DOI: 10.5061/dryad.djh9w0vx3
title: Data from: An invasive insect, hemlock woolly adelgid, indirectly impacts Louisiana Waterthrush nest site selection and nest survival in the southern Appalachians

description: Eastern hemlock (Tsuga canadensis) is declining throughout the eastern
 United States due to hemlock woolly adelgid (Adelges tsugae Annand), an
 invasive insect from Asia. In the southern Appalachians, hemlock is
 concentrated in moist ravines and its decline threatens riparian
 ecosystems. Previous research on this invasion has focused on adelgid
 control and how hemlock decline affects community composition or forest
 processes; few studies have evaluated the consequences for demography of
 obligate riparian species. The Louisiana Waterthrush (Parkesia motacilla)
 is an obligate riparian species that could be sensitive to hemlock
 condition in this region, but how individuals respond to decline is
 currently unknown. To address this knowledge gap, we leveraged recent
 adelgid treatment efforts in Great Smoky Mountains National Park to
 evaluate the relationship(s) between hemlock decline and waterthrush
 habitat selection (foraging and nest site) and vital rates (nest and adult
 survival). We found that hemlock decline was unrelated to foraging habitat
 selection and apparent adult survival, but was related to nest site
 selection through an interaction with percent ground cover of exposed live
 tree roots: birds selected for nest sites in areas with more exposed live
 roots but only when hemlock were in poor condition. Nest survival was
 lower in areas where deciduous species (vs. evergreen species) dominated
 the understory, suggesting that adelgid invasion could indirectly impact
 waterthrush fitness depending on how vegetative succession proceeds
 following hemlock decline. Our results suggest that the short-term
 consequences of adelgid invasion on this riparian avian species are
 minimal in this area, but these relationships are likely dynamic and
 dependent on local habitat features and the predator community response to
 hemlock decline.Eastern hemlock (Tsuga canadensis) is declining throughout
 the eastern United States due to hemlock woolly adelgid (Adelges tsugae
 Annand), an invasive insect from Asia. In the southern Appalachians,
 hemlock is concentrated in moist ravines and its decline threatens
 riparian ecosystems. Previous research on this invasion has focused on
 adelgid control and how hemlock decline affects community composition or
 forest processes; few studies have evaluated the consequences for
 demography of obligate riparian species. The Louisiana Waterthrush
 (Parkesia motacilla) is an obligate riparian species that could be
 sensitive to hemlock condition in this region, but how individuals respond
 to decline is currently unknown. To address this knowledge gap, we
 leveraged recent adelgid treatment efforts in Great Smoky Mountains
 National Park to evaluate the relationship(s) between hemlock decline and
 waterthrush habitat selection (foraging and nest site) and vital rates
 (nest and adult survival). We found that hemlock decline was unrelated to
 foraging habitat selection and apparent adult survival, but was related to
 nest site selection through an interaction with percent ground cover of
 exposed live tree roots: birds selected for nest sites in areas with more
 exposed live roots but only when hemlock were in poor condition. Nest
 survival was lower in areas where deciduous species (vs. evergreen
 species) dominated the understory, suggesting that adelgid invasion could
 indirectly impact waterthrush fitness depending on how vegetative
 succession proceeds following hemlock decline. Our results suggest that
 the short-term consequences of adelgid invasion on this riparian avian
 species are minimal in this area, but these relationships are likely
 dynamic and dependent on local habitat features and the predator community
 response to hemlock decline.
description: This dataset was collected following field protocol outlined in
 the associated manuscript (individual birds were monitored throughout the
 season; GPS points were collected at foraging sites; nests were searched
 for and monitored to determine fate; and habitat and hemlock surveys were
 conducted at used, nests, and available locations within each
 territory). R was used for analyzing forgaging habitat selection, nest
 site selection, and apparent annual survival data, and for calculating 85%
 confidence intervals for nest survival data. Program MARK was used for
 analyzing nest survival and data. Generalized linear mixed modeling and an
 information theoretic framework with Akaike inforamation criterion
 corrected for small sample sizes (AICc) were used for analyses.
description: Each data file has a metadata tab describing variables. The
 data tabs within each file should be saved as .csv files for use in R and
 the nest survival data tab should be saved as a .inp file for use in
 Program MARK. There are no missing values. An R script file is included
 for each analysis.