Effects of an alien ant invasion on abundance, behavior, and reproductive success of endemic island birds

Biological invaders can reconfigure ecological networks in communities, which changes community structure, composition, and ecosystem function. We investigated whether impacts caused by the introduced yellow crazy ant (Anoplolepis gracilipes), a pantropical invader rapidly expanding its range, exten...

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Veröffentlicht in:Conservation biology : the journal of the Society for Conservation Biology. - 1999. - 22(2008), 5 vom: 01. Okt., Seite 1165-76
1. Verfasser: Davis, Naomi E (VerfasserIn)
Weitere Verfasser: O'Dowd, Dennis J, Green, Peter T, Nally, Ralph Mac
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2008
Zugriff auf das übergeordnete Werk:Conservation biology : the journal of the Society for Conservation Biology
Schlagworte:Comparative Study Journal Article Research Support, Non-U.S. Gov't
Beschreibung
Zusammenfassung:Biological invaders can reconfigure ecological networks in communities, which changes community structure, composition, and ecosystem function. We investigated whether impacts caused by the introduced yellow crazy ant (Anoplolepis gracilipes), a pantropical invader rapidly expanding its range, extend to higher-order consumers by comparing counts, behaviors, and nesting success of endemic forest birds in ant-invaded and uninvaded rainforest on Christmas Island (Indian Ocean). Point counts and direct behavioral observations showed that ant invasion altered abundances and behaviors of the bird species we examined: the Island Thrush (Turdus poliocephalus erythropleurus), Emerald Dove (Chalcophaps indica natalis), and Christmas Island White-eye (Zosterops natalis). The thrush, which frequents the forest floor, altered its foraging and reproductive behaviors in ant-invaded forest, where nest-site location changed, and nest success and juvenile counts were lower. Counts of the dove, which forages exclusively on the forest floor, were 9-14 times lower in ant-invaded forest. In contrast, counts and foraging success of the white-eye, a generalist feeder in the understory and canopy, were higher in ant-invaded forest, where mutualism between the ant and honeydew-secreting scale insects increased the abundance of scale-insect prey. These complex outcomes involved the interplay of direct interference by ants and altered resource availability and habitat structure caused indirectly by ant invasion. Ecological meltdown, rapidly unleashed by ant invasion, extended to these endemic forest birds and may affect key ecosystem processes, including seed dispersal
Beschreibung:Date Completed 22.01.2009
Date Revised 28.10.2008
published: Print-Electronic
Citation Status MEDLINE
ISSN:1523-1739
DOI:10.1111/j.1523-1739.2008.00984.x