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An invasive prey provides long-lasting silver spoon effects for an endangered predator

June 22, 2022

The natal environment can have long-term fitness consequences for individuals, particularly via ‘silver spoon’ or ‘environmental matching’ effects. Invasive species could alter natal effects on native species by changing species interactions, but this potential remains unknown. Using 17 years of data on 2588 individuals across the entire US breeding range of the endangered snail kite (Rostrhamus sociabilis), a wetland raptor that feeds entirely on Pomacea snails, we tested for silver spoon and environmental matching effects on survival and movement and whether the invasion of a non-native snail may alter outcomes. We found support for silver spoon effects, not environmental matching, on survival that operated through body condition at fledging, explained by hydrology in the natal wetland. When non-native snails were present at the natal site, kites were in better condition, individual condition was less sensitive to hydrology, and kites fledged across a wider range of hydrologic conditions, leading to higher survival that persisted for at least 10 years. Movement between wetlands was driven by the current (adult) environment, and birds born in both invaded and uninvaded wetlands preferred to occupy invaded wetlands post-fledging. These results illustrate that species invasions may profoundly impact the role of natal environments on native species.

Publication Year 2022
Title An invasive prey provides long-lasting silver spoon effects for an endangered predator
DOI 10.1098/rspb.2022.0820
Authors Caroline L. Poli, Ellen P. Robertson, Julien Martin, Abby Powell, Robert J. Fletcher Jr.
Publication Type Article
Publication Subtype Journal Article
Series Title Proceedings of the Royal Society B
Index ID 70239352
Record Source USGS Publications Warehouse
USGS Organization Wetland and Aquatic Research Center