Madagascar is home to a group of unusual primates – the lemurs. A recently published study proposes that the answer to their uniqueness may lie in the quality of the fruit they eat.
The study published on 31 October in the journal Scientific Reports, saw a multi-national team of ecologists and primatologists perform a global comparison to test the idea that fruits in Madagascar contain insufficient proteins to meet primate metabolic requirements.
The work, led by Dr Giuseppe Donati, Reader in Primatology at Oxford Brookes University and Professor Joerg U Ganzhorn, Head of Animal Ecology and Conservation at Hamburg University, used a large data set of fruit protein concentrations from 62 forest sites across three continental areas.
Proteins are essential parts of organisms and their availability in the environment has been suggested to constrain the survival of animals. This is why a strict fruit based diet is rare in animals since fruits alone contain too little proteins to meet metabolic requirements.
Dr Giuseppe Donati, Department of Social Sciences, Oxford Brookes University, UK
Among mammals and birds, America has a greater number of fruit-eating species compared with Africa and Asia, while Madagascar has very few species that have made this dietary choice. The cause of this uneven representation of fruit-eating mammals and birds in different areas of the tropics represent a long-standing enigma in ecology.
Results showed that fruits in Madagascar contain lower average proteins than those in tropical America, Asia and continental Africa. While in America, Asia and Africa the amount of proteins in fruits is well above the minimum requirements for primates, values for Madagascar are below the lower limit. This points to low fruit protein concentrations being a specific constraint on the island, but one that has not become effective in other parts of the world.
Dr Giuseppe Donati said: “Our results add an additional dimension to the existing hypotheses depicting the island of Madagascar as ecologically challenging environment for primates. Lemurs show a number of unusual primate traits. Over the last two decades the most accepted idea to explain many of these traits was based on the driving force of extended periods of food scarcity, the low predictability of fruiting and the high frequency of cyclones which characterise the island of Madagascar”
“Our results indicate that the low nutritional quality of the fruits in Madagascar may have caused lemurs to differentiate their diet and develop some of the unique traits that we can see today such as the irregular activity patterns over day and night”.
(Source: Oxford Brookes University news release, 31.10.2017)