Strategies of food detection in a captive cathemeral lemur, Eulemur rubriventer

Abstract

The senses involved in food detection in primates in general, and lemurs in particular, remain poorly investigated. However, as lemurs include diurnal, nocturnal, and cathemeral species they represent a good model to test whether prey detection is dependent on activity pattern. As both diurnal and nocturnal species have been investigated previously we here aim to quantify the relative importance of different sensory modalities during prey detection in a cathemeral species, the red-bellied lemur (Eulemeur rubriventer). A series of experiments was performed using a group of four Eulemur rubriventer (Zoo de La Londe les Maures, France) to test the role of visual, olfactory and acoustic cues in prey detection. Both unimodal and multimodal cues were tested. The responses obtained in the different experiments show that visual cues are essential for prey detection in this species, at least in captivity. However, the use of multiple sensory modalities improves the success of detection suggesting that cathemeral species may benefit from the use of multiple sensory modalities.

The importance of auditory, olfactory, and visual cues for insect foraging in owl monkeys (Aotus nancymaae)

“…Under these multimodal conditions, the owl monkeys readily approached and touched the experimental boxes and spent the greatest amount of time within arm's reach of the actual insects. In studies with a similar experimental setup, nocturnal gray mouse lemurs ( M. murinus ) and cathemeral red‐bellied lemurs ( E. rubriventer ) were most successful at interacting with the testing apparatus and locating insect food rewards when they were presented with multimodal cues of the insects (Perrenoud et al, 2015; Piep et al, 2008). Because there are trade‐offs in the development of sensory organs due to the energetic costs associated with neural tissue (Niven & Laughlin, 2008), strong selective pressures may have led to the use of multimodal cues to facilitate efficient foraging.…”

“…Contrary to these findings, nocturnal gray mouse lemurs were successful at locating insects when they were only presented with the sound of the insects rustling or flying (Piep et al, 2008; Siemers et al, 2007). Cathemeral red‐bellied lemurs also located insects when presented with only auditory cues of the insects, although they were not as successful as gray mouse lemurs (Perrenoud et al, 2015).…”

“…We investigated the sensory ecology of insect foraging in nocturnal A. nancymmae . Similar to several species of cathemeral, diurnal, and nocturnal lemurs (Perrenoud et al, 2015; Piep et al, 2008; Rushmore et al, 2012), owl monkeys used multiple sensory cues simultaneously to locate food. Not only were owl monkeys able to locate insect prey when presented with a mixture of sensory stimuli, but they also successfully detected insects when exclusively using olfactory cues.…”

“…Experiments examining the sensory ecology of strepsirrhines revealed the importance of olfactory, visual, and multimodal cues in foraging (Perrenoud et al, 2015; Piep et al, 2008; Siemers et al, 2007). Although nocturnal omnivorous gray mouse lemurs ( Microcebus murinus ) can locate hidden fruit using only olfaction (Siemers et al, 2007), both they and cathemeral red‐bellied lemurs ( Eulemer rubriventer ) were most successful at detecting insect prey using visual cues alone and when using multimodal cues (a combination of different sensory cues) (Perrenoud et al, 2015; Piep et al, 2008; Siemers et al, 2007). Owl monkeys may be expected to rely upon similar sensory cues when foraging for insects given their comparable nocturnal lifestyle, but this may not be the case given their divergent evolutionary history.…”