Author: Ronald Jildmalm

Conclusion

White-handed gibbons are selective feeders that prefer to meet their daily requirements of metabolic energy by consuming carbohydrate-rich fruits.

Food preferences in relation to nutrient composition in captive white-handed
gibbons,
Hylobates lar

Acknowledgments

I would like to thank my supervisor Matthias Laska for the amount of energy and engagement that he has put into this work. I would also like to thank Mats Amundin as well as the carpenters and gibbon caretakers at Kolmården zoological park for all their help. Finally, I would like to thank Åsa Holm for her help and support.

Contact information
Ronald Jildmalm
Telephone: 0707-858709
Email: ronji497@student.liu.se
Website: http://cms.ifm.liu.se/edu/biology/master_projects/2008/presentation-of-master-th/web-pages/jildmalm-ronald/

Final thesis. International Master Programe Applied biology 2008
Ronald Billy George Jildmalm
Supervisor: Professor Matthias Laska

Background

Material & Method

Results

White-handed gibbons (Hylobates lar) are highly selective fruit eating primates that spend a considerable proportion of their time and energy on searching for preferred foods. Studies that have investigated this selective food choice have found that gibbons tend to choose ripe, large fruits, with a juicy-soft flesh and thin skin. However, to the best of my knowledge no one has so far investigated if there may be a connection between the choice of fruit and the nutrients that they contain.
The aim of this study was therefore to assess the occurrence of spontaneous food preferences in captive white-handed gibbons and to analyse whether these preferences show a relationship with nutritional content.

I assessed the food preferences of three captive gibbons by using a two-alternative choice test. The animals were presented with pairs of food items, and their choice behaviour, i.e., which of the two food items they consumed first, was recorded. In total, I tested ten types of food, and each pair of food items was presented to an animal for a total of 12 times. The foods used were apple, avocado, banana, cantaloupe melon, carrot, cucumber, fig, grape, pear and tomato.

Male gibbon choosing between two simoultaneously presented food items.

The order of preference that the gibbon displayed are presented in the graph below.

This order of preference showed a strong relationship with the total carbohydrate, fructose and glucose content of the fruits, but not with the contents of total energy, fat or protein. Further, the content of water, vitamins, fibre, acids, and minerals also failed to show any relationship with this food preference order.