Yellow-headed Blackbird

The Yellow-headed Blackbird resembles the Red-winged Blackbird. Both nest in marshes, both are mostly black with a splash of color, and both have a coarse and metallic sounding call. While similar, the Yellow-headed Blackbird is singular in the absolute frenzy of its call, its yellow head, and its more fine-tuned habitat preferences. Yellow-headed Blackbirds nest in areas with more than 30cm of water, in emergent vegetation and floodplain forests.

Photo by Mick Thompson

Wisconsin is on the edge of the breeding range of the Yellow-headed Blackbird. It is a more western bird, and its range stops abruptly at Lake Michigan. Isolated populations in Wisconsin and northeastern Illinois are of conservation concern since populations here have diminished greatly in recent decades. While the core breeding area shows an increasing population trend, Wisconsin and Illinois show steep declines.

Beyond Breeding Bird Survey data, local lore tells a similar story. A barn along I-94 west of Lake Mills used to have a large fading mural of a yellow-headed blackbird, since replaced with species from a global perspective. A pond along Highway 89 used to be called the blackbird pond, since Yellow-headed Blackbirds nested there, but since conifer plantings crowded the edge of the water, blackbirds can’t see the pothole pond’s enticing features.

Research in Illinois suggests that Yellow-headed Blackbirds have an interesting problem: immigration. In their favor, blackbird nests in Illinois and Wisconsin tend to be productive, and Yellow-headed Blackbirds defend their territories from Red-winged Blackbirds quite well. They have high reproductive output and relatively low mortality, so why is the population declining here?

Juvenile Yellow-headed Blackbird, photo by Arlene Koziol

It appears that juvenile birds are not immigrating to these isolated breeding ranges. There are many spots in southeastern Wisconsin with extensive emergent vegetation, appearing to be very good Yellow-headed Blackbird habitat, but no breeding pairs. I’ve wondered why restored marshes, sloughs, and ponds at Faville Grove don’t have Yellow-headed Blackbirds. They need immigration reform. Juvenile birds have low fidelity to nest sites, so when they migrate in spring, the austere drainage of Illinois and eastern Iowa proves uninviting. Presented with a landscape of parched wetlands, the birds teeter to the northwest, to the core of their range.

Photo by Arlene Koziol

You could find migrating Yellow-headed Blackbirds at Faville Grove, but for a breeding colony you could head to Zeloski Marsh, Rose Lake, Schoeneberg Marsh, or along the Bark River; you can’t miss their song, which sounds like a malfunctioning robot.

Written by Drew Harry, Faville Grove Sanctuary land steward

Cover photo by Arlene Koziol

Foster's Tern

This summer, a great blue heron spent what seemed like its every waking (and sleeping) moment on a wood duck box on the Hwy 89 pond. Every walk around the pond yielded a surprise when a tall figure against the backdrop of prairie, pothole, and aspen turned out to be the heron, again perched on the wood duck box.

There was one instance where this heron departed from its usual routine, as far as we saw it. While the interns and I were on North Shore Road, we witnessed the heron land in the pond. We observed the bird with binoculars for a minute, before it quickly stabbed a bullhead out of the water, gulped it down after a couple of tries, and then returned—where else—to the wood duck box.

In his regular perch. Photo by Drew Harry

I was surprised by the size of the fish in the pond. Yet years past have seen egrets, pelicans, and great blue herons raiding this resource.

I was also surprised, on July 19, when I witnessed a Forster’s tern flying over the 89 pond. This is an endangered bird in Wisconsin that nests in colonies, so my sighting was unlikely to be breeding individual of the immediate area. However, my sighting occurred right around the time when young are fledging, and after this period, parents often disperse more widely to forage for minnows in lakes, rivers, and ponds.

Foster’s tern at Hwy 89 pond. Photo by Drew Harry

In the area of Faville Grove, one nearby location stands out as a potential breeding location for Forster’s terns. The Chub and Mud Lake Riverine Marsh to the north, in Dodge County, covers nearly 7,000 acres of wetland habitat and harbors the appropriate riverine marsh habitat often preferred by Forster’s terns. Portions of this area were never platted during the Public Land Survey, because they were presumed to be a lake. For Wisconsin’s second Breeding Bird Atlas, a number of probable breeding pairs were found in this area.

Faville Grove likely holds wetlands too small and isolated to host breeding Forster’s terns. These birds look for extensive wetland marshes, often nesting on well-concealed islands of vegetation to avoid mammalian predators. Raccoons, skunks, opossums, and weasels, could all decimate the eggs of a colony of Forester’s terns, so nest site selection is key for these birds.

For this reason, only a few colonies in Wisconsin traditionally produce offspring. These areas include Big Muskego Lake, the upriver lakes of the Winnebago Pool, Rush Lake, and the western shore of Green Bay.

It’s interesting to note that many wetlands in the immediate vicinity of Faville Grove contain islands of potential habitat for Forster’s terns. Due perhaps to the unique chemical makeup of these low-lying areas, most boggy lowlands are surrounded by a “moat” of open water, which typically rings the entirety of the wetland.

Wetland “moat” at Faville marsh. Narrow areas of water are likely due to erosion. Native vegetation will replace agricultural field and hold the soil in place in the far upper left of this photo, credit Rob Couey

There are a number of explanations for this moat, including runoff from uplands that increases decomposition and fires running into the edge of the wetland and increasing decomposition. The result is an open island of wetland vegetation with portions dominated sedges and cattails—seemingly perfect habitat for Forster’s terns. Farm field erosion can complicate dynamics of this moat, however. Runoff and siltation from upland areas can fill in this moat, and allow predators to access the island, while also making it more likely that it dries down during summer and fall.

Overall, the Forster’s tern is a chance occurrence at Faville Grove, but we’re happy to support their post-breeding foraging efforts. These birds have migrated through southern Wisconsin at this point, and are likely somewhere in Central or South America. These birds will return in late April, looking for the perfect island of wetland vegetation.

Written by Drew Harry, Faville Grove Sanctuary land steward

Sora

Chris Ribic in 2006 wrote in the Atlas of the Breeding Birds of Wisconsin, “Clap your hands in a wetland or slap your canoe paddle on the water in May or June, and you will likely hear the whinny of North America’s most common rail.” 

Ribic also reported that Wisconsin wetland bird researchers “have found that sora occur in higher densities in cat-tail or bulrush marshes compared to sedge/grass meadows.”  We search for them in shallow water areas.

Range map provided by Cornell Lab of Ornithology

If you are lucky to see this small rail (that weighs less than three ounces) fly, it appears to be a weak flyer and only flies short distances.  But don’t be fooled by this illusion: soras migrate south hundreds of miles to the coastal marshes and central America for the winter. 

The Cornell Lab of Ornithology reports “Their population was stable between 1966 and 2015… they rely on wetland habitat that is dwindling due to urban and agricultural development”.  In Columbia County, we where we are conducting the Breeding Bird Atlas II surveys, we are finding soras in several thousand acres of restored Wetland Reserve Program (WRP) lands.

Columbia County atlasers have been out for the past four nights and are impressed with the number of soras found.  Mark and Brand Smith walked in a large WRP wetland for 1.5 miles from 8:45 p.m. to 10:30 p.m. They stopped seven times and played songs/calls of sora, Virginia rail, least bittern, and American bittern and were rewarded by hearing 22 sora and two American bitterns. Only one sora called before the recording of the call was played. (Click here to read about the “Proper Use of Playback in Birding”.)

Mark and Brand also stopped at two other sites along a road in a sedge meadow and found nine soras and three Virginia rails, all within 100 yards of the stops. 

Sora rail (check out its giant feet!). Photo by Becky Matsubara

We always thought that the best time for surveying for rails was after sunset and before sunrise. However, we learned that they can also call during the day when Brand was surveying for red-shouldered hawks by playing the hawk call and a sora answered. He then switched to calling rails and had replies from 8 Virginia and 11 soras. Impressive, since he was out in the early afternoon.

Our goal is to search the 18 priority atlas blocks in Columbia County for rails and bitters in the next month. Graham searched all the rail habitat (less than five acres) in the Arlington CE block and was lucky to hear a sora that was calling within 100 yards of the interstate.

Mark and Graham recently conducted a waterfowl count at Goose Pond and flushed four sora rails. On May 16, they conducted a rail count on a beautiful spring night with a lot of frogs and toads calling, and two males responded to the calls. They will survey again in a week and if they hear the rails call, the species will be upgraded to “probably nesting” in the Breeding Bird Atlas II project.

We encourage you to check out “rail” wetlands and see what you can find. Two locations in Jefferson County to explore are Zeloski Marsh (purchased by Madison Audubon and donated to the DNR) and Rose Lake/Dorothy Carnes Park (donated to Jefferson County) near Fort Atkinson. Look for shallow waters with cattails, bullrushes, and marshy habitat. You might get lucky enough to hear that magical whinny.

We are always looking for help with the atlas and welcome rail surveyors (goosep@madisonaudubon.org) or you can help with the DNR survey for Secretive Marsh Birds including rails. There are 13 open routes within Madison Audubon’s chapter boundaries.

Written by Mark Martin and Sue Foote-Martin, Goose Pond Sanctuary resident co-managers

Cover photo by Arlene Koziol

Scaup

The term “scaup” refers to both the greater and lesser scaup, and they are very similar in appearance. Greater scaup are about one fifth larger than lesser scaup, and their heads are more round with an iridescent green sheen as opposed to purple of the lesser. A black nail on the tip of the bill is more prominent in greater scaup. Greater scaup breed in the far north on tundra wetlands, while lesser scaup range all the way from western Alaska to Ontario and south to the Dakotas. Of the two, lesser scaup are far more common, and probably make up more than 99% of the scaup counted at Goose Pond.

Greater scaup, photo by Paul Sullivan, FCC

Lesser scaup, photo by Mike Bons

During migration, scaup can gather into massive groups, and they are iconic birds to those who maintain an intimate relationship with large water bodies. In Wisconsin, this means the Mississippi River, Lake Superior, Lake Michigan, Lake Poygan, and Lake Mendota. There is a long and unique history of hunting scaup (or “bluebills” to waterfowlers) on Lake Winnebago. That is not to say, however, that they don’t use smaller habitats scattered through every county in the state. Twenty-five people from Wisconsin Society for Ornithology visited Goose Pond on a field trip to view the migration on March 23. Tom Schultz helped lead the field trip, and he reported seven lesser scaup and a single greater scaup.

Scaup are “diving ducks” which feed in over a foot of water and consume more animal matter, as opposed to ‘“puddle ducks” that skim the water or “tip” feeding mostly on vegetation. Even though row crop fields are terrible habitat for usual diving duck prey species like snails and mussels, scaup can take advantage of waste corn. Scaup banding efforts even bait their swim in traps with corn. The highest scaup concentrations at Goose Pond Sanctuary occur on flooded agricultural fields.

Lesser scaup pair, photo by Richard Armstrong

North American scaup populations have dropped by almost 50% from 8 million birds in 1975 to 4 million 2017 according to the US Fish and Wildlife Service estimates, and the downward trend is continues. Ongoing research spans habitat selection, migratory food preferences, and migration chronology among other important life history events. Hopefully it will reveal the best strategies for conserving this once abundant species.Although there is not a definitive cause, here are a few proposed theories for scaup decline:

Greater scaup hen, photo by Andrew Reding, FCC

Low Hen Survival- The survival of adult breeding hens has been shown to significantly influence population change. This is a well established perspective that spans the waterfowl community. We know it’s important, but data on the major drivers for hen survival is limited. Predation at nesting sites takes a heavy toll on hens, and unlike more reproductively competitive duck species, scaup don’t breed until their second year. This factor is readily visible at Goose Pond; only about 20% of the scaup surveyed were hens.

Contamination- Biomagnification causes higher heavy metal concentrations to build up in predators that feed in contaminated areas. Selenium can result in duckling deformities and poor health. To complicate this issue, recent studies show that scaup have been increasing their dependence on invasive zebra mussels as a food source, which contain more selenium than most of their native counterparts. Selenium enters the environment through mining, industrial manufacturing, and other human influence.

Wetland Loss- Much of the water in Canada and Alaska lies over a solid layer of permafrost. As permafrost melts, surface water is allowed to infiltrate into the ground and the land dries out. Canada is warming at twice the rate of the global average, and wetland loss related to melting permafrost will likely be a major contributor to the decline of scaup and an unknown number of species across biotic groups.

A graph showing the fluctuating presence of scaup, ringnecks, and canvasbacks at Goose Pond Sanctuary.

On March 29, I counted 620 scaup around Goose Pond, a record high count since MAS staff started regular waterfowl surveys started here in 1980. To be fair, the all time high count of 800 scaup was reported by William Hilsenhoff on April 9, 1960. They can presently be seen from Goose Pond Road or Kampen Road at ten yards or less associating with canvasbacks, redheads, and ring-necked ducks. Runoff from snowmelt caused Goose Pond water levels to rise to unprecedented levels, and waterfowl of all kinds are utilizing the flooded landscape for food and rest. Scaup populations are in rough shape, but seeing hundreds of them wheel around Goose Pond sparks optimism for the future of this striking species.

Written by Graham Steinhauer, Goose Pond Sanctuary land steward

Cover photo, lesser scaup by Mike Bons

Marsh Wren

Video/audio by brevardjay (YouTube)

Many visitors to Goose Pond this spring and summer were rewarded by hearing the rich harsh staccato with few pure musical notes of the marsh wrens around the edges of the pond. 

Sam Robbins wrote “In summer this is a “fun bird” to see and hear. You can stand near a cattail marsh before dawn, after dusk, or even in the middle of the night, and hear the delightful rattle of the “long-bill”. Once it is light, you can see considerable activity as the nervous birds move around.”

Marsh wrens, formerly called long-billed marsh wrens, can be confused with sedge wrens. The easiest way to separate the two is by knowing their preferred habitat. Marsh wrens live in deep or shallow cattail or river bulrush marshes while sedge wren nest in sedge meadows and wet to mesic prairies.

Photo by Mick Thompson

Most marsh wren nests are 2–5 feet above the ground and are dome-shaped, with strips of cattail, sedges (bulrush), and grasses woven together. The nest is oblong with a small hole at the top and an enclosed cup at the bottom. The nest is about 7 inches tall and 5 inches wide. Females line the active nests with strips of grass, sedge, cattail down, feathers, and rootlets. Clutches can range between 3-10 brown spotted eggs and the incubation/nesting period is 25 to 31 days long.

A marsh wren nest is well hidden in the cattails. Photo by Graham Steinhauer

Males migrate north before females and build a number of nests in preparation for their arrival. Once the females arrive, the male escorts the lady he is courting to his various nests, putting on quite a display of bowing, bobbing, and showing off his tail and his handiwork. The female selects a mate and she may build her own nest if his nests do not suit her. Together, they defend their nesting territory, and even destroy the eggs and nestlings of other marsh wrens and nesting birds. Males often mate with multiple females in the area (does he take these ladies on the same tour of his collection of nests that the previous female dismissed as inadequate?).

Our goal this year was to confirm marsh wrens nesting at Goose Pond. Wisconsin Department of Natural Resources staff Daryl Christensen and Sumner Matteson found 10 males calling in mid-June while surveying for eared grebes, but unlike some other bird species (like eared grebes), marsh wrens cannot be confirmed by seeing the birds carry nesting material. A pair can build a number of “dummy” nests, and in fact, researchers have found that male marsh wrens may build up to 22 nests!

The first week in July, Goose Pond manager Mark Martin, land steward Graham Steinhauer, and interns Siena Muehlfeld, Tanner Pettit, and Henry Weidmeyer searched for marsh wrens on the north side of the pond. This was a new experience for the interns and they thought it would be easy to confirm nesting for the Breeding Bird Atlas project. It started out strong: six males were found calling in a two-acre area.

Henry, Tanner, and Graham search through river bulrush in knee-deep water on the north side of Goose Pond. The quest: marsh wren nests. Photo by Mark Martin

When the first of 12 nests was found the interns thought that the species was confirmed. Mark mentioned that marsh wrens build many nests, so a confirmed nest has to contain eggs or young. Since one cannot see into the nests, and Mark recommended they gently poke a finger through the entrance hole and see if eggs or young could be felt. At nest #10, Tanner found a nest with 3 eggs – a new confirmed species at Goose Pond! And those six singing marsh wrens? Tanner noted that “nests were always found near singing males.”

The federal breeding bird surveys conducted in the United States from 1966 to 2015 found an increase in marsh wren numbers by 130% and researcher estimated their population at 9.7 million, putting them in to the category of "low conservation concern." However, draining and filling wetlands and marshes could create problems for this species. Conservation Biologist Randy Hoffman said that the largest numbers of marsh wrens in North America is found at Horicon Marsh, which is also the largest cattail marsh in North America.

We are still on the look-out for marsh wren nests, as there's still time for nestlings to grow big and strong enough to make the fall migration to Florida, Texas, New Mexico, Arizona, and Mexico. On July 24, Daryl and Sumner checked on our wetland birds and found six males still calling and observed males carrying bulrush leaves to the arrowhead for constructing nests. Will we have another chance to gently poke our fingers into nests and find more eggs? Stay tuned to find out!

Written by Mark Martin and Susan Foote-Martin, Goose Pond Sanctuary resident managers, and Brenna Marsicek, director of communications

Cover photo by Arlene Koziol