Speed Birding: Whimbrel Capture: Week One, April 23-28

On friday morning (April 23), Alex and I set out for Virginia to start our new job tracking whimbrel, which we would start saturday afternoon. We didn't have very many birds along the way, and our red-tail count was less than ten. Near Waynesboro, PA, we picked up chimney swifts, a new year bird. As soon as we got near Hampton, VA, we saw three bald eagles chasing eachother in the air. Our destination (before heading to Cape Charles, VA) was the Great Dismal Swamp NWR, which is a huge wildlife refuge in south eastern Virginia and northern North Carolina. Here, birders had been seeing many new spring warblers, including Swainson's warblers and prothonotary warblers. We got there a little late in the day, but did find a few prothonotary and prairie warblers, in addition to yellow-rumped, common yellowthroat, and yellow-throated warblers. Prothonotary warblers are large bright yellow warblers that are unmistakable in the field, and were a lifer for Alex and I.

prothonotary warbler

More numerous than the warblers however were at least 13 species of butterfly. Palamedes swallowtail and tiger swallowtail flew by periodically as we were trying to photograph the smaller, quicker butterflies. These included easter-tailed blue, pearl crescent, Horace's duskywing, and spring azure. At the trailhead on Jericho ditch, there was a "butterfly bar," or a collection of feeding butterflies. This included black, tiger, Palamedes, and zebra swallowtail. There were at least 50 butterfly on the bar and many, many more in the air around the parking lot. Other butterflies included great spangled fritillary, clouded sulfur, cabbage white, Carolina satyr, Henry's elfin, and southern pearly eye, the last three all being new butterflies for us. On the trail near Jericho Ditch, Alex spotted a ruby throated hummingbird, a FOY bird for me. There was also a group of great-crested flycatchers in the area, anotehr FOY bird for both of us. We also birded Washington Ditch, where I was greeted by nothing but angry mosquitos and horseflies. An eastern comma was perched on the boardwalk, looking exactly like a leaf in the dark and damp woods, but I decided to run back to the car to escape the bugs instead of photographing it. Dismal swamp is an excellent name for this place.....apparently in the summer, you can find many species of venemous snakes here, in addition to a large population of black bears, and many, many more bugs. We also found a bobolink sitting on a powerline near the refuge, another FOY bird.

zebra swallowtail

Horace's duskywing

regal darner

Carolina satyr

Horace's duskywing

Henry's elfin

southern pearly-eye

butterfly "bar"

zebra swallowtail

tiger swallowtail

Palamede's swallowtail

broad-headed skink

FOY ruby-throated hummingbird

FOY bobolink

Our next destination was Virginia Beach. There was a large movement of migrating brown pelicans, in addition to many double-crested cormorants. Out at sea, we saw a good number of Northern gannets and caspian terns. There weren't any waterfowl anywhere, though. We also stopped along the Chesapeke Bay Bridge Tunnel (CBBT) to look for birds, but didn't see anything but ring-billed, herring, laughing, and black-backed gulls.

The first island you reach after cross the CBBT is Fisherman Island, which contains Fisherman Island NWR (cloesd to the public). As soon as we got on the island, Alex spotted a very dark merlin fly across the road. We drove through the island, and quickly arrived at our destination, the Eastern Shore of Virginia National Wildlife Refuge, which is where we will be living until June 5. We met our co-worker Amy, who is one of the two red-knot resighting field technicians. In the morning, the three of us went birding on the refuge, and found wood duck and blue-winged teal on a refuge pond. Apparently a common teal has been around the refuge, but we didn't see it. We also flushed a snipe in a small marsh. All around the boat ramp we could hear clapper rails, but couldn’t see any. Greater yellowlegs and two green heron were in the marsh as well, in addition to a few common yellowthroats. Also by the water’s edge was on osprey nest with an incubating female. On a refuge trail, we spotted a few blue-grey gnatcatchers, prairie and pine warblers, Carolina wren, and cedar waxwings. In a shrub/scrub field we heard a few bobwhites, and flushed them upon walking in. On our way home we found a cottontail that was absolutely covered in ticks. Ticks are VERY abundant here and I wouldn’t venture into the woods if someone paid me to, especially after seeing that rabbit.

Later in the day, our boss Fletcher Smith arrived. We put some whimbrel trapping nets into the van and drove to Box Tree Marsh, where most of the whimbrels in past years have been caught. Here we set up two rocket nets, which consist of a huge net attached to three rockets, with the net stuffed into a large, heavy box. The rockets are launched off the top when the charge is set, sending the net out over the foraging whimbrel (and any other birds that happen to be there). Weights hold the other end of the net down. The whole box/net setup is placed on a small table so that the high tide doesn't get it wet. There were about 100 whimbrel in the vicinity, but none looked interested in the foraging area around our boxes. The nets are all placed in areas that are the last to be flooded by high tide, and act as a retreat for the whimbrels and a last place to forage before they must find more suitable high ground.

Alex setting the blasting wire to a rocket net

rocket net camoflagued with rack

Other common birds around Box tree include laughing and herring gulls, Forster’s terns, dunlin, black-bellied plover, spotted sandpiper, willet, and clapper rails. At high tide, a few rails can usually be seen running, swimming, or flying as their marshy homes become temporarily flooded. Clapper rail was a FOY bird for us, when Amy flushed one from the marsh.

Finally for the day, while standing around the yard in the evening, Fletcher pointed out a Chuck Will’s Widow flying by, eating insects. This was another lifer for Alex and I. Amy had heard one that morning, but we had assumed it would be a whippoorwill. Hopefully we see more this month on the refuge, as I only saw it for about .2 seconds. (Update-saw two this morning in the road on the refuge! Likely a nesting pair)

On Sunday, all of us, including Tom, the second red-knot field technician, went to Box Tree to see if the nets made it through high tide, which has been late in the evening. We are approaching a full moon, so the tides are higher and more dramatic each day. All of the boxes were dry. We then headed out to a huge mudflat where many shorebirds were foraging. There were around 100-150 whimbrels in sight, pecking away at fiddler crabs, which make up the bulk of their diet right now. One bird was tagged with a green flag, but was too far away to be able to read the three letter code on it. This bird was tagged by Fletcher in the vicinity some time in the last two years. We set up another net, and waited for some whimbrel to come in, but again, none looked interested. Many were just coming in from migration though, and joining the other birds on roost, as the primary foraging mud flat became submerged under water. This is the pattern lately, as the high tides are occurring later and later in the day. This occurs so close to roost that the whimbrel decide to fly to roost instead of the trap sites.

On sunday night we went out during an extremely high tide to capture saltmarsh sharp-tailed sparrows, Nelson's sharp-tailed sparrows, and seaside sparrows. Fletcher led a team over the winter and trapped many over the season. We caught 15, mostly Nelson's sharp-tailed sparrows. Most of the birds were recaptures from the winter season. During high tides, the sparrows retreat to the vegetation that is not under water. During this extremely high tide, this habitat was limited, allowing us push them to the edge of the water, then flush them towards the nets. Also, because the tide was unusually high, many rails were taking refuge on these islands of vegetation, and got pushed out onto tiny peninsulas as the tide rose, allowing a rare opportunity to see a clapper rail for more than 5 seconds!

sparrows hitting the mist net after being flushed

Alex holding a Nelson's sharp-tailed sparrow

Saltmarsh sharp-tailed sparrow in molt

seaside sparrow

Alex flushed 7 sparrows off this island of vegetation

On Monday, Amy and Tom headed out on their boat to begin looking for red-knots. They didn’t find any on Monday or Tuesday, but Fletcher predicts they will be here by Friday with a southwest wind. Fletcher and I headed back out to Box Tree, and Alex left early in the morning to head back to school to finish his final exams. The tide got one net wet, so we pulled it in. We left two nets out, but didn’t have much hope they would stay dry for the next high tide. Out on the flats, there were at least 200 whimbrel foraging on both sides. There were also black-bellied and semi-palmated plover, in addition to dunlin and willet foraging with them. We spotted two flagged birds, but with a looming fog, we couldn’t read the bands. We watched as small groups of whimbrel got up with the high tide, and moved inland a few hundred meters to a small mud flat not yet covered by the tide. Most however, were flying to roost. At least 40-50 circled the marsh, looking for another suitable place to land, just out of view of our traps. We scoped a potential trap area where a few whimbrel jumped to and spent time if our other trap sites fail us. We waited by our other trap sites in the boat, as small groups of whimbrel appeared out of the fog and really out of nowhere, but from the south. We assume these birds were just coming in from a long migration. A few took interest in our trap sites, but the tide was rising too quickly to make a successful catch.

On Tuesday morning, I took a stab at making some whimbrel flagged bands at the house. The bands come as flat pieces of green plastic with a three letter code engraved on them. After the ink is soaked off, the bands are dipped in boiling water for a few seconds to make them malleable. The bands can then be bent around the right size drill bit and clamped so that they form a flag on the end of a round band. Once the right shape is achieved, the band is dipped in boiling water again to set the shape and then cold water to stop the heating. This is easier said than done...I'm glad I don't get paid by the number of bands I can make an hour.
After this, Fletcher and I went back out to Box Tree to check the nets before high tide. Both nets we left out were wet with the extremely high tide, and had to be pulled out to dry. Being that it was still low tide, this was a muddy task with the banks of the channel very soft. We also lost one table (that the net boxes sit on) to the high tide, when the net box was pushed off by the water. We didn’t have any opportunities to trap whimbrel; they seemed to sense the approaching rain storm and apparently flew to roost early, skipping the normal foraging session on the flats. By 5:00 pm, radar was showing the approaching storm the whimbrel predicted, so we decided to pull the nets and call it a night. The highlight this day was a clapper rail that quickly ran to the edge of the water, took a ten second bath, then quickly snuck back in the cover of the spartina.

clapper rail taking a bath

clapper making a quick appearance

whimbrel food: fiddler crab...can be seen all around Box Tree marsh

This morning, the wind was too strong for Amy and Tom to go out and look for red-knots, so they joined us at Box Tree. We got there by 6:00 am and put out three nets. Eventually, a few hundred whimbrel started coming in small flocks. We were waiting by the charge box to set the charge, when about 17 whimbrel flew in to the trap area known as the point. This was a few too many to catch at once (ideally you want no more than 10), so we waited for the group to spread out over the bank. Eventually they did, and four were in site to be trapped. Tom set the charge, and the net flew out, trapping 3 whimbrel and one common tern.

The common tern and one whimbrel were easy to extract (I got to extract the common tern, a lifer), but two whimbrel had been pushed into the water and got pretty tangled. Fletcher got them out though, and we gave all three flagged green bands, a yellow leg band, a USFWS metal band, and a small radio transmitter, which we glued to their backs (will fall off in a little over a month). It was satisfying to finally catch a few after almost a week of moving boxes around and a few missed opportunities! Tomorrow we will go out early again, and after the full moon tomorrow, the high tides should begin to recede and not be so dramatic. FOY birds today were gull-billed tern and Marbled godwit, and a potential Hudsonian godwit that made a quick appearance (a little too quick to add to the year list).