Differences in Japanese White-eye and Japanese Bush Warbler dawn vocalization frequencies caused by the mating system.
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- OSAKA Hideki
- こまたん（高麗山花水川探鳥会）
Bibliographic Information
- Other Title
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- 配偶様式の違いが現れたメジロとウグイスの夜明けの鳴き声頻度
- ハイグウ ヨウシキ ノ チガイ ガ アラワレタ メジロ ト ウグイス ノ ヨアケ ノ ナキゴエ ヒンド
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Description
<p>1)The onset and frequency of Japanese White-eye Zosterops japonicus and Japanese Bush Warbler Horornis diphone vocalizations (i.e. calls and songs) were recorded at Oiso Hill, Kanagawa Prefecture from July 2014 to March 2016. The horizontal light intensity was estimated</p><p>from the sun’s height and weather during the breeding season and non-breeding seasons of both species. Japanese White-eye: light intensity and onset of vocalization (average±SD)</p><p>- breeding season (April to July) (n=19)-18.3 ±4.4 min, 59.0±67.5 Lx</p><p>- winter (November to January) (n=22) -24.8 ±7.9 min, 21.7±25.7 Lx</p><p>Japanese Bush Warbler: light intensity and onset of vocalization</p><p>- breeding (March to June) (n=19)-15.5 ±4.0 min, 96.6 ±86.4 Lx</p><p>- winter (November to January) (n=22) -12.36 ±10.37 min, 201±459 Lx</p><p>Light intensity at the onset of Japanese White-eye vocalization during both the breeding and non-breeding seasons was more stable than that of the Japanese Bush Warbler.</p><p>2) Based on the time of sunrise, the onset of Japanese Bush Warbler vocalization was -18.3 ± 4.4 min during the breeding season in 2015 and continued to vocalize 90 minutes after sunrise when stopped recording. On the other hand, Japanese White-eye vocalized from -18.8 ± 3.5 min to +6.1±6.4 min and decreased very early in the morning. Vocalization length was 25.0 ± 5.6 min.</p><p>3) It is thought that the difference in mating systems Bush Warblers are polygamous and the male does not participate in breeding duties except for courting, copulation and defending the territory. Therefore the male doesn't stop singing that is also a means of warning the nesting female of dangers.</p><p>4) The reason for both the Japanese White-eye and Japanese Bush Warbler singing intermittently at dawn and early morning at the beginning of the breeding season may differ. The reason for Japanese White-eye singing may be in the selection and guarding of their nest site and territory which coincides with a successful breeding rate. The reason for Japanese Bush Warbler singing may be for the purpose of practicing their song and at the same time guarding their territory. The Japanese White-eye singing is short which may also be practice.</p><p>5) At the peak of the breeding season (May 17) the dawn and early morning singing of the Japanese Bush Warbler was disrupted. This may be due to the arrival of an avian brood parasite (Little Cuckoo Cuculus poliocephalus) at this time.</p>
Journal
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- BINOS
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BINOS 24 (0), 27-40, 2017-11-01
Wild Bird Society of Japan Kanagawa Branch