Aquatic and terrestrial resources are not nutritionally reciprocal for consumers

Cornelia W. Twining, James T Brenna, Peter Lawrence, David W. Winkler, Alexander S. Flecker, Nelson G. Hairston

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Aquatic and terrestrial ecosystems are connected through reciprocal fluxes of energy and nutrients that can subsidize consumers. Past research on reciprocal aquatic–terrestrial subsidies to consumers has generally focused on subsidy quantity while ignoring major differences in the nutritional composition of aquatic and terrestrial resources. Because aquatic resources contain substantially more highly unsaturated omega-3 fatty acids (HUFAs) than terrestrial resources, aquatic subsidies may play a unique role by supplying these critical compounds to both aquatic and terrestrial consumers. Here, we first characterized nutritional quality in terms of HUFA content in aquatic and terrestrial insect prey. We then used bulk stable isotope analyses to estimate subsidy use by stream and riparian consumers coupled with compound-specific stable isotope analyses, which allowed us to document consumer HUFA sources. Finally, in order to understand the nutritional importance of aquatic-derived HUFAs for riparian consumers, we conducted manipulative diet experiments on Eastern Phoebe (Sayornis phoebe) chicks in the laboratory. Aquatic insects were significantly enriched in HUFAs, mainly in terms of eicosapentaenoic acid (EPA), compared with terrestrial insects. Stream fishes relied mainly upon aquatic resources, while insectivorous birds varied in their use of aquatic subsidies across sites. However, like stream fishes, Eastern Phoebe chicks received HUFAs from aquatic insects, even when they were heavily reliant upon terrestrial insects for their overall diet. In the laboratory, dietary HUFAs, such as those supplied by aquatic insects, increased the growth rate and condition of Eastern Phoebe chicks. This study demonstrates that aquatic and terrestrial subsidies are not nutritionally reciprocal from the perspective of consumers because aquatic resources are the main source of critical fatty acids for both stream and riparian consumers. It also confirms previous findings on the nutritional importance of HUFAs for riparian birds, demonstrating that an insectivorous riparian lifestyle influences avian nutritional needs. Finally, our findings raise the possibility that birds and other riparian insectivores may experience nutritional mismatches with terrestrial prey if they do not have access to high-quality aquatic subsidies as a consequence of aquatic habitat degradation or shifts in consumer and resource phenology. A plain language summary is available for this article.

Original languageEnglish (US)
JournalFunctional Ecology
DOIs
StatePublished - Jan 1 2019

Fingerprint

unsaturated fatty acids
omega-3 fatty acids
subsidies
fatty acid
Phoebe
resource
insect
aquatic insects
chicks
insects
bird
stable isotopes
birds
stable isotope
insect growth
diet
insectivores
aquatic habitat
insectivore
eicosapentaenoic acid

Keywords

  • aerial insectivores
  • aquatic insects
  • compound-specific stable isotopes
  • ecological subsidies
  • highly unsaturated omega-3 fatty acids

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Cite this

Aquatic and terrestrial resources are not nutritionally reciprocal for consumers. / Twining, Cornelia W.; Brenna, James T; Lawrence, Peter; Winkler, David W.; Flecker, Alexander S.; Hairston, Nelson G.

In: Functional Ecology, 01.01.2019.

Research output: Contribution to journalArticle

Twining, Cornelia W. ; Brenna, James T ; Lawrence, Peter ; Winkler, David W. ; Flecker, Alexander S. ; Hairston, Nelson G. / Aquatic and terrestrial resources are not nutritionally reciprocal for consumers. In: Functional Ecology. 2019.
@article{ff150f52f6564d88bf19df8c4754959a,
title = "Aquatic and terrestrial resources are not nutritionally reciprocal for consumers",
abstract = "Aquatic and terrestrial ecosystems are connected through reciprocal fluxes of energy and nutrients that can subsidize consumers. Past research on reciprocal aquatic–terrestrial subsidies to consumers has generally focused on subsidy quantity while ignoring major differences in the nutritional composition of aquatic and terrestrial resources. Because aquatic resources contain substantially more highly unsaturated omega-3 fatty acids (HUFAs) than terrestrial resources, aquatic subsidies may play a unique role by supplying these critical compounds to both aquatic and terrestrial consumers. Here, we first characterized nutritional quality in terms of HUFA content in aquatic and terrestrial insect prey. We then used bulk stable isotope analyses to estimate subsidy use by stream and riparian consumers coupled with compound-specific stable isotope analyses, which allowed us to document consumer HUFA sources. Finally, in order to understand the nutritional importance of aquatic-derived HUFAs for riparian consumers, we conducted manipulative diet experiments on Eastern Phoebe (Sayornis phoebe) chicks in the laboratory. Aquatic insects were significantly enriched in HUFAs, mainly in terms of eicosapentaenoic acid (EPA), compared with terrestrial insects. Stream fishes relied mainly upon aquatic resources, while insectivorous birds varied in their use of aquatic subsidies across sites. However, like stream fishes, Eastern Phoebe chicks received HUFAs from aquatic insects, even when they were heavily reliant upon terrestrial insects for their overall diet. In the laboratory, dietary HUFAs, such as those supplied by aquatic insects, increased the growth rate and condition of Eastern Phoebe chicks. This study demonstrates that aquatic and terrestrial subsidies are not nutritionally reciprocal from the perspective of consumers because aquatic resources are the main source of critical fatty acids for both stream and riparian consumers. It also confirms previous findings on the nutritional importance of HUFAs for riparian birds, demonstrating that an insectivorous riparian lifestyle influences avian nutritional needs. Finally, our findings raise the possibility that birds and other riparian insectivores may experience nutritional mismatches with terrestrial prey if they do not have access to high-quality aquatic subsidies as a consequence of aquatic habitat degradation or shifts in consumer and resource phenology. A plain language summary is available for this article.",
keywords = "aerial insectivores, aquatic insects, compound-specific stable isotopes, ecological subsidies, highly unsaturated omega-3 fatty acids",
author = "Twining, {Cornelia W.} and Brenna, {James T} and Peter Lawrence and Winkler, {David W.} and Flecker, {Alexander S.} and Hairston, {Nelson G.}",
year = "2019",
month = "1",
day = "1",
doi = "10.1111/1365-2435.13401",
language = "English (US)",
journal = "Functional Ecology",
issn = "0269-8463",
publisher = "Wiley-Blackwell",

}

TY - JOUR

T1 - Aquatic and terrestrial resources are not nutritionally reciprocal for consumers

AU - Twining, Cornelia W.

AU - Brenna, James T

AU - Lawrence, Peter

AU - Winkler, David W.

AU - Flecker, Alexander S.

AU - Hairston, Nelson G.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Aquatic and terrestrial ecosystems are connected through reciprocal fluxes of energy and nutrients that can subsidize consumers. Past research on reciprocal aquatic–terrestrial subsidies to consumers has generally focused on subsidy quantity while ignoring major differences in the nutritional composition of aquatic and terrestrial resources. Because aquatic resources contain substantially more highly unsaturated omega-3 fatty acids (HUFAs) than terrestrial resources, aquatic subsidies may play a unique role by supplying these critical compounds to both aquatic and terrestrial consumers. Here, we first characterized nutritional quality in terms of HUFA content in aquatic and terrestrial insect prey. We then used bulk stable isotope analyses to estimate subsidy use by stream and riparian consumers coupled with compound-specific stable isotope analyses, which allowed us to document consumer HUFA sources. Finally, in order to understand the nutritional importance of aquatic-derived HUFAs for riparian consumers, we conducted manipulative diet experiments on Eastern Phoebe (Sayornis phoebe) chicks in the laboratory. Aquatic insects were significantly enriched in HUFAs, mainly in terms of eicosapentaenoic acid (EPA), compared with terrestrial insects. Stream fishes relied mainly upon aquatic resources, while insectivorous birds varied in their use of aquatic subsidies across sites. However, like stream fishes, Eastern Phoebe chicks received HUFAs from aquatic insects, even when they were heavily reliant upon terrestrial insects for their overall diet. In the laboratory, dietary HUFAs, such as those supplied by aquatic insects, increased the growth rate and condition of Eastern Phoebe chicks. This study demonstrates that aquatic and terrestrial subsidies are not nutritionally reciprocal from the perspective of consumers because aquatic resources are the main source of critical fatty acids for both stream and riparian consumers. It also confirms previous findings on the nutritional importance of HUFAs for riparian birds, demonstrating that an insectivorous riparian lifestyle influences avian nutritional needs. Finally, our findings raise the possibility that birds and other riparian insectivores may experience nutritional mismatches with terrestrial prey if they do not have access to high-quality aquatic subsidies as a consequence of aquatic habitat degradation or shifts in consumer and resource phenology. A plain language summary is available for this article.

AB - Aquatic and terrestrial ecosystems are connected through reciprocal fluxes of energy and nutrients that can subsidize consumers. Past research on reciprocal aquatic–terrestrial subsidies to consumers has generally focused on subsidy quantity while ignoring major differences in the nutritional composition of aquatic and terrestrial resources. Because aquatic resources contain substantially more highly unsaturated omega-3 fatty acids (HUFAs) than terrestrial resources, aquatic subsidies may play a unique role by supplying these critical compounds to both aquatic and terrestrial consumers. Here, we first characterized nutritional quality in terms of HUFA content in aquatic and terrestrial insect prey. We then used bulk stable isotope analyses to estimate subsidy use by stream and riparian consumers coupled with compound-specific stable isotope analyses, which allowed us to document consumer HUFA sources. Finally, in order to understand the nutritional importance of aquatic-derived HUFAs for riparian consumers, we conducted manipulative diet experiments on Eastern Phoebe (Sayornis phoebe) chicks in the laboratory. Aquatic insects were significantly enriched in HUFAs, mainly in terms of eicosapentaenoic acid (EPA), compared with terrestrial insects. Stream fishes relied mainly upon aquatic resources, while insectivorous birds varied in their use of aquatic subsidies across sites. However, like stream fishes, Eastern Phoebe chicks received HUFAs from aquatic insects, even when they were heavily reliant upon terrestrial insects for their overall diet. In the laboratory, dietary HUFAs, such as those supplied by aquatic insects, increased the growth rate and condition of Eastern Phoebe chicks. This study demonstrates that aquatic and terrestrial subsidies are not nutritionally reciprocal from the perspective of consumers because aquatic resources are the main source of critical fatty acids for both stream and riparian consumers. It also confirms previous findings on the nutritional importance of HUFAs for riparian birds, demonstrating that an insectivorous riparian lifestyle influences avian nutritional needs. Finally, our findings raise the possibility that birds and other riparian insectivores may experience nutritional mismatches with terrestrial prey if they do not have access to high-quality aquatic subsidies as a consequence of aquatic habitat degradation or shifts in consumer and resource phenology. A plain language summary is available for this article.

KW - aerial insectivores

KW - aquatic insects

KW - compound-specific stable isotopes

KW - ecological subsidies

KW - highly unsaturated omega-3 fatty acids

UR - http://www.scopus.com/inward/record.url?scp=85069871004&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85069871004&partnerID=8YFLogxK

U2 - 10.1111/1365-2435.13401

DO - 10.1111/1365-2435.13401

M3 - Article

AN - SCOPUS:85069871004

JO - Functional Ecology

JF - Functional Ecology

SN - 0269-8463

ER -