Welcome to the Pectoral Sandpiper (Calidris melanotos) stopover ecology study Web resource! This is a collaborative effort between Iowa State University, The U.S. Army Corps of Engineers (under authority of the Sustainable Rivers Program [SRP]), and the Iowa Department of Natural Resources to track migrating Pectoral Sandpipers at Iowa stopover sites (Red Rock and Coralville lakes) during fall migration.
The Pectoral Sandpiper breeds across the Arctic in western North America and eastern Siberia and winters primarily in central and southern South America (Farmer et al. 2020). It is a common spring (late March through late May) and fall (early July through late October) migrant in Iowa. Fall concentrations can number in the thousands in late July and August. Consistent fall stopover locations in Iowa include Red Rock and Saylorville reservoirs in central Iowa, Union Slough National Wildlife Refuge in north-central Iowa, and Coralville Reservoir (Hawkeye Wildlife Area) in eastern Iowa, as long as habitat conditions are ideal. Little is known about their stopover dynamics in Iowa or the Midwest (Murphy and Dinsmore 2014).
The Sustainable Rivers Program is a collaborative effort between the U.S. Army Corps of Engineers and The Nature Conservancy that aims to learn how environmental flows can be incorporated into reservoir pool management strategies. Environmental flows are scientific prescriptions for the timing, quality, and quantity of water flows needed to sustain environmental function and species' habitat (The Nature Conservancy 2020). Environmental pool management began at Red Rock in fall 2021 with the goal of dropping the pool beginning in late July to benefit migratory shorebirds (Calomeni et al. 2022). The plan calls for a 1.5 foot drop ending in late August, followed by a pool raise in early September when most shorebirds have departed. The exposed mudflats are rapidly colonized by vegetation, which when reflooded in fall provide food and cover for waterfowl and other wildlife.
Our research group at Iowa State University studies the population ecology of birds and other taxa. This particular project is led by Victoria Fasbender (M.S. student in my lab) and Emily MMichalzik (M.S. student in my lab) with support from Iowa Department of Natural Resources and U.S. Army Corps of Engineers staff. For this study we use the Pectoral Sandpiper to investigate how long they stop over at Red Rock and Coralville, how they make use of the varied habitat that is available because of the SRP environmental flows, and where they go once they depart our area.
We are excited to report that in June 2025 we worked with collaborators near Utqiagvik, Alaska to fit six female Pectoral Sandpipers incubating nests with Ornitela 2.8 g tags. We tracked these birds during their travels between Alaska and wintering grounds in South America.
Project objectives:
- Estimate residency time for the Pectoral Sandpiper during fall migration.
- Characterize local movements of the Pectoral Sandpiper at Lake Red Rock in response to SRP environmental flows.
- Describe the annual movements of Pectoral Sandpipers with a focus on individuals passing through Iowa in fall.
- Share bird tracking data with the public (this Web page).
Field methods
Pectoral Sandpipers (Calidris melanotos) are captured with the use of mist nets, which is a standard shorebird capture technique. We use 60 mm mesh mist nets that are 12 m long and 3 m tall and deploy them in areas frequented by foraging shorebirds. Our research group has successfully used this approach with this species at a site in northwestern Iowa in 2012, and also with other migratory shorebirds at Saylorville Lake (2016-2020) and Lake Red Rock (2021-2022). We collect basic morphometric data for all captured birds, including flattened wing chord, tarsus length, and body mass and use established formulae to assign sex to each individual (wing chord >133 mm is a male and <133 mm is a female).
Each Pectoral Sandpiper that meets minimum weight requirements (~80 g) is fitted with a Lotek PinPoint ARGOS satellite tag weighing 4 g. Each tag is affixed to the bird using using glue to adhere to the back feathers; the tag drops off when the bird molts these feathers in fall. These tags have a dedicated battery that provides ~75 location fixes that are programmed to a specific schedule that is intended to focus on local movements at Lake Red Rock. We anticipate that residency time is approximately one week based on other studies, so the tags will be programmed to record ~15 locations per day for 5 days.
The tracking devices
We are using three tag types to track Pectoral Sandpipers, each with different capabilities that are geared to answer specific questions. The first tag, which is used on most of our birds, is the Lotek PinPoint GPS ARGOS tag weighing 4 grams. We're using this tag to collect frequent (~hourly) locations of sandpipers at Red Rock to better understand how they use this site during migration. It has a dedicated battery and no solar panel meaning we'll get a maximum of ~75 locations before the tag battery dies. The second tag is the LOTEK Sunbird Solar ARGOS tag weighing ~2 grams. This tag does not collect GPS locations, meaning the fix accuracy is lower than with the PinPoint tags. However, this tag is rechargeable and theoretically lasts much longer, allowing us to track movements at and away from tagging locations. The third tag is the Ornitela OrniTrack 2.8 gram solar tag, which can take many more location fixes per day and last 3+ years. We're hoping that by using these tags we can better understand Pectoral Sandpiper movements and local and hemisphere scales. All work is approved by the ISU Institutional Animal Care and Use Committee (IACUC protocol #22-150) and federal and state banding permits held by SJD.
Tag update (3/25/2025): The PinPoint tags have worked exceptionally well and we're getting >150 locations from each tag, sometimes more. However, the Sunbird tags have not performed well and all have stopped transmitting data within 3 months of deployment. We're uncertain if this is because of a tag failure or because the bird died in such a manner that the tag could no longer recharge and transmit location data. Either way we plan to test other tags in 2025 in an effort to learn more about the complete annual movements of these birds.
Tag update (8/13/2025): In 2025 we began using Ornitela OrniTrack-2.8 tags because they are lighter (2.8 grams), have a solar panel, and will last up to 3 years. We tested a few on nesting Pectoral Sandpipers at Utqiagvik, Alaska in June and they are working well. Stay tuned below for migration updates.
Here are the latest tracks for the birds we've tagged so far. Please recall that these locations are unfiltered and some points are clearly incorrect and will be edited out at a later time. This is a cost of providing the data in real time. Enjoy!
2026 Iowa Pectoral Sandpipers
Coralville Lake
Bird 373655 Tracked to near Bloomington, IN
Bird 373657 Tracked to near Tadó, Colombia
Bird 373658 Never left Coralville Lake
Bird 373659 Tracked to Jaibon, Dominican Republic
Bird 373660 Tracked to Terrapin Island, AL
Bird 373669 Tracked to Esperanza, Dominican Republic
Bird 373670 Tracked to near Tompkinsville, KY
Bird 384196 Tracked to near Reno, IN
Bird 384198 Never left Coralville Lake
Red Rock Lake
Bird 267325 Tag apparently failed
Bird 373656 Tracked to near Tiptonville, TN
Bird 373662 Tracked to near Planeta Rica, Colombia
Bird 373663 Tracked to near Crowley, LA
Bird 373664 Tracked to near Neiva, Colombia
Bird 373665 Tracked to near Carepa, Colombia
Bird 373666 Tracked to near Lake Arthur, LA
Bird 363667 Tracked to near Cali, Colombia
Bird 373671 Tracked to near Decatur, IL
Bird 373672 Tracked to the Gulf of Mexico off Mobile, AL
Bird 384217 Tracked to the eastern edge of Jamaica
Polk County agricultural sheetwater
Bird 384200 Never left area where it was tagged
Bird 284201 Tracked to near Chiriguaná, Colombia
Bird 284203 Tracked to offshore of Naples, FL
Bird 284204 Tracked to the Straits of Florida
Bird 284206 Tracked to near Bowling Green, KY
Bird 284207 Tracked to near El Prado, Colombia
Bird 284208 Tracked to near Ambergris Key, Belize
Bird 284209 Never left area where it was tagged
Bird 284211 Never left area where it was tagged
Bird 284213 Tracked to near Los Córdobas, Colombia
Bird 284214 Tracked to near Monteria, Colombia
Bird 284215 Never left area where it was tagged
2025 Iowa Pectoral Sandpipers
Coralville Lake
Bird 373661 Tracked to the Gulf of Mexico
Bird 267326 Never left Coralville Lake
2025 Alaska Pectoral Sandpipers
2024 Iowa Pectoral Sandpipers
**Note that none of these 2024 birds is still transmitting tracking data
Red Rock Lake
Bird 267278 Never left Red Rock Lake
Bird 267279 Never left Red Rock Lake
Bird 267280 Never left Red Rock Lake
Bird 267281 Never left Red Rock Lake
Bird 267282 Never left Red Rock Lake
Bird 267283 Never left Red Rock Lake
Bird 267284 Tracked to Mississippi River in Mercer Co., IL
Bird 267285 Never left Red Rock Lake
Bird 267287 Never left Red Rock Lake
Bird 267288 Never left Red Rock Lake
Bird 267290 Never left Red Rock Lake
Bird 267294 Never left Red Rock Lake
Bird 267295 Tracked to near Pulaski, TN
Bird 267296 Tracked to Gulf of Mexico south of Tallahassee, FL
Bird 267298 Never left Red Rock Lake
Bird 267299 Tracked to Atlantic Ocean east of Florida
Bird 267300 Tracked to near Great Guana Cay, Bahamas
Bird 267301 Never left Red Rock Lake
Bird 267302 Tracked to Caribbean Sea off Colombia
Bird 267304 Never left Red Rock Lake
Bird 267305 Tracked to near Rosedale, MS
Bird 267306 Tracked to the Gulf of Mexico north of the west end of Cuba
Bird 267307 Never left Red Rock Lake
Bird 267308 Never left Red Rock Lake (bird appeared to be depredated)
Bird 267310 Tracked to Haiti
Bird 267311 Tracked to south of Tampico, Mexico
Bird 267312 Never left Red Rock Lake
Bird 267313 Never left Red Rock Lake
Bird 267314 Never left Red Rock Lake
Bird 267315 Never left Red Rock Lake
Bird 267316 Tracked to east of Lake Okeechobee, FL
Bird 267317 Tracked to south of Lake Okeechobee, FL
Bird 267318 Never left Red Rock Lake
Bird 267319 Never left Red Rock Lake
Bird 267320 Never left Red Rock Lake
Bird 267321 Never left Red Rock Lake
Bird 267322 Tracked to Gulf of Mexico west of Florida
Bird 267323 Tracked to the Caribbean Sea south of Jamaica
Bird 267324 Tracked to eastern Panama
Bird 267339 Tracked to between Cuba and Jamaica
Bird 267340 Never left Red Rock Lake
Bird 267354 Tracked to south of New Orleans, LA
Bird 267355 Tracked to near Churuguara, Venezuela
Bird 267356 Tracked to near Albany, KY
Bird 267357 Tracked to near Lago Xolotian, Nicaragua
Bird 267359 Never left Red Rock Lake
Bird 267361 Tracked to near Naples, Florida
Coralville Lake
Bird 267289 Never left Coralville Lake
Bird 267291 Tracked to Colombia
Bird 267292 Tracked to Brazil
Bird 267293 Never left Coralville Lake
Bird 267297 Never left Coralville Lake
Saylorville Lake
Bird 267337 Tracked to the Caribbean Sea south of Jamaica
Bird 267338 Tracked to near Whitehall, IL
Bird 267342 Tracked to southwest of Lake Okeechobee, FL
Bird 267360 Tracked to the Straits of Florida
2023 Iowa Pectoral Sandpipers
**Note that none of the 2023 birds is still transmitting tracking data
Bird 252421 Tracked to Lake Rathbun, IA
Bird 252422 Tracked to the Dominican Republic
Bird 252423 Never left Red Rock Lake
Bird 252424 Tracked to Colombia
Bird 252425 Tag was a partial failure
Bird 252426 Tracked to Colombia
Bird 252427 Tracked to Venezuela
Bird 252428 Never left Red Rock Lake
Bird 252429 Never left Red Rock Lake
Bird 252430 Never left Red Rock Lake
Bird 252431 Tracked to Colombia
Bird 252432 Tracked to near Goldston, NC
Bird 252433 Tracked to near Hopeulikit, GA
Bird 252434 Never left Red Rock Lake
Bird 252435 Never left Red Rock Lake
Bird 252436 Never left Red Rock Lake
Bird 252437 Tracked to Colombia
Bird 252438 Never left Red Rock Lake
Bird 252439 Tracked to Venezuela
Bird 252440 Never left Red Rock Lake
Bird 252441 Never left Red Rock Lake
Bird 252442 Never left Red Rock Lake
Bird 252443 Never left Red Rock Lake
Bird 252444 Never left Red Rock Lake
Bird 252446 Never left Red Rock Lake
Bird 253348 Tracked to near Grimes, IA
Bird 253349 Tracked to Puerto Rico
Bird 253350 Tracked to Venezuela
Bird 253351 Tracked to Venezuela
**Tracks updated 12 October 2026
Acknowledgments
We thank the U.S. Army Corps of Engineers and the Sustainable Rivers Program for funding this work. Thanks are due to the many individuals who have helped with this work, especially Todd Gosselink, Richard Lanctot, Kevin Murphy, Rachel Ruden, and Perry Thostenson.
Literature Cited
Calomeni, A. J., C. Theiling, and B. C. Suedel. 2022. Planning and Implementation of Environmental Pool Management at Lake Red Rock, Des Moines River, Iowa. EWN Technical Notes Collection. ERDC/TN EWN-22-6. Vicksburg, MS. US Army Engineer Research and Development Table.
Farmer, A., R. T. Holmes, and F. A. Pitelka. 2020. Pectoral Sandpiper (Calidris melanotos), version 1.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.pecsan.01
Murphy, K. T., and S. J. Dinsmore. 2014. Stopover dynamics of fall migrant Pectoral Sandpipers in Iowa. Wader Study Group Bulletin 121:186-192.
TNC (The Nature Conservancy). 2020. Sustainable Rivers Program: Modernizing Water Infrastructure to Maximize Benefits. Land and Water Stories. https://www.nature.org/en-us/what-we-do/our-priorities/protect-water-and-land/land-and-water-stories/sustainable-rivers-project/.
For more information or comments please email Dr. Stephen J. Dinsmore, Iowa State University ( cootjr@iastate.edu ).
Preferred citation for this page:
Dinsmore, S. J. 2025. Iowa Pectoral Sandpiper Stopover Study. https://faculty.sites.iastate.edu/cootjr/iowa-pectoral-sandpiper-stopov…