Volodina Elena V, Volodin Ilya A, Chelysheva Elena V, Frey Roland
Scientific Research Department, Moscow Zoo, Moscow, 123242, Russia.
Department of Vertebrate Zoology, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia.
BMC Res Notes. 2018 Jan 9;11(1):12. doi: 10.1186/s13104-017-3103-x.
Vocalization as part of vigilance behaviour is widespread across animal taxa, including ruminants. Calls of wild-living giraffes have never been recorded and spectrographically investigated. This study reports the acoustic structure of vigilance-related hiss and snort calls of wild-living giraffes Giraffa camelopardalis.
The hiss and snort calls were emitted during five recording sessions produced by nine individual giraffes (8 adults and 1 subadult) in their natural environment in Namibia (3 individuals) and Kenya (6 individuals). These calls attended vigilance behaviour toward humans in hides or in vehicles and cheetahs as natural predators of giraffe young. This study provides spectrographic analyses of 22 hiss and 20 snort calls. The giraffe hisses were broadband vocalizations of an average duration of 0.72 s (from 0.24 to 1.04 s) and a peak frequency of 0.69 kHz. The giraffe snorts were broadband pulsed calls of an average duration of 0.28 s (from 0.13 to 0.55 s), a peak frequency at 0.20 kHz and comprised a prominent low-frequency pulsation of 23.7 pulses/s. The acoustic structure of giraffe hisses is reminiscent of vigilance-related hisses of musk deer Moschus moschiferus. Giraffe snorts differ from snorts of other ruminants by their prominent pulsed pattern.
发声作为警惕行为的一部分在包括反刍动物在内的动物分类群中广泛存在。野生长颈鹿的叫声从未被记录和进行过频谱研究。本研究报告了野生长颈鹿（长颈鹿属）与警惕相关的嘶嘶声和喷鼻声的声学结构。
嘶嘶声和喷鼻声是在纳米比亚（3只个体）和肯尼亚（6只个体）的自然环境中，由9只个体长颈鹿（8只成年个体和1只亚成年个体）在5次录音过程中发出的。这些叫声伴随着对隐藏在隐蔽处或车辆中的人类以及作为长颈鹿幼崽自然捕食者的猎豹的警惕行为。本研究提供了对22次嘶嘶声和20次喷鼻声的频谱分析。长颈鹿的嘶嘶声是宽带发声，平均持续时间为0.72秒（从0.24秒到1.04秒），峰值频率为0.69千赫。长颈鹿的喷鼻声是宽带脉冲叫声，平均持续时间为0.28秒（从0.13秒到0.55秒），峰值频率为0.20千赫，包含23.7次脉冲/秒的明显低频脉动。长颈鹿嘶嘶声的声学结构让人联想到麝（Moschus moschiferus）与警惕相关的嘶嘶声。长颈鹿的喷鼻声因其突出的脉冲模式而与其他反刍动物的喷鼻声不同。
