2026-06-30 イリノイ大学アーバナ・シャンペーン校
＜関連情報＞
- https://aces.illinois.edu/news/how-long-does-it-take-grow-tree-supports-endangered-indiana-bats-0
- https://www.sciencedirect.com/science/article/abs/pii/S0378112726004408?via%3Dihub
絶滅危惧種のコウモリが利用する木のねぐらは、形成にほぼ1世紀かかる Tree roosts used by an endangered bat require almost a century to develop
Joseph L. Pettit, R. Justin DeRose, James H. Speer, Marilyn Kitchell, Dale Sparks, Susan C. Loeb, Joy M. O’Keefe
Forest Ecology and Management Available online: 27 May 2026
DOI:https://doi.org/10.1016/j.foreco.2026.123942
Highlights
- Indiana bats used roost trees that ranged from 31 to 283 years old.
- Maximum emergence of bats from a roost tree was not impacted by roost tree age.
- Early-successional roost trees develop quickly, within decades.
- Late-successional roost trees develop in 130 ± 54 years but remain standing longer.
Abstract
As a forest-dependent species, the endangered Indiana bat (Myotis sodalis) is reliant on large-diameter tree roosts (hereafter, “roosts”), which are usually snags. Such large trees develop as a product of time and species-specific growth rates. To better understand the ecology of bat roost habitat, we explore the putative trade-offs between tree age, size, and growth rates on the development of roosts. Specifically, we quantify the age, size, and longevity of roosts of Indiana bats using dendrochronology at three study sites across the species’ range in the eastern USA. On average, roosts were alive for 97.8 years (range = 31–283), 7.4 years elapsed after tree death before bats used them as roosts, and snag longevity was 10.8 years. Bats selected roosts based on size and not age. Fast-growing, early-successional species attained desirable roost size more quickly than slow-growing, mid- and late-successional species. Early-successional species, e.g. Populus deltoides and Pinus strobus, were suitable as roosts at ∼72 years versus 130 years for late-successional species. Tree growth rate, a trait related to successional status, was negatively correlated with roost age at use, and longevity prior to falling. Consequently, fast-growing trees fell more quickly. Therefore, species’ successional status and growth rate are key factors that determine the timeframe necessary for roost development, and their longevity as snags. A lack of selection by bats for tree age indicates that desirable roost habitat can be developed within decades, by promoting early-successional trees, but speed of development must be weighed against snag longevity.
