Continental-scale biomass redistribution by migratory birds in response to seasonal variation in productivity

Wee Hao Ng; Daniel Fink; Frank A. La Sorte; Tom Auer; Wesley M. Hochachka; Alison Johnston; Adriaan M. Dokter

doi:10.1111/geb.13460

Continental-scale biomass redistribution by migratory birds in response to seasonal variation in productivity

Wee Hao Ng^*, Daniel Fink, Frank A. La Sorte, Tom Auer, Wesley M. Hochachka, Alison Johnston, Adriaan M. Dokter

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

Aim

Animal migration is often explained as the result of resource tracking in seasonally dynamic environments. Therefore, resource availability should influence both the distributions of migratory animals and their seasonal abundance. We examined the relationship between primary productivity and the spatio-temporal distributions of migratory birds to assess the role of energy availability in avian migration.

Location

North America.

Time period

Full annual cycle, 2011-2016.

Major taxa studied

Nocturnally migrating landbirds.

Methods

We used observations of nocturnally migrating landbirds from the eBird community-science programme to estimate weekly spatial distributions of total biomass, abundance and species richness. We related these patterns to primary productivity and seasonal productivity surplus estimated using a remotely sensed measure of vegetation greenness.

Results

All three avian metrics showed positive spatial associations with primary productivity, and this was more pronounced with seasonal productivity surplus. Surprisingly, biomass showed a weaker association than did abundance and richness, despite being a better indicator of energetic requirements. The strength of associations varied across seasons, being the weakest during migration. During spring migration, avian biomass increased ahead of vegetation green-up in temperate regions, a pattern also previously described for herbivorous waterfowl. In the south-eastern USA, spring green-up was instead associated with a net decrease in biomass, and winter biomass greatly exceeded that of summer, highlighting the region as a winter refuge for short-distance migrants.

Main conclusions

Although instantaneous energy availability is important in shaping the distribution of migratory birds, the stronger association of productivity with abundance and richness than with biomass suggests the role of additional drivers unrelated to energetic requirements that are nonetheless correlated with productivity. Given recent reports of widespread North American avifaunal declines, including many common species that winter in the south-eastern USA, understanding how anthropogenic activities are impacting winter bird populations in the region should be a research priority.

Original language	English
Pages (from-to)	727-739
Number of pages	13
Journal	Global Ecology and Biogeography
Volume	31
Issue number	4
Early online date	20 Feb 2022
DOIs	https://doi.org/10.1111/geb.13460
Publication status	Published - 1 Apr 2022

Keywords

Abundance
Biomass
eBird
North America
Productivity
Seasonal bird migration
Species–energy relationship
Species richness
Vegetation greenness

Access to Document

10.1111/geb.13460

Ng et al 2022 Supplementary information Accepted article
Copyright © 2022 John Wiley & Sons Ltd. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1111/geb.13460.
Accepted author manuscript, 4.61 MB
Ng et al 2022 Main paper Accepted article
Copyright © 2022 John Wiley & Sons Ltd. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1111/geb.13460.
Accepted author manuscript, 1.96 MB

Total biomass, abundance and species richness of nocturally migrating landbirds in North America
Ng, W. H. (Contributor), Fink, D. (Contributor), La Sorte, F. (Contributor), Auer, T. (Contributor), Hochachka, W. (Contributor), Johnston, A. (Contributor) & Dokter, A. (Contributor), Figshare, 26 Jan 2022
DOI: 10.6084/m9.figshare.15085275.v1
Dataset

Cite this

@article{241f156e89c94019ba881531ab5a8b36,

title = "Continental-scale biomass redistribution by migratory birds in response to seasonal variation in productivity",

abstract = "Aim Animal migration is often explained as the result of resource tracking in seasonally dynamic environments. Therefore, resource availability should influence both the distributions of migratory animals and their seasonal abundance. We examined the relationship between primary productivity and the spatio-temporal distributions of migratory birds to assess the role of energy availability in avian migration. LocationNorth America.Time period Full annual cycle, 2011-2016. Major taxa studied Nocturnally migrating landbirds. Methods We used observations of nocturnally migrating landbirds from the eBird community-science programme to estimate weekly spatial distributions of total biomass, abundance and species richness. We related these patterns to primary productivity and seasonal productivity surplus estimated using a remotely sensed measure of vegetation greenness. Results All three avian metrics showed positive spatial associations with primary productivity, and this was more pronounced with seasonal productivity surplus. Surprisingly, biomass showed a weaker association than did abundance and richness, despite being a better indicator of energetic requirements. The strength of associations varied across seasons, being the weakest during migration. During spring migration, avian biomass increased ahead of vegetation green-up in temperate regions, a pattern also previously described for herbivorous waterfowl. In the south-eastern USA, spring green-up was instead associated with a net decrease in biomass, and winter biomass greatly exceeded that of summer, highlighting the region as a winter refuge for short-distance migrants. Main conclusions Although instantaneous energy availability is important in shaping the distribution of migratory birds, the stronger association of productivity with abundance and richness than with biomass suggests the role of additional drivers unrelated to energetic requirements that are nonetheless correlated with productivity. Given recent reports of widespread North American avifaunal declines, including many common species that winter in the south-eastern USA, understanding how anthropogenic activities are impacting winter bird populations in the region should be a research priority.",

keywords = "Abundance, Biomass, eBird, North America, Productivity, Seasonal bird migration, Species–energy relationship, Species richness, Vegetation greenness",

author = "Ng, {Wee Hao} and Daniel Fink and {La Sorte}, {Frank A.} and Tom Auer and Hochachka, {Wesley M.} and Alison Johnston and Dokter, {Adriaan M.}",

note = "Funding: This work was funded in part by The Leon Levy Foundation, The Wolf Creek Foundation and the National Science Foundation (ABI sustaining: DBI-1939187; MSA: DEB-2017817; computing support from CNS-1059284 and CCF-1522054).",

year = "2022",

month = apr,

day = "1",

doi = "10.1111/geb.13460",

language = "English",

volume = "31",

pages = "727--739",

journal = "Global Ecology and Biogeography",

issn = "1466-822X",

publisher = "Wiley-Blackwell",

number = "4",

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TY - JOUR

T1 - Continental-scale biomass redistribution by migratory birds in response to seasonal variation in productivity

AU - Ng, Wee Hao

AU - Fink, Daniel

AU - La Sorte, Frank A.

AU - Auer, Tom

AU - Hochachka, Wesley M.

AU - Johnston, Alison

AU - Dokter, Adriaan M.

N1 - Funding: This work was funded in part by The Leon Levy Foundation, The Wolf Creek Foundation and the National Science Foundation (ABI sustaining: DBI-1939187; MSA: DEB-2017817; computing support from CNS-1059284 and CCF-1522054).

PY - 2022/4/1

Y1 - 2022/4/1

N2 - Aim Animal migration is often explained as the result of resource tracking in seasonally dynamic environments. Therefore, resource availability should influence both the distributions of migratory animals and their seasonal abundance. We examined the relationship between primary productivity and the spatio-temporal distributions of migratory birds to assess the role of energy availability in avian migration. LocationNorth America.Time period Full annual cycle, 2011-2016. Major taxa studied Nocturnally migrating landbirds. Methods We used observations of nocturnally migrating landbirds from the eBird community-science programme to estimate weekly spatial distributions of total biomass, abundance and species richness. We related these patterns to primary productivity and seasonal productivity surplus estimated using a remotely sensed measure of vegetation greenness. Results All three avian metrics showed positive spatial associations with primary productivity, and this was more pronounced with seasonal productivity surplus. Surprisingly, biomass showed a weaker association than did abundance and richness, despite being a better indicator of energetic requirements. The strength of associations varied across seasons, being the weakest during migration. During spring migration, avian biomass increased ahead of vegetation green-up in temperate regions, a pattern also previously described for herbivorous waterfowl. In the south-eastern USA, spring green-up was instead associated with a net decrease in biomass, and winter biomass greatly exceeded that of summer, highlighting the region as a winter refuge for short-distance migrants. Main conclusions Although instantaneous energy availability is important in shaping the distribution of migratory birds, the stronger association of productivity with abundance and richness than with biomass suggests the role of additional drivers unrelated to energetic requirements that are nonetheless correlated with productivity. Given recent reports of widespread North American avifaunal declines, including many common species that winter in the south-eastern USA, understanding how anthropogenic activities are impacting winter bird populations in the region should be a research priority.

AB - Aim Animal migration is often explained as the result of resource tracking in seasonally dynamic environments. Therefore, resource availability should influence both the distributions of migratory animals and their seasonal abundance. We examined the relationship between primary productivity and the spatio-temporal distributions of migratory birds to assess the role of energy availability in avian migration. LocationNorth America.Time period Full annual cycle, 2011-2016. Major taxa studied Nocturnally migrating landbirds. Methods We used observations of nocturnally migrating landbirds from the eBird community-science programme to estimate weekly spatial distributions of total biomass, abundance and species richness. We related these patterns to primary productivity and seasonal productivity surplus estimated using a remotely sensed measure of vegetation greenness. Results All three avian metrics showed positive spatial associations with primary productivity, and this was more pronounced with seasonal productivity surplus. Surprisingly, biomass showed a weaker association than did abundance and richness, despite being a better indicator of energetic requirements. The strength of associations varied across seasons, being the weakest during migration. During spring migration, avian biomass increased ahead of vegetation green-up in temperate regions, a pattern also previously described for herbivorous waterfowl. In the south-eastern USA, spring green-up was instead associated with a net decrease in biomass, and winter biomass greatly exceeded that of summer, highlighting the region as a winter refuge for short-distance migrants. Main conclusions Although instantaneous energy availability is important in shaping the distribution of migratory birds, the stronger association of productivity with abundance and richness than with biomass suggests the role of additional drivers unrelated to energetic requirements that are nonetheless correlated with productivity. Given recent reports of widespread North American avifaunal declines, including many common species that winter in the south-eastern USA, understanding how anthropogenic activities are impacting winter bird populations in the region should be a research priority.

KW - Abundance

KW - Biomass

KW - eBird

KW - North America

KW - Productivity

KW - Seasonal bird migration

KW - Species–energy relationship

KW - Species richness

KW - Vegetation greenness

U2 - 10.1111/geb.13460

DO - 10.1111/geb.13460

M3 - Article

SN - 1466-822X

VL - 31

SP - 727

EP - 739

JO - Global Ecology and Biogeography

JF - Global Ecology and Biogeography

IS - 4

ER -

Continental-scale biomass redistribution by migratory birds in response to seasonal variation in productivity

Abstract

Keywords

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Datasets

Total biomass, abundance and species richness of nocturally migrating landbirds in North America

Cite this