TY - JOUR

T1 - Sight or scent: lemur sensory reliance in detecting food quality varies with feeding ecology.

AU - Rushmore, Julie

AU - Leonhardt, Sara

AU - Drea, Christine M.

N1 - Funding was provided by National Science Foundation grants (BCS-0409367 and IOS-0719003), Duke University's Molly Glander Awards (http://lemur.duke.edu/research/funding-o​pportunities/) and Undergraduate Research Support grants (http://undergraduateresearch.duke.edu/), and a German Academic Exchange Program (DAAD), Nordamerika Vollzeitstipendium (http://www.daad.org/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

PY - 2012/8/3

Y1 - 2012/8/3

N2 - Visual and olfactory cues provide important information to foragers, yet we know little about species differences in sensory reliance during food selection. In a series of experimental foraging studies, we examined the relative reliance on vision versus olfaction in three diurnal, primate species with diverse feeding ecologies, including folivorous Coquerel's sifakas (Propithecus coquereli), frugivorous ruffed lemurs (Varecia variegata spp), and generalist ring-tailed lemurs (Lemur catta). We used animals with known color-vision status and foods for which different maturation stages (and hence quality) produce distinct visual and olfactory cues (the latter determined chemically). We first showed that lemurs preferentially selected high-quality foods over low-quality foods when visual and olfactory cues were simultaneously available for both food types. Next, using a novel apparatus in a series of discrimination trials, we either manipulated food quality (while holding sensory cues constant) or manipulated sensory cues (while holding food quality constant). Among our study subjects that showed relatively strong preferences for high-quality foods, folivores required both sensory cues combined to reliably identify their preferred foods, whereas generalists could identify their preferred foods using either cue alone, and frugivores could identify their preferred foods using olfactory, but not visual, cues alone. Moreover, when only high-quality foods were available, folivores and generalists used visual rather than olfactory cues to select food, whereas frugivores used both cue types equally. Lastly, individuals in all three of the study species predominantly relied on sight when choosing between low-quality foods, but species differed in the strength of their sensory biases. Our results generally emphasize visual over olfactory reliance in foraging lemurs, but we suggest that the relative sensory reliance of animals may vary with their feeding ecology.

AB - Visual and olfactory cues provide important information to foragers, yet we know little about species differences in sensory reliance during food selection. In a series of experimental foraging studies, we examined the relative reliance on vision versus olfaction in three diurnal, primate species with diverse feeding ecologies, including folivorous Coquerel's sifakas (Propithecus coquereli), frugivorous ruffed lemurs (Varecia variegata spp), and generalist ring-tailed lemurs (Lemur catta). We used animals with known color-vision status and foods for which different maturation stages (and hence quality) produce distinct visual and olfactory cues (the latter determined chemically). We first showed that lemurs preferentially selected high-quality foods over low-quality foods when visual and olfactory cues were simultaneously available for both food types. Next, using a novel apparatus in a series of discrimination trials, we either manipulated food quality (while holding sensory cues constant) or manipulated sensory cues (while holding food quality constant). Among our study subjects that showed relatively strong preferences for high-quality foods, folivores required both sensory cues combined to reliably identify their preferred foods, whereas generalists could identify their preferred foods using either cue alone, and frugivores could identify their preferred foods using olfactory, but not visual, cues alone. Moreover, when only high-quality foods were available, folivores and generalists used visual rather than olfactory cues to select food, whereas frugivores used both cue types equally. Lastly, individuals in all three of the study species predominantly relied on sight when choosing between low-quality foods, but species differed in the strength of their sensory biases. Our results generally emphasize visual over olfactory reliance in foraging lemurs, but we suggest that the relative sensory reliance of animals may vary with their feeding ecology.

KW - Biology

KW - Ecosystems Research

UR - http://www.scopus.com/inward/record.url?scp=84864571538&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/c8e3370c-3fc7-3bdd-bd71-7dd5784c85e5/

U2 - 10.1371/journal.pone.0041558

DO - 10.1371/journal.pone.0041558

M3 - Journal articles

C2 - 22870229

VL - 7

JO - PLoS ONE

JF - PLoS ONE

SN - 1932-6203

IS - 8

M1 - e41558

ER -