Investigating the evolution of leaf foraging senses in nocturnal lemurs

Monday, 11 December 2017

Avahi meridionalis by Silvia Battisti

How do night-active lemurs that have typically poor colour vision identify the nutritious, tasty leaves to eat while avoiding the harmful ones?

Dr Giuseppe Donati at Oxford Brookes University is embarking on new research that aims to answer this question.  

Vision is considered the essential foraging tool in primates since they are unique among mammals for the full perception of colours in most monkeys and in apes. Colour vision enables day-active primates to identify the age of leaves and the presence of chemical plant defences ensuring that they select the right leaves as food.  

Some Malagasy lemurs however are both leaf eaters and night-active, meaning that they have to distinguish subtle differences between leaves despite their poor colour vision. This makes them a unique model to investigate the evolution of foraging sense in primates.  

Dr Giuseppe Donati, Reader in Primatology and Biological Anthropology said: “My team and I will be investigating the role of vision and smell in foraging leaves in southern woolly lemurs, Avahi meridionalis, assessing the role of the sensory system of this night-active primate in its foraging.

The discovery of basal primate fossils has inspired a range of hypotheses to explain primate initial evolution. One of the central areas of debate around these theories has been the dietary profile of ancestral primates and the role of the different senses to obtain food.

Dr Giuseppe Donati, Reader in Primatology and Biological Anthropology, Oxford Brookes University

“We will also be exploring how leaf eating evolved in early primates. Since night-active lemurs represent good models of early primates, woolly lemurs offer the opportunity to gather insights into how the senses may have evolved to detect leaf defences before the emergence of colour vision.  

“The discovery of basal primate fossils has inspired a range of hypotheses to explain primate initial evolution. One of the central areas of debate around these theories has been the dietary profile of ancestral primates and the role of the different senses to obtain food.”  

Sensory ecology is an area of study that has increased in viability thanks to the development of technology that allows researchers to test sensory aspects of dietary resources.  

Dr Donati and his team will be conducting their study through a mixture of field and lab work and will involve collaboration with other institutions.

The initial phase of the project to collect leaf samples will take place in Ampasy Field Station (Tsitongambarika Protected Area) in south eastern Madagascar. Research collaborators from the University of Wolverhampton and the University of Hamburg will provide odour analyses and nutritional analyses on leaf samples, respectively.

Dr Giuseppe Donati is one of the recipients of the Research Excellence Awards 2017/18, part of Oxford Brookes’ commitment to supporting research-active academics.

The funding is providing him with the opportunity to extend his research, including funding a research assistant and aiding lab analysis.

In October the findings of a study led by Giuseppe were published in the journal Scientific Reports; the research 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.  

Image: Avahi meridionalis by Silvia Battisti