Technical Summary 

OCS Study MMS 2009-034 

 

STUDY TITLE: Pre-migratory Ecology and Physiology of Shorebirds Staging on Alaska’s North Slope 

REPORT TITLE: Pre-migratory Ecology and Physiology of Shorebirds Staging on Alaska’s North Slope

CONTRACT NUMBER: OCS Study MMS 2009-034; TASK ORDER (TO): 36269

SPONSORING OCS REGION: Alaska 

APPLICABLE PLANNING AREA: Beaufort Sea 

FISCAL YEAR OF PROJECT FUNDING: 2004-2006 

COMPLETION DATE OF REPORT: December 2008 

COST: FY 2004-2005: $123,600; FY 2006: $146,000 

CUMULATIVE PROJECT COST: $269,600 

PROJECT MANAGER: Audrey R. Taylor 

AFFILIATION: University of Alaska Fairbanks 

ADDRESS: Department of Biology and Wildlife, 211 Irving I, University of Alaska Fairbanks, Fairbanks 

AK 99775 

PRINCIPAL INVESTIGATOR: Abby N. Powell 

KEY WORDS: shorebirds, postbreeding, staging, aerial survey, abundance, distribution, phenology, 

habitat use, movements, physiology, North Slope, Beaufort Sea, Chukchi Sea 

BACKGROUND: 

 Preliminary work conducted in the 1970’s in Barrow, Alaska, indicated that arctic littoral habitats 

were of critical importance for most arctic-breeding shorebirds during the staging period (prior to 

southbound migration to wintering areas). However, relatively little recent, quantitative information exists 

regarding pre-migratory abundance and distribution of shorebirds staging along the Chukchi and Beaufort 

coasts of Alaska. We also lack current data on species-specific phenology, habitat selection, length of 

stay, movement patterns, or relative site quality. This information is critical given increased levels of 

human activity and industrial development near North Slope coastlines. This project was initiated in 2004 

to gain a better understanding of the overall ecology of postbreeding shorebirds during the staging period, 

and to inform assessments of how future industrial and human activity across the North Slope may affect 

shorebird populations. 

OBJECTIVES: 

 Our goals for this project were to: (1) assess the abundance and distribution of shorebirds using 

North Slope coastlines prior to fall migration, with particular emphasis on identifying important staging 

sites; (2) quantify staging phenology, species-specific habitat selection, length of stay at staging sites, 

and movement patterns of shorebirds across the North Slope after the breeding season; and (3) examine 

the feasibility of using differences in measures of physiological condition (fattening rates and stress 

hormone concentrations) among species and staging sites as metrics for relative site quality. 

DESCRIPTION: 

 During the summers of 2005-2007, we conducted aerial surveys for shorebird abundance and 

distribution along the North Slope coast from the southwest end of Kasegaluk Lagoon on the Chukchi 

Sea to Demarcation Bay in the Beaufort Sea, at the Alaska/Canada border. Our objective for this portion 

of our research was to assess whether there are persistent concentration areas for shorebirds on the 

North Slope that may be considered important staging sites. We also collected data on staging 

phenology, community characteristics, and habitat use in 2005 and 2006 by surveying transects at six 
Technical Summary 

OCS Study MMS 2009-034 

ground camps: Kasegaluk Lagoon, Peard Bay, Barrow, Colville River Delta, Sagavanirktok River Delta, 

and Okpilak River Delta. We captured and radio-equipped shorebirds at each of these ground camps to 

examine the length of time individual birds remained at staging sites after capture (time to departure) and 

the large-scale movement patterns exhibited by shorebirds once they leave their capture site. We also 

sampled the birds we captured for triglyceride levels (an index of fattening rate) and baseline/maximal 

corticosterone levels (indices of an individual’s body condition/ability to respond to a stressful situation) to 

assess whether either of these physiological parameters could be used as a measure of staging site 

quality. 

SIGNIFICANT CONCLUSIONS: 

 We found concentrations of staging shorebirds that persisted within and between years at Peard 

Bay, Elson Lagoon (including Point Barrow and the Plover Islands), Cape Simpson, between Smith Bay 

and Cape Halkett (including Pitt Point/Pogik Bay), Camden Bay, and at the Jago and Kongakut River 

deltas in the eastern Beaufort Sea. 

 We also determined there were species-specific differences in staging phenology, habitat use, 

time to departure, and movement patterns. Semipalmated sandpipers exhibited the earliest arrival and 

departure dates from North Slope staging areas. Red and red-necked phalaropes had intermediate 

arrival and departure dates. Western sandpipers arrived at staging areas later than semipalmated 

sandpipers and departed later from the North Slope. Dunlin were present throughout most of the staging 

period at most sites. Adults of three common species (semipalmated sandpiper, red phalarope, and rednecked phalarope) left staging areas earlier than juvenile birds. In general, black-bellied plovers, red 

phalaropes, red-necked phalaropes, ruddy turnstones, and sanderlings were found in gravel beach 

habitat, whereas dunlin and semipalmated sandpipers used mudflats. American golden-plovers, longbilled dowitchers, pectoral sandpipers, and western sandpipers used salt marshes. Stilt sandpipers were 

found in pond edge habitat, as were several species that were also found in other habitats: long-billed 

dowitchers, pectoral sandpipers, red-necked phalaropes, and western sandpipers. We examined time to 

departure for radio-equipped shorebirds of five species, using a Cormack-Jolly-Seber mark-recapture 

model that allowed survival to vary by species. Semipalmated sandpipers exhibited the shortest time to 

departure (4.3 days); both phalarope species combined had similar but slightly longer time to departure 

(4.5 days); western sandpipers showed an intermediate time to departure (7.9 days); dunlin exhibited the 

longest time to departure (12.9 days). After leaving their initial capture sites, semipalmated sandpipers 

moved mainly west to east across the North Slope, and many were detected on or near the Canning 

River Delta in the eastern Beaufort Sea, suggesting that this species may use the Canning River as a 

migration corridor south through the Brooks Range. Movement patterns of dunlin, red phalaropes, and 

red-necked phalaropes were variable and reflected major differences in individuals’ movement directions 

during the staging period. 

 We examined triglyceride and corticosterone levels for semipalmated sandpipers, dunlin, and 

western sandpipers. Semipalmated sandpipers had significantly higher triglyceride levels than dunlin in 

both years. Western sandpipers had intermediate triglyceride levels in 2005 but had similar levels as 

semipalmated sandpipers in 2006. Semipalmated sandpipers captured in Barrow had the highest 

triglyceride levels across our six ground camps, suggesting that site quality in terms of fattening rate was 

highest in Barrow. Comparison of corticosterone levels across the six ground camps for semipalmated 

sandpipers were equivocal, in that baseline and maximal levels did not show the same trends among 

camps. However, semipalmated sandpipers captured in Barrow had high maximal corticosterone levels, 

indicating that individuals using this site may be more capable of responding to a stressful event and 

therefore better prepared to deal with the uncertainties of migration. 

 

STUDY RESULTS: 

 This research represents the first large-scale survey of shorebirds staging on the North Slope of 

Alaska prior to fall migration. As a result of this extensive survey effort, we determined that aerial surveys 

may be more reliable for assessing shorebird abundance and distribution if conducted frequently within a 

single year, repeated across multiple years, and combined with ground surveys for species composition 

and habitat use. Ground surveys in particular may increase our understanding of detectability differences 

for various species and habitats. Examining site quality from a physiological perspective using 

triglyceride (recommended for ease of analysis and interpretation) or corticosterone levels may lend 

mechanistic insight into patterns of abundance, distribution, and movement of postbreeding shorebirds, 
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OCS Study MMS 2009-034 

because physiological metrics may reflect food availability or quality, which is of paramount importance to 

birds preparing for long-distance migration. We suggest that future studies of sites that appear to be 

important to postbreeding shorebirds compare both patterns of site use by shorebirds and physiological 

characteristics of individuals using each site. 

STUDY PRODUCTS: 

Taylor, A.R., A.N. Powell, and R.B. Lanctot. October 2008. Distribution and movements of staging 

shorebirds on Alaska’s North Slope. Minerals Management Service, 11th Information Transfer Meeting, 

Anchorage, AK (oral presentation by A. Powell). 

Taylor, A.R., A.N. Powell, and R.B. Lanctot. March 2008. Length of stay of staging shorebirds on 

Alaska’s Chukchi and Beaufort coasts. 13th Annual Alaska Bird Conference, Fairbanks, Alaska (oral 

presentation by A. Taylor). 

Taylor, A.R., A.N. Powell, and R.B. Lanctot. February 2008. Use of radio telemetry to determine tenure 

time and movement patterns of staging shorebirds on Alaska’s North Slope. Coastal Marine Institute 

Annual Research Review, Fairbanks, AK (oral presentation by A. Powell). 

Powell, A.N., A.R. Taylor, and R.B. Lanctot. September 2007. Pre-migratory movements and physiology 

of shorebirds staging on Alaska’s North Slope. Annual report to Coastal Marine Institute. 

Taylor, A.R., R.B. Lanctot, and A.N. Powell. July 2007. Using radiotelemetry to determine tenure time 

and movement patterns of staging shorebirds on Alaska’s North Slope. Association of Field 

Ornithologists’ Annual Meeting, Orono, ME (oral presentation by A. Taylor). 

Taylor, A.R., A.N. Powell, and R.B. Lanctot. February 2007. Distribution and movements of staging 

shorebirds on Alaska’s North Slope: patterns and conservation implications. Coastal Marine Institute 

Annual Research Review, Fairbanks, AK (oral presentation by A. Taylor). 

Powell, A.N., A.R. Taylor, and R.B. Lanctot. September 2006. Pre-migratory movements and physiology 

of shorebirds staging on Alaska’s North Slope. Annual report to Coastal Marine Institute. 

Taylor, A.R., R.B. Lanctot, A.N. Powell, and T.D. Williams. March 2006. Should I stay or should I go 

now: importance of staging sites on Alaska’s North Slope. Shorebird Science in the Western Hemisphere 

Conference, Boulder CO (oral presentation by A.Taylor). 

Taylor, A.R., A.N. Powell, and R.B. Lanctot. February 2006. Staging shorebirds on Alaska’s North Slope: 

results from intensive camps and an extensive survey. Coastal Marine Institute Annual Research 

Review, Fairbanks, AK (oral presentation by A. Taylor). 

Powell, A.N., A.R. Taylor, and R.B. Lanctot. September 2005. Pre-migratory movements and physiology 

of shorebirds staging on Alaska’s North Slope. Annual report to Coastal Marine Institute. 

Taylor, A.R., A.N. Powell, R.B. Lanctot, and T.D. Williams. February 2005. Staging behavior and 

physiology of shorebirds on Alaska’s North Slope. Coastal Marine Institute Annual Research Review, 

Fairbanks, AK (oral presentation by A. Taylor). 

Taylor, A.R., A.N. Powell, R.B. Lanctot, and T.D. Williams. January 2005. Using fat metabolites to infer 

staging site quality for post-breeding shorebirds on Alaska’s North Slope. Waterbird Society Annual 

Meeting, Portland, OR (poster presentation by A. Taylor). 

Powell, A.N., A.R. Taylor, and R.B. Lanctot. September 2004. Pre-migratory movements and physiology 

of shorebirds staging on Alaska’s North Slope. Annual report to Coastal Marine Institute. 
Technical Summary 

OCS Study MMS 2009-034