The influence of El Niño on the spring fallout of Asian bird species at Attu Island

Sultan Hameed, Henry H. Norwood, Michael Flanagan, Steven Feldstein, Chien Hsiung Yang

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Several studies have documented the effect of the recent secular climate warming on the distributions and geographical ranges of birds. Here the authors report the strong impact of a recurring climatic pattern in the equatorial Pacific, the El Niño-Southern Oscillation (ENSO) cycle of warm (El Niño) and cold (La Niña) events, on spring migrants along the Far Eastern flyway in northeast Asia. In El Niño years, an unusually large number of birds that use the flyway are observed at Attu Island, westernmost of the Aleutian Islands, nearly 960 km away from the Asian coast. This study is based on a 20-yr dataset documenting the year-to-year variation of Asian birds arriving on Attu in the spring season and uses a three-phased analytical methodology to examine climate impacts on bird movements and populations. The authors offer evidence that birds are displaced toward the Attu area in strong eastward-moving storms. They also present results from a reverse trajectory model that was used to simulate trajectories that a sample of Attu arrivals likely followed in reaching the island. In a statistical analysis, it is shown that 79% of the variation of the Asian birds is explained by a single climate variable: sea surface temperature in the eastern equatorial Pacific in the previous fall. It is the rise in sea surface temperature in this region, more than 8000 km from Attu, that characterizes the onset of an El Niño episode. Examining those years for which there was a strong ENSO signal in the fall, it is found that the following May is characterized by anomalously strong westerly winds in the northwest Pacific, conditions that are appropriate for large Asian bird fallouts at Attu. Because of the time lag between the fall sea surface temperatures in the El Niño region and the spring Asian bird count at Attu, and the strong correlation between these two quantities, the number of Asian birds arriving at Attu in spring is predictable in the previous autumn. Such predictions are presented for several years.

Original languageEnglish (US)
JournalEarth Interactions
Volume13
Issue number7
DOIs
StatePublished - Dec 1 2009

Fingerprint

fallout
bird
sea surface temperature
Southern Oscillation
trajectory
bird species
spring (season)
climate effect
climate
westerly
statistical analysis
warming
autumn
methodology
coast
prediction

All Science Journal Classification (ASJC) codes

  • Earth and Planetary Sciences(all)

Cite this

Hameed, Sultan ; Norwood, Henry H. ; Flanagan, Michael ; Feldstein, Steven ; Yang, Chien Hsiung. / The influence of El Niño on the spring fallout of Asian bird species at Attu Island. In: Earth Interactions. 2009 ; Vol. 13, No. 7.
@article{7736f04fb5664dd5bb5930022105bb15,
title = "The influence of El Ni{\~n}o on the spring fallout of Asian bird species at Attu Island",
abstract = "Several studies have documented the effect of the recent secular climate warming on the distributions and geographical ranges of birds. Here the authors report the strong impact of a recurring climatic pattern in the equatorial Pacific, the El Ni{\~n}o-Southern Oscillation (ENSO) cycle of warm (El Ni{\~n}o) and cold (La Ni{\~n}a) events, on spring migrants along the Far Eastern flyway in northeast Asia. In El Ni{\~n}o years, an unusually large number of birds that use the flyway are observed at Attu Island, westernmost of the Aleutian Islands, nearly 960 km away from the Asian coast. This study is based on a 20-yr dataset documenting the year-to-year variation of Asian birds arriving on Attu in the spring season and uses a three-phased analytical methodology to examine climate impacts on bird movements and populations. The authors offer evidence that birds are displaced toward the Attu area in strong eastward-moving storms. They also present results from a reverse trajectory model that was used to simulate trajectories that a sample of Attu arrivals likely followed in reaching the island. In a statistical analysis, it is shown that 79{\%} of the variation of the Asian birds is explained by a single climate variable: sea surface temperature in the eastern equatorial Pacific in the previous fall. It is the rise in sea surface temperature in this region, more than 8000 km from Attu, that characterizes the onset of an El Ni{\~n}o episode. Examining those years for which there was a strong ENSO signal in the fall, it is found that the following May is characterized by anomalously strong westerly winds in the northwest Pacific, conditions that are appropriate for large Asian bird fallouts at Attu. Because of the time lag between the fall sea surface temperatures in the El Ni{\~n}o region and the spring Asian bird count at Attu, and the strong correlation between these two quantities, the number of Asian birds arriving at Attu in spring is predictable in the previous autumn. Such predictions are presented for several years.",
author = "Sultan Hameed and Norwood, {Henry H.} and Michael Flanagan and Steven Feldstein and Yang, {Chien Hsiung}",
year = "2009",
month = "12",
day = "1",
doi = "10.1175/2009EI272.1",
language = "English (US)",
volume = "13",
journal = "Earth Interactions",
issn = "1087-3562",
publisher = "American Meteorological Society",
number = "7",

}

The influence of El Niño on the spring fallout of Asian bird species at Attu Island. / Hameed, Sultan; Norwood, Henry H.; Flanagan, Michael; Feldstein, Steven; Yang, Chien Hsiung.

In: Earth Interactions, Vol. 13, No. 7, 01.12.2009.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The influence of El Niño on the spring fallout of Asian bird species at Attu Island

AU - Hameed, Sultan

AU - Norwood, Henry H.

AU - Flanagan, Michael

AU - Feldstein, Steven

AU - Yang, Chien Hsiung

PY - 2009/12/1

Y1 - 2009/12/1

N2 - Several studies have documented the effect of the recent secular climate warming on the distributions and geographical ranges of birds. Here the authors report the strong impact of a recurring climatic pattern in the equatorial Pacific, the El Niño-Southern Oscillation (ENSO) cycle of warm (El Niño) and cold (La Niña) events, on spring migrants along the Far Eastern flyway in northeast Asia. In El Niño years, an unusually large number of birds that use the flyway are observed at Attu Island, westernmost of the Aleutian Islands, nearly 960 km away from the Asian coast. This study is based on a 20-yr dataset documenting the year-to-year variation of Asian birds arriving on Attu in the spring season and uses a three-phased analytical methodology to examine climate impacts on bird movements and populations. The authors offer evidence that birds are displaced toward the Attu area in strong eastward-moving storms. They also present results from a reverse trajectory model that was used to simulate trajectories that a sample of Attu arrivals likely followed in reaching the island. In a statistical analysis, it is shown that 79% of the variation of the Asian birds is explained by a single climate variable: sea surface temperature in the eastern equatorial Pacific in the previous fall. It is the rise in sea surface temperature in this region, more than 8000 km from Attu, that characterizes the onset of an El Niño episode. Examining those years for which there was a strong ENSO signal in the fall, it is found that the following May is characterized by anomalously strong westerly winds in the northwest Pacific, conditions that are appropriate for large Asian bird fallouts at Attu. Because of the time lag between the fall sea surface temperatures in the El Niño region and the spring Asian bird count at Attu, and the strong correlation between these two quantities, the number of Asian birds arriving at Attu in spring is predictable in the previous autumn. Such predictions are presented for several years.

AB - Several studies have documented the effect of the recent secular climate warming on the distributions and geographical ranges of birds. Here the authors report the strong impact of a recurring climatic pattern in the equatorial Pacific, the El Niño-Southern Oscillation (ENSO) cycle of warm (El Niño) and cold (La Niña) events, on spring migrants along the Far Eastern flyway in northeast Asia. In El Niño years, an unusually large number of birds that use the flyway are observed at Attu Island, westernmost of the Aleutian Islands, nearly 960 km away from the Asian coast. This study is based on a 20-yr dataset documenting the year-to-year variation of Asian birds arriving on Attu in the spring season and uses a three-phased analytical methodology to examine climate impacts on bird movements and populations. The authors offer evidence that birds are displaced toward the Attu area in strong eastward-moving storms. They also present results from a reverse trajectory model that was used to simulate trajectories that a sample of Attu arrivals likely followed in reaching the island. In a statistical analysis, it is shown that 79% of the variation of the Asian birds is explained by a single climate variable: sea surface temperature in the eastern equatorial Pacific in the previous fall. It is the rise in sea surface temperature in this region, more than 8000 km from Attu, that characterizes the onset of an El Niño episode. Examining those years for which there was a strong ENSO signal in the fall, it is found that the following May is characterized by anomalously strong westerly winds in the northwest Pacific, conditions that are appropriate for large Asian bird fallouts at Attu. Because of the time lag between the fall sea surface temperatures in the El Niño region and the spring Asian bird count at Attu, and the strong correlation between these two quantities, the number of Asian birds arriving at Attu in spring is predictable in the previous autumn. Such predictions are presented for several years.

UR - http://www.scopus.com/inward/record.url?scp=77956931035&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77956931035&partnerID=8YFLogxK

U2 - 10.1175/2009EI272.1

DO - 10.1175/2009EI272.1

M3 - Article

AN - SCOPUS:77956931035

VL - 13

JO - Earth Interactions

JF - Earth Interactions

SN - 1087-3562

IS - 7

ER -