The uniqueness of lemurs is related to the quality of fruits in Madagascar

Tuesday, 31 October 2017

Red-fronted lemur

Madagascar is home to a group of unusual primates – the lemurs. A new study published today (31 October) proposes that the answer to their uniqueness may lie in the quality of the fruit they eat.

The study published 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.  

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.  

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.

Dr Giuseppe Donati, Reader in Primatology, Oxford Brookes University

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”.

 Anosy mouse lemur (Microcebus tanosi)

“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”.  

The full article, ‘Low Levels of Fruit Nitrogen as Drivers for the Evolution of Madagascar’s Primate Communities’ is available as an open access publication on the Scientific Reports website

The study involved a multi-national team of over 30 collaborators, including additional colleagues from Oxford Brookes academics Dr Matthew McLennan, Professor Anna Nekaris and Professor Vincent Nijman and PhD students Michela Balestri and Marco Campera.  

Oxford Brookes University offers a unique primatology programme where students from all over the world come to Oxford to learn about primate conservation and working collaboratively to find real-world solutions to urgent environmental issues. Find out more about available courses on the website.

Images (1) Eulemur rufifrons (Red-fronted lemur) by Luca Santini (2) Microcebus tanosi (Anosy mouse lemur) by George Selley