Cottontop Tamarin

The Cottontop tamarin is a small species of monkey found in the forests of South America. The Cottontop tamarin was named because of it's elegant white fur that flows over it's head and shoulders. The cottontop tamarin is found in tropical forest edges and secondary forests from Costa Rica to north western Columbia where the cottontop tamarin spends the majority of it's life in the trees.

## Description

Cottontop tamarins are among the smallest of the primates with a body length of 17 cm and tail length of 25 cm. The forelimbs of the cottontop tamarin are shorter than the hind limbs, and unlike other monkeys the thumb of the cottontop tamarin is not opposable and it does not have a prehensiletail.

The cottontop tamarin is a diurnal primate which means that the cottontop tamarin is most active during the day and rests in the safety of the tree tops during the night. cottontop tamarins are very sociable animals and inhabit their territory with their rest of the cottontop tamarin troop which generally have between 2 and 14 members. Cottontop tamarin troops are led by the eldest female and have predominantly male members.

## Diet and Predators

The cottontop tamarin is an omnivorous animal meaning that the cottontop tamarin hunts both plants and other animals in order to survive. Fruits, insects and green plants make up the majority of the cottontop tamarin's diet along with small rodents and reptiles, eggs and tree sap.

Due to the relatively small size of the cottontop tamarin, it has a number of predators within it's natural environment. Wild cats, dogs, snakes and birds of prey are primary predators of the cottontop tamarin, along with humans who are destroying their natural habitat.

### **Communication**

The cotton-top tamarin vocalizes with bird-like whistles, soft chirping sounds, high-pitched trilling, and staccato calls. Researchers describe its repertoire of 38 distinct sounds as unusually sophisticated, conforming to grammatical rules. Jayne Cleveland and Charles Snowdon performed an in-depth feature analysis to classify the cotton-top's repertoire of vocalizations in 1982. They concluded that it uses a simple grammar consisting of eight phonetic variations of short, frequency-modulated "chirps"—each representing varying messages—and five longer constant frequency "whistles". They hypothesize that some of these calls demonstrate that the cotton-top tamarin uses phonetic syntax, while other calls may be exemplars of lexical syntax usage. Each type of call is given a letter signifier; for example, C-calls are associated with finding food and D-calls are associated with eating. Further, these calls can be modified to better deliver information relevant to auditory localization in call-recipients. Using this range of vocalizations, the adults may be able to communicate with one another about intention, thought processes, and emotion, including curiosity, fear, dismay, playfulness, warnings, joy, and calls to young.

#### **Language Acquisition**

Over the first 20 weeks after a cotton-top tamarin is born, it is not fully capable of producing the range of vocalizations that an adult monkey can. Despite this limitation on speech producibility, researchers believe that language acquisition occurs early on with speech comprehension abilities arising first. Infants can at times produce adult-like chirps, but this is rarely done in the correct context and remains inconsistent across the first 20 weeks of life. Regardless, infant cotton-tops are able to respond in behaviorally appropriate ways to varying contexts when presented with adult chirps. This indicates that verbal perception is a quickly acquired skill for offspring, followed closely by auditory comprehension, and later by proper vocal producibility.

Castro and Snowdon (2000) observed that aside from inconsistent adult-like chirping, cotton-top infants most often produce a prototype chirp that differs in vocalization structure from anything seen in the full adult range of vocalizations. Infants are thought to imitate adult speakers, which use differing calls in various contexts, but by using solely the infant prototypical chirp. For instance, adult cotton-tops are known to significantly reduce the amount of general alarm calling in the presence of infants. This is likely adapted so that adults in close proximity to the group's young do not attract attention of predators to infant-dense areas. Additionally, infants reduce their prototype chirping in the presence of predators. Whether infants are shadowing the calling behavior of adults or they are comprehending danger remains unclear. However, researchers argue that young cotton-top tamarins are able to represent semanticinformation regardless of immature speech production.

To confirm the notion that language acquisition occurs as a progression of comprehension before production, Castro and Snowdon (2000) showed that infants respond behaviorally to vocalizing adults in a fashion that indicates they can comprehend auditory inputs. When an adult produces a C-call chirp, used to indicate food preference and when navigating to a food source, an infant approaches the adult caller to be fed, but do not use the prototype calling as a proxy for C-calls. This finding argues for the idea that infants are able to understand vocalizations first, and later acquire the ability to communicate with adult vocalizations.

#### **General Calling**

Among the typical cotton-top tamarin communicative vocalizations, the combination long call (CLC) and the alarm call (AC) are the most heavily represented in the literature. CLCs encompass a range of contact calls that are produced by isolated individuals using chirps and whistles. This type of call is also used for seemingly altruistic alarm calls, thus adding to its range of cooperative behaviors. It is issued in the presence of kin when a threatening llamas predator is seen. Predators of the cotton-top tamarin include snakes, ocelots, tayras, and most notably, hawks. Early observations by Patricia Neyman even showed that cotton-tops produce diverse sets of alarm calls that can discriminate the presence of birds of prey versus ground-based predators.

## Reproduction

The cottontop tamarin usually breeds between the months of April and July, when the female cottontop tamarin will give birth to twins (or a single infant) after a four to five month gestation period. The male cottontop tamarins carry and groom infants more than the females do, but females clean the infant more than the males do. Older siblings are also known to contribute to infant care, although infants prefer to be carried by their parents than by their siblings. Infant cottontop tamarins become mobile at 2 to 5 weeks, and begin eating solid food at 4 to 7 weeks. They are independent at 10 to 18 weeks and are fully weaned at 15 to 25 weeks. Sexual maturity is attained at about 2 years of age.

## Conservation

Today, the cottontop tamarin is considered to be a critically endangered species with an estimated wild cottontop tamarin population of just 6,000. The main reason for the severe decline in the cottontop tamarin population is that they have lost more than 75% of their natural habitat to deforestation