Table 2.

Behaviourally derived audiometric parameters, group size and interaural distance across the primate order.

species	60 dB high-frequency limit (kHz)a	frequency of best sensitivity (kHz)	species mean group sizeb	interaural distance (mm)c
Aotus trivirgatus, owl monkey	44.5	10.0	2.9	28.49
Callithrix jacchus, common marmoset	44.9	7.0	11.0	20.1
Galago senegalensis, bushbaby	65.0	8.0	1.0	19.94
Homo sapiens, human	17.6	4.0	37.5	81.68
Macaca fascicularis, long-tailed macaque	—	16.0	27.5	38.3
Macaca fuscata, Japanese macaque	36.5	4.0	36.6	43.07
Macaca mulatta, rhesus macaque	—	16.0	35.5	40.8
Papio cynocephalus, yellow baboon	41.0	8.0	55.5	53.17
Perodicticus potto, potto	42.0d	16.0	1.0	26.6
Phaner furcifer, fork-marked lemur	60.0	16.0	2.0	20.47
Saimiri sp., squirrel monkeye	42.5	12.0	23.0	27.28

^aPublished free-field behaviourally derived data [22,53].

^bForaging group sizes were averaged from the literature [42–51,54].

^cInteraural distances from Coleman [34].

^dBased on the electronic supplementary material from Heffner, see http://homepages.utoledo.edu/rheffne/.

^eSpecies designation is uncertain for the auditory data, thus group size and interaural distance data are estimated from multiple species within the genus.