Breeding biology and chick food of Varied Tit Parus varius in Korea

Abstract

1. Breeding biology of the Varied Tit Parus v. varius was studied with 35 nest-boxes (19 in 1963, 16 in 1964) at Seoul and Kwang Nung experimental forests during 1963-64.
2. The Varied Tit is a dominant hole-nesting forest bird, permanently resident throughout Korea. It usually lives in broad-leaved and mixed woods, though it wanders in winter to sparce bushy area.
3. Both sexes are engaged in nest-building 4-7 days. The nest is basically built with moss, lined inside with hairs of Water-deer, Korean Badger, Racoon Dog, bird feathers and grass roots.
4. First egg is laid on the day, or 3-4 days after, the nest was completed in the nest-box. Laying period is from early April to early June. The clutch-size varies 4-10, usually 7-8, and the egg is laid daily.
5. The both sexes incubate in turn for 12-14 days, the hatching period being May to June, and the feeding period is middle of May to early July, lasting 12-17 days.
6. First chick foods are mostly soft worms, spiders and insect larvae and as chicks grow adult insects and some vegetable matter become mixed. The food composition collected by collar method was: 54.69% insect larvae, 13.85% adult insects, 1.5% pupae, 29.59% other animal foods and 0.37% vegetable matter. The frequent larvae were Noctuidae, Geometridae, Cerruidae and Lymantridae. In adult insects Xiphidion was dominant and among other animal species Araneina occupied 26.97%. Spiders decreased and insects increased with the chick growth.
7. From the point of view of forestry, 45.32% of all food items were noxious insects, 27.71% were spiders and 26.97% were miscellaneous animal matters. Therefore more provision of nestboxes is intended.
8. Wood-board nest-box with entrance 3cm. in diameter well fitted to this tit but relatively higher ones, about 6m., were more successful, being safer from human damage.