Small patches of broadleaf trees influence nest-site selection and reproductive performance of two tit species (Paridae) in a Japanese cedar plantation

ABSTRACT

Conifer plantations generally provide less food for woodland birds such as tit species than do broadleaf or mixed forests. We examined whether small patches of broadleaf (thus, caterpillar-rich) trees in a Japanese cedar (Cryptomeria japonica) plantation could improve the breeding success of coal tits (Periparus ater) and varied tits (Poecile varius) using nest boxes in the plantation. We evaluated the relationships between the distribution of the broadleaf trees (the minimum distance from each nest box to the nearest patch and the total area of broadleaf patches within 25, 50, 100, and 200 m from each nest box) and breeding performance (clutch size, number, and body mass of fledglings, fledging success, fledge rate, and nestling period). Coal tits selected nest boxes regardless of the distribution of broadleaf patches. By contrast, varied tits nested preferentially within 50 m of broadleaf patches and, within 50 m, favored boxes near a larger total area of broadleaf patches than coal tits. The breeding performance of both species was not affected by the distribution of patches; however, the clutch size of varied tits (but not coal tits) tended to decline in nests ≥50 m from broadleaf patches, and there were no large clutches in such positions. The broadleaf trees might have improved the habitat quality, particularly for varied tits, by providing food resources. Thus, broadleaf patches as foraging sites and nest boxes as breeding sites could both be critical to the breeding success of woodland birds in conifer plantations.

KEYWORDS:

• Breeding ecology
• conifer plantation
• foraging site
• patches of broadleaf trees
• tit (Paridae)

Acknowledgements

We thank the anonymous reviewers for their helpful remarks and suggestions. We are also grateful to H. Hayase, Y. Imaizumi, H. Ando, N. Yamaguchi, N. Takabe, and the members of the Laboratory of Forest Protection, Nagoya University for helpful suggestions and assistance. The work was supported in part by a Grant-in-Aid (No. 21380093) for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology [Grant Number: 21380093].

Notes on contributors

Takashi Kondo

Takashi Kondo is a doctoral student of the Forest Protection Laboratory, Graduate School of Bioagricultural Sciences, Nagoya University. His current research subject, initiated in 2011, is the breeding ecology of woodland birds (Paridae), focusing on factors contributing to their nesting and breeding success in conifer plantations.

Mizuki Mizutani

Mizuki Mizutani is an assistant professor of the Institute of Nature Education in Shiga Heights, Faculty of Education, Shinshu University, since 2015. After received a PhD in Forest Sciences from Nagoya University in 2002, he joined the Fukui prefectural government and was engaged in environmental and agricultural administrations. His specialty is forest ecology, and he has widely been dealing with applied research subjects, mainly those related to the wildlife management and conservation.

Naoki Hijii

Naoki Hijii is a professor of the Forest Protection Laboratory, Graduate School of Bioagricultural Sciences, Nagoya University. Since received a PhD in Forest Sciences from Nagoya University in 1985, he has made various areas of research, mainly in forest entomology focusing on insect–plant and insect–fungus interactions and in forest ecology on the interactions of biological communities, such as arthropods and woodland birds, and their functioning in forest ecosystems.