Increase of an introduced bird competitor in old-growth forest associated with restoration
Autor: | Leonard A. Freed, Rebecca L. Cann |
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Jazyk: | angličtina |
Rok vydání: | 2012 |
Předmět: |
restoration
Forest management Population exponential population growth Introduced species Plant Science Aquatic Science Biology Population density ddc:590 time-lag propagule pressure education lcsh:QH301-705.5 Ecology Evolution Behavior and Systematics biotic resistance geography education.field_of_study geography.geographical_feature_category Introduced bird Ecology Ecological Modeling Propagule pressure Old-growth forest lcsh:Biology (General) Animal ecology Insect Science Wildlife refuge Animal Science and Zoology competition |
Zdroj: | NeoBiota, Vol 13, Iss 0, Pp 43-60 (2012) NeoBiota 13: 43-60 |
ISSN: | 1314-2488 1619-0033 |
Popis: | Many successful invasions involve long initial periods in which the invader exists at low densities followed by sudden population increases. The reasons for such time-lags remain poorly understood. Here we document a sudden increase in density of the introduced Japanese white-eye (Zosterops japonicus) in a restoration area contiguous with old-growth forest at Hakalau Forest National Wildlife Refuge on the Island of Hawaii. The refuge, with very high density of native birds, existed in a pocket of low white-eye density that persisted for at least 20 years since the late 1970s. The refuge began an extensive native trees restoration project in 1989 within a 1314 ha abandoned pasture above old-growth forest. This area was soon colonized by white-eyes and their population grew exponentially once the trees had grown tall enough to develop a canopy. This increase was in turn followed by significantly more white-eyes in the open and closed forests adjacent to the restoration area. Competition between white-eyes and native species was documented on study sites within these forests. Density data indicate that competition was more widespread, with loss of tens of thousands of native birds in the 5371 ha area surveyed. Our results are consistent with the view that ecological barriers may delay the population increase of invaders and that human-derived activities may help invaders cross these barriers by creating new ecological opportunities. Control of white-eye numbers may be essential for recovery of native species. |
Databáze: | OpenAIRE |
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