Shiloh Schulte, Manomet’s senior shorebird scientist, recently spent four weeks in the Arctic National Wildlife Refuge, continuing several studies delayed by COVID-19. Working closely with the U.S Fish and Wildlife Service, Shiloh deployed GPS tracking tags on Whimbrel, American Golden-Plovers, Pectoral Sandpipers, and other species as part of an ongoing study of local movement patterns and long-distance migration pathways and stopover sites. In addition to the tracking work, Shiloh collaborated to develop methods for remote monitoring of shorebird nests and mentored new USFWS technicians and volunteers.

Shiloh recently shared his experiences on Alaska’s Katakturuk River tagging Whimbrels to study local movement patterns and long-distance migration pathways and stopover sites.

I have been lying flat in the sedge, hiding behind a tundra mound for the last 20 minutes. A cloud of frustrated mosquitos is whining all around but unable to reach me through my bug shirt and headnet. One hundred and fifty meters away, a male Whimbrel is slowly making his way back toward his nest, head up and on high alert. It is the morning of June 23, and it’s our last morning in the Katakturuk River valley in Alaska’s Arctic National Wildlife Refuge. Our trip has already been a huge success, with five Whimbrels tagged with GPS transmitters in the last three days. But, we have one last transmitter to put out, and we really want to catch this bird. Two hundred meters along the slope, I can barely see the tan camouflage of Kirsti Carr’s bug jacket as she also lies flat in the sedge, watching from another angle and ready to radio the moment the Whimbrel gets back on the nest.

A Whimbrel watches us as we search for her nest in the tall tundra sedge.

Kirsti and I arrived in the Katakturuk Valley on June 20 to find any Whimbrel nests in the area and hoping to catch up to six adults for tagging. Kirsti is a volunteer for the U.S. Fish and Wildlife Service (USFWS) and working with me to catch and tag sandpipers because of her previous experience GPS tagging Red-headed Woodpeckers in Minnesota. The Katakturuk is about 35km to the Southeast of the USFWS Canning River Delta Camp, which is only about 25 minutes away by helicopter. Eric Lane, our pilot from Pollux Aviation, dropped us off and even helped set up our spike camp before heading out.

Kirsti Carr and Shiloh Schulte search for Whimbrel and American Golden-Plover nests in the Katakturuk River Valley in the Arctic National Wildlife Refuge.

The Katakturuk River valley is a patchwork of dry tundra covered in Dryas flowers and lichen and hummock wetlands dominated by a mix of sedge species. After a couple of weeks of daily walking on the wet, uneven ground of the Canning River Delta, the good footing and stunning landscape were a welcome change. The last time I was here was in June 2019. Manomet and the USFWS had a small joint camp in the Katakturuk Valley that year. We conducted Program for Regional and International Shorebird Monitoring surveys (PRISM) for breeding shorebirds; estimated shorebird nest survival across the Arctic coastal plain; and deployed tags on Pectoral Sandpipers and American Golden-Plovers to assess their use of the coastal plain and migration pathways and strategies. 2020 was supposed to be the second year of all of these projects, but like so many other things, COVID shut those plans down at least temporarily. We had hoped to resume fieldwork in 2021, but we again had to postpone most of the work with the uncertainty around COVID rules and vaccine availability. Fortunately, I was able to get vaccinated in time to join the USFWS team going to the Canning River Delta camp in June. My goal was to deploy transmitters on Pectoral Sandpipers, American Golden-Plovers, and Whimbrel, and assist the USFWS team with their work at the Canning River camp.

Kirsti Carr opens the wing of a captured Whimbrel so we can document molt and feather condition

A Whimbrel fitted with a GPS tag that will allow us to track its migration and habitat use over several years.

Back in 2019, the Katakturuk Valley held several surprises for us. We discovered a high density of nesting Whimbrel in the area, which led to questions about the importance of the Refuge coastal plain for this species. We were curious to learn if these birds were part of the Mackenzie Delta group that migrates east and crosses the Atlantic to South America, or if they were associated with the rest of the Whimbrel in Alaska, which migrates down the west coast. In 2019, we tagged one bird with a GPS transmitter and discovered that he went the Eastern route and ended up in Brazil by way of the Hudson Bay flats and an impressive multi-day flight over the Atlantic Ocean. This year, we hoped to expand the project with six new GPS tags that would track the Whimbrels over multiple years.

Watching through my binoculars over the top of the mound, I see the Whimbrel dip out of sight very close to the nest and not reappear. After a couple of moments, I radio to Kirsti:

“Can you still see him?”

“No, he just dropped out of sight, but I think he is on the nest.”

This Whimbrel had opinions about our presence in her territory. Whimbrels are highly defensive of their nests and territories and will harass predators and battle with their neighbors.

I wait several more moments before seeing a slight movement through the sedge as the bird turns his head. He is definitely on the nest now. Holding my breath, I give a hard pull on the trigger line and then immediately start sprinting toward the nest. The traps are very reliable, but there is a chance the bird can escape given enough time. Whimbrel are so wary that we have to hide quite a distance from the nest. Speed is of the essence. Hurdling mounds and avoiding mud pits, I somehow make it to the trap without falling on my face. Bird in the trap!

Moments later we add a USGS metal band with a unique code and then complete a series of measurements to confirm sex and assess molt and body condition. Next, we add a field readable leg flag (EY5) and a solar-powered GPS transmitter that should last several years and allow us to track this bird through his incredible annual journey.

Senior Scientist, Shiloh Schulte prepares to release a GPS-tagged Whimbrel

After a final check, EY5 is ready for release. He launches into the air with a hard beat of his wings, rising up and out towards the river, giving a loud alarm call. His mate has been standing nearby and leaps up to follow. We quickly gather our supplies and move out of the area so they can return to their nest as quickly as possible. Elated with the morning’s work, we head back to camp to finish packing and wait for the helicopter to pick us up. In three and a half days, we found three nesting Whimbrel pairs and one pair of American Golden-Plovers and managed to catch all eight birds and fit them with GPS tags. When we return to the Canning Camp, we will complete the tagging work for the season with 13 tags on female Pectoral Sandpipers. We will track all these birds through the fall and winter, and these Whimbrel tags should keep providing valuable data for several years.

A recently tagged Whimbrel in flight

Whimbrel (Numenius phaeopus) have been identified as a conservation priority in the Atlantic Flyway, with a population that has declined by 50% between the early 1990s and the mid-2000s at key Atlantic staging areas. Manomet, along with the Center for Conservation Biology at William & Mary and many other partners are working together to gather all the information we need to apply conservation action to Whimbrel populations. In April 2021, Manomet’s Brad Winn and I headed to the Gulf coast to expand our recent work in the Atlantic flyway into the Midcontinent Flyway. Our goal for this trip? To delineate key staging areas for Whimbrel in Louisiana and Texas and build relationships with the key conservation players.

Why are we so focused on the spring staging areas for Whimbrel? In the conservation field, monitoring population size and trend is essential to understanding the cause-effect links between management actions and population response. Therefore, one of the first questions we need to ask as we build a conservation strategy is: How many Whimbrel are there, and how do we count them? This, in itself, is quite the challenge. For ¾ of the year, Whimbrel are largely inaccessible. During the breeding season, they are thinly dispersed throughout the vast Arctic and sub-Arctic tundra. During fall migration, a large percentage fly straight out over the Atlantic Ocean, without ever passing through the lower 48 states. During the winter months, they are dispersed along the coasts of the Caribbean and northern South America, a coastline which is remote and difficult to survey. Therefore, the only time to do population-level headcounts of Whimbrel is at spring staging areas, and particularly at their nocturnal roost sites. There may just be a few of these roosts in a region, pooling birds from up to 50 miles away and numbering thousands of birds.

Manomet and our partners have been identifying these sites developing survey strategies in the Atlantic Flyway for the past several years, and we have built a monitoring network for roost sites along the Atlantic coast, including focal areas such as Virginia, South Carolina, and Georgia. Our goal in 2021 is to expand this monitoring network into the Gulf coast.

Where to survey

Over the last 10 years, Manomet and our team of partners have deployed over 40 transmitters on Whimbrel at various sites in North America. This mountain of data has vastly improved our understanding of Whimbrel migratory pathways, resource use, and survival. For our trip to the Gulf coast, the information relayed from these transmitters combined with publicly available ebird data helped us hone in on key sites to explore. For example, we analyzed the daily commutes of a satellite tagged bird in Louisiana, as it traveled from a coastal roost site inland to rice and crawfish fields to feed during the day. Those feeding areas happened to coincide with the largest concentrations of Whimbrel reported in ebird over the past decade, some of which numbered over 500 individuals. This allowed us to hypothesize that the coastal roost site identified by the satellite data could be functioning as a nocturnal roost for all those birds.

To test this hypothesis, we coordinated with refuge staff to do an evening survey in Rockefeller Wildlife Refuge, the location of the potential roost site. While we knew at least one bird (the satellite-tagged bird) was roosting there, we entered the night of 4/19 not knowing if any other birds would show up. We climbed onto an excavator to gain some elevation and started scanning the horizon for Whimbrels. What started out as a trickle soon turned into a flood, and by the end of the survey, we had tallied over 3,000 Whimbrels arriving onto the refuge. A great discovery! This count alone puts south-central Louisiana on the map as one of the top spring staging areas for Whimbrel on the Atlantic and Gulf Coasts. We did subsequent surveys the following two nights and were joined by State Ornithologist for LDWF, Robert Dobbs. We were thrilled to share our methods with Robert, and he and Louisiana Audubon have now joined forces to continue the surveys.

During the day, we covered the working lands north of Rockefeller, which mostly include vast rice and crawfish fields. In addition to the roost surveys, we are keen on increasing our understanding of how Whimbrels are using this landscape and finding the resources they need to successfully continue their migration.

Texas

After Louisiana, we headed to east Texas and the area surrounding Anahuac NWR. Similar to Louisiana, a combination of historical surveys, e-bird observations, and our transmitter data had clearly highlighted this area as a major concentration point for Whimbrels. We met up with Joseph Marty, the refuge biologist, and once again plotted our survey strategy. We had also received helpful intel from a team of University of Oklahoma researchers, who had been out scouting the previous week. We did four days of dawn and dusk surveys, and also spent the daytime scouting the terrain to find out what areas the birds were feeding on. Our peak count for the roost on the refuge was over 5,000 birds, making this the second-largest concentration of Whimbrels we know of on the Atlantic and Gulf coasts.

In Texas, we found Whimbrel using a surprising variety of habitats and feeding on a wide array of food items. This covered the spectrum from browsing on dewberries in overgrown pastureland to gorging on ghost shrimp on coastal flats with Willets and Long-billed Curlews.

The best way to survey for Whimbrel is at dawn and dusk when they are commuting from and to their communal roosts, which can be located in coastal impoundments, peninsulas, and islands. They fly in flocks both big and small, with roosts sometimes numbering several thousand individuals. With a total population for the Hudsonian subspecies likely under 60,000 total birds, identification and conservation of these roosts is a major priority.

We met up with USFWS biologists in the area of the mouth of the Brazos River to explore the staging area for Ahanu, a Whimbrel we tagged in Massachusetts in 2018. While we didn’t spot Ahanu, we did see lots of Whimbrels. They were foraging for fiddler crabs and ghost shrimp in the tidal flats and Salicornia, and hopping onto driftwood at the mouth of the river to roost.

Buff-breasted Sandpipers are another priority shorebird species that relies heavily on the Midcontinent Flyway during spring migration. Concentrations of several hundred can be found in shortgrass habitats, including cattle pastures and turf farms. Manomet is one of several organizations working together to put the pieces together to ensure that we are taking the right steps to ensure their survival.

Big picture

After just 10 days in the field, we left feeling that we had accomplished a great deal. At the same time, we view this trip as just the first step in developing a conservation strategy for Whimbrels on the Gulf coast. In addition, we as an organization are also focused on the big picture, and we are intent on increasing our role as a leader in applied science and conservation work in the Midcontinent Flyway. We want to focus our work on high priority species such as Whimbrels and Buff-breasted Sandpipers, while also expanding our shorebird monitoring across the Gulf coast. We are also focused on laying the groundwork to identify and build coalitions to nominate new WHSRN sites in Louisiana and Texas.