Olfactory sensitivity for aliphatic esters in spider monkeys (Ateles geoffroyi)

Area of Science:

• Primate Olfaction
• Sensory Neuroscience
• Animal Behavior

Background:

• Olfactory sensitivity varies significantly across species.
• Neuroanatomical features are often used to predict olfactory performance, but this can be unreliable.
• Spider monkeys (Ateles geoffroyi) are primates with less-studied olfactory capabilities.

Purpose of the Study:

• To investigate the olfactory sensitivity of spider monkeys to aliphatic esters.
• To compare their olfactory performance to other mammalian species.
• To evaluate the predictive power of neuroanatomy for olfactory abilities.

Main Methods:

• A conditioning paradigm was employed to test olfactory discrimination.
• Three spider monkeys were exposed to a homologous series of aliphatic esters and their isomers.
• Detection thresholds were determined for various odorants, including concentrations below 1 part per million (ppm).

Main Results:

• Spider monkeys demonstrated significant olfactory discrimination at concentrations below 1 ppm for all tested odorants.
• Individual monkeys exhibited detection thresholds below 1 part per billion (ppb) for some substances.
• The olfactory sensitivity of spider monkeys for aliphatic esters was found to be comparable or superior to that of rats, mice, and dogs.

Conclusions:

• Spider monkeys possess a highly developed sense of smell for aliphatic esters.
• Olfactory performance does not solely depend on neuroanatomical comparisons between species.
• These findings challenge the assumption that brain structure accurately predicts olfactory capabilities across diverse species.