Saito Miho, Takagi Naoko, Tanaka Masayuki, Yamanashi Yumi
Wildlife Research Center, Kyoto University, 2-24, Tanaka-Sekiden-cho, Sakyo-ku, Kyoto 606-8203, Japan,
Center for Research and Education of Wildlife, Kyoto City Zoo, Okazaki Koen, Okazakihoshojicho, Sakyo-ku, Kyoto 606-8333, Japan.
Zoolog Sci. 2020 Feb;37(1):1-6. doi: 10.2108/zs190094.
Suckling behaviors are useful to better understand mother-offspring relationships. However, in many species, knowledge about nighttime suckling behavior is sparse. In the present study, we investigated suckling behavior in four calves of the reticulated giraffe () and their mother in the Kyoto City Zoo, Japan, by analyzing video clips of 9614 h. The relation between a calf's age and the mean duration and frequency of suckling were consistent with the results of previous daytime studies: the longest duration (80 ± 4 s) and highest frequency (0.41/h) of suckling occurred when the calves were young, and decreased thereafter. Suckling frequency was lower at night than during the day, probably because the mother spent much of the time resting at night. The mother initiated suckling behavior in offspring until six months of age. Most often, the mother terminated suckling except during the first few weeks after birth. Additionally, we reported that the average weaning period was 448 days ( = 5) and that the last born (sixth) continued to suckle for more than 750 days, which is a rare phenomenon. We believe the present report helps to fill the lack of knowledge about nighttime suckling behavior in giraffe.
吮乳行为有助于更好地理解母婴关系。然而，在许多物种中，关于夜间吮乳行为的了解却很稀少。在本研究中，我们通过分析9614小时的视频片段，调查了日本京都动物园里4只网纹长颈鹿幼崽及其母亲的吮乳行为。幼崽年龄与吮乳平均时长和频率之间的关系与之前白天研究的结果一致：幼崽年幼时吮乳时长最长（80±4秒）、频率最高（0.41次/小时），之后则下降。夜间吮乳频率低于白天，可能是因为母亲在夜间大部分时间都在休息。母亲会在幼崽六个月大之前发起吮乳行为。大多数情况下，除了出生后的头几周，母亲会终止吮乳。此外，我们报告称平均断奶期为448天（n = 5），最后出生的（第六只）幼崽持续吮乳超过750天，这是一种罕见的现象。我们相信本报告有助于填补长颈鹿夜间吮乳行为知识的空白。
