faville grove

Vesper Sparrow

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Vesper, a rather antiquated word originating from the evening star, actually refers to a planet rather than a star—Venus. Wonderful integrations of this word relate in some way to the setting of the sun and the coming of night. Vesperate is a verb meaning to darken or become night. Vespertilio is a delightful 17th century word for bat. Vespering describes anything headed toward the setting sun, coined by poet Thomas Hardy. You could say the vesperate sky witnessed thousands of vespertilios vespering, while the vesper sparrows headed east, into the darkness, their chattery and cheery call complementing the peace of the setting sun.

If you did use that sentence, the most modern clause might include the vesper sparrow, as this bird name appropriately clings to the sparrow because the bird routinely sings at dusk and into the vesperate sky.

While its initial song notes resemble the song sparrow, the vesper song ends in repeated notes. You can find these repeated notes in a variety of dry, open habitats, from sand barrens to pine and oak barrens, to prairies and orchards. Because of the necessity of open ground for nesting, the vesper sparrow will often nest in agricultural fields. This sparrow is an early nester, beginning egg laying in late April to early May, however; later nesting attempts in agricultural fields may result in nest failure due to damage caused by heavy machinery.

Photo by Tom Murray

Photo by Tom Murray

Despite its preference for open habitats across the state, the vesper sparrow has seen declines in line with other grassland bird species. In Wisconsin's second Breeding Bird Atlas, only a half dozen vesper sparrows have been confirmed nesting in the southeastern part of Wisconsin. This species is most common in the central sands, where abundant open and sparse habitats create excellent nesting opportunities.

These birds follow cold fronts during their migrating months of September and October, and now might be a good time to see vesper sparrows moving through Faville Grove Sanctuary. While these migrating birds likely won't be singing their dusk song, identification can be determined in flight with their white outer tail feathers. As these October skies see the earlier setting of the sun, you'd be unlikely to see any vespering vesper sparrows, as they instead head south to their wintering grounds of Mexico and the southern United States.

Written by Drew Harry, Faville Grove Sanctuary land steward

Cover photo by Lynnea Parker

American Bittern

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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

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

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

Indigo Bunting

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Indigo bunting photo by Kelly Colgan Azar

Indigo bunting photo by Kelly Colgan Azar

The Indigo Bunting, cerulean on its body and a brilliant indigo on its head, enjoys brushy early successional habitat throughout Wisconsin. These birds settle into the summer breeding season with the blooming Blephilia, exploding onto the scene with the blue spiderwort. Blue is a rare color in the matrix of communities and animals calling southern Wisconsin home. Bellflower, spiderwort, bottle gentian, and the alien roadside chicory are some of the few plants with blue blooms.

Indigo Bunting by Jim Hudgins, US Fish and Wildlife Service

Indigo Bunting by Jim Hudgins, US Fish and Wildlife Service

But the indigo is not truly blue. The bird does not have blue pigment, but rather refracts blue light. If you hold a bunting feather facing the sun, you will see, the dull brown color of melanin. If instead the sun comes from behind the feather, microscopic structures will refract that unmistakable cerulean back toward you.

Indigo buntings use stars as more than just plumage enhancement. Besides refracting the sun's rays, the birds also use the stars to orient themselves during migration. The behavior is learned, as a sort of map from other buntings. Researchers discovered this by studying indigo buntings in a planetarium versus a natural setting under the night sky.

Another extraordinary feature of the bird is that they have worked around brown-headed cowbird nest parasitism. Indigo buntings will abandon their nest if cowbirds parasitize it, or they will build over the cowbird egg. They will readily re-nest and will sometimes nest late enough to avoid the cowbird breeding season and thus avoid parasitism. 

You can find plentiful indigo buntings throughout Faville Grove this summer, especially in the Ledge Savanna off of Prairie Lane. Come see them for yourself!

By Drew Harry, Faville Grove Sanctuary land steward

Chestnut-sided Warbler

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Photo by Jeff Bryant

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

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

Scarlet Tanager

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The scarlet tanager, ostensibly one of the most beautiful birds in Wisconsin, can be a wonder to behold for the first time (and any time, really). This neotropical migrant and breeding season resident can typically be found in mature oak woodlands. Almost all of the tanagers I've seen have been in mature white oak trees, shimmering on burly branches ornamenting the Quercus alba.

Photo by Kelly Colgan Azar

Photo by Kelly Colgan Azar

One might ask, “why are scarlet tanagers so red? Doesn't that make them more visible to predators?” Indeed it likely makes them more susceptible to predation, however it also makes them more visible to potential mates. It's been found that a gene is likely responsible for the red pigment in tanagers, and other red-feathered birds. The gene is expressed in not only the skin, but also the liver of these red birds. It is theorized that the birds with the brightest plumage could also have the healthiest livers and are thus able to break down toxins in the environment. Adult tanagers will often feed on diverse samplings of berries, and the gene responsible for the red color may aid in the elimination of toxins from the diet.

Biodiversity Heritage Library

Biodiversity Heritage Library

If the female finds a sufficiently red male to mate with, she'll begin constructing a nest high in the canopy with an assemblage of twigs. Usually completed in 3-4 days, the nest is composed of leaves, bark, and grasses. Nest building starts around this week, and eggs are typically found by the middle of June, with 3-4 eggs per clutch.

Scarlet tanagers prefer larger forest tracts, but can still be found in smaller forest fragments. Here at Faville Grove, you might find these birds in Faville Woods or in the savannas surrounding the Kettle Pond. While these birds can be more easily seen than heard, if you get close enough you can't miss this beautiful sign from the tropics.

Written by Drew Harry, Faville Grove Sanctuary land steward