scratching and, to a lesser extent, time spent self-grooming significantly increased when ambient temperature and/or relative humidity increased. These results are interpreted in relation to the differences in ultimate function that exist between allogrooming (with both hygienic and social functions) and self-grooming and scratching (with a solely hygienic function).     

Conflict,displacement activities,and menstrual cycle in long-tailed macaques

This study was aimed at testing whether the female menstrual cycle is associated with changes in social tension experienced by eight heterosexual pairs of long-tailed macaques (Macaca fascicularis). Displacement activities were considered as a behavioral measure of social tension and recorded during the periovulatory and the menstrual flow phases of the cycle. While male yawning and body shake underwent nonsignificant increases, male autogrooming and scratching increased significantly during the periovulatory phase. Female displacement activities did not show any significant difference between the two phases. Male and female socio-sexual behavior was not affected by the menstrual cycle. These results suggest that the male conflictual state, but not the female one, is affected by female menstrual cycle.     

The costs of dominance: testosterone, cortisol and intestinal parasites in wild male chimpanzees

Background

Male members of primate species that form multi-male groups typically invest considerable effort into attaining and maintaining high dominance rank. Aggressive behaviors are frequently employed to acquire and maintain dominance status, and testosterone has been considered the quintessential physiological moderator of such behaviors. Testosterone can alter both neurological and musculoskeletal functions that may potentiate pre-existing patterns of aggression. However, elevated testosterone levels impose several costs, including increased metabolic rates and immunosuppression. Cortisol also limits immune and reproductive functions.

Methods

To improve understanding of the relationships between dominance rank, hormones and infection status in nonhuman primates, we collected and analyzed 67 fecal samples from 22 wild adult male chimpanzees (Pan troglodytes schweinfurthii) at Ngogo, Kibale National Park, Uganda. Samples were analyzed for cortisol and testosterone levels as well as intestinal parasite prevalence and richness. 1,700 hours of observation data were used to determine dominance rank of each animal. We hypothesized that dominance rank would be directly associated with fecal testosterone and cortisol levels and intestinal parasite burden.

Results

Fecal testosterone (but not cortisol) levels were directly associated with dominance rank, and both testosterone and cortisol were directly associated with intestinal parasite richness (number of unique species recovered). Dominance rank was directly associated with helminth (but not protozoan) parasite richness, so that high ranking animals had higher testosterone levels and greater helminth burden.

Conclusions

One preliminary interpretation is that the antagonist pleiotropic effects of androgens and glucocorticoids place a cost on attaining and maintaining high dominance rank in this species. Because of the costs associated with elevated steroid levels, dominance status may be an honest signal of survivorship against helminth parasites.     

Grooming site preferences in primates and their functional implications

The hypothesis that skin care is an important function of allogrooming in primates was evaluated in the light of data on its physical distribution in a wide range of species. It was found that the distribution of autogrooming (assumed to be primarily utilitarian) and allogrooming over 17 body sites were complementary and that allogrooming was concentrated on areas which are inaccessible and/or invisible to an autogrooming animal. However, within accessible and inaccessible site categories, allogrooming was evenly distributed over the body surface, despite any special social or communicatory significance that particular sites may have. Intertaxonomic differences in the distributions of both types of grooming, notably between anthropoids and lemurs, lent further support to the notion of complementarity. It was concluded that the data support previous suggestions linking allogrooming site preferences with a utilitarian function, analytic and methodological differences being the probable explanation for discrepancies between these results and those obtained in another study.     

Allogrooming in cattle: Relationships between social preferences,feeding displacements and social dominance

The aim of this study was to describe the allogrooming behaviour of group-housed lactating cows (Bos taurus) as it relates to social dominance, friendship, parity and level of feeding competition. We measured the socio-negative (displacements at the feeder and in the lying stalls) and socio-positive interactions (allogrooming and preferential spatial associations) in six groups of eight dairy cows. This experimental model has been shown to be useful in investigating the effects of high social pressure in groups of cattle. The level of social competition was manipulated by halving the access to the feeder. Allogrooming was observed mostly at the feeder after fresh feed delivery and during the night between 12 and 2 a.m. Dominance rank had no effect on the expression of allogrooming. When competition between animals increased, allogrooming declined, especially in low-ranking, primiparous animals. In addition to its role in coat hygiene and potential role in reducing tension between animals competing for feed, we conclude that allogrooming may be a behaviour reflecting friendship in cows, because it is correlated to preferential associations between partners at the feeder. We suggest that primiparous cows are more susceptible to suffer from a lack of hygiene or socio-positive relationships when submitted to high competitive pressure, especially when they are mixed with more experienced animals that could have better coping strategies in a high competition situation.     

Effects of exposure to 30 kV/m, 60-Hz electric fields on the social behavior of baboons

We tested the hypothesis that exposure to a 30-kV/m, 60-Hz electric field produces significant change (stress) in the social behavior of adult male baboons (Papio cynocephalus anubis). One group of eight baboons was exposed to an electric field (12 hours per day, 7 days per week for 6 weeks) while a second group of eight baboons was maintained in a sham-exposure (control) condition. Exposed subjects and control subjects were compared over three, six-week experimental periods (pre-exposure, exposure, and post-exposure). Performance rates of six categories of social behaviors (passive affinity, active affinity, approach, tension, threat, and attack) and four categories of nonsocial behaviors (forage, manipulate, posture, and stereotypy) were used to compare the two groups. The results of our study indicate that 1) there were no significant differences between the two groups during the pre-exposure or post-exposure periods; 2) during the exposure period, experimental and control groups exhibited statistically significant differences in the mean performance rates of three behavior categories; 3) within-group comparisons across periods indicate that the experimentally exposed group exhibited statistically significant changes in passive affinity, tension, and stereotypy; and 4) changes in behavior performance among the exposed subjects reflect a stress response to the electric field.     

Grooming site preferences in wild white-handed gibbons (Hylobates lar)

During a four-month study of wild white-handed gibbons in Thailand one group was observed for 131 hr. The individuals spent 5.2% of their activity period allogrooming. Several body sites received more respectively less allogrooming than expected. Surface areas easy to clean by autogrooming such as the belly received significantly less allogrooming than expected. Upper body areas which are likely to be infested by parasites and other matter received significantly more allogrooming than lower body parts. Thus, grooming in gibbons seems to reflect a primarily hygienic function.     

Agonistic dominance in male baboons: An alternative view

Data on baboons have generated both the concepts normally associated with male dominance hierarchies among primates and the tests of their significance. The priority-of-access model has been used to predict the relationship between dominance rank and resource acquisition. While the correlation between these two factors, or between rank and measures of reproductive success, has varied among different primate species, most recent baboon field-workers have interpreted their results to be consistent with the model. Based on 1200 hr of observation of a troop of savannah baboons near Gilgil, Kenya, this paper presents data on male agonistic interactions and on male acquisition of resources. Predictions of the priority-of-access model are tested and an inverse relationship is found between agonistic dominance rank and acquisition of two limited resources, estrous females and meat. The importance of the residency status of males is explored and an alternative hypothesis is presented to account for the anomalous pattern in the data. The relationship of male reproductive success and dominance rank is evaluated in light of the data on these baboons and the “residency” hypothesis.     

Hormonal correlates of natal dispersal and rank attainment in wild male baboons

In many mammals, maturational milestones such as dispersal and the attainment of adult dominance rank mark stages in the onset of reproductive activity and depend on a coordinated set of hormonal and socio-behavioral changes. Studies that focus on the link between hormones and maturational milestones are uncommon in wild mammals because of the challenges of obtaining adequate sample sizes of maturing animals and of tracking the movements of dispersing animals. We examined two maturational milestones in wild male baboons—adult dominance rank attainment and natal dispersal—and measured their association with variation in glucocorticoids (fGC) and fecal testosterone (fT). We found that rank attainment is associated with an increase in fGC levels but not fT levels: males that have achieved any adult rank have higher fGC than males that have not yet attained an adult rank. This indicates that once males have attained an adult rank they experience greater energetic and/or psychosocial demands than they did prior to attaining this milestone, most likely because of the resulting participation in both agonistic and sexual behaviors that accompany rank attainment. In contrast, natal dispersal does not produce sustained increases in either fGC or fT levels, suggesting that individuals are either well adapted to face the challenges associated with dispersal or that the effects of dispersal on hormone levels are ephemeral for male baboons.     

Sun avoidance in the yellow baboons (Papio cynocephalus cynocephalus) of Ruaha National Park, Tanzania. Variations with season, behavior and weather

Do free-ranging baboons avoid traveling towards the sun? Sun avoidance, in addition to resource and predator locations, may influence troop movement and non-random use of the home range. This paper investigates how sun avoidance, as measured by facial exposure to sunlight, influences directional choices. It hypothesizes that baboons should avoid the sun in the hot, dry season and show indifference to it in the cool, lush season. This paper also hypothesizes that baboons employ sun-avoidance behaviors more while they forage or travel to resting sites than when they travel to foraging sites or engage in active social behaviors; lastly this paper hypothesizes that sun altitude, temperature, humidity, and cloud cover influence sun-avoidance behavior. Using focal-animal techniques on 21 males from free-ranging baboon troops, I collected locational data, accurate to within 1.6 m, over 15 months. I calculated the difference between baboon bearings and the sun’s azimuth in angular degrees. Both linear and circular statistics indicate that baboons put significantly (P<0.01) more than 90° between their bearing and the sun’s azimuth under certain conditions. Contrary to hypotheses based on the detrimental effects of insolation, baboons in the cool, lush season avoid the sun, while baboons in the hot, dry season do not. In the lush season, the extent to which baboons avoid the sun does not depend on their other behaviors. Dry-season baboons demonstrate stronger sun avoidance while resting than when engaged in other behaviors. Finally, in the dry season, temperature drives sun avoidance; humidity drives it in the lush season.     

Male-female interactions of sika deer (cervus nippon) in nara park through allogrooming during breeding and rutting seasons

The frequency and pattern of interactions between males and females of sika deerCervus nippon were surveyed in 3 sites of Nara Park, central Japan, mainly via observation of allogrooming frequency and aggressive behavior throughout the breeding and rutting seasons. In the breeding season, the Daibutsuden group contained several adult males while Ukimido and Hakuba groups contained only a few. Most allogroomers were adult and subadult females. Females groomed the same sex more than the opposite sex at Daibutsuden, but at the other 2 sites, there was no such difference. In general, male-female interactions through allogrooming frequencies in the breeding season were not significantly fewer than intra-sex interactions. Males that attacked females tended to be groomed by females in the breeding season. In the rutting season, all adult males identified in the breeding season were absent at the usual observation sites, and newly arrived males showed defensive and/or mating behaviors. Females groomed adult males in the rutting season regardless of group status or display of sexual interactions. This suggests that male-female allogrooming in the breeding season does not relate to mating in the following rutting season, but may reduce tension in the group during the current breeding season.     

Social dominance, task performance and nutrition: implications for reproduction in eusocial wasps

Dominance status is associated with individual differences in reproductive capacity in many animal societies, but the mechanisms that link social dominance to reproductive physiology are poorly understood. We propose a model for social dynamics that incorporates the nutritional costs and benefits of behavior: dominant individuals avoid energy-expensive behavior and build their nutritional reserves, thereby increasing their potential for reproduction. Greater reproductive capacity, once achieved, favors increased social dominance. To test the model, we measured relationships of females' nutrient storage and reproductive capacities with dominance status and task performance in the eusocial wasp Mischocyttarus mastigophorus. Ovary development was positively related with high levels of nutrient storage and with high rates of dominance behavior, but was not correlated with task performance. In contrast, high levels of nutrient storage were positively related with the performance of nutrient garnering and conserving tasks, but not with dominance behavior. These data support a model which places the nutritional costs of task performance as an intermediate causal link that connects dominance status with the accumulation of nutrient stores. Nutrient flow may be a general causal mechanism linking dominance status to reproductive capacity in animal societies.     

Food distribution,dominance, and aggressive behaviors in bonnet macaques

Resource availability or distribution may affect interindividual competition in species such as primates, which forage in social groups, and several field studies suggest that dominance status predicts access to restricted food sources. Increased competition due to restricted resources may result in the intensification of aggressive behaviors. The study reported here examines the impact of manipulation of the distribution of food resources in a laboratory-housed group of bonnet macaques to assess the impact of distribution on aggressive behaviors. Food was restricted to a space which allowed access to only one or two individuals at a time or was dispersed throughout the living enclosure to allow universal access in alternating periods. During periods of clumped distribution, the monkeys obtained access to the food in order of their dominance status in the group. In addition, overall levels of aggressive behaviors increased, submissive behavior increased, and play decreased during periods of clumped distribution of food. These results confirm the findings from field studies indicating increases in agonism with restriction of food resources. These findings also have implications for primate colony management, in terms of developing strategies for minimizing intragroup aggression in captive groups.     

Tail carriage in baboons (Papio cynocephalus): relationship to dominance rank and age.

Several metric and categorical variables were used to assess tail carriage in 717 photographs of 54 yellow baboons (Papio cynocephalus) of known identity, sex, dominance rank, and estimated or known age. Analyses of these data demonstrated that age was the primary factor, influencing tail carriage of baboons not engaged in social interaction. Specifically, the proximal segment of the tail was carried increasingly close to the vertical with increasing age; other changes in tail angles and segment curvature were also correlated with age. There was no relationship between dominance rank and neutral tail carriage in adult male or female baboons, nor was the neutral tail carriage of the first-ranking male or female either distinctive or characteristic. The morphological basis of ontogenetic changes in neutral tail carriage in baboons is also discussed.