Simultaneous production of low- and high-frequency sounds by neonatal finless porpoises.
Phocoenids are generally considered to be nonwhistling species that produce only high-frequency pulsed sounds. Here our results show that neonatal finless porpoises (Neophocaena phocaenoides) frequently produce clear low-frequency (2-3 kHz) pulsed signals, without distinct high-frequency energy, just after birth and can produce both low- (2-3 kHz) and high-frequency (>100 kHz) pulsed signals simultaneously until about 20 days postnatal. The results indicate that low-frequency signals of neonatal finless porpoises are not an early form of high-frequency signals and suggest that low- and high-frequency signals may be produced by different sound production mechanisms.
Li
Songhai
S
Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, People's Republic of China.
Wang
Kexiong
K
Wang
Ding
D
Dong
Shouyue
S
Akamatsu
Tomonari
T
D000818:Animals; D000831:Animals, Newborn; D008297:Male; D019576:Porpoises / Q000502:physiology*; D013018:Sound Spectrography; D013997:Time Factors; D014828:Vocalization, Animal