Cotton-top Tamarin Vocalizations

Cotton-top tamarins have an extensive vocal repertoire which is derived from the variation of two basic elements and the sequential combination of those elements (Cleveland and Snowdon 1982). The vocalizations described here were recorded over 18 months from a captive colony in Madison, Wisconsin with a Uher 4200 stereo tape recorder using a Sennheiser MD 441 microphone and either Scotch 209 or 177 low noise recording tape. Recordings were done at 9.5 cm/s. Sound spectrograms were made on a Kay Sonagraph Model 6061 B using a narrow band pass filter (90 Hz) over the frequency range of 160 to 16,000 Hz.

By assessing the structural and behavioral correlates of the vocalizations, 38 distinct sounds or combinations of sounds were identifies. The simplify the description of the repertoire, the sounds were grouped into six major classes based on structure.

CLICK ON THE SPECTROGRAM TO HEAR THE VOCALIZATION

Class 1: Single Frequency Modulated Syllables

A. Short Duration Calls - Chirps were categorized according to four structural parameters: presence or absence of stem upsweep, duration, peak frequency, and frequency change. See Table 1 for call parameters.

Type A Chirp (Mobbing)	During mobbing behavior, to sudden animated stimuli. By some groups to preferred foods. Rarely given to acoustical stimuli.
Type B Chirp (Directed Investigatory)	To human observers or familiar object.
Type C Chirp (Pre-food)	During approach to food or when individual approaches object that will be hand-held and orally explored.
Type D Chirp (Post-food)	When animal actually possesses food or object.
Type E Chirp (General Alarm)	To sudden visual and acoustic stimuli. To sudden leaping movement by group members if animal startled.
Type F Chirp (Intergroup)	During intergroup antiphonal calling of Normal Long Calls. To audible outgroup vocalizations.
Type G Chirp (Nonspecific Investigatory)	During relaxed environmental investigation.
Type H Chirp (Mild Alarm)	To novel visual stimuli at close proximity.

Table 1. Parameters differentiating types of chirps.

B. Long Duration Calls

Squeal	During active physical contact by the passive participant: during wrestle play or face pressing between two individuals.
Slicing Scream	Same as Type A Chirp

Class 2: Pulsed Vocalizations

Twitter	Same as Squeal. Results from intensification of Squeal Context.
Hooked Chatter	Same as Type D Chirp (food related). As infants approach.
Chevron Chatter	Towards humans when animal is netted or placed in small cage. Also by some animals in response to human approaching them closely in home cage.
Type E Chirp Chatter	Same as for Type A Chirp only when animal is more highly aroused.
Type F Chirp Trill	Same as for Type F Chirp. Tilling indicative of a higer state of arousal than Type F Chirp alone.
Type H Chirp Trill	Same as for Type H Chirp.
Type A Trill	During Antiphonal Call play interactions prior to attempted play mounts.
Type B Trill	By individuals as they approach young infants to retrieve them. Also given by animals carrying young infants when infants move, vocalize or attempt to climb off.
Type C Trill	Signals the end of a nursing bout, interspersed with Terminally Modulated Whistles.

Class 3: Single Whistles

Squeak	In vigilance, foraging and investigatory activities. Increase in rate of emission with increase in arousal.
Large Initially Modulated Whistle	Given greater than 0.6 m from other animals in low arousal situation. Not given during resting, grooming, nursing, except occasionally when animals break contact. Occurs during Antiphonal Call play
Small Initially Modulated Whistle	Same as Large Initially Modulated Whistle except given at distances less than 0.6 m from other group members.
Terminally Modulated Whistle	By individuals in resting contact, during grooming, by mothers during nursing, by parents and siblings retrieving and carrying infants.
Flat Whistle	Given following Type F, H or E Chirp Trills

Class 4: Multiple Whistle Calls

Ascending Multi-Whistle (Intragroup)	By animals in huddles, by mothers nursing infants.
Descending Multi-Whistle (Intragroup)	Same as Ascending Multi-Whistle and Terminally Modulated Whistle. More commonly given to infants.
Partial Quiet Long Call (Intragroup)	By mothers nursing infants. By subadults during close huddle contact and pauses during wrestle play.
Rapid Whistles (Intragroup)	Before an approach to mount during Anti-phonal Call play.
Quiet Long Call (Intergroup)	To audible Single Whistles, Chevron Chatters, Type H Trills, Twitters, Long Calls from unfamiliar animals. Occasionally given to no obvious stimulus during group huddles.
Normal Long Call (Intergroup)	To distant non-group Combination Long Calls, Normal Long Calls, Type F Chirps. During isolation.

Class 5. Combination Vocalizations

Small Modulated Multi-Level	Same as Small Initially Modulated Whistle
Large Modulated Multi-Level	Same as Large Initially Modulated Whistle
Combination Long Call	During play, isolation or when socially disturbed. When animal not in contact.
Inverted U + Whistle	In alarm to faint acoustical stimuli after an alert has been signaled.
Type F Chirp + Whistle	By individuals less confident than when giving Normal Long Calls. As response to Combination or Normal Long Calls or non-group Type F Chirps. In isolation.

Class 6. Noisy Calls

Squawk	By recipient of aggressive behavior. In some animals as an appeasement gesture, by others as an invitation for grooming.
Scream	When animals attempt to steal food.
Sneeze	After eating, drinking water, sniffing or as result of rubbing nose on substrate or with hand.