Colour vision in sengis (Macroscelidea, Afrotheria, Mammalia): choice experiments indicate dichromatism

What is it about?

Sengis, small African mammals, belong to the clade Afrotheria. Little research has been conducted on their senses, and up to now behavioural investigations about the animals' vision are completely missing. Other members of the Afrotheria, such as manatees, elephants, tenrecs and rock hyraxes are dichromats, having two types of cone photoreceptors in the retina. We tested the hypotheses of dichromatic colour vision in sengis. With choice experiments, we examined the potential of two species of sengis to discriminate between trained colours, i.e. blue, green and red, and different shades of grey, as well as to differentiate between trained UV-reflecting and UV-absorbing plates. Both species of sengis recognised the blue and green colours and could distinguish them from all tested shades of grey. The ability to perceive red and ultraviolet could not be proven. Thus, the sengis are most likely dichromats based on two receptor types being sensitive in the green and blue wavelengths.

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