Animal Cognition

, Volume 17, Issue 4, pp 947–961

The ecology of spatial memory in four lemur species

Authors

    • Department of PsychologyYale University
  • Kerri Rodriguez
    • Department of Evolutionary AnthropologyDuke University
  • Brian Hare
    • Department of Evolutionary AnthropologyDuke University
    • Center for Cognitive NeuroscienceDuke University
Original Paper

DOI: 10.1007/s10071-014-0727-2

Cite this article as:
Rosati, A.G., Rodriguez, K. & Hare, B. Anim Cogn (2014) 17: 947. doi:10.1007/s10071-014-0727-2

Abstract

Evolutionary theories suggest that ecology is a major factor shaping cognition in primates. However, there have been few systematic tests of spatial memory abilities involving multiple primate species. Here, we examine spatial memory skills in four strepsirrhine primates that vary in level of frugivory: ruffed lemurs (Varecia sp.), ring-tailed lemurs (Lemur catta), mongoose lemurs (Eulemur mongoz), and Coquerel’s sifakas (Propithecus coquereli). We compare these species across three studies targeting different aspects of spatial memory: recall after a long-delay, learning mechanisms supporting memory and recall of multiple locations in a complex environment. We find that ruffed lemurs, the most frugivorous species, consistently showed more robust spatial memory than the other species across tasks—especially in comparison with sifakas, the most folivorous species. We discuss these results in terms of the importance of considering both ecological and social factors as complementary explanations for the evolution of primate cognitive skills.

Keywords

MemorySpatial cognitionLemursEcologyCognitive evolution

Supplementary material

10071_2014_727_MOESM1_ESM.docx (244 kb)
Supplementary material 1 (DOCX 243 kb)
View video

Test trial in Study 1 (memory after a one-week delay). The mongoose lemur is centered at the starting position by Experimenter 2 (E2) using a small piece of, while E1 baits the food cups. Once the baiting process is complete, E2 says start and removes the centering food. Here, the lemur chooses the correct (baited) cup. In the initial introductory session one week previously, lemurs could self-correct their choice following incorrect responses, to ensure equal experience with the correct location. In the test session one week later (shown here), lemurs could not self-correct (MOV 6738 kb)

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Learning and probe trial in Study 2 (memory mechanisms). In the learning trial, the sifaka is centered at the normal staring position by Experimenter 2 (E2) using a small piece of food, while E1 baits the cups. As in Study 1, the lemur can self-correct following incorrect choices in learning trials. Here, the sifakas correctly chooses the baited side. In the probe trial, the sifakas begins the trial from the flipped orientation, and E1 baits both locations. Here, the sifakas makes a habit-based response (turning right) rather than a spatial response (toward the previously rewarded spatial location). E1 removes the food from the alternative location following the choice (MOV 10113 kb)

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Search phase in Study 3 (memory for multiple locations). The ruffed lemur enters the room and searches at four of the eight landmarks. In the previous exposure phase, four test locations were baited with visible food, whereas the four control locations were empty. In the search phase shown here, all locations are baited with food, which are hidden by a lid covering the food boxes. Here, the lemur first searches at two control locations, and then at two test locations (MOV 38046 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2014