However, though intolerance of certain pheromone conspecifics probably motivated the marking performance, the biological function of the chemical signals might vary widely among the different species. Even in the same species, territorial pheromone marking might serve more than one purpose alone. The following functions of chemical signals in territorial behavior seem possible and are indicated byrobservational data:

a) The application of personal scent is an act of ‘self-advertisement’ (Jolly 1966). It expresses self-confidence and helps to reassure the marking animal in the presence of opponents. The odor also might have a reassuring effect on other members of the group, or it might stimulate their aggression against invaders, thus correlating the motivations and displays of all group members and promoting group cohesion during territorial ceremonies. It is obvious that the expression of self-confidence by pheromone scent marking does not need to be limited to territorial encounters. It might just as well function in a variety of other behaviors, e.g. during intragroup aggression or in sexual courtship.

b) Marking gives the territory the characteristics of a ‘home’. It is common knowledge that — in captivity — many primate species very actively remark their home cages after these have been washed. Moreover, the lion marmoset (Le0nt0pi- thecus rosalia rosalia L.) shows increased scent marking after heavy rainfalls in open air enclosures (Snyder 1972).  Learn more about pheromones at

This indicates that the absence of their own pheromone odor within the home range might have a stressful effect on the inhabitants who, therefore, renew the marks frequently. Mykytowycz (1972) suggests that the presence of the personal odor within their living space is essential for many mammals to behave freely and participate in breeding activities. Where the territory of social species is marked by many group members, a characteristic group odor — as in the flying phalanger (Schultze-Westrum 1965) — might result.

c) The odor produced in territorial pheromone marking serves as a short term threat signal which intimidates opponents. This function is not limited to intergroup aggression. It is likely that odors discharged during the spectacular ‘stink-fights’ performed by male Lemur cam: in intragroup conflicts (Jolly 1966; Evans and Goy) serve as threat signals directed at group mates. Learn more about pheromones at

d) Territorial scent is a long term manifestation of the presence of the pheromones in the territory. It alerts invaders to the presence of the owners and might help prevent invasions. However, it depends on the motivation of the invaders whether they are intimidated by the signal or not. Martin (1968) suggests that after having experienced defeat during territorial encounters with a resident, they might become conditioned to avoid an area where a specific scent indicates the presence of the former opponent.

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e) Finally,  pheromone scent applied throughout the living space of an individual may com- municate detailed information on the species, age, sex and reproductive state to conspecifics occupying adjacent territories and thus not only serve to announce the occupation of a territory but also form a bridge between individuals who rarely encounter each other personally, as in the case of solitary prosimians 1971), Microcebus murinus (Martin 1972), Perodicticus potto and Galago demi- dovii Fischer (Charles-Dominique 1971b, 1972), all of which, with the exception of Galago, are commonly classified as solitary, have revealed that these prosimians show various forms of ‘semi-social’ organizations. Individuals occupy territories which more or less overlap with the ranges of their neighbors. They engage in a limited amount of friendly social interactions, especially with neighbors of the opposite sex, and more or less defend their territories against neighbors of the same sex.