• Journal of Ecology and Environment
• /
• v.35 no.1
• /
• pp.9-14
• /
• 2012

Yellow bitterns (Ixobrychus sinensis) are a small wetland bird common to Asian countries including South Korea, Japan, and China. The aim of this study is to describe diet of yellow bitterns during the breeding season in artificial wetland of northeastern South Korea between May to August 1999-2001. For the purposes of this paper, we observe the frequency of nest visiting by parents during the chick rearing period. A total of 98 boluses regurgitated by 52 chicks aged 1 day to 11 days after hatching form the sample and are shown to contain 323 food items. A bolus contained mean 3.8 items and weighs 0.2 g to 7.7 g. The most regularly occurring food items recorded are fish (63%) and insets (33%). In terms of fish, top mouth minnows (Pseudorasbora parva) and crucian carps (Carassius auratus) are frequently observed. In terms of insects, there are mosquitoes (Diptera), instars of dragonfly (Libelluidae), damselflies (Coenagrinonidae) and water bugs (Diplonychus japonicus). Yellow bitterns were also shown to feed on bull frogs (Rana catesbeiana), shrimp (Palaemonidae), and spiders (Araneae). The size of fish in a bolus ranged from 15.56 mm to 93.73 mm (mean, 37.08 mm). The amount of food can be observed to increase with the age of chicks (r = 0.279, P = 0.025, N = 64) but parents did not provide larger fish as chicks grew. Parent birds visited nests more frequently when they have a larger brood ($F_{1,21}$ = 14.529, P = 0.001). Our results suggest that fish is the most important prey during the breeding season and that age of chicks is related to amount of diet in yellow bitterns.

• Journal of Wetlands Research
• /
• v.11 no.1
• /
• pp.29-37
• /
• 2009

This study was conducted on the marsh of Paldang dam and Gyungan-cheon, Gyeonggi-do province. 6 species bred on the emergent plants and the nests of Common Coots Fulica atra, Common Moorhens Gallinula chloropus, Great Reed-Warblers Acrocephalus orientalis, Yellow Bitterns Ixobrychus eurhythmus, Little Grebes Podiceps ruficollis and Great Crested Grebes Podiceps cristatus were found. The main vegetations of the nests were Narrow Leaf Cattails Typha angustata, Reeds Phragmites communis, and Wild Rices Zizania latitolia. Particularly, Narrow Leaf Cattails were the most favorite plants for breeding birds. Few nests were found on the emergent plants covered with rubbish, or on high density. And no nests found on the inside shrubs. The mean density of nests on the marsh was 3.1 nests per ha and the nests were highest in Non-island as 17 nests per ha. The nest density on the area of Sonae-islands was higher than the area of Kyangdong-kyo bridge. This would be related on the bulk of narrow-leaf cattails and the quality of water.