Chestnut-sided Warbler

Photo by Jeff Bryant

The chestnut-sided warbler, decorated as it is with chestnut-streaked flanks, almost resembles an oak leaf. Indeed, in southern Wisconsin the breast of a chestnut-sided warbler could very well extend from a cured black oak leaf—a potential spot for finding this warbler during the breeding season.

I love the appearance of a chestnut-sided warbler: with its yellow cap it declares its warbler-ness while its messy chestnut streak resembles spilled coffee down its side. Likewise endearing is its call—the mnemonic I've come up with is “choo choo choo god-bless-you!” Unlike the eastern towhee which admonishes you to “drink your tea,” or the yellow warbler (which can have a confusingly similar song) in its braggadocios endowment of itself as “sweet, sweet, sweeter than sweet,” the chestnut-sided warbler sneezes and humbly excuses itself.  

There's more to that song than the trivial way a human remembers it, however. Ending the chestnut-sided's song is either an accented or unaccented syllable. When the accent is used, the male is attempting to attract a mate, while the unaccented song is employed for territory defense when other males are around. So, we have some idea of the language of the chestnut-sided warbler: if he's on a nest, you might expect to hear the territorial song (unaccented) while his accented ending may mean he's still looking for a mate.

Photo by Arlene Koziol

Further research into chestnut-sided warbler song has revealed that certain songs are associated with greater reproductive success. It turns out, in chestnut-sided warblers, high-pitched and steady wins the race. Males who sing with a high and steady pitch and consistent timing are more likely to have a successful breeding season. If you hear a chestnut-sided warbler in the woods that's mapping new vocal territory with each song, it's not as likely that a female will choose this variable warbler.

When I've encountered chestnut-sided warblers it's been in oak barrens areas in northeastern Wisconsin, where the bird is common north of Marathon County. It's uncommon in central Wisconsin, and a rare breeder in southern Wisconsin where I've seen it in regenerating oak scrub in the southern Kettle Moraine. While this bird's preferred habitat is rather rare in Wisconsin (oak savanna and barrens), the advent of large-scale logging operations proved a great benefit to chestnut-sided warbler populations. These birds will readily occupy cut-over land, and as such they have a secure population in northern Wisconsin.

Written by Drew Harry, Faville Grove Sanctuary land steward

Banner photo by Arlene Koziol

The 2019 Great Backyard Bird Count in a Tough Winter

The 2019 Great Backyard Bird Count in a Tough Winter

We always look forward to participating in the Great Backyard Bird Count (GBBC). This year we kept close watch at the bird feeders at both Madison Audubon residences at Goose Pond Sanctuary on Monday, February 18, the last of the four-day time period. The Martins also counted birds at feeders at their cabin (Wildland) north of Rio in Columbia County on Sunday, February 17.

The GBBC gives us a snapshot of bird usage at our feeders in late winter. Despite the name, birds can also be counted and reported from anywhere, not just backyards. Nine of the 14 species observed at three feeders were in the top 10 species recorded world-wide in 2018 (see spreadsheet below).

Factors contributing to the higher species count and higher number of individuals included more diverse the habitat, the number and types of feeders, and the variety of seeds present.  We find that the best seeds for us are black-oil sunflowers, medium sunflower chips, white millet, and suet. This year our sunflower chip feeders were new Wild Birds Unlimited Eco-clean feeders, which reduce disease transmission when birds congregate in high densities. 

On Thursday afternoon, February 21, GBBC reports were still being entered but at that time, world-wide totals included 178,200 (160,000 in 2017) checklists, 6,293 (6,031) species, and 28,700, 000 (25,300,000) birds counted as part of the event. This is an impressive number that reflects the amount of people interested in birds, and more people participated this year than last. In Wisconsin, bird watchers submitted 2,454 (2,400) checklists and reported 115 (121) species.

Last year we had good numbers of common redpolls and pine siskins, which are very uncommon this year in southern Wisconsin. The eight turkeys at the Wildland cabin were feeding on sunflowers at the bird feeders and on apples in the orchard. The Goose Pond wildlife food plot of sorghum and sunflowers is helping 250 tree sparrows and 25 ring-necked pheasants make it through the winter.

Shelter is another critical need for birds in the winter. The Kampen Road residence contains an “old growth” Norway spruce windbreak and mature pines, and spruces on the neighbor’s land at the Martin’s cabin provide birds with ideal winter roosting cover. Nine years ago at the Kampen Road residence we planted Norway spruce, white cedar, red osier dogwoods, apples and crab apples. These plantings offer additional cover and also serve as a windbreak.

The Kamepn Road residence windbreak offers important shelter for birds and other wildlife. Photo by Mark Martin

We are planning on planting more woody species this year and encourage others to provide habitat around their residences.  In addition to creating cover for the birds, the trees help stop the wind and reduced energy costs.

Thanks to everyone that feed birds already. If you live in suitable habitat we encourage you to start feeding them as well. A friend mentioned the importance of feeding the birds and asked us “how would you like to go to the store in winter and find the shelves empty.” The color and variety of species brighten our winter days, and make us feel good knowing that we can provide them with quality habitats and nutritious food.

The winter weather has been tough on other birds as well. On Wednesday January 30, Jerry Schulz who works at the UW Arlington Research Farms was driving on Goose Pond Road when he saw an eagle in the road "jumping up and down" close to the Manthe farm. As he approached he could see an adult eagle, and it appeared the eagle had just killed a snowy owl. The adult eagle flushed carrying the owl. That day felt like the arctic with a low of - 30 degrees and a high of -12 with -50 wind chill. Snowy owls can withstand the weather, but we have no idea why the eagle was able to take the owl or why the owl was in this location. It is possible that the owl had been hit by a vehicle or had health problems. It is sad to lose one of our feathered friends, and very surprising to learn of this report.

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

Cedar Waxwing

This medium-sized marauder pillages from a variety of sources, all with one commonality: hackberries, winterberries, nannyberries, elderberries, black cherries, serviceberries, strawberries, raspberries, blackberries. Berries!

Of course, one of the most important berries in the diet of this bird is the juniper berry, from cedar trees. Cedar waxwings flock to these trees in winter. The two burly cedars in front of my house on Prairie Lane provide winter supplies to hungry waxwings and robins, but the tree also has its own interests at heart; juniper berries that have been ingested by waxwings germinate at a much higher rate than those that haven't passed through the bird, and 1.5-3.5 times as many of those seeds will germinate.

Cedar waxwing, photo by Kelly Colgan Azar

A frugivore, the diet of the cedar waxwing provides fascinating insight into seed dispersal and phenology. For instance, one study of waxwing diets analyzed their relationship with highbush cranberry, a native shrub. The red berries of this bush almost always remain on the bush through winter, and researchers supposed the waxwings consumed these fruits in April and May the next year because of higher sugar concentrations. However, when captive waxwings were given a choice between the fresher winter berries and next year's sugar-concentrated berries, the birds almost always chose the winter berries.

From this same research, observations in the field indicated that waxwings that consumed highbush cranberry in April or May complemented this meal with catkin pollen from cottonwood trees. In the lab, diets of cranberry or catkin alone caused the waxwings to lose mass, while a combination diet saw a gain in body mass. While the cranberry presents a rich source of carbohydrates, the cottonwood pollen offers high protein.

Highbush cranberry, photo by Barbara Gail Lewis, FCC

With a diet of only cranberry, waxwings saw nitrogen losses in their diets; secondary compounds in the cranberry make it very acidic, and in order to process this acidity waxwings had to catabolize protein to produce a bicarbonate buffer, according to researchers. The protein from the pollen offset these losses.

All of this is to say that the waxwings eat a well-balanced diet. While their dietary choices may seem like the whims of the flock, the menu of a cedar waxwing has important ecological implications for seed dispersal and for the bird's overall health.

In addition, berries amount to a sort of social currency in cedar waxwings. These birds exhibit delayed plumage maturation, where the tips of their secondaries turn a waxy red color. The length and vibrancy of this color is diet-related—waxwings consuming the invasive honeysuckle (with an orange berry) will develop orange tips. In a study of the reproductive success of waxwings, it was discovered that males and females with similar tips would mate. Those pairs with longer tips nested earlier and had larger broods and fledged more young than those pairs that were younger, with shorter waxy tips.

This is a bird that revolves around berries. From overall health to seed dispersal throughout the ecosystem to social status, berries make the bird, and the birds certainly help disperse the trees and shrubs that make the berries. You can find these interesting flocks at Faville Grove around any fruiting trees and shrubs.

Written by Drew Harry, Faville Grove Sanctuary land steward

Cover photo by Kelly Colgan Azar

American Bittern

Some birds, so very bird-like in appearance, become mixed up in the particulars of being a bird. Do the auriculars have a dark spot on the rear; is there a white median crown-stripe like in the grasshopper sparrow? Other birds, so very bird-like in sound, become mixed up in the minutiae of sounding like a bird. Was that a Cape May warbler singing or another bird in its flight call?

The American bittern, however, is a singular bird, rivaled in appearance only by the least bittern—whose descriptor eliminates it from competition—and unmatched with its weird and enchanting call.

Photo by Arlene Koziol

Looking like a great blue heron that has been squashed into a frame less than a meter tall, the American bittern can be recognized by its squat build, its long stocky neck, and its streaking brown colors along the body. The bird appears to be a shorter cousin of the great blue heron that spends more time in the weight room—squatting and leg pressing, with special attention paid to neck rolls.  

This is a bird rarely seen but more often heard. If seen, the bittern stands vertical and slightly sways with the breeze, becoming uniform with the marsh and cattail environs which it inhabits.

Hearing an American bittern is a special treat. It sounds like the beginning of some strange underwater symphony, a resonant and liquid noise that, to the uninitiated sounds more frog-like. These low frequency calls carry farther than higher pitched calls through dense marsh vegetation, thus enabling males and females to locate one another.

Their interesting and adaptable diet includes: fish, insects, crustaceans, amphibians, reptiles, and small mammals. The birds often sit rigidly still and slowly lower their bill until they suddenly strike the water, swallowing prey with a gulp.

Bitterns inhabit marshlands with cattails, reeds, and sedges. Nesting takes place in these dense marshy areas but can also occur on dry land in grasslands. Because of its crepuscular (active at twilight) and concealed habits, the American bittern is difficult to survey. Wisconsin's second Breeding Bird Atlas has few breeding confirmations, with the bird being uncommon throughout the state.

Photo by Arlene Koziol

At Faville Grove, American bitterns are occasionally seen or heard, and just this week I was lucky enough to see a bird on the Kettle Pond as it stalked awkwardly through arrowhead and sedges. For a split second I thought it could be a green heron, but the overwhelming quirkiness of the bird revealed it to be that odd marsh inhabitant, the American bittern. 

Written by Drew Harry, Faville Grove Sanctuary land steward

Hooded Warbler

Searching for this bird for the better part of the summer, I had more or less given up hope of seeing it this year. A denizen of the forest interior, the bird is on the far northwestern edge of its range in Wisconsin, and has never been recorded in Faville Grove Sanctuary, but manages to find breeding habitat in a few extensive southeastern Wisconsin woodlands. Glorious in its breeding plumage, the colors might light up the forest understory brush habitat where it occurs; but I wouldn't know as I haven't seen the species.

That is, until a few weeks ago when I stumbled upon a hooded warbler on a field trip with our summer interns. As a part of the 12-week internship, we take educational field trips to State Natural Areas and other sites where they learn from land managers about ecological restoration. This particular morning found us in a bog in the Kettle Moraine surrounded by oak forest, a spot where hooded warblers had been documented earlier in the year. However, I wasn't hopeful we'd find one as it was early August and the birds were likely to be quiet, especially given that it was already 9am on a hot day. We stumbled through the forest, eventually finding the bog and only hearing an eastern wood pewee, blue jay, eastern towhees, and robins. It was a quiet morning.  

On our walk back to the truck, the interns started to run down the hills along the trail, which ran perpendicular to the moraines so characteristic of the area.  As I neared the truck I stopped and listened for a moment and my ears perked up to hear the song of what I presumed to be a hooded warbler. Binoculars from a dozen different vantage points did not yield any conclusive evidence, and soon the bird stopped singing. About 75% sure that this was a hooded warbler, I was unsatisfied. On my phone, I clicked my volume as low as it could go and played an audio recording of a hooded warbler. Okay, now I was about 90% sure this was indeed a hooded warbler. One second later, I was 100% certain this was a hooded warbler as the bird flashed in front of my face and landed on a nearby shrub, tilting its head curiously at me. The bird stayed for a good few minutes, and I got excellent views of its brilliant black hood, yellow face, and olive upper parts.

Photo by Gary Leavens

As the bird lost interest in this man in a blue t-shirt curiously speaking hooded warbler, it entertained us as it flared its tail and hunted for insects. Just as soon was it gone, but what a wonderful few minutes of birding.

The habitat of the bird we found is typical of where one might find the species in southern Wisconsin. As part of the extensive forests of the Kettle Moraine, this bird was occupying a mostly contiguous block of forest about 280 acres in size. Research in Wisconsin has shown that forest blocks of 250-1,400 acres are necessary for hooded warblers to successfully breed.

Hooded warbler nest, photo by Richard Bonnett

Within that forested area, hooded warblers actually seek out opening in the forest canopy; areas filled with dense shrubs like wild plum, blackberry, raspberry, and grapevine provide excellent cover. Nest placement occurs within these shrubs usually from knee to waist height on a human.

Thus, some stand thinning and management can stimulate the more open sites where this species breeds. Indeed, where I found this recent hooded warbler, there were dead oak trees with an understory of brambles, grapevine, buckthorn, and honeysuckle.

It's unlikely that these birds might breed at Faville Grove Sanctuary, but some areas in Faville Woods have the structural characteristics that hooded warblers look for. Nearby areas would likely need to gain forest cover in order for that to happen. It's possible to see these birds in migration, and they should be on the move at about this time, continuing through the middle of September. They tend to migrate through dense forest patches with openings, much like their breeding preference.

Another treasure this bird left me with was an appreciation for the beauty of many of the common birds around the sanctuary. The hooded warbler looks similar to another warbler—the common yellowthroat—but the brilliant colors of the yellowthroat are taken for granted due to its abundance. What beautiful birds, each in their own right.

Hooded warbler, photo by Andy Reago & Chrissy McClarren

Common yellowthroat, photo by Kelly Colgan Azar

Written by Drew Harry, Faville Grove Sanctuary land steward

Cover photo by Dave Inman