Infant capuchin monkeys

Issue 10, December 1997

What do young monkeys do when they come across new food they have never seen or tasted before? Do they cat a small amount of it, do they eat a lot of it, do they avoid it and do the actions of other monkeys influence their behaviour?

A recent study* investigated what captive infant capuchin monkeys (Cebus apella), see Figure 1, do in the company of other monkeys when they find new and unfamiliar foods.

Figure 1. An adult capuchin monkey.

The researchers used seventeen novel foods and two familiar foods and studied the infant monkeys' behaviour in the presence of monkeys of the same age (peers) and older monkeys (their mothers, older juveniles and other adults).

All the foods were presented in 2 x 2 x 2 cm cubes. The researchers recorded the frequency with which the food was eaten. The results are shown in Figure 2. They also recorded the interest the infant monkeys showed in the eating behaviour of others in the group. These results are shown in Figure 3.

Figure 2. Rate at which monkeys ate novel and familiar foods.

Figure 3. Interest (frequency/h) shown by infants in the food of other monkeys in the group.

* Fragaszy, D., Visalberghi, E. and Galloway, A. 1997. Infant tufted capuchin monkeys' behaviour with novel foods: opportunism not selectivity.

Intermediate tier

1. Which familiar food was eaten most frequently by the monkeys? (1)
2. Which unfamiliar food was eaten most often by the infant monkeys? (1)
3. Which novel food was eaten roughly twice as frequently as hot dogs? (1)
4. Explain why the food was cut into similar size pieces. (1)
5. Suggest why some unfamiliar foods appeared to be more attractive than others to the infant monkeys. (2)
6. Suggest two reasons why tuna and sardines may have been less frequently selected by the monkeys in this study. (2)
7. Figure 3 shows how interested infant capuchin monkeys were in the foods that other monkeys were eating. Describe the findings illustrated in Figure 3. (2)
8. Explain why mothers seem to be the most influential group regarding how interested infant capuchin monkeys are in what others were eating. (2)

Higher tier

1. Which novel food was eaten roughly twice as frequently as hot dogs? (1)
2. Explain why the food was cut into similar size pieces.(1)
3. Suggest two reasons why tuna and sardines may have been less frequently selected by the monkeys in this study. (2)
4. Figure 3 shows how interested infant capuchin monkeys were in the foods that others were eating. Describe the findings that are illustrated in Figure 3. ( 2
5. Explain why mothers seem to be the most influential group regarding how interested infant capuchin monkeys are in what others were eating. (2)
6. Outline one limitation of this experimental study. (1)
7. What might be a disadvantage to young capuchin monkeys of eating unfamiliar foods in the wild? (1)
8. The researchers also found that older infants were more interested in others' food than were younger infants. Suggest why this may be so. (2)