The movement ecology of migratory animals, especially extreme endurance migrant birds, fascinates me. Alaska migratory shorebirds have links to all hemispheres, requiring international collaborations to implement effective conservations efforts.
Through an emeritus position at the Alaska Science Center my research is focused on: 1) collaborations with an international suite of colleagues to assess the movement ecology of extreme endurance migrant shorebirds and identify the global-scale conservation issues facing their populations, and 2) releasing data to the public domain and publishing results associated with information collected during my five-decade-long tenure as a research biologist.
Professional Experience
2015 - present Scientist Emeritus USGS, Alaska Science Center, Anchorage, AK
1996 - 2015 Research Wildlife Biologist USGS, Alaska Science Center, Anchorage, AK
1993 - 1996 Wildlife Biologist NBS Alaska Science Center, Anchorage, AK
1987 - 1993 Wildlife Biologist USFWS, Alaska Fish and Wildlife Research Center, Anchorage, AK
1984 - 1987 Wildlife Biologist Denver Wildlife Research Center, Anchorage, AK
1981 - 1983 Wildlife Biologist Seattle National Fisheries Research Center, Anchorage, AK
1976 - 1980 Wildlife Biologist US Fish and Wildlife Service, Anchorage, AK
1973 - 1976 Wildlife Biologist California Department of Fish and Game, Sacramento, CA
Education and Certifications
Ph. D. 2010 - present Groningen University, The Netherlands
M.S. 1972 San Jose State University, San Jose, CA Biology
B.A. 1970 San Jose State College, San Jose, CA Wildlife Management
Affiliations and Memberships*
Alaska Shorebird Group (Founding member)
American Ornithologists' Union (Life member, Elective Member 1983, Fellow 2011)
Arctic Institute of North America (Life member)
Australasian Wader Studies Group (North American Representative, 2001-2010)
Canada Shorebird Plan (Member, Scientific Advisory Committee, 1998-2001)
Cooper Ornithological Society (Life member)
East Asian-Australasian Shorebird Working Group (U.S. representative, 2002-2007)
Global Flyway Network (Member, Scientific Advisory Board (2001-present)
International Wader Study Group (Life member; Executive Committee, 1999-2008; Editorial Advisory Board, 2012-present)
New Zealand Wader Study Group
Pacific Shorebird Migration Project (Co-PI, 2006-present)
Russian Working Group on Waders
Western Hemisphere Shorebird Group (Founding Member; Advisory Board, 2008-present)
Western Field Ornithologists (Board of Directors, 1999-2015; Assoc. Editor, 2005-present)
Western Hemisphere Shorebird Reserve Network (Chair, Scientific Advisory Board, 2004-2012)
U.S. Shorebird Conservation Plan (Chair, Research and Monitoring Group, 1998-2001)
Abstracts and Presentations
Five invited keynote, 14 invited, and >60 contributed presentations before various scientific bodies.
Science and Products
Shorebird Research
With its vast size and geographic position at the northern end of several migration pathways, Alaska is a critically important site for the world’s shorebirds. Thirty-seven shorebird species regularly breed in Alaska. Most of these species conduct epically long migrations to take advantage of Alaska’s abundant food resources and breeding habitat, making Alaska a global resource for shorebirds...
USGS Alaska Science Center Adult Shorebird Morphological Measurement Data
This dataset consists of three tables, 1) taxonomy, 2) contributors, and 3) shorebird morphological measurements collected from various species captured from 1977-2021. In addition, photographs of plumage patterns are available for several species. Researchers with the U.S. Geological Survey - Alaska Science Center, along with collaborators from many government agencies and research institutions,
Juvenile Shorebird Morphological Data Collected in Alaska and Canada
This dataset consists of shorebird chick measurements (wing, primary feather 10, diagonal tarsus, and bill length) and body mass for various shorebird species captured in Alaska and Canada during 1978-2022. Researchers with the U.S. Geological Survey - Alaska Science Center, and collaborators from many government agencies and research institutions have studied shorebirds at numerous sites across N
Measurements of Surfbirds (Calidris virgata), Southcentral Alaska 1997-1999
These morphometric data are in two tables from surfbirds (adults and chicks) captured at two locations in southcentral Alaska, 1997-1999.
Tracking Data for Whimbrels (Numenius phaeopus)
This metadata document describes the data contained in the "processedData" folder of this data package. This data package contains all data collected by the Argos System from 32 satellite transmitters attached to Whimbrels on their breeding range in arctic and western Alaska, 2006-2010. The raw data were processed to accomplish two goals: flag implausible location estimates and decode raw sensor d
Measurements Used to Determine the Sex of Bristle-thighed Curlews (Numenius tahitiensis)
This data set contains bill and tarsal measurements from 114 Bristle-thighed Curlews, captured on breeding grounds in Alaska, and non-breeding areas in Hawaii and Reitoru atoll, French Polynesia.
Tracking Data for Marbled Godwits (Limosa fedoa)
This metadata document describes the data contained in the "rawData" folder of this data package. This data package contains all data collected by the Argos System from nine satellite transmitters attached to Marbled Godwits on their breeding range in southwest Alaska, USA. Five data files are included in the "rawData" folder of this data package. Two data files (with identical content) contain th
Migratory Timing and Site Use of Marbled Godwits Breeding in Alaska, 2008-2015
This dataset contains migration timing and land-based location information from nine Marbled Godwits (Limosa fedoa beringiae) equipped with solar-powered satellite transmitters on breeding grounds near Ugashik, Alaska, in June of 2008. Transmitters were programmed with a duty cycle of 10 hr on and 48 hr off, yielding 10,858 locations (47-3,490 locations per bird, depending on the duration of each
Data for Montane-breeding Bird Distribution and Abundance across National Parks of Southwestern Alaska, 2004-2008
Observation data and model covariate data from breeding bird inventory conducted during May-June 2004 and 2008 primarily in montane areas (>100 m above sea level) in Aniakchak National Monument and Preserve (Aniakchak NMP), Katmai National Park and Preserve (Katmai NPP), and Lake Clark National Park and Preserve (Lake Clark NPP) in southwestern Alaska. Observers conducted 1,021 point counts along
Filter Total Items: 92
The Pacific as the world’s greatest theater of bird migration: Extreme flights spark questions about physiological capabilities, behavior, and the evolution of migratory pathways
The Pacific Basin, by virtue of its vastness and its complex aeroscape, provides unique opportunities to address questions about the behavioral and physiological capabilities and mechanisms through which birds can complete spectacular flights. No longer is the Pacific seen just as a formidable barrier between terrestrial habitats in the north and the south, but rather as a gateway for specialized
Authors
Theunis Piersma, Robert E. Gill, Daniel R. Ruthrauff, Christopher G. Guglielmo, Jesse R. Conklin, Colleen M. Handel
Mismatch-induced growth reductions in a clade of Arctic-breeding shorebirds are rarely mitigated by increasing temperatures
In seasonal environments subject to climate change, organisms typically show phenological changes. As these changes are usually stronger in organisms at lower trophic levels than those at higher trophic levels, mismatches between consumers and their prey may occur during the consumers’ reproduction period. While in some species a trophic mismatch induces reductions in offspring growth, this is not
Authors
Thomas Lameris, Pavel S. Tomkovich, James A. Johnson, R.I. Guy Morrison, Lucas Decicco, Maksim N. Dementyev, Ingrid Tulp, Simeon Lisovski, Robert E. Gill, Job ten Horn, Theunis Piersma, Z. Pohlen, Hans Schekkerman, Mikhail Soloviev, E. Syroechkovsky, Mikhail Zhemchuzhnikov, Jan A. van Gils
Physiomorphic transformation in extreme endurance migrants: Revisiting the case of bar-tailed godwits preparing for trans-pacific flights
In a 1998 paper entitled “Guts don’t fly: small digestive organs in obese bar-tailed godwits,” Piersma and Gill (1998) showed that the digestive organs were tiny and the fat loads huge in individuals suspected of embarking on a non-stop flight from Alaska to New Zealand. It was suggested that prior to migratory departure, these godwits would shrink the digestive organs used during fuel deposition
Authors
Theunis Piersma, Robert E. Gill, Daniel R. Ruthrauff
Diverse patterns of migratory timing, site use, and site fidelity by Alaska-breeding Whimbrels
Birds that conduct long-distance migrations exhibit varied patterns of consistency in migratory timing and site use. Understanding variation in these traits among populations can help uncover mechanisms driving migratory behaviors and identify potential population threats. Whimbrels (Numenius phaeopus) are long-distance migratory shorebirds with a Holarctic breeding distribution, and recent studie
Authors
Daniel R. Ruthrauff, Christopher M. Harwood, Lee Tibbitts, Nils Warnock, Robert E. Gill
Further information on the avifauna of St. Matthew and Hall Islands, Bering Sea, Alaska
In June and July 2018 and July 2019 we surveyed birds on St.
Matthew and Hall islands, isolated in the central Bering Sea. Our surveys were
focused on the McKay’s Bunting (Plectrophenax hyperboreus), Rock Sandpiper
(Calidris ptilocnemis ptilocnemis), and Pelagic Cormorant (Phalacrocorax pelagicus)
but encompassed all birds and yielded 13 species and four subspecies new to the
islands’ avifaunal li
Authors
Bryce W. Robinson, Jack J. Withrow, Rachel M. Richardson, Steven M. Matsuoka, Robert E. Gill, Andrew S. Johnson, Irby J. Lovette, James A. Johnson, Anthony R. DeGange, Marc D. Romano
Through thick and thin: Sexing Bristle-thighed Curlews Numenius tahitiensis using measures of bill depth
Birds often exhibit diagnostic traits that differ among individuals of the same species with regard to factors like sex, age, or breeding status. Shorebirds exhibit a wide diversity of colors, shapes, and sizes of their bills, and these traits are commonly used to determine the sex of individuals. In curlews (genus Numenius), length alone accurately separates the sexes in some species, but the sha
Authors
Daniel R. Ruthrauff, Colleen M. Handel, T. Lee Tibbitts, Robert E. Gill
Flexible timing of annual movements across consistently used sites by Marbled Godwits breeding in Alaska
The study of avian movement has detailed a spectrum of strategies for the timing and use of sites throughout the annual cycle, from near randomness to complete consistency. New tracking devices now permit the repeated tracking of individual animals throughout the annual cycle, detailing previously unappreciated levels of variation within migratory systems. Godwits (genus Limosa) have featured prom
Authors
Daniel R. Ruthrauff, T. Lee Tibbitts, Robert E. Gill
Trends and traditions: Overview and synthesis
This paper provides an overview by the editors of a collection of 25 papers for the Studies of Western Birds, to be published in a single volume by Western Field Ornithologists. The title of the volume is: "Trends and traditions: Avifaunal change in western North America."
Authors
W David Shuford, Robert E. Gill, Colleen M. Handel
Shorebirds adjust spring arrival schedules with variable environmental conditions: Four decades of assessment on the Yukon–Kuskokwim Delta, Alaska
Arctic summers are brief, and there has been strong selection for migratory birds to
arrive in Arctic nesting areas as early as possible to time breeding with peak food availability
and complete reproduction. The timing of emergence of nesting habitat in spring is, however,
extremely variable in the Arctic, and few long-term studies have examined the ability of avian
migrants to track spring condi
Authors
Craig R. Ely, Brian McCaffery, Robert E. Gill
Montane-breeding bird distribution and abundance across national parks of southwestern Alaska
Between 2004 and 2008, biologists conducted an inventory of breeding birds during May–June primarily in montane areas (>100 m above sea level) in Aniakchak National Monument and Preserve (Aniakchak NMP), Katmai National Park and Preserve (Katmai NPP), and Lake Clark National Park and Preserve (Lake Clark NPP) in southwestern Alaska. Observers conducted 1,021 point counts along 169 transects within
Authors
Courtney L. Amundson, Colleen M. Handel, Daniel R. Ruthrauff, T. Lee Tibbitts, Robert E. Gill
Energetic solutions of Rock Sandpipers to harsh winter conditions rely on prey quality
Rock Sandpipers Calidris ptilocnemis have the most northerly non-breeding distribution of any shorebird in the Pacific Basin (upper Cook Inlet, Alaska; 61°N, 151°W). In terms of freezing temperatures, persistent winds and pervasive ice, this site is the harshest used by shorebirds during winter. We integrated physiological, metabolic, behavioural and environmental aspects of the non-breeding ecolo
Authors
Daniel R. Ruthrauff, Anne Dekinga, Robert E. Gill, Theunis Piersma
Nesting ecology of Whimbrels in boreal Alaska
Breeding ecology studies of boreal waders have been relatively scarce in North America. This paucity is due in part to boreal habitats being difficult to access, and boreal waders being widely dispersed and thus difficult to monitor. Between 2008 and 2014 we studied the nesting ecology of Whimbrels Numenius phaeopus hudsonicus in interior Alaska, a region characterized by an active wildfire regime
Authors
Christopher M. Harwood, Robert E. Gill, Abby Powell
Science and Products
- Science
Shorebird Research
With its vast size and geographic position at the northern end of several migration pathways, Alaska is a critically important site for the world’s shorebirds. Thirty-seven shorebird species regularly breed in Alaska. Most of these species conduct epically long migrations to take advantage of Alaska’s abundant food resources and breeding habitat, making Alaska a global resource for shorebirds... - Data
USGS Alaska Science Center Adult Shorebird Morphological Measurement Data
This dataset consists of three tables, 1) taxonomy, 2) contributors, and 3) shorebird morphological measurements collected from various species captured from 1977-2021. In addition, photographs of plumage patterns are available for several species. Researchers with the U.S. Geological Survey - Alaska Science Center, along with collaborators from many government agencies and research institutions,Juvenile Shorebird Morphological Data Collected in Alaska and Canada
This dataset consists of shorebird chick measurements (wing, primary feather 10, diagonal tarsus, and bill length) and body mass for various shorebird species captured in Alaska and Canada during 1978-2022. Researchers with the U.S. Geological Survey - Alaska Science Center, and collaborators from many government agencies and research institutions have studied shorebirds at numerous sites across NMeasurements of Surfbirds (Calidris virgata), Southcentral Alaska 1997-1999
These morphometric data are in two tables from surfbirds (adults and chicks) captured at two locations in southcentral Alaska, 1997-1999.Tracking Data for Whimbrels (Numenius phaeopus)
This metadata document describes the data contained in the "processedData" folder of this data package. This data package contains all data collected by the Argos System from 32 satellite transmitters attached to Whimbrels on their breeding range in arctic and western Alaska, 2006-2010. The raw data were processed to accomplish two goals: flag implausible location estimates and decode raw sensor dMeasurements Used to Determine the Sex of Bristle-thighed Curlews (Numenius tahitiensis)
This data set contains bill and tarsal measurements from 114 Bristle-thighed Curlews, captured on breeding grounds in Alaska, and non-breeding areas in Hawaii and Reitoru atoll, French Polynesia.Tracking Data for Marbled Godwits (Limosa fedoa)
This metadata document describes the data contained in the "rawData" folder of this data package. This data package contains all data collected by the Argos System from nine satellite transmitters attached to Marbled Godwits on their breeding range in southwest Alaska, USA. Five data files are included in the "rawData" folder of this data package. Two data files (with identical content) contain thMigratory Timing and Site Use of Marbled Godwits Breeding in Alaska, 2008-2015
This dataset contains migration timing and land-based location information from nine Marbled Godwits (Limosa fedoa beringiae) equipped with solar-powered satellite transmitters on breeding grounds near Ugashik, Alaska, in June of 2008. Transmitters were programmed with a duty cycle of 10 hr on and 48 hr off, yielding 10,858 locations (47-3,490 locations per bird, depending on the duration of eachData for Montane-breeding Bird Distribution and Abundance across National Parks of Southwestern Alaska, 2004-2008
Observation data and model covariate data from breeding bird inventory conducted during May-June 2004 and 2008 primarily in montane areas (>100 m above sea level) in Aniakchak National Monument and Preserve (Aniakchak NMP), Katmai National Park and Preserve (Katmai NPP), and Lake Clark National Park and Preserve (Lake Clark NPP) in southwestern Alaska. Observers conducted 1,021 point counts along - Multimedia
- Publications
Filter Total Items: 92
The Pacific as the world’s greatest theater of bird migration: Extreme flights spark questions about physiological capabilities, behavior, and the evolution of migratory pathways
The Pacific Basin, by virtue of its vastness and its complex aeroscape, provides unique opportunities to address questions about the behavioral and physiological capabilities and mechanisms through which birds can complete spectacular flights. No longer is the Pacific seen just as a formidable barrier between terrestrial habitats in the north and the south, but rather as a gateway for specializedAuthorsTheunis Piersma, Robert E. Gill, Daniel R. Ruthrauff, Christopher G. Guglielmo, Jesse R. Conklin, Colleen M. HandelMismatch-induced growth reductions in a clade of Arctic-breeding shorebirds are rarely mitigated by increasing temperatures
In seasonal environments subject to climate change, organisms typically show phenological changes. As these changes are usually stronger in organisms at lower trophic levels than those at higher trophic levels, mismatches between consumers and their prey may occur during the consumers’ reproduction period. While in some species a trophic mismatch induces reductions in offspring growth, this is notAuthorsThomas Lameris, Pavel S. Tomkovich, James A. Johnson, R.I. Guy Morrison, Lucas Decicco, Maksim N. Dementyev, Ingrid Tulp, Simeon Lisovski, Robert E. Gill, Job ten Horn, Theunis Piersma, Z. Pohlen, Hans Schekkerman, Mikhail Soloviev, E. Syroechkovsky, Mikhail Zhemchuzhnikov, Jan A. van GilsPhysiomorphic transformation in extreme endurance migrants: Revisiting the case of bar-tailed godwits preparing for trans-pacific flights
In a 1998 paper entitled “Guts don’t fly: small digestive organs in obese bar-tailed godwits,” Piersma and Gill (1998) showed that the digestive organs were tiny and the fat loads huge in individuals suspected of embarking on a non-stop flight from Alaska to New Zealand. It was suggested that prior to migratory departure, these godwits would shrink the digestive organs used during fuel depositionAuthorsTheunis Piersma, Robert E. Gill, Daniel R. RuthrauffDiverse patterns of migratory timing, site use, and site fidelity by Alaska-breeding Whimbrels
Birds that conduct long-distance migrations exhibit varied patterns of consistency in migratory timing and site use. Understanding variation in these traits among populations can help uncover mechanisms driving migratory behaviors and identify potential population threats. Whimbrels (Numenius phaeopus) are long-distance migratory shorebirds with a Holarctic breeding distribution, and recent studieAuthorsDaniel R. Ruthrauff, Christopher M. Harwood, Lee Tibbitts, Nils Warnock, Robert E. GillFurther information on the avifauna of St. Matthew and Hall Islands, Bering Sea, Alaska
In June and July 2018 and July 2019 we surveyed birds on St. Matthew and Hall islands, isolated in the central Bering Sea. Our surveys were focused on the McKay’s Bunting (Plectrophenax hyperboreus), Rock Sandpiper (Calidris ptilocnemis ptilocnemis), and Pelagic Cormorant (Phalacrocorax pelagicus) but encompassed all birds and yielded 13 species and four subspecies new to the islands’ avifaunal liAuthorsBryce W. Robinson, Jack J. Withrow, Rachel M. Richardson, Steven M. Matsuoka, Robert E. Gill, Andrew S. Johnson, Irby J. Lovette, James A. Johnson, Anthony R. DeGange, Marc D. RomanoThrough thick and thin: Sexing Bristle-thighed Curlews Numenius tahitiensis using measures of bill depth
Birds often exhibit diagnostic traits that differ among individuals of the same species with regard to factors like sex, age, or breeding status. Shorebirds exhibit a wide diversity of colors, shapes, and sizes of their bills, and these traits are commonly used to determine the sex of individuals. In curlews (genus Numenius), length alone accurately separates the sexes in some species, but the shaAuthorsDaniel R. Ruthrauff, Colleen M. Handel, T. Lee Tibbitts, Robert E. GillFlexible timing of annual movements across consistently used sites by Marbled Godwits breeding in Alaska
The study of avian movement has detailed a spectrum of strategies for the timing and use of sites throughout the annual cycle, from near randomness to complete consistency. New tracking devices now permit the repeated tracking of individual animals throughout the annual cycle, detailing previously unappreciated levels of variation within migratory systems. Godwits (genus Limosa) have featured promAuthorsDaniel R. Ruthrauff, T. Lee Tibbitts, Robert E. GillTrends and traditions: Overview and synthesis
This paper provides an overview by the editors of a collection of 25 papers for the Studies of Western Birds, to be published in a single volume by Western Field Ornithologists. The title of the volume is: "Trends and traditions: Avifaunal change in western North America."AuthorsW David Shuford, Robert E. Gill, Colleen M. HandelShorebirds adjust spring arrival schedules with variable environmental conditions: Four decades of assessment on the Yukon–Kuskokwim Delta, Alaska
Arctic summers are brief, and there has been strong selection for migratory birds to arrive in Arctic nesting areas as early as possible to time breeding with peak food availability and complete reproduction. The timing of emergence of nesting habitat in spring is, however, extremely variable in the Arctic, and few long-term studies have examined the ability of avian migrants to track spring condiAuthorsCraig R. Ely, Brian McCaffery, Robert E. GillMontane-breeding bird distribution and abundance across national parks of southwestern Alaska
Between 2004 and 2008, biologists conducted an inventory of breeding birds during May–June primarily in montane areas (>100 m above sea level) in Aniakchak National Monument and Preserve (Aniakchak NMP), Katmai National Park and Preserve (Katmai NPP), and Lake Clark National Park and Preserve (Lake Clark NPP) in southwestern Alaska. Observers conducted 1,021 point counts along 169 transects withinAuthorsCourtney L. Amundson, Colleen M. Handel, Daniel R. Ruthrauff, T. Lee Tibbitts, Robert E. GillEnergetic solutions of Rock Sandpipers to harsh winter conditions rely on prey quality
Rock Sandpipers Calidris ptilocnemis have the most northerly non-breeding distribution of any shorebird in the Pacific Basin (upper Cook Inlet, Alaska; 61°N, 151°W). In terms of freezing temperatures, persistent winds and pervasive ice, this site is the harshest used by shorebirds during winter. We integrated physiological, metabolic, behavioural and environmental aspects of the non-breeding ecoloAuthorsDaniel R. Ruthrauff, Anne Dekinga, Robert E. Gill, Theunis PiersmaNesting ecology of Whimbrels in boreal Alaska
Breeding ecology studies of boreal waders have been relatively scarce in North America. This paucity is due in part to boreal habitats being difficult to access, and boreal waders being widely dispersed and thus difficult to monitor. Between 2008 and 2014 we studied the nesting ecology of Whimbrels Numenius phaeopus hudsonicus in interior Alaska, a region characterized by an active wildfire regimeAuthorsChristopher M. Harwood, Robert E. Gill, Abby Powell - News
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government