Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bolivian rainforest study suggests feeding behavior in monkeys and humans have ancient, shared roots

20.05.2009
Behavioural ecologists working in Bolivia have found that wild spider monkeys control their diets in a similar way to humans, contrary to what has been thought up to now.

Rather than trying to maximize their daily energy intake, the monkeys tightly regulate their daily protein intake, so that it stays at the same level regardless of seasonal variation in the availability of different foods.

Tight regulation of daily protein intake is known to play a role in the development of obesity in humans, and the findings from this research suggest that the evolutionary origins of these eating patterns in humans may be far older than suspected. Until now it was thought humans' eating patterns originated in the Palaeolithic era (between 2.4 million and 10,000 years ago).

The research, published online today (Wednesday 20 May) in the journal Behavioral Ecology [1], also provides valuable information about which trees are important for the monkeys' diet, which is relevant to conservation; in addition, it may help to improve the care of captive primates, which can be prone to obesity and related health problems due to their diet.

Dr Annika Felton, a Departmental Visitor at the Fenner School of Environment and Society, The Australian National University, Canberra, Australia, spent a year in the Bolivian rainforest (in Departmento Santa Cruz) familiarising the Peruvian spider monkeys (Ateles chamek) to her presence and then observing their feeding habits.

She followed 15 individual monkeys (7 adult males, 8 adult females), conducting continuous observations of the same animal from dawn to dusk, and following each of the monkeys for at least one whole day a month. During observations she recorded everything they did and ate and for how long. Where possible, she counted every fruit and leaf they ate, and collected samples of what they had eaten from the actual trees the monkeys had chosen. The samples were then dried and sent to the laboratory in Australia where they were analysed for their nutritional content. It is unusual for a study of feeding habits in wild primates to be conducted in this detailed way. It enabled Dr Felton and her colleagues to calculate how much an individual monkey had consumed and the nutrients involved; usually, other field studies are only able to calculate averages for a group of animals.

Dr Felton said: "We found that the pattern of nutrient intake by wild spider monkeys, which are primarily fruit eaters, was almost identical to humans, which are omnivores. What spider monkeys and humans have in common is that they tightly regulate their daily protein intake, i.e. they appear to aim for a target amount of protein each day, regardless of whether they only ate ripe fruit or mixed in other vegetable matter as well. Finding this result in spider monkeys was unexpected because, previously, ripe fruit specialists were thought to be 'energy maximisers'. In other words, they would aim to maximise their daily energy intake. Our findings show this is not the case.

"The consequence of tight protein regulation is the same for monkeys and humans: if the diet is poor in protein but rich in carbohydrates and fats (energy dense food) individuals will end up ingesting a great deal of energy in order to obtain their protein target, which can lead to weight gain. This 'protein leverage effect' is thought to play a significant role in the human obesity problem found in modern western societies. Our results suggest that an adjustment of the nutritional balance of diets as a means to manage human obesity might similarly be an option for mitigating obesity in captive primates.

"Our findings are also interesting from an evolutionary point of view. Similarity in the regulatory pattern of protein intake between distantly related species, such as humans and spider monkeys, possessing very different dietary habits, may indicate that the evolutionary origins of such regulatory patterns are quite old, potentially far older than the Palaeolithic era. If we are not dealing with convergent evolution here – in other words that spider monkeys and humans have evolved this trait independently – then this trait may have been shared by our common ancestor. Spider monkeys are New World primates that split from the Old World primates about 40 million years ago.

"Finally, our research shows that nutritionally-balanced food sources that are used extensively by a wild population may need special attention in terms of conservation planning, perhaps by regulating logging and selecting certain tree species for re-planting. The majority of the monkeys' nourishment was sourced from a species of fig tree, Ficus boliviana, that is currently being harvested for timber in Bolivia."

Dr Felton and her colleagues found that the monkeys ate a wide variety of fruit and vegetables – 105 different plants belonging to 63 species during the 12 months of observation. Figs were particularly popular. The monkeys rarely ate insects, which are rich in protein.

The spider monkeys did not specifically select either the most energy-rich or the most protein-rich foods that were available, and the daily amount of food they ate varied quite widely, averaging about 1 kg a day, but sometimes as much as 2.4 kg a day. However, they maintained their daily protein intake around 0.2 MJ (11 grams), whereas their intake of carbohydrates and fats varied between 0.7-6.2 MJ. The availability of sweet, ripe fruit was significantly related to the variation in their daily energy intake – the more there was, the more they ate.

"To maintain a stable intake of protein, spider monkeys consumed large amounts of carbohydrates and fats when protein content in the food was low, for instance when their diet consisted entirely of ripe fruit, and consumed far fewer carbohydrates and fats when feeding on items rich in protein," said Dr Felton.

She concluded: "What is perhaps most fascinating about our paper is not the answers we provide, but the questions that our findings raise. For example, why do these frugivores have the same pattern of nutritional intake as human omnivores? Is this due to convergent evolution or is it a remaining trait from a common ancestor?

"I am also pleased that our findings can be applied to the management of captive primates (where obesity is a problem), and possibly the management of spider monkey forest habitat.

"Also, importantly, we have shown that the combination of intensive data collection and the application of an innovative analytical framework can dramatically change our perceptions of the nutritional ecology of a species."

[1] Protein content of diets dictates the daily energy intake of a free-ranging primate. Behavioural Ecology. Published online under advance access. doi:10.1093/beheco/arp021

Emma Mason | EurekAlert!
Further information:
http://www.oxfordjournals.org

More articles from Ecology, The Environment and Conservation:

nachricht Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>