Tracking Semipalmated Sandpipers in Brazil

During November and December of 2018, a team of shorebird scientists led by New Jersey Audubon and Tulane University went on a month-long expedition to Brazil. The trip, a part of a multi-year regional effort, centered around the deployment of nano-tags on Semipalmated Sandpipers (Calidris pusilla) to help generate overwinter survival estimates for the species. These estimates will be used along with survival estimates from studies during migration and breeding periods to develop life cycle migratory network models to investigate what period during the annual cycle might be driving population declines. The target locations for this trip were two sites on either side of the mouth of the Amazon River, in the states of Amapá and Pará.

Our team included Dr. David Mizrahi of New Jersey Audubon, John Herbert of Tulane University, Bracken Brown, a Pennsylvania ornithologist and teacher, Onofre Montiero of Aquasis in Brazil, and Alan Kneidel, Staff Biologist at Manomet. We were also joined by Dr. Carlos David Santos, Professor at the Federal University of Pará.

The photos and captions below, taken and composed by Alan, are meant to share the team’s experience.

satellite photo

Located south of the mouth of the Amazon River, the Brazilian state of Pará is a tropical, biodiverse region. This satellite image gives an idea of what the coastline looks like there. While many parts of the interior have been deforested, the sinuous, mangrove-bordered coastline is comparatively remote. This region extends into the neighboring state of Maranhão and the area known as Reentrâncias Maranhenses, a WHSRN site of hemispheric importance for Nearctic shorebirds. While hosting many species, this habitat is of particular importance to populations of Black-bellied Plover (Pluvialis squatarola), Ruddy Turnstone (Arenaria interpres), Eastern Willet (Tringa semipalmata semipalmata), Whimbrel (Numenius phaeopus), Red Knot (Calidris canutus rufa), and Semipalmated Sandpiper (Calidris pusilla).


Access is difficult, and the isolated communities rely on boats for transportation. The boats themselves come in a flamboyant array of colors and designs. The assistance of the locals was invaluable, both for logistics and for their insight into local shorebird behavior.


We successfully deployed over 70 nano-tags on Semipalmated Sandpipers (Calidris pusilla). Nano-tag technology allows for up to 2,000 tags to be assigned to a single radio frequency while retaining the ability to identify individual animals. Transmitters are picked up through a network of widely-spaced towers that have been constructed along the coastline. The towers take a solid two days of work to erect. Here, one of the two towers we built is adopted as a favorite perch by a Black Vulture (Coragyps atratus).

Bird Processing

The team processes birds in our mobile field station on the Ilha de Maracá in the state of Amapá. At this site, our trapping efforts centered on a mangrove high-tide roost, often forcing us to work through the night.

fiddler crab

Fiddler crabs (Uca sp.) are widespread in mangroves and saltmarshes throughout the world. Wherever they are found, they serve as a principal food source for a variety of coastal waterbirds. In Brazil, Whimbrel (Numenius phaeopus) and Scarlet Ibis (Eudocimus ruber) use their long, curved bills to extract crabs from their burrows. Meanwhile, birds such as Eastern Willet (Tringa semipalmata semipalmata), Wilson’s Plover (Charadrius wilsonia) and Gull-billed Tern (Gelochelidon nilotica) have stout bills, specialized for feeding on actively foraging fiddler crabs.

wilson's plover

The Brazilian coast is home to a substantial population of Wilson’s Plovers (Charadrius wilsonia), likely augmented by wintering birds from the north. At one of our field sites, we found a flock of 50+ in the dry dune ridges. Among the Wilson’s were lesser numbers of Collared Plover (Charadrius collaris) and Semipalmated Plover (Charadrius semipalmatus).


Many shorebirds molt their feathers while on their wintering grounds, a process that is energetically demanding. This Sanderling (Calidris alba) is replacing its greater coverts, revealing the vivid white base to the secondary feathers.

flying Whimbrel group

According to estimates, the Brazilian coast is home to up to 44% of the South American population of (Hudsonian) Whimbrel (Numenius phaeopus hudsonicus). This number includes adult birds that spend the winter months here before returning to North America to breed, as well as juvenile birds that can stay for over a full calendar year. To better understand the migration ecology of this declining subspecies, shorebird researchers in the Atlantic Flyway (Center for Conservation Biology, Georgia DNR, Manomet) have been tagging Whimbrel with satellite transmitters over the past several years. Many of these birds have spent the non-breeding season along this portion of the Brazilian coastline, including Ahanu, a Whimbrel tagged by Manomet staff on Cape Cod in the fall of 2018. Ahanu continues to winter on the outskirts of São Luis, Brazil.

upclose Whimbrel flying

Poaching is one of the greatest problems facing shorebird conservation in Brazil. In the Brazilian state of Ceará, the Whimbrel (Numenius phaeopus) is called “Pirão Gordo.” “Pirão” is a mixture of fat and flour used to make a thick gravy, and “gordo” means fat in Portuguese, referring to the Whimbrel’s size. While the hunting of shorebirds is illegal in Brazil, enforcement is a challenge.

roosting Whimbrel flock

As is the case for most birds that rely on the intertidal zone for foraging, high tide is a time for roosting. Whether a tern, skimmer, shorebird, or heron, the sand spit outside of the small village we stayed in was the place to be at high tide. Here, a flock of over 200 Whimbrel (Numenius phaeopus) rest.


A flock of Semipalmated Sandpipers (Calidris pusilla) and Short-billed Dowitchers (Limnodromus griseus) wheel about as they settle into their high-tide roost.

Bar-tailed Godwit

Among the regular suspects in Pará, we also spotted a few (European) Bar-tailed Godwits (Limosa lapponica lapponica). Recent explorations to this stretch of coastline have begun to reveal a pattern of regular occurrence for this species in Brazil.

scarlet ibis

Without a doubt, the bird most emblematic of this region is the Scarlet Ibis (Eudocimus ruber). We regularly saw ibis feeding on the tidal mudflats and flying to and from their roosts at dusk and dawn. In Portuguese, the ibis is known as Guará, a word originating from the indigenous Tupi people.

Southern Caracara

This Southern Caracara (Caracara plancus) has just finished gorging on a washed-up carcass. The crop, bulging out through the breast feathers, is used to temporarily store food prior to digestion. Being able to store food like this is all the more important when competing with the local Turkey Vultures (Cathartes aura) and Black Vultures (Coragyps atratus).

team walking in Apeu

The team walks down the main street of Apeu, in Pará. From left to right: Bracken Brown, Onofre Montiero, John Herbert, and David Mizrahi. The trip to this village required a full day of driving on dirt roads followed by an overnight journey by boat.


The Last Days

The breeding bird scene on the Canning River Delta begins to wind down in earnest by the second week of July. Active shorebirds nests dwindle into the single digits, and soon only loons and a few waterfowl nests are all that remain active. Flocks of sandpipers and plovers are seen flying overhead and in the distance skeins of sea ducks can be seen following the coast westward. The Beaufort Sea ice has devolved into bergy bits and rumors of Polar Bears on the barrier islands trickle through the satellite communication waves.

Just like the shifting seasons, life in the Canning camp begins to change as well. Our nest-checking circuits through the study area shorten and the pile of completed nest cards grows. Hours spent nest-searching become hours spent entering data and contemplating the future. Fresh bread and vegetables become a distant memory, replaced by pilot bread and peanut butter. The time has come for the literal scraping of the bottom of the barrel and the redefinition of delicacy. Yes. It is time to throw stuffing mix into a bowl of ramen noodles and eat handfuls of Hall’s throat lozenges for dessert.

What are the last few days of camp really like? Here is a series of photos that help encapsulate what Patches, Alex, and I were up to.


Ever wonder what permafrost looks like? The bluffs along the Beaufort Sea slump in the mid-summer heat, revealing their icy core. The tundra wetlands that Arctic wildlife rely upon sit atop this frozen layer, creating habitats typical of much wetter environments.


One of the fixtures of mid-July at the Canning is waterfowl migration. It all starts with the exodus of males from the breeding grounds, like this flock of White-winged Scoters flying high directly over camp.

One of our final nights through camp, we spotted a medium-sized Caribou herd in the distance headed our way. Alex and I laid low in the tundra mounds and the herd continued in our direction. Turn up the volume and listen to those grunts!


Before anything could get packed up, we had to do a complete inventory of camp, covering everything from the number of tuna cans (60) and rolls of toilet paper (1) to the number of binder clips (75) and tent stakes (200). While doing this, we had to decide which items could stay in camp and which would need to return to Fairbanks for the winter. Then, we assigned each item staying in camp to a bear-proof metal drum that we lined with a thick plastic contractor bag and sealed up with a desiccant. Here Alex takes a break to scan for mammals while getting photobombed by just a few midnight mosquitos.


Spearheaded by the enthusiasm of Patches, we set out to bury two barrels to be used as refrigerators for the 2018 field crew. This is a task that can only be done during mid-summer, when the permafrost has receded enough to allow excavation. Come next spring, the barrels will be locked into the frozen soil. What does that translate to? More cheese!


The final task was to assemble all gear that was remaining in camp into a fortified pile to withstand the Arctic winter blitzkrieg of -50°F temperatures, hurricane force winds, and darkness. How to prepare for such an onslaught? In addition to sealing everything in metal drums, we used wooden planks to elevate everything we could and used two large weather resistant canvas tarps as protection, driving large nails through each grommet. We then used all the rope we had to tie the beast down in every direction.


On the morning of July 17th, I called refuge pilot Dan Shelden in Fairbanks to report a 1,000 ft. cloud ceiling and improving visibility of the Brooks Range. He reported that the weather was suitable for flying on his end. Showtime!  After the four-day scramble to pack up camp, all there was left to do was to drag everything headed back to Fairbanks down to the runway and wait for the sounds of the Cessna 185. This photo shows my personal belongings after I broke down my tent and before I descended to the riverbank landing strip. Dan arrived around 1:00 pm and made two flights to Galbraith Lake ferrying Alex and gear before heading from camp back to Fairbanks with Patches and me on the 3rd and final flight.

Our flight back to Fairbanks took us from our camp on the Arctic coastal plain back south over the Brooks Range and into the boreal forest. To be able to observe this unspoiled wilderness from this perspective is something that will stay with me forever. The rainbow wasn’t bad either!

This project is a partnership between Manomet Inc., the U. S. Fish and Wildlife Service, the Wildlife Conservation Society, the U.S. Geological Survey, and BP Alaska Inc.  Major funding was provided by the National Fish and Wildlife Foundation, and by donors to Manomet.

Arctic Podcast

In this podcast, Alan Kneidel updates us on this year’s Shorebird Science project in the Arctic National Wildlife Refuge, including ongoing nest monitoring as chicks hatch and retrieval of geolocators placed on Dunlin in 2016. For a refresher on this year’s project, check out Shiloh’s first blog post this year which described the GPS tags the crew placed on Semipalmated Sandpiper and Dunlin to help us understand which coastal sites they use for feeding prior to migration and if these include areas where oil from oil spills may concentrate, areas proposed for oil and gas development, and areas currently being used by native communities and industry, as well as how changes caused by climate change and coastal development are affecting shorebirds on the Arctic Coast.

caribou2July began with a large herd of roughly 3,000 Caribou passing through the study area. They are making their way to the windswept coast to seek refuge from biting flies. Photo by Alan Kneidel

cariibousCaribou crossing the slough. Photo by Alan Kneidel

arctic flowersArctic Dryad and Arctic Poppies bloom on the frostboil tundra. Photo by Alan Kneidel

bye metta and shilohShiloh and Metta load up the Cessna 185 on June 30th as they prepare leave camp. Photo by Alan Kneidel

vocal sesaThe tundra in July is full of chattering shorebird parents. Here a Semipalmated Sandpiper communicates with its young to lay low as I pass through the area. Photo by Alan Kneidel

vocal snbuA male Snow Bunting has taken up shop in camp. Here it sings lustily from the top of one of our solar panels. It also likes to sing from the tops of our tents and forages among the rocks on the shore of the slough. Photo by Alan Kneidel

This project is a partnership between Manomet Inc., the U. S. Fish and Wildlife Service, the Wildlife Conservation Society, the U.S. Geological Survey, and BP Alaska Inc.  Major funding was provided by the National Fish and Wildlife Foundation, and by donors to Manomet.