friday feathered feature

Eastern Meadowlark

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Stout and confident, this bird attains reach with its melodic song. From pasture to prairie and back, those inhabiting this grassy world know that song to belong to the eastern meadowlark, as even the star-nosed mole (functionally blind) stops and listens to the meadowlark’s declaration “spring of the year.

An eastern meadowlark sings “spring-of-the-year!” Photo by Pat Ready

An eastern meadowlark sings “spring-of-the-year!” Photo by Pat Ready

A lemon yielded from a leafless gray hickory tree seems quite unlikely, yet every spring the meadowlark makes its way north into Wisconsin where grass will host it, revealing itself as a sweet and tart spring treat, all the way from Blue Mounds to Door County to the Bayfield Peninsula and back.

This bird, not a member of the lark family but rather of the tribe of blackbirds, possesses similar habits in feeding to other blackbirds; the eastern meadowlark will probe its beak into the soil, open the beak, then pick through the open hole for invertebrates. Crickets, grasshoppers, caterpillars, and grubs make up much of the diet during the summer breeding season.

An eastern meadowlark nest, tucked in the grass and litter. Photo by Carolyn Byers

An eastern meadowlark nest, tucked in the grass and litter. Photo by Carolyn Byers

Enjoying large fields and savannas of open grassland, meadowlarks prefer taller vegetation, and are rather choosy about breeding in unburned prairies. This litter accumulation helps conceal the nest from potential predators, and the nest structure becomes a tent that hides the eggs/chicks, and can be quite effective camouflage.

Meadowlarks are among the first species to stake their claim to the recently defrosted Wisconsin landscape, arriving as early as February. Migration south occurs from mid-September through early November, though a handful of meadowlarks have overwintered in Wisconsin in the past decade. On that southern journey, meadowlarks will reside in open areas as far north as central Illinois, but commonly overwinter in the south-central United States.

Here at Faville Grove, I’ve seen just one meadowlark this spring, singing on from the top of the shed on Prairie Lane. The absence of meadowlarks here is curious, given the abundant grassland habitat and large acreage of prairie restorations, which meadowlarks are typically not shy about occupying. Recent sightings from eBird, as of 4/26/19, show the relative absence of meadowlarks in the centrally located area.

eBird shows observations of eastern meadowlarks to be pretty sparse in the Faville Grove area.

eBird shows observations of eastern meadowlarks to be pretty sparse in the Faville Grove area.

Significant population declines have occurred since the 1960’s, according to data from the National Breeding Bird Survey. Changes in agricultural practices have had major impacts on many grassland birds, including meadowlarks. Increased haying destroys nests, conversion from grass hay fields to alfalfa degrades habitat, and conversion of pastured areas to row crops eliminates habitat entirely. It’s possible that the intensity of agriculture and development north of Lake Koshkonong has considerably degraded habitat for meadowlarks. In any case, growing areas of prairie restoration at Faville Grove should provide ample breeding habitat, and we hope to see more meadowlarks in the future.

Written by Drew Harry, Faville Grove Sanctuary land steward

Header photo by Arlene Koziol

Common Loon

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One of the most iconic species of summer in the northern forest, the common loon beckons admiration, from wooden carvings, gift shop trinkets, ring tones, and paintings. For those spending a vacation around a campfire in northern Wisconsin, loons lay the soundtrack in equal parts to the campfire.

In fact, I think the distribution of common loon breeding in northern Wisconsin is a good approximation for the southern limits of “up north.”

Rough approximation of “up north” based on common loon breeding range in Wisconsin. Image courtesy of eBird

Rough approximation of “up north” based on common loon breeding range in Wisconsin. Image courtesy of eBird

The Journal Sentinel has developed a map where you can draw your own line for where “up north” is located; most agree, it follows a line a little north of Green Bay west to about Chippewa Falls.

Over the course of the year, loons will move through southern Wisconsin, typically occupying larger bodies of water along the way. Lake Mendota in Madison and Rock Lake in Lake Mills are two excellent spots to view the common loon right now as it migrates through the area.

Colorful common loon on Lake Monona, April 4, 2019. Photo by Pat Ready

Colorful common loon on Lake Monona, April 4, 2019. Photo by Pat Ready

Lake Monona loon, april 4, 2019. Photo by Pat Ready

Lake Monona loon, april 4, 2019. Photo by Pat Ready

During migration, loons with tracking devices have been recorded on dives of 174 feet.  If you see any loons on Lake Mendota this spring, imagine the deep hole between Picnic Point and Maple Bluff. That’s 82 feet deep, so loons can dive to depths of more than two Lake Mendota’s!

Listen to the calls of the common loon, and watch how it deftly dives and swims underwater. Video by BR Valley.

Historical accounts indicate that loons did nest in parts of southern Wisconsin. A number of factors conspired to limit the loon’s range to the northern expanse of Wisconsin, including wetland loss and degradation, mercury bioaccumulation, and lead poisoning.

Loons nest within a few feet of the water, and wetlands at the edge of lakes are critical to nesting success. A common spot for loon nests is on the floating sphagnum mat at the edge of relatively acidic lakes in northern Wisconsin. Unfortunately for loons, lakefront development can negatively impact the ability to nest.

Good habitat on a sphagnum mat, inset: no habitat. Photo courtesy of Mike Meyer, “Twenty Four Years of Common Loon Research in Wisconsin”

Good habitat on a sphagnum mat, inset: no habitat. Photo courtesy of Mike Meyer, “Twenty Four Years of Common Loon Research in Wisconsin”

Researchers have found that development of housing greater than 25 buildings per kilometer of shoreline prevents loons from nesting in the area. Housing development usually leads to the degradation or elimination of wetland habitat along shorelines.  It doesn’t need to be this way. Many alternatives to a barren lawn exist that beautify the yard and add habitat for wildlife, and protect the erosion into the lake.  You can find numerous excellent examples here.

The map below is from the USDA Forest Service’s North Central Research Station and shows how housing density has increased in northern Wisconsin since 1940.

Image from  Wisconsin’s Land Legacy Report

Image from Wisconsin’s Land Legacy Report

Having the pleasure of loons on your lake can come with a number of responsibilities. Known nesting sites should not be disturbed during the summer. If there are known nesting sites, efforts should be made to reduce wake in those areas. Additionally, lead fishing tackle contributes to significant mortality each season. In Minnesota, one study found that 15-20% of dead loons had lead poisoning. Using non-lead alternatives is good for loons and the whole ecosystem. One of the biggest items on Wisconsin’s Conservation Congress hearings this past week was a ban on lead tackle and ammunition. This would have positive impacts for the loon population, and it is estimated that a lead ban would save over 50 loons in Wisconsin each year.

An issue outside of a loon enthusiast’s direct control is the emission of mercury from coal-generated power plants. As stated before, loons are sensitive to the bioaccumulation of methyl mercury because they are high in the food chain, long lived, fish-eaters, and nest on acidic lakes, which tend to have higher availability of mercury to move up the food chain (pictured below).

As pH decreases (becomes more acidic) mercury concentrations increase in both adults and chicks of common loons. Graph courtesy of Mike Meyer, “Twenty Four Years of Common Loon Research in Wisconsin”

As pH decreases (becomes more acidic) mercury concentrations increase in both adults and chicks of common loons. Graph courtesy of Mike Meyer, “Twenty Four Years of Common Loon Research in Wisconsin”

A new EPA proposal would roll back some limits on emissions of mercury for coal-burning power plants. This could have a huge effect on public health, and different accounting estimates calculate the potential indirect benefit of saving thousands of lives due to the “co-benefit” of also decreasing particulate matter linked to lung and heart disease. In Wisconsin, coal-burning power plants have been granted exceptions for mercury emissions. Beyond public health, mercury for loons spells trouble. 

As mercury increases, hatching rates decrease beyond a sustainable number. With high mercury concentrations in the food chain, adults become lethargic and might not reproduce at all. This decreases the likelihood of success for the common loon, which already faces difficult enough odds on its breeding grounds where approximately 50% of nests fail, due to predation, flooding, or other causes.

Another twist might occur as the climate continues to change. With flooding more likely, the amount of mercury in aquatic systems may also increase. Research from UW-Madison’s Center for Limnology has found an interesting correlation between annual water levels and the concentration of mercury in walleye. You can see that interesting blog post here. With flooding and high water levels, loons may be even more susceptible to mercury bioaccumulation.

While fragile, the outlook for loons in Wisconsin is rather positive. Since 1980, the population has nearly doubled and continues to increase. If you’re able to help, you can sign up for Northland College’s Loonwatch, which aids research in a number of areas.

Written by Drew Harry, Faville Grove Sanctuary land steward

Cover photo by Arlene Koziol

Sources

Stewart, S. I., Hammer, R.B., Radeloff, V.C., Dwyer, J.F., & Voss P.R. 2003. Mapping Housing Density across the North Central U.S., 1940-2000 [Slide show]. Available: http://www.ncrs.fs.fed.us/IntegratedPrograms/lc/pop/hd/title.htm

Meyer, Mike. "Twenty Four Years of Common Loon Research in Wisconsin." Microsoft PowerPoint file. Accessed here.

Scaup

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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

Greater scaup, photo by Paul Sullivan, FCC

Lesser scaup, photo by    Mike Bons

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

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

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.

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

Tundra Swan

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I first knew swans to be nasty things. A mute swan on a neighborhood pond would lunge at me when I got too near, and the popular depiction of swans as graceful elegant birds for me morphed into a fear of their hissing aggressiveness.

Tundra swans, meanwhile, are beautiful Holarctic migrants, moving through Wisconsin each spring and fall in large flocks, often associating with diving ducks like canvasbacks and redheads. These diving ducks will access tubers and grain in the bottoms of ponds and flooded ponds, while the swans can do the same with their long necks.

Tundra swans can be identified by their all white feathers, their black bill, and  a yellow spot on the lores. The birds will typically form pair bonds for life, and can live to be over 20 years old.

Unlike the non-native and stocked mute swan, which often sits solitary on a residential pond, the tundra swans congregate in great flocks of thousands of birds. In spring, these birds are moving from their wintering grounds on the Chesapeake Bay to breeding habitat on the Arctic Circle. 

Photos by Drew Harry

In the past week, a flooded field north of Faville Grove Sanctuary has been occupied by over 1,000 tundra swans and thousands of waterfowl including northern pintails, canvasbacks, redheads, scaup, mallards, northern shovelers, and ring-necked ducks. These huge migratory flocks tend to be uncommon at Faville Grove, since there are not any huge open water wetlands within the sanctuary. However, a wet start to spring has provided excellent habitat for migrating waterfowl in these flooded fields.

It’s not hard to appreciate the huge flocks of birds, especially the large and alluring tundra swans, as they make their way on an 1,800 mile journey to the north.

Written by Drew Harry, Faville Grove Sanctuary land steward

Cover photo by Monica Hall

Crows, and Blue Jays, and West Nile, oh my

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For some people, American crows and blue jays are considered the bullies of the avian world. In Wisconsin, a hunting season on crows was established to deal with their overpopulation in urban areas where they and their noisy blue jay buddies cause problems. But a friend who lives in Illinois shared that he has noticed that crow population has greatly declined, and he wondered what was causing it.

Could this decline in corvid numbers be caused by the West Nile virus (WNV), a disease that has been a factor in the decline of birds for some time? We looked at population trends of these two species by examining data from our citizen science project, the Poynette Christmas Bird Count, to learn a little more about WNV and the impacts on crows and blue jays in the area. We also looked at recent statistics of the Center for Disease Control (CDC), recent articles written on the subject, and the work of other agencies that are associated with WNV.

Photo by Eric Begin

Photo by Eric Begin

The CDC states that “West Nile virus has been detected in a variety of bird species. Some infected birds, especially crows and jays, are known to get sick and die from the infection.” The DNR also follows this virus and its effect on wildlife, and the USGS Wildlife Health Center in Madison has been studying this virus for decades in an attempt to find a way counter WNV.

The Wisconsin Division of Public Health states “WNV is an arbovirus that is transmitted by a bite of an infected mosquito. West Nile virus (WNV), which has been widespread in Africa, southern Europe, the Middle East and western Asia, first appeared in the New York City area of the United States in 1999. The first human cases of WNV in Wisconsin appeared in 2002. Few mosquitoes actually carry the virus.”

In nature, mosquitoes become infected by feeding on infected birds and can transmit the virus to other animals, birds, and humans. The Wisconsin Division of Public Health monitors dead birds for WNV as an early warning system to indicate that the virus may be present in an area. “This information is important to heighten awareness in the prevention and control of WNV disease.”

The number of dead bird cases per year where WNV was the cause of mortality.

The number of dead bird cases per year where WNV was the cause of mortality.

From 2004 Laura Erickson’s For the Birds Radio Program: West Nile Virus: Crows dealing with grief

“Now that it’s October, West Nile Virus is once again rearing its ugly head. Since the disease first appeared in America in 1999, 625 people have died from the disease. So far this year, the human death toll is 59, including 2 in Minnesota and 1 in Wisconsin.

As bad as West Nile Virus is for humans, it’s even worse for birds. Most of us have probably already been exposed to the virus and developed immunity. Fewer than 5% of people who are infected with the virus get sick at all, and of them, most get only minor flu symptoms. The people most vulnerable are those with immune system deficiencies, and so it’s very important to protect ourselves and especially the very old and the very young and people who’ve been sick from mosquito bites. We can go to a store and buy repellants, and we live in houses that can be fairly effectively closed off from insects.

Birds are helpless to defend themselves against biting insects, and are far more vulnerable to this disease than we are. 99 – 100% of all crows exposed to the virus not only get sick—they die. Great Horned Owls, Red-tailed Hawks, Blue Jays, and chickadees are other species that are extremely susceptible to the disease.

A crow in flight, photo by Arlene Koziol

A crow in flight, photo by Arlene Koziol

American Crow counts fell to a 15-year low in the Midwest on Christmas Bird Counts for 2002-2003, and in Ithaca, New York, where the disease first appeared in 1999, the crow population has been decimated. That particular local crow population has been under close scrutiny since 1988 by Kevin McGowan of the Cornell Laboratory of Ornithology and his students, who have marked as many as a thousand individual crows and keep track of each bird as an individual. Crows are extraordinarily intelligent and sociable, and family units remain together for a long time, with young birds typically helping their parents raise new broods for a few years before they find a mate and start their own families. But in 2002, fully a third of McGowan’s study birds were found dead from West Nile Virus, and last year another third died. McGowan likens the impact on crows to the effect the Black Death had on humans. Crows don’t abandon their family members as they die—McGowan says that at least one crow always remains with a dying bird. In one family unit of 8 birds, all but 2 have died from the disease, and the surviving females have joined other family units and help them raise their babies. Orphaned fledgling crows have been adopted by other crows. Widowed adults are moving back in with their parents. Crows apparently can’t live alone, and even pairs won’t nest without a whole group, which will slow the speed at which the survivors will repopulate the area. Many people don’t like crows, the most human-like of all birds with their complex language and social behaviors and intelligence. But our measure as human beings is related to how much compassion we have for all the creatures on this little planet.”

Average number of individual crow and blue jays counted during the Poynette Christmas Bird County

Average number of individual crow and blue jays counted during the Poynette Christmas Bird County

These tables provide us with rough ideas of American crow and blue jay numbers for our area in late December for the past 39 years of the Poynette Christmas Bird Count.

One can see that there is a lot of difference between highs and lows with the number of dead birds reported to the health Department and also in Poynette CBC data. Crows fluctuated between 215 to 1,293 while blue jay numbers fluctuated between 123 and 586. It is impressive in the past 39 years that our Christmas bird counters tallied 29,300 crows and 12,700 blue jays. Overall, without a lot of statistical data, it appears that our crow and blue jay populations have not been greatly impacted by WNV.

Photo by Kelly Colgan Azar

Photo by Kelly Colgan Azar

A crow calling in the distance was the first bird heard this morning from the house. The first report on the breeding bird atlas this week was a crow carrying nesting materials. We are ready for spring to resume the work of the breeding bird atlas by recording species of crows and blue jays. We wonder if warming temperatures that accompany climate change affect mosquito populations and result in an increase of WNV.

Thanks to Laura Erickson who spoke at the 50th anniversary celebration for Goose Pond Sanctuary for her information on crows and WNV.

Written by Mark Martin and Sue Foote-Martin, Goose Pond Sanctuary resident managers, and Graham Steinhauer, Goose Pond Sanctuary land steward