Similar dietary but different numerical responses to nonnative tamarisk (Tamarix spp.) by two native warblers

Sean M. Mahoney, Tad Theimer, Matthew J. Johnson, Jeffrey T Foster

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Native species can have a range of responses to nonnative introductions, from negative to positive, and understanding how and why native species respond differently to nonnatives remains an important management challenge. Based on differences and similarities in ecology and behavior, we predicted how abundance and diet of two native warblers, Lucy’s warbler (Oreothlypis luciae) and yellow warbler (Setophaga petechia), would differ in habitats with different amounts of nonnative tamarisk trees and the three nonnative insects obligately dependent on tamarisk (Tamarix spp.). Specifically, we predicted that Lucy’s warblers would have similar densities across sites, yellow warbler densities would be inversely related to tamarisk cover, and both warblers, being generalist insectivores, would incorporate tamarisk biocontrol insects in their diet. Based on point counts and fecal samples at six sites along the Virgin River in the southwestern United States, we found that yellow warblers decreased in abundance with increasing tamarisk cover, while Lucy’s warbler abundance did not and that diet of the two warblers did not differ, with both species exhibiting strong selection for the nonnative tamarisk weevil (Coniatus splendidulus) and weak to no selection for the nonnative tamarisk leafhopper (Opsius stactogalus). Both warblers showed negative selection for the tamarisk beetle (Diorhabda carinulata) and its larvae, even when those insects were 10–100 times more abundant during outbreaks. Although both warblers exploited the novel food resources offered by tamarisk, with those insects contributing half or more of total prey biomass, Lucy’s warblers were better able to maintain densities in tamarisk habitats. We hypothesize this was due to the Lucy’s warbler’s ability to exploit a broader array of habitats surrounding tamarisk sites and its cavity nesting habit that buffers its nests from the higher temperatures and lower humidity of tamarisk-dominated habitat. Our results suggest that predictions based on detailed knowledge of the form and function of native and nonnative species can be used to predict native bird response to nonnatives.

Original languageEnglish (US)
Pages (from-to)1-16
Number of pages16
JournalBiological Invasions
DOIs
StateAccepted/In press - Mar 20 2017

Fingerprint

numerical response
Tamarix
insect
insects
indigenous species
habitat
diet
habitats
Opsius stactogalus
native species
Setophaga
novel foods
insectivore
Southwestern United States
insectivores
Cicadellidae
generalist
Curculionidae
humidity
beetle

Keywords

  • Behavioral plasticity
  • Biological control agent
  • Salt cedar
  • Tamarisk leaf beetle
  • Tamarisk weevil
  • Tamarix spp.
  • Warbler

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology

Cite this

Similar dietary but different numerical responses to nonnative tamarisk (Tamarix spp.) by two native warblers. / Mahoney, Sean M.; Theimer, Tad; Johnson, Matthew J.; Foster, Jeffrey T.

In: Biological Invasions, 20.03.2017, p. 1-16.

Research output: Contribution to journalArticle

@article{c95d7325fab34a66acd86c2dc297aea5,
title = "Similar dietary but different numerical responses to nonnative tamarisk (Tamarix spp.) by two native warblers",
abstract = "Native species can have a range of responses to nonnative introductions, from negative to positive, and understanding how and why native species respond differently to nonnatives remains an important management challenge. Based on differences and similarities in ecology and behavior, we predicted how abundance and diet of two native warblers, Lucy’s warbler (Oreothlypis luciae) and yellow warbler (Setophaga petechia), would differ in habitats with different amounts of nonnative tamarisk trees and the three nonnative insects obligately dependent on tamarisk (Tamarix spp.). Specifically, we predicted that Lucy’s warblers would have similar densities across sites, yellow warbler densities would be inversely related to tamarisk cover, and both warblers, being generalist insectivores, would incorporate tamarisk biocontrol insects in their diet. Based on point counts and fecal samples at six sites along the Virgin River in the southwestern United States, we found that yellow warblers decreased in abundance with increasing tamarisk cover, while Lucy’s warbler abundance did not and that diet of the two warblers did not differ, with both species exhibiting strong selection for the nonnative tamarisk weevil (Coniatus splendidulus) and weak to no selection for the nonnative tamarisk leafhopper (Opsius stactogalus). Both warblers showed negative selection for the tamarisk beetle (Diorhabda carinulata) and its larvae, even when those insects were 10–100 times more abundant during outbreaks. Although both warblers exploited the novel food resources offered by tamarisk, with those insects contributing half or more of total prey biomass, Lucy’s warblers were better able to maintain densities in tamarisk habitats. We hypothesize this was due to the Lucy’s warbler’s ability to exploit a broader array of habitats surrounding tamarisk sites and its cavity nesting habit that buffers its nests from the higher temperatures and lower humidity of tamarisk-dominated habitat. Our results suggest that predictions based on detailed knowledge of the form and function of native and nonnative species can be used to predict native bird response to nonnatives.",
keywords = "Behavioral plasticity, Biological control agent, Salt cedar, Tamarisk leaf beetle, Tamarisk weevil, Tamarix spp., Warbler",
author = "Mahoney, {Sean M.} and Tad Theimer and Johnson, {Matthew J.} and Foster, {Jeffrey T}",
year = "2017",
month = "3",
day = "20",
doi = "10.1007/s10530-017-1408-2",
language = "English (US)",
pages = "1--16",
journal = "Biological Invasions",
issn = "1387-3547",
publisher = "Springer Netherlands",

}

TY - JOUR

T1 - Similar dietary but different numerical responses to nonnative tamarisk (Tamarix spp.) by two native warblers

AU - Mahoney, Sean M.

AU - Theimer, Tad

AU - Johnson, Matthew J.

AU - Foster, Jeffrey T

PY - 2017/3/20

Y1 - 2017/3/20

N2 - Native species can have a range of responses to nonnative introductions, from negative to positive, and understanding how and why native species respond differently to nonnatives remains an important management challenge. Based on differences and similarities in ecology and behavior, we predicted how abundance and diet of two native warblers, Lucy’s warbler (Oreothlypis luciae) and yellow warbler (Setophaga petechia), would differ in habitats with different amounts of nonnative tamarisk trees and the three nonnative insects obligately dependent on tamarisk (Tamarix spp.). Specifically, we predicted that Lucy’s warblers would have similar densities across sites, yellow warbler densities would be inversely related to tamarisk cover, and both warblers, being generalist insectivores, would incorporate tamarisk biocontrol insects in their diet. Based on point counts and fecal samples at six sites along the Virgin River in the southwestern United States, we found that yellow warblers decreased in abundance with increasing tamarisk cover, while Lucy’s warbler abundance did not and that diet of the two warblers did not differ, with both species exhibiting strong selection for the nonnative tamarisk weevil (Coniatus splendidulus) and weak to no selection for the nonnative tamarisk leafhopper (Opsius stactogalus). Both warblers showed negative selection for the tamarisk beetle (Diorhabda carinulata) and its larvae, even when those insects were 10–100 times more abundant during outbreaks. Although both warblers exploited the novel food resources offered by tamarisk, with those insects contributing half or more of total prey biomass, Lucy’s warblers were better able to maintain densities in tamarisk habitats. We hypothesize this was due to the Lucy’s warbler’s ability to exploit a broader array of habitats surrounding tamarisk sites and its cavity nesting habit that buffers its nests from the higher temperatures and lower humidity of tamarisk-dominated habitat. Our results suggest that predictions based on detailed knowledge of the form and function of native and nonnative species can be used to predict native bird response to nonnatives.

AB - Native species can have a range of responses to nonnative introductions, from negative to positive, and understanding how and why native species respond differently to nonnatives remains an important management challenge. Based on differences and similarities in ecology and behavior, we predicted how abundance and diet of two native warblers, Lucy’s warbler (Oreothlypis luciae) and yellow warbler (Setophaga petechia), would differ in habitats with different amounts of nonnative tamarisk trees and the three nonnative insects obligately dependent on tamarisk (Tamarix spp.). Specifically, we predicted that Lucy’s warblers would have similar densities across sites, yellow warbler densities would be inversely related to tamarisk cover, and both warblers, being generalist insectivores, would incorporate tamarisk biocontrol insects in their diet. Based on point counts and fecal samples at six sites along the Virgin River in the southwestern United States, we found that yellow warblers decreased in abundance with increasing tamarisk cover, while Lucy’s warbler abundance did not and that diet of the two warblers did not differ, with both species exhibiting strong selection for the nonnative tamarisk weevil (Coniatus splendidulus) and weak to no selection for the nonnative tamarisk leafhopper (Opsius stactogalus). Both warblers showed negative selection for the tamarisk beetle (Diorhabda carinulata) and its larvae, even when those insects were 10–100 times more abundant during outbreaks. Although both warblers exploited the novel food resources offered by tamarisk, with those insects contributing half or more of total prey biomass, Lucy’s warblers were better able to maintain densities in tamarisk habitats. We hypothesize this was due to the Lucy’s warbler’s ability to exploit a broader array of habitats surrounding tamarisk sites and its cavity nesting habit that buffers its nests from the higher temperatures and lower humidity of tamarisk-dominated habitat. Our results suggest that predictions based on detailed knowledge of the form and function of native and nonnative species can be used to predict native bird response to nonnatives.

KW - Behavioral plasticity

KW - Biological control agent

KW - Salt cedar

KW - Tamarisk leaf beetle

KW - Tamarisk weevil

KW - Tamarix spp.

KW - Warbler

UR - http://www.scopus.com/inward/record.url?scp=85015608932&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85015608932&partnerID=8YFLogxK

U2 - 10.1007/s10530-017-1408-2

DO - 10.1007/s10530-017-1408-2

M3 - Article

SP - 1

EP - 16

JO - Biological Invasions

JF - Biological Invasions

SN - 1387-3547

ER -