1. Nest tree characteristics of Grey-headed Woodpeckers (Picus canus) in boreal forests.
- Author
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Pakkala, Timo, Tiainen, Juha, Pakkala, Heikki, Piha, Markus, and Kouki, Jari
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TAIGAS , *BIRD nests , *WOODPECKERS , *EUROPEAN aspen , *TREE cavities , *NESTS - Abstract
Woodpeckers are important species in forest ecosystems because they make tree cavities that are microhabitats for several other taxa. However, even in boreal areas where most tree cavities are made by woodpeckers, the properties of woodpeckers' nest trees and cavities are poorly known. We studied nest tree characteristics of the Grey-headed Woodpecker (Picus canus) in a 170-km2 forest-dominated area in southern Finland during 1987-2019. The data included 76 nest trees with 80 nest cavities in five different tree species. During the study period, 44% of all nesting attempts were in old cavities. Nestswere found in four forest types, but the proportions ofnest tree species differed between them. In all, aspen (Populus tremula) with 70% ofnest trees, and with 71% ofnest cavities was the dominant cavity tree species. Mostnesttrees (85%) were dead or decaying, and most cavities (70%) were excavatedat visible trunk injury spots. The mean diameterofanest tree atbreastheight(DBH)was 37.2 cm and the meanheightofacavityhole was 7.8 m; these were significantly positively correlated. The results highlight the importance of large aspens as nest cavity sites for the species. Conservation and retention of group s of large aspens in main habitats, including clear-cuts, are important for continuous availability of nest trees. This applies particularly to managed boreal forest landscapes where scarcity of suitable trees may be a limiting factor for the species. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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