Social Spacing
The
cotton-top tamarins live in small home ranges, and they defend a core
area within the home-range. This core area that is defended by the
tamarin may be scent-marked or physically defended. There are
cases in which home range overlap within the species has been identified. Researchers
have found that the cotton-top tamarin’s home
ranges vary from complete home range overlap and
no territoriality
to only 13% overlap and territoriality (Smuts et.al,
1987). Therefore, it is possible to conclude that
different groups
of tamarins have different defensible behaviors
based on the resources available in their home range.
Their home
range is about 7.8 to 10 hectares (Clapp, 1993).
The tamarin
usually spans a distance of about 1 to 2 km per day
(Smuts et.al, 1987). Deforestation in Colombia has
caused the
tamarin to retreat to living in small, patchy forest
areas (Savage, 1990).
Cotton-top tamarins use “long calls” as territorial defense to alarm members in their group of intruders or predators. When tamarins hear a “long call” they respond by raising their hairs and scent marking. The adult and sub-adults defend their core area within their home range by bluff charges and aggression, while others partake in vocal displays (Savage, 1990). Territoriality and vocal communication within the home ranges of tamarins promotes intra-group cohesion and maintains separation of the area. The core area within the home-range is used for foraging, feeding, and sleeping (Taub, 1986). As a result, they try to decrease competition within the area, even though there are accounts of home-range of overlap. However, defense is more defined when the resources are scarcer within the area.
http://www.zooschool.ecsd.net/cotton%20topped%20tamarin.htm
The cotton-top tamarin also uses olfactory communication as a way of social interaction. They have scent glands in the “anogenital, suprapubic, and sternal regions” that aid in scent marking (Reichard et.al, 2003). Scent marking is used to define territories, as defense, indicate social status, reproduction, and male attraction (Reichard et.al, 2003).
It
has been found that inter-group encounters can range from 1 hour
to
one day
and it consists
of loud vocalizations and aggression (Smuts
et.al, 1987). The patterns that researchers often observed with inter-group
encounters vary. Some researchers report aggressive fighting within
these encounters. However, others have stated that the majority of
the encounters observed did not include physical contact. Researchers
agree that chasing occurs between the dominant male of the home-range
and subordinate males/females from the intruding group. The goals of
these inter-group encounters are that they enforce the boundary, and
the subordinates are able to “scope-out” the range for
possible mates, or find a partner that they could emigrate to a new
area with (Smuts et.al, 1987). It has also been observed that
adult males were usually not aggressive towards juvenile males that
intruded into their core area. This is significant because juvenile
males were not determined to be a threat to the adult males because
they were non-reproductive. As a result, the adult males would not
have to compete with them for a mate.
