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Saguinus oedipus in a Habitat of Brotherly Love

By: Haley Atkinson | Mentor: Frank Logiudice

Introduction

The purpose of this study is to determine the cause of previously-occurring aggression between the second youngest (Ted) and youngest (Mini) males in a troupe of nine captive cotton-top tamarins, S. oedipus, found at the Central Florida Zoo and Botanical Gardens located in Sanford, FL, how they interact with each other, and the cause of specific aggressive behavior demonstrated between them. Determining the cause of aggression will suggest the actions necessary to mitigate or reduce this behavior. Of the two, Ted is the primary individual that exhibits unprovoked aggression towards Mini. For his part, Mini is rarely observed initiating aggression. I conclude that the aggressive behavior is a simple matter of competition and space.

In the wild, blatant attacks are rare since individuals are able to leave their own troupe to join another (Neyman, 1977), which can lessen or prevent aggression within the troupe. In captivity, overt aggression is common and is directly related to spacing issues (Moyihan, 1970).

S. oedipus belong to the New World monkey family Callitrichidae. They are found in a very restricted area of northern Colombia, South America. S. oedipus typically inhabit deciduous forests but have adapted to secondary forests because of deforestation (Cawthon, 2005). Due to habitat loss and the pet trade, their numbers have dwindled, and they are now confined to national parks and reserves that have been established for the purpose of research and conservation (Savage, 2018). The International Union for Conservation of Nature and Natural Resources (IUCN) Red List classifies S. oedipus as critically endangered with 6,000 individuals remaining (Savage & Causado, 2014).

Habitat

When this study began in January 2018, the S. oedipus troupe in question was housed in a hexagonal enclosure that measures 2.7m x 3.9m x 2.7m (Enclosure A, Figure 1). Two older sets of twins and a younger set of triplets had been born to the breeding pair, totaling nine individuals in Enclosure A. An expansion was added during the study measuring 2.4m x 2.4m x 2.4m (Enclosure B, Figure 1).

Figure 1. Enclosure A (left) and Enclosure B (right)

Communication

S. oedipus utilize auditory, chemical, and visual communication to convey messages. Communication is primarily auditory and chemical since their natural environment of tropical dry forests is heavily vegetated, which hinders most visual communication from a distance (Snowdon & Soini, 1988). S. oedipus have over 38 vocalizations (Savage, 2018) and several movements (Moyihan, 1970) to express their intentions. Since the troupe in question is captive, Enclosures A and B do not directly imitate their natural habitat of dry tropical forests. Nevertheless, the captive S. oedipus troupe in this study relies heavily on vocalizations even though their habitat does not resemble the wild.

Acoustic Communications

The vocalizations of focus in this studyare twitters, trills, loud sharp notes, long rasps, and broken rasps, as described by Moyihan (1970), which are associated with agonistic or hostile intentions (Table 1).

Table 1. Description of acoustic communications described by Moyihan (1970)

Visual Communication

The movements of focus in this study are silent freeze, head down posture, crown smoothing, crown raising, and a displacement behavior as described by Moyihan (1970) (Table 2). A displacement behavior encompasses any unritualized display, a behavior that is not normal for S. oedipus, that develops from a nervous mannerism.

Table 2. Description of visual communications described by Moyihan (1970)

Figure 2. (a) Focal subject Ted performing a silent freeze in response to focal subject Mini.

Figure 2. (b) Focal subject Ted (left) performing a head down posture in association with crown smoothing in response to focal subject Mini (right).

Materials and Methods >>