Scent-marking behaviour of the honey badger, Mellivora capensis (Mustelidae), in the southern Kalahari

We investigated sexual and seasonal patterns in scent-marking behaviour of the honey badger, by direct observations of habituated individuals (five females, four adult males, two young males). Four categories of scent-marking behaviour were identified: (1) scent marking at latrines; (2) token urination in holes along the foraging path; (3) squat marking at single-use sites; and (4) functional excretion. Females and young males used all four types of scent marking, but adult males were not observed to use token urination. A strategy of hinterland scent marking was used, as was predicted from the large home ranges of both male and female honey badgers. There were significant sexual differences in marking rate: adult males primarily used latrines and adult females favoured token urination. Latrine scent marking in adult male honey badgers provides support for the ‘scent-matching’ hypothesis. Females visited latrines when they were in oestrus. However, the low level of marking activity during a visit and the intensive smelling suggested a scent-matching function rather than reproductive advertisement. Token urination appeared to be related to the maintenance of spatiotemporal separation in females, although we also observed token urination in young males. While the placement of urine in foraging holes and its relation with successful digging attempts offer some support for the foraging efficiency hypothesis, we consider this unlikely, because we did not observe it in adult males and there was no seasonal pattern. Squat marking occurred under a wide range of conditions in both males and females and may be related to marking valuable resources. It is likely that scent marking in honey badgers has many functions.     

The role of scent marking in the social communication of wild golden lion tamarins, Leontopithecus rosalia

The role of scent marking in the social communication of mammals is widely variable. One reason for this variation is that the function of scent marking may vary with different ecological and social conditions. The purpose of this study was to test four nonexclusive hypotheses explaining the role of scent-marking frequency in different ecological and social contexts for wild golden lion tamarins. Relative to ecological contexts, we compared scent-marking frequency during seasons of abundant and scarce food resources. Relative to social contexts, we compared scent-marking frequency when groups were isolated and when groups were in the presence of neighbouring groups. We found that the tamarins used scent marking to mark the location of food resources. Additionally, males used scent marking to communicate intrasexual dominance within their groups, while females did not. Our results also indicate that alpha females increased their scent-marking frequency to communicate to members of other groups, while the presence of members of other groups did not elicit a similar response by alpha males. We did not find evidence for a territorial function of scent marking in golden lion tamarins. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour      

Sex differences in scent marking in Propithecus edwardsi of Ranomafana National Park, Madagascar

In this study we compared the scent-marking rates of females with those of males. Specifically, we examined the ability of season, dominance status, and natal status to explain the frequency of scent marking in female sifakas living wild in Ranomafana National Park, Madagascar, and compared the results with those published for males [Pochron et al., American Journal of Primatology, in press]. We also sought to determine whether vulnerability to infanticide affects marking frequency in adults of either sex, and whether female reproductive status affects female marking behavior. We found that males marked at twice the rate of females, and like males, females in single-female groups marked at the highest rates. Dominant females and non-natal females marked at higher rates than did subordinate females and natal females, a pattern also seen in males. This suggests that scent marks may convey important information about status. Neither females nor males varied their marking frequency with the presence of vulnerable infants. Females did not alter marking frequency with reproductive state, and like males, they marked at higher rates in the period prior to the mating season than they did in the mating season itself. This implies that females may use scent marks more for intrasexual aggression or territoriality than for mate attraction.     

Do cavity‐nesting primates reduce scent marking before retirement to avoid attracting predators to sleeping sites?

The largest population of endangered golden lion tamarins (Leontopithecus rosalia, GLTs) decreased from approximately 330 to 220 individuals between 1995 and 2000 due to a dramatic increase in predation at sleeping sites. We used behavioral data from eight social groups in this population to test two hypotheses: First, if GLTs attempt to mitigate the risk of predation at sleeping sites, they should reduce their rates of scent marking just prior to retirement. Second, if the benefits of scent marking prior to entering the sleeping site merit an increase in the rate of marking, then tamarins should increase their rate of pre-retirement scent marking during the breeding season, when such behavior would have its greatest impact on reproductive fitness. We used a generalized linear model (GLM) repeated-measures analysis to compare rates of daytime scent marking with rates of marking just prior to retirement for males and females. In addition, we compared scent marking prior to retiring in the nonbreeding season to marking rates before retirement in the breeding season for males and both sexes considered concurrently. Contrary to our expectations, GLTs significantly increased their rates of scent marking during the 30 min prior to entering their sleeping site-an observation driven by an increase in male (but not female) rates of marking. Rates of marking before entering the sleeping site were greater in the nonbreeding season compared to the breeding season, when both sexes were considered concomitantly and when males were evaluated alone. We conclude that GLTs do not attempt to minimize predation risk by decreasing scent marking in the period before they enter their sleeping site, and that tamarins do not scent mark at this time of day in order to transmit information about reproductive status or to control reproduction of subordinates. We speculate that scent marking in the 30 min prior to entering sleeping sites may serve to reduce predation risk by enabling tamarin groups to return quickly to favored sleeping sites in the evening when crepuscular predators are active.     

Sociosexual development,pair bond formation,and mechanisms of fertility suppression in female cotton-top tamarins (Saguinus oedipus oedipus)

The effect of various social environments on sociosexual behavior was examined in six young female cotton-top tamarins (Saguinus oedipus oedipus) and in three established breeding females. Behavioral observations and hormonal samples were collected on young females while they were living with their families, when they were isolated from conspecifics, and after they were paired with an unrelated male. While living with the family, all females showed a suppression of fertility and low frequencies of sociosexual behavior. Following removal from the family, isolated females displayed an increase in rate of scent marking and an increase in hormonal levels. When young females were paired with males, they were exposed to scent secretions from their natal families, from an unfamilar family, and from a control for a total of 24 weeks. After pairing, hormonal levels increased dramatically, and ovarian cyclicity began. An increase in sociosexual behavior and elevated levels of scent marking accompanied this physiological change. Newly paired females had higher rates of affiliative behavior and scent marking than did established breeding females. However, both newly paired and established breeding males were more likely to initiate contact, grooming bouts, and social sniffing than were females. Time to first ovulation was later in females who were exposed to scent secretions from their natal families than it was in those females given a control for the first 8 weeks following pairing. No female conceived during exposure to scent secretions. However, once normal ovarian cycling had begun or a pregnancy was established, exposure to scent secretions had no effect. Thus, the social environment influences the fertility, sociosexual behavior, and pair bond formation of cotton-top tamarins. In addition, chemical stimuli found in the scent secretions produced by the natal family are most likely involved in reproductive suppression.     

Scent marking strategies of New World primates

This paper reviews recent findings on scent-marking behavior in wild New World primates. These findings are used to examine three functional hypotheses: territoriality, regulation of social and reproductive dominance, and mating competition/mate attraction. Available data provide little evidence for a territorial function of scent-marking behavior in New World primates. Evidence for a function in the regulation of social and reproductive dominance is ambiguous. The patterns of scent marking found so far (i.e., rates of scent marking according to sex and social or reproductive status, and the spatial distribution of scent marks), and the sparse information on responses to scent marks are consistent with a hypothesized function in intrasexual competition and intersexual mate choice. Suggestions for future research are made.     

Scent-marking in the tamarin, Saguinus oedipus: Sex differences and ontogeny

Many mammalian species which exhibit scent-marking behaviour show a pronounced sexual dimorphism in marking behaviour and scent gland morphology. However, several species of marmosets and tamarins do not show dimorphism in these traits. We examined sex differences in scent-marking structures and behaviour in cotton-top tamarins (Saguinus o. oedipus; Primates: Callitrichidae). While body size and weight were virtually identical in adult males and females, there were pronounced sex differences in scent gland size and in rates of marking behaviour. Females possessed larger anogenital and suprapubic glands and showed 10-fold higher rates of anogenital marking and slightly higher rates of suprapubic marking than males. Observations on the development of anogenital marking revealed a lack of dimorphism during the first 2 years. Adult rates of anogenital marking in females were only observed in females housed separately from their natal family group. The onset of adult levels of marking behaviour corresponds with the adoption of the role of a breeding adult female, suggesting that anogenital marking plays a role in sexual communication.     

Subadult brown bears (Ursus arctos) discriminate between unfamiliar adult male and female anal gland secretion

Olfactory cues have been investigated in social carnivores, many of which use anal/anogenital gland secretion (AGS) for scent marking. However, little is known about how solitary carnivores, such as ursids, use AGS in communication. We hypothesized that subadult (1–3 years) brown bears (Ursus arctos) have the ability to discriminate between unfamiliar adult male and female AGS. Confrontations, especially with adult males, carry high risks for dispersing subadults, so they benefit from the ability to assess potential threats based on olfactory cues, including sex, enabling them to avoid risky encounters. We presented AGS from free-ranging adult brown bears (male = 10, female = 10) to subadult brown bears (male = 13, female = 7) in outdoor zoo experiments, and predicted that subadults would avoid male more than female AGS. Neither male nor female AGS were avoided, but subadults quickly habituated to female AGS. However, male AGS was investigated more intensively and the subadults delayed revisiting it. Subadult tended to take longer to complete 6 visits to male than female AGS, which indicated sexual discrimination. We suggest that subadults that store information for the purpose of scent matching in future encounters may reduce their potential costs of conflict based on their prior assessment of the likely outcome of the encounter.     

Does human infrastructure shape scent marking in a solitary felid?

Human development, such as construction of roads and trails, can affect several animal behaviour traits and is increasing worldwide. Despite the importance of scent marking for communication and social organization in many mammals, it is not clearly understood how scent marking is affected by human habitat modification. We used snow tracking data collected across six winters to study the effects of road infrastructure on the marking behaviour of Eurasian lynx (Lynx lynx) in a human-dominated landscape. We found that lynx marked at higher rates (11.2 urine sprays/km) on human routes (forest roads and logging trails) than when walking in natural habitat (5.8 sprays/km). This pattern was noted in both sexes, although males walked on human routes more frequently and scent marked more often than females. Compared to previous studies the mean marking rates we observed were the highest documented so far for wild felids. This may mainly be due to regular use of human routes (42% of all lynx movement) and the high scent marking rates found thereon. Human routes channelize lynx movement, and scent marking on these routes likely increases the probability of the chemical message being received by a conspecific; therefore human routes might enable more effective communication in territorial felids. Since most of the landscapes worldwide are covered by road networks and various human objects, the marking behaviour of wild mammals may be profoundly changed due to human-caused habitat modifications.     

Dominance,aggression and physiological stress in wild male Assamese macaques (Macaca assamensis)

In group-living animals relative rank positions are often associated with differences in glucocorticoid output. During phases of social stability, when dominance positions are clear and unchallenged, subordinates often face higher costs in terms of social stress than dominant individuals. In this study we test this prediction and examine additional potential correlates of stress, such as reproductive season, age and amount of aggression received in wild, seasonally breeding Assamese macaques (Macaca assamensis). During a mating and a non-mating season we collected 394 h of focal observational data and 440 fecal samples of six adult and six large subadult males living in a multimale–multifemale group in their natural habitat in northeastern Thailand. The mating season was characterized by a general increase in aggressive behavior and glucocorticoid excretion across all males compared to the non-mating season. Among adult males, mating season glucocorticoid levels were significantly negatively related with dominance rank and positively with the amount of aggression received. Both relationships were non-significant among large subadult males. Thus, our results suggest that in adult Assamese macaques a high dominance position is not associated with high costs. Low costs of dominance might be induced by strong social bonds among top-ranking males, which exchange frequent affiliative interactions and serve as allies in coalitionary aggression against potentially rank-challenging subordinate males.     

Dominance, aggression and physiological stress in wild male Assamese macaques (Macaca assamensis)

In group-living animals relative rank positions are often associated with differences in glucocorticoid output. During phases of social stability, when dominance positions are clear and unchallenged, subordinates often face higher costs in terms of social stress than dominant individuals. In this study we test this prediction and examine additional potential correlates of stress, such as reproductive season, age and amount of aggression received in wild, seasonally breeding Assamese macaques (Macaca assamensis). During a mating and a non-mating season we collected 394 h of focal observational data and 440 fecal samples of six adult and six large subadult males living in a multimale–multifemale group in their natural habitat in northeastern Thailand. The mating season was characterized by a general increase in aggressive behavior and glucocorticoid excretion across all males compared to the non-mating season. Among adult males, mating season glucocorticoid levels were significantly negatively related with dominance rank and positively with the amount of aggression received. Both relationships were non-significant among large subadult males. Thus, our results suggest that in adult Assamese macaques a high dominance position is not associated with high costs. Low costs of dominance might be induced by strong social bonds among top-ranking males, which exchange frequent affiliative interactions and serve as allies in coalitionary aggression against potentially rank-challenging subordinate males.     

Tamarine – die etwas anderen Primaten

Tamarins – the slightly different primates Unusual for primates, callitrichids are characterized in their social organization by a male‐biased sex ratio and in their social breeding system by a high degree of flexibility with prevailing polyandry, particularly in tamarins. Social polyandry contrasts with a general monopolization of paternities by a single male, i.e. genetic monogamy. Unique amongst primates (and very rare amongst mammals in general) is the cooperative breeding, where apart from fathers other group members, particularly adult males, participate in the transport of infants, generally twins. Finally, female tamarins show much higher rates of scent marking and possess much larger scent glands than males. In combination with the chemical composition of scent marks, this is most plausibly interpreted as a “quality indicator” in the sense of sexual selection theory.     

Scent-marking in captive red pandas (Ailurus fulgens)

Three male and three female captive red pandas (Ailurus fulgens) were observed during and outside of the breeding season to examine changes in scent-marking behavior. Variation in scent-marking was analyzed with respect to site preferences, sex differences, onset of breeding, behavioral correlates, and environmental factors. Both males and females exhibited significant preferences for particular marking sites, those being prominent points in the enclosures. Males showed significantly higher scent-marking frequencies than females, except in one enclosure where increased marking behavior was associated with the presence of young. Sexual dimorphism in the pattern of marking was also observed, with males showing a bidirectional mark and females a unidirectional mark. Female marking was greater during the breeding season. Sniffing and number of waddles per mark were associated with scent-marking. Temperature change was not related to frequency of scent-marking. These results are compared with scent-marking behaviors in other species of carnivores and functional explanations are suggested.     

Assessment of dominance hierarchy through urine scent marking and its chemical constituents in male blackbuck Antelope cervicapra, a critically endangered species

In ungulates the process of chemical communication by urinary scent marking has been directly related to reproductive dominance, territorial defense and proximity to resources. The differences in the frequency of urine marking and chemical composition of urine of males Antelope cervicapra before, during and after the dominance hierarchy period were assessed. The variations in the urine marking and its chemical profiles of dominant males (n = 9), bachelors (n = 5) and sub-adult males (n = 5) were compared to find out how the dominance hierarchy influences the confined blackbuck herd under semi-natural captive conditions. The frequency of urine marking is significantly higher (p < 0.001) in dominant males. Twenty-eight major constituents were identified in the urine of dominant males (before, during and after the dominance hierarchy period), bachelor and sub-adult males. Among these, three specific compounds namely, 3-hexanone (I), 6-methyl-5-hepten-2-one (II) and 4-methyl-3-heptanone (III) were seen only in dominant males urine during the dominance hierarchy period. Based on the behavioural observation and the unique chemical constituents in the urine, it is concluded that the dominant male scent odor suppresses aggression, scent marking, scent production and territorial patrolling activities of subordinate males, through which the dominant male establish their hierarchy and attains success in reproduction.     

Dominance hierarchy and space use pattern in male captive muntjacs,Muntiacus reevesi

Social behaviour and space use patterns of 15 male muntjacs (Muntiacus reevesi) were studied in a large enclosure in 1979 and 1980. Males often interacted aggressively with each other showing distinct aggressive behaviour patterns. A dominance hierarchy was established and 4 adult males emerged as co-dominant. Movements of these dominant males were confined within small areas which did not overlap with each other and partitioned the enclosure. They defended and maintained the areas by aggressive behaviour and scent marking.     

Cheetah behaviour at scent-marking sites indicates differential use by sex and social rank

Scent-marking is an important form of communication for solitary species, as the information remains for the receiver after the sender has left the area. Individuals of different demographic or dominance classes (ranks) need to provide different information to conspecifics. Therefore, the use of scent-marking sites is of particular value for solitary species, but their functional role may vary between demographic classes. Using camera traps, we video-recorded the behaviour of cheetahs at scent-marking sites, assessing how individuals of different sex and social rank use the sites for different roles. We tested hypotheses that these sites are for territorial marking, reproductive signalling and information gathering. We found that females visit the sites infrequently, apparently to signal oestrous events, while males visit the sites frequently for territorial marking and information gathering. Among males, dominant individuals scent-marked the most and reacted to female visitation by vocalizing. In contrast, subordinate males, although also visiting the sites, were not recorded scent-marking nor vocalizing. These differences in the functional use of scent-marking sites among sex and social rank support the hypotheses that cheetah s use these scent-marking sites for both territorial and reproductive signalling, as well as to gather information.     

Scent-marking and intrasexual competition in a cooperative carnivore with low reproductive skew

Most mammals scent-mark and a variety of hypotheses have been put forward to explain this behaviour. Differences in the main function of scent-marking between species are likely to be related to differences in social systems. Here, we investigate the functions of scent-marking in a cooperatively breeding carnivore. In the banded mongoose ( Mungos mungo ), individuals of both sexes commonly breed in their natal group and reproductive skew within groups is low. Using experimental scent-mark presentations, we tested predictions of the intrasexual competition, self-advertisement to potential mates and dominance assertion hypotheses. Both males and females responded more intensely to scent marks of same-sexed than of opposite-sexed individuals. Dominant individuals counter-marked more than subordinate ones and males showed higher counter-marking rates than females, but only marginally so. During oestrus, responses to scent marks were increased by both sexes. Our findings strongly indicate that scent-marking in the banded mongoose primarily serves a purpose in intrasexual competition both between and within groups. Unlike in other social herpestids and some solitary rodents, we found little evidence for self-advertisement. We suggest that the peculiar social system of the banded mongoose results in self-advertisement losing importance in this species, shifting the main function of scent-marking to intrasexual competition.     

Preliminary field observations on the marmoset,Callithrix humeralifer intermedius (Hershkovitz, 1977) at Dardanelos,Rio Aripuanã, Mato Grosso

The recently discoveredCallithrix humeralifer intermedius occurs between the Rios Roosevelt and Aripuanã in Brazil. This paper presents some preliminary observations ofC. h. intermedius in the wild from May to November 1978. They occupy dense primary forest, second growth and low white sand forest. Group size is between 4 and 13, the larger groups comprised of more than one adult pair. One group, watched for 160.5 hr, occupied a home range of 13.75 ha, during this period, travelling between 740 and 1,500 m during the day. Principal foods include small fruits, flowers, tree exudates and insects. Groups were observed with one pair of newborn infants during September and October, at the end of the dry season. Observations of social behaviour (including agonistic behaviour, grooming, tail coiling behaviour and scent marking), development of young, vocalizations and potential predators are described.     

Male and female agonistic and affiliative relationships in a social group of farm cats (Felis catus L.)

A dominance hierarchy based on the outcome of agonistic encounters was found among male and female domestic cats. A female dominated over some males. The dominance concept is also discussed in terms of social bonding. The relationships among adult females were amicable, whereas adult males showed reciprocal tolerance. The flow of affiliative behaviour was directed mainly from females to one male of the group. The analysis of marking behaviour showed that this male sprayed urine and rubbed the perioral and cheek regions of the face on the objects of the environment at a higher rate than the other members of the group. Nevertheless, rubbing the perioral and cheek regions of the face on objects was not correlated to dominance rank, possibly because it has some function in social communication other than territorial defence against strangers. No relationships have been found between claw scratching, rolling on the ground and social rank, or between the former and other marking behaviour. It is concluded that claw scratching and rolling were not utilised to mark territory.