Primate Update E-Newsletter, Vol. 4, Issue 3, Part 3

CONTINUING EDUCATION

Special Topic: Intern Mary
Communication in spider monkeys: the function and mechanisms underlying the use of the whinny.

Spider monkeys are capable of making a wide variety of vocalizations each with a different meaning and purpose. Many of the vocalizations made by spider monkeys have been defined, as in the table below, however the only vocalization that has been thoroughly analyzed is the whinny.

Montana in the Sun

The whinny is described as a medium to high frequency squealing, similar to a horse’s whinny but with a much higher pitch. There are variations in length and frequency of the whinny and each variation alters the meaning of the call itself. For example a long high frequency whinny most likely indicates the caller’s position to the other members of their group. This specific version of the whinny is also thought to have slight variations. These variations in the high frequency long call whinny have been hypothesized to indicate the location of feeding sites and possibly the location of predators. The whinny is most often used when individual monkeys become separated from each other and is also used more often by males than females.

Unlike other calls made by spider monkeys such as the bark, a vocalization made in the direct presence of predators or other disturbances, the whinny does not always elicit a reaction from the recipient(s) of the call. Due to the inability to visualize an immediate response to the whinny, researchers are unable to verify the exact purpose of the call.

Carlos and Montana, the spider monkeys at Pacific Primate Sanctuary, make a wide variety of vocalizations. They use the whinny vocalization when they see a volunteer delivering their diets. Just as with wild spider monkeys there is no way of knowing for certain whether they are making this call to each other regarding the presence of food, if they are indicating their location to the volunteer, or to each other, or if they are using the call for something else entirely.

Campbell, Christina J. Spider Monkeys: Behavior, Ecology, and Evolution of the Genus Ateles (Cambridge Studies in Biological and Evolutionary Anthropology). UK. Cambridge University Press. 2008.


Special Topic: Intern Annabel: A Study on Aging in Marmosets
What is Aging?

Although he is elderly, 

Abraham is still in great health and 

enjoys exploring his outdoor enclosure

In order to provide the best care for elderly monkeys here at PPS, we must first understand what aging is and how it affects callitrichids. For many humans, aging is a disease- the ultimate disease of one’s mortal existence. For most species, however, aging simply represents the approaching completion of one experiment in adaption (Bowden, 1979). Marmosets are often referred to as “old aged” (our equivalent of a pensioner) at 8 years of age (Abbot et al, 2003). A study conducted at the New England Primate Research Centre (NEPRC) analyzed age-related pathology in marmosets. They allowed these animals to live out their life spans and monitored them closely. They discovered that as the animals aged, they became more prone to diseases such as neoplasia (tissue masses/tumors), infectious processes, renal (kidney) disease, amyloid protein accumulation, and diabetes mellitus. These are common factors in the rate of illness and mortality in aging marmosets. By understanding the most common diseases prevalent in aging marmosets, we can know what symptoms to look for as the monkeys at Pacific Primate Sanctuary get older. This will allow us to catch diseases early on, and provide better care.

Further analysis showed that the average weight at death was within the low to normal weight range for healthy animals: 321g (males 316g females 326g) (Tardif et al, 2008). This differs from what we see in human aging. As people get older they often start to lose a lot of weight. Data from this study show that there is possibly a correlation between early life weight and longevity. It is possible that the bigger you are in your peak (around 3 years), the longer you will live (Tardif et al, 2008). We provide the monkeys at the Sanctuary with a specialized diet, designed to fit their nutritional needs. We also customize this diet, adding high calorie foods for the monkeys who tend to be underweight. By making sure the monkeys are at a healthy weight when they are young, we are helping to ensure they live a longer, healthy life.

References
-Abbot DH, Barnett DK, Colman RJ, Yamamoto ME, Schultz-Darken NJ. 2003. Aspects of common marmoset basic biology and life history important for biomedical research.

-Bowdon D. M. Aging in Non Human Primates, 1979

-Tardif S, Araujo A, Arruda M, French J, Sousa M, Yamamoto M. Reproduction and Aging in marmosets and Tamarins, 2008

-Tardif S, Keith G, Mansfield, Ratnam R, Ross C, Ziegler T, The Marmoset as a Model of Aging and Age-Related Diseases, 2008

Special Topic: Intern Linda
Marmosets and Tamarins Chapter 8: Flexibility and Co-Operation as Unifying Themes in Saguinas Social Organization and Behavior

Before the 1980’s New World Primates were rarely used in behavioral studies. They were considered simple, primitive, and hard to observe to nature. Many also believed that their lineage was too far from the human lineage to be considered for research. However, by the mid 1980’s marmosets and tamarin research garnered much interest, which continues to the present.

Tamarins have been used to study social organization and behavior because of three distinct traits: flexibility, co-operation, and tolerance. Tamarins have a wide geographic range. They are found from Panama all the way to Brazil. They also can adapt to many
different types of niches, indicating they are very flexible. Co-operation and tolerance are other defining characteristics. Co-operation can be seen in the extensive childcare, where members of the group, other than the mother, (father, siblings) play a role in parental care. Various members of the family group carry the baby for hours and the infant returns to the mother mainly for nursing. Tamarins are also known to be very tolerant of the rest of their group. Members of the group give food calls even when the amount of food found is small, and aggression is rare for free ranging groups.

-Rylands, A.B. Marmosets and Tamarins. Systematics, Behavior, and Ecology. Oxford, U.K.: Oxford University Press, 1993.

Cotton top tamarin father Adam assists

 with child rearing by carrying his sons

“Life is life - whether in a cat, or dog or man. There is no difference there between a cat or a man. The idea of difference is a human conception for man's own advantage.”               ~Sri Aurobindo




We hope you have enjoyed this issue of Pacific Primate Sanctuary’s E-Newsletter. Thank you for your support of our life saving work. Because of compassionate people, the Sanctuary can continue to provide a place of peace and happiness for 70 primates saved from research laboratories, animal dealers, and tourist attractions. Here they can heal, form families, and live free from exploitation.

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