Green Birds of Chicago: 17 Species From Herons to Hummingbirds

Chicago’s diverse ecosystems—from Lake Michigan’s shoreline to forest preserves and urban parks—attract an impressive variety of birds with green plumage. Whether you’re scanning the treetops for migratory warblers or watching waterfowl glide across lagoons, the city offers year-round opportunities to spot these colorful species.

You’ll find everything from the unexpected Monk Parakeet colonies to subtle olive-green warblers that pass through during spring and fall migrations.

This guide covers 17 distinct green birds you can observe throughout the Chicago area, including identification tips, seasonal patterns, and the best locations to find each species.

From the iridescent green heads of male ducks to the bright yellow-green plumage of woodland warblers, you’ll learn to recognize these birds whether you’re an experienced birder or just starting to explore Chicago’s avian diversity.

1. Monk Parakeet

The Monk Parakeet (Myiopsitta monachus) stands out as Chicago’s most unexpected green bird—a tropical parrot thriving in an urban Midwestern environment. These bright green parakeets with gray faces and breasts have established feral colonies throughout the city since the 1970s, when pet birds escaped or were released. You’ll immediately recognize them by their loud, screeching calls and their distinctive communal stick nests built on utility poles and light towers.

These social birds measure about 11-12 inches long with predominantly bright green plumage covering their backs, wings, and tails. Their gray foreheads and breasts create a distinctive contrast against the green, while their sturdy, pale bills are perfectly adapted for cracking seeds. According to research from the University of Chicago, Monk Parakeets have successfully naturalized in 23 U.S. states despite originating from South America.

Pro Tip: Look for Monk Parakeet colonies at Harold Washington Park near Hyde Park, where their massive communal nests are visible year-round on light poles near the athletic fields.

Unlike most parrots, Monk Parakeets build elaborate stick nests rather than nesting in tree cavities. These structures can weigh hundreds of pounds and house multiple breeding pairs in separate chambers. You’ll find these colonies most easily in Hyde Park, South Shore, and near the Museum of Science and Industry. The birds remain active throughout winter, often visiting backyard feeders for sunflower seeds and other offerings.

Listen for their distinctive calls—loud, harsh squawks that sound like “quak quak” or “screee”—which often alert you to their presence before you spot them. They’re most active during early morning and late afternoon, when flocks fly between feeding areas and their colonial nests.

The Chicago Bird Alliance notes these parakeets have adapted remarkably well to urban life, even surviving Chicago’s harsh winters by huddling together in their insulated nests.

2. Green Heron

The Green Heron (Butorides virescens) is a compact, stocky wading bird that hunts along Chicago’s waterways from spring through early fall. Despite its name, this heron appears more dark blue-gray than bright green, though its back and wings display a distinctive greenish-blue iridescence in good light. You’ll recognize this crow-sized heron by its hunched posture, short legs, and chestnut-colored neck and chest.

These solitary hunters measure 16-18 inches long with a wingspan of about 26 inches. Their dark cap extends down the back of the neck, creating a shaggy crest when raised.

The legs appear bright orange-yellow during breeding season, fading to greenish-yellow later in the year. Watch for their remarkable hunting technique—they’ll stand motionless at the water’s edge or on low branches, sometimes dropping small objects like insects or twigs onto the water’s surface to attract fish.

You’ll find Green Herons along the Chicago River, in Lincoln Park’s lagoons, and throughout the forest preserve wetlands from late April through September. They prefer shallow waters with overhanging vegetation where they can hunt from cover. Unlike the larger Great Blue Heron, Green Herons rarely wade in open water, instead stalking prey from the shoreline or perched on branches just above the surface.

Key Insight: Green Herons are one of the few bird species known to use tools—they’ve been observed placing bait on the water’s surface to lure fish within striking distance.

These herons feed primarily on small fish, but also take aquatic insects, frogs, and crayfish. When alarmed, they stretch their necks upward and freeze, relying on camouflage rather than flight to avoid detection. Their call is a sharp, explosive “skeow” that often reveals their presence in dense vegetation. Look for them in the early morning or evening hours when they’re most active, particularly in areas where other waterbirds congregate during migration.

3. Ruby-throated Hummingbird

The Ruby-throated Hummingbird (Archilochus colubris) is Chicago’s only regular hummingbird species, visiting gardens and parks from late April through September. Males display brilliant metallic green backs and crowns that shimmer in sunlight, while their famous ruby-red throat patch flashes like a jewel when they turn toward you. Females and immature birds show the same metallic green upperparts but lack the red throat, instead displaying white underparts with buff-colored flanks.

These tiny birds measure just 3-3.5 inches long with a wingspan of 4-4.5 inches, weighing less than a penny. Their wings beat 53 times per second during normal flight and up to 200 times per second during courtship displays.

You’ll hear a distinctive humming sound as they hover at flowers, along with aggressive chipping calls when defending territory. Males perform dramatic U-shaped dive displays during breeding season, plummeting from heights of 50 feet or more.

Ruby-throated Hummingbirds arrive in Chicago during late April and early May after migrating across the Gulf of Mexico—a non-stop flight of over 500 miles. They’re attracted to tubular red and orange flowers, particularly native species like cardinal flower, bee balm, and trumpet vine.

According to the Chicago Botanic Garden, providing nectar feeders and native flowering plants significantly increases your chances of attracting these remarkable migrants.

These hummingbirds feed every 10-15 minutes throughout the day, consuming half their body weight in nectar and small insects daily. They’re remarkably aggressive for their size, often chasing away much larger birds from feeding territories. Males typically depart for their southern wintering grounds by early September, while females and juveniles may linger into early October. You can attract them to your yard by planting native flowers and maintaining clean nectar feeders with a 4:1 water-to-sugar ratio.

4. Black-throated Green Warbler

The Black-throated Green Warbler (Setophaga virens) is one of Chicago’s most striking spring and fall migrants, passing through in significant numbers during May and again from late August through September. Males display bright yellow faces that contrast dramatically with their black throats and olive-green backs, creating an unmistakable field mark. Females and fall birds show similar patterns but with reduced black on the throat and more subdued coloring overall.

These small songbirds measure 4.5-5 inches long with white wing bars and white underparts streaked with black along the flanks. Their olive-green backs and crowns give them their name, though the yellow face and black throat are more distinctive identification features. You’ll often hear them before seeing them—their song is a distinctive, buzzy “zee-zee-zee-zoo-zee” that sounds like “trees, trees, murmuring trees” according to birding mnemonics.

During migration, Black-throated Green Warblers actively forage in the mid to upper canopy of deciduous and mixed forests, searching for caterpillars, beetles, and other insects. They prefer mature trees with dense foliage, making Chicago’s forest preserves like Palos and Ned Brown ideal stopover habitat. Watch for them moving methodically through branches, often hanging upside-down to inspect the undersides of leaves.

Pro Tip: Visit the Magic Hedge at Montrose Point during peak migration (early to mid-May) for excellent views of Black-throated Green Warblers at eye level as they feed in the shrubby habitat before crossing Lake Michigan.

Spring migration peaks in early to mid-May, with males arriving slightly before females. These warblers breed in coniferous and mixed forests across Canada and the northeastern United States, making Chicago an important stopover site as they travel between wintering grounds in Mexico and Central America and breeding territories to the north.

Fall migration is more prolonged, with birds passing through from late August into early October. They’re often found in mixed-species foraging flocks with other warblers, vireos, and chickadees during migration.

5. Pine Warbler

The Pine Warbler (Setophaga pinus) is a relatively large, sturdy warbler that occasionally appears in Chicago during migration, particularly in areas with coniferous trees. Males display olive-green backs and bright yellow throats and breasts, with white wing bars and relatively plain faces lacking the bold facial patterns of many other warblers. Females and immature birds show more subdued coloring with grayish-olive upperparts and pale yellow underparts.

These warblers measure 5-5.5 inches long—noticeably larger and chunkier than most warbler species. Their relatively long tails and thick bills give them a distinctive profile compared to other yellow-green warblers. Unlike many warbler species that constantly flit through foliage, Pine Warblers move more deliberately, often feeding on tree trunks and large branches in a manner similar to nuthatches.

As their name suggests, Pine Warblers show a strong preference for pine trees and other conifers, though they’ll forage in mixed woodlands during migration. In the Chicago area, look for them in forest preserves and parks with planted pine groves, particularly during spring migration from late March through May. They’re among the earliest warblers to migrate north, sometimes arriving when snow still covers the ground.

Pine Warblers feed primarily on insects during breeding season but readily eat seeds and berries during migration and winter—unusual behavior for warblers. This dietary flexibility allows them to winter farther north than most warbler species.

Their song is a musical trill similar to a Chipping Sparrow but typically softer and more musical. According to Great Lakes Audubon, Pine Warblers are less common in Chicago than other warbler species but can be reliably found in appropriate habitat during peak migration periods.

6. Tennessee Warbler

The Tennessee Warbler (Leiothlypis peregrina) is a common spring and fall migrant through Chicago, though its name is misleading—it neither breeds nor winters in Tennessee. Spring males display clean gray heads, bright olive-green backs, and white underparts with a distinctive white eyebrow stripe. Fall birds and females appear much more yellow-green overall with less distinct head patterns, making identification more challenging.

These small, active warblers measure 4.5-5 inches long with thin, pointed bills perfectly adapted for gleaning insects from foliage. Unlike many warblers, they lack wing bars, and their relatively plain appearance can make them easy to overlook among more colorful species. However, their energetic feeding behavior and distinctive song make them conspicuous during migration peaks.

Tennessee Warblers are among the most abundant migrants through Chicago during spring, with peak numbers occurring in mid to late May. They forage actively in the upper and middle canopy, often joining mixed-species flocks with other warblers and vireos. These birds breed in the boreal forests of Canada and winter in Central and South America, making Chicago an important stopover site where they can replenish energy reserves for the journey ahead.

Key Insight: Tennessee Warbler populations fluctuate dramatically based on spruce budworm outbreaks in their breeding range—during outbreak years, their numbers can increase tenfold as they take advantage of this abundant food source.

Their song is a loud, rapid series of notes that increases in speed, often described as “ticka-ticka-ticka-ticka-swit-swit-swit-chew-chew-chew-chew.” During fall migration from late August through September, Tennessee Warblers appear much yellower and can be confused with other species like Orange-crowned Warblers.

Look for the Tennessee Warbler’s white undertail coverts and more prominent eyebrow stripe to distinguish it from similar species. They’re particularly attracted to flowering trees during spring migration, where they feed on both insects and nectar.

7. Cape May Warbler

The Cape May Warbler (Setophaga tigrina) is a striking migrant that passes through Chicago in moderate numbers during spring and fall. Breeding males are unmistakable with bright yellow faces marked by distinctive chestnut cheek patches, yellow-green backs heavily streaked with black, and yellow underparts with bold black streaking. Their unique appearance makes them one of the most sought-after warblers during migration season.

These medium-sized warblers measure about 5 inches long with relatively short tails. Females and fall birds show more subdued coloring with grayish-olive upperparts, pale yellow underparts with fine streaking, and a distinctive yellow patch behind the ear. All plumages show white wing patches that flash conspicuously during flight. The species has a unique tubular tongue adapted for drinking nectar—an unusual feature among warblers.

Cape May Warblers prefer the upper canopy of deciduous and coniferous trees, making them challenging to observe without good binoculars or a spotting scope. During spring migration in May, they’re particularly attracted to flowering trees where they feed on both insects and nectar. Look for them in Chicago’s forest preserves and lakefront parks, especially during fallout conditions when weather forces migrants to land in large numbers.

These warblers breed in the spruce forests of Canada, where their populations fluctuate dramatically based on spruce budworm abundance—their primary food source during breeding season. During outbreak years, Cape May Warbler numbers increase significantly, while populations decline during non-outbreak years. Fall migration occurs from late August through September, with birds appearing less colorful and more challenging to identify than spring adults.

Cape May Warblers feed primarily on small caterpillars and other insects during migration, often hovering briefly to glean prey from branch tips and leaf clusters. Their song is a thin, high-pitched series of notes—”tsee-tsee-tsee-tsee”—that can be difficult to hear, especially for birders with age-related hearing loss.

They’re most often found in mixed-species foraging flocks with other warblers during migration, making careful observation essential for picking them out from similar colorful migrants.

8. Magnolia Warbler

The Magnolia Warbler (Setophaga magnolia) is one of Chicago’s most beautiful and commonly observed migrants, with spring males displaying stunning yellow underparts heavily streaked with black, blue-gray heads with white eyebrows, and yellow-green backs.

Their most distinctive feature is the bold white tail patches visible from below, creating a unique “necklace” pattern across the breast. These markings make them one of the easiest warblers to identify during spring migration.

These small warblers measure 4.5-5 inches long with relatively short tails and prominent white wing patches. Females show similar but more subdued patterns with olive-green backs and less extensive black streaking. Fall birds of both sexes appear quite different—grayish above with faint streaking below and a distinctive white eye ring, though the white tail patches remain diagnostic in all plumages.

Magnolia Warblers are among the most abundant migrants through Chicago, with peak numbers occurring in mid-May during spring and late August through September during fall migration. Unlike many warbler species that forage high in the canopy, Magnolias typically feed at mid-level heights and often come quite close to the ground, making them excellent birds for beginning birders to observe and identify.

Pro Tip: Magnolia Warblers are often the most approachable warblers during migration—they frequently forage at eye level in shrubs and small trees, making them perfect subjects for photography and close observation.

These warblers actively forage by hopping along branches and making short flights to snatch insects from foliage. They frequently fan their tails, displaying the distinctive white patches that help identify them even in poor lighting conditions. Their song is a short, musical “weeta-weeta-weeteo” that rises slightly at the end. During migration, they’re found in a variety of wooded habitats from dense forest preserves to urban parks with mature trees.

Magnolia Warblers breed in young coniferous forests across Canada and the northeastern United States, building their nests low in small spruce or fir trees. They winter in Mexico and Central America, with some birds reaching northern South America.

The species was named by pioneering ornithologist Alexander Wilson, who first observed it feeding in magnolia trees during migration—though magnolias are not its preferred habitat. Look for them in mixed foraging flocks during migration, where their distinctive markings and mid-level feeding behavior make them stand out from other warbler species.

9. Chestnut-sided Warbler (Breeding)

The Chestnut-sided Warbler (Setophaga pensylvanica) is an easily identified spring migrant through Chicago, with breeding males displaying distinctive chestnut streaks along their flanks, bright yellow crowns, and clean white underparts. Their lime-green backs and bold white eye rings create a striking appearance that makes them favorites among birdwatchers. These warblers are commonly observed during May migration as they pass through on their way to northern breeding grounds.

These small warblers measure about 5 inches long with a perky, upright posture and habit of holding their tails cocked upward. Breeding males are unmistakable with their combination of yellow crown, black facial markings, chestnut sides, and white underparts.

Females show similar but more subdued patterns with less extensive chestnut and yellow. Fall birds appear completely different—lime-green above with white eye rings and grayish-white underparts, lacking any trace of chestnut or yellow.

Chestnut-sided Warblers prefer young deciduous forests and shrubby second-growth habitats, making them one of the few warbler species that actually benefited from historical deforestation in eastern North America. During migration through Chicago, they forage actively in the lower to mid-canopy levels, often in shrubby edges and regenerating woodlands. They’re particularly common in forest preserves with diverse understory vegetation.

These warblers feed primarily on caterpillars and other insects, methodically working through branches and frequently drooping their wings to display their distinctive plumage. Their song is a distinctive, emphatic “pleased-pleased-pleased-to-MEET-cha” with the final note strongly accented.

According to Chicago Academy of Sciences, Chestnut-sided Warblers are among the most reliably observed warbler species during spring migration, particularly in early to mid-May.

Spring migration peaks in early to mid-May, with birds passing through in good numbers during optimal weather conditions. They breed in regenerating forests and shrubby habitats across the northeastern United States and southern Canada, building cup-shaped nests low in shrubs or small trees.

Fall migration occurs from late August through September, though fall birds can be challenging to identify due to their dramatically different plumage. Look for them in mixed-species foraging flocks with other warblers, particularly in areas with dense shrub cover and forest edges.

10. Orange-crowned Warbler

The Orange-crowned Warbler (Leiothlypis celata) is an uncommon but regular migrant through Chicago, appearing in small numbers during spring and fall. Despite its name, the orange crown patch is rarely visible in the field, making this one of the plainest and most challenging warblers to identify. These birds display dull olive-green upperparts, yellowish-olive underparts with faint streaking, and a subtle broken eye ring that gives them a somewhat “plain-faced” appearance.

These small warblers measure 4.5-5 inches long with relatively thin, pointed bills. They lack the bold wing bars, eye stripes, or distinctive markings that characterize most other warbler species. The overall impression is of a drab, greenish-yellow bird with very few distinguishing features. The orange crown patch—actually more rusty-orange than bright orange—is typically concealed by olive feathers and only visible when the bird is agitated or during display.

Orange-crowned Warblers arrive later in spring than most warbler species, with peak migration occurring in late May into early June. They’re more common during fall migration from late September through October, when they can occasionally linger into November. These warblers forage lower in vegetation than many other species, often feeding close to the ground in dense shrubbery and understory growth.

Important Note: Orange-crowned Warblers are easily confused with Tennessee Warblers in fall plumage—look for the Orange-crowned’s blurry breast streaking, yellow undertail coverts (white in Tennessee), and broken eye ring to distinguish the two species.

These warblers feed on small insects, spiders, and occasionally nectar and fruit. They’re known for their habit of probing flowers for insects and nectar, sometimes hovering briefly like a tiny hummingbird. Their song is a simple, rapid trill that drops in pitch at the end—”ch-ch-ch-ch-ch-ch-chew”—though migrants rarely sing in Chicago. The call note is a sharp, metallic “chip” that helps locate these otherwise inconspicuous birds.

Orange-crowned Warblers breed across much of Alaska, Canada, and the western United States in shrubby habitats and forest edges. The subspecies that migrates through Chicago breeds in the northern boreal forest and winters primarily in the southern United States and Mexico.

During migration, they’re often found in weedy fields, forest edges, and parks with dense understory vegetation—habitats that other warbler species may overlook. Their plain appearance and preference for low, dense cover means they’re often overlooked by birders focused on more colorful species in the canopy.

11. Ruby-crowned Kinglet

The Ruby-crowned Kinglet (Corthylio calendula) is a tiny, energetic bird that migrates through Chicago in spring and fall, with some individuals occasionally lingering into early winter. These diminutive songbirds display olive-green upperparts, pale underparts, prominent white eye rings, and two white wing bars. Males possess a brilliant ruby-red crown patch that’s usually concealed but flares dramatically when the bird is excited or agitated.

These kinglets measure just 3.5-4.5 inches long—barely larger than a hummingbird—and weigh only about 6 grams. Despite their tiny size, they’re remarkably active and constantly in motion, flicking their wings nervously as they forage. The white eye ring gives them a distinctive “big-eyed” appearance that helps distinguish them from similar small birds. The ruby crown patch is rarely visible on males and completely absent in females, making it an unreliable field mark for identification.

Ruby-crowned Kinglets are common migrants through Chicago, with spring migration peaking in late April and early May, and fall migration extending from late September through October. Some individuals linger into November and occasionally attempt to overwinter in areas with sufficient food resources. They forage actively in both coniferous and deciduous trees, constantly hovering and gleaning tiny insects from foliage, bark, and branch tips.

These kinglets feed primarily on small insects, spiders, and insect eggs, using their thin bills to probe bark crevices and leaf clusters. They’re remarkably acrobatic, often hanging upside-down or hovering briefly while foraging. Despite their tiny size, they’re quite vocal—their call is a distinctive, husky “ji-dit” that’s often the first clue to their presence. Their song is surprisingly loud and complex for such a small bird, consisting of a series of high, thin notes followed by rich, warbling phrases.

Ruby-crowned Kinglets breed in coniferous forests across Canada and the western mountains, building tiny, well-concealed nests suspended from conifer branches. They winter across the southern United States and Mexico, with Chicago serving as an important stopover site during migration.

During migration, they’re often found in mixed-species foraging flocks with chickadees, nuthatches, and other small songbirds. Their constant activity and distinctive wing-flicking behavior make them entertaining birds to observe, despite their small size and often challenging viewing conditions in dense foliage.

12. Red-eyed Vireo

The Red-eyed Vireo (Vireo olivaceus) is one of Chicago’s most common summer residents, arriving in early May and remaining through September. These medium-sized songbirds display olive-green backs and crowns, clean white underparts, and distinctive facial markings including a white eyebrow stripe bordered by black lines above and below. Despite their name, the red iris is difficult to see in the field and is not a reliable identification feature.

These vireos measure 5-6 inches long with relatively thick bills compared to warblers—a reflection of their different feeding techniques. Their crown appears gray compared to the olive-green back, and the clean white underparts lack any streaking or yellow tones. The bold facial pattern with white eyebrow stripe and dark eye line creates a distinctive “spectacled” appearance that separates them from other vireo species in the Chicago area.

Red-eyed Vireos are abundant in Chicago’s deciduous forests and wooded parks during summer, where their persistent singing makes them one of the most frequently heard birds. They forage methodically in the mid to upper canopy, moving deliberately along branches as they search for caterpillars, beetles, and other insects. Unlike the constant motion of warblers, vireos move more slowly and deliberately, carefully inspecting each leaf and branch.

Key Insight: Red-eyed Vireos hold the record for the most songs delivered in a single day—one persistent male was documented singing over 22,000 songs during a summer day, earning them the nickname “preacher bird” for their seemingly endless vocalizations.

Their song is a series of short, robin-like phrases delivered continuously throughout the day, even during the heat of midday when most other birds fall silent. The phrases sound like questions and answers: “here I am, where are you, see me, hear me” repeated endlessly from the canopy.

This persistent singing makes them easy to detect but often challenging to actually see in dense foliage. According to local birding experts, learning to identify birds by sound is essential for detecting canopy species like Red-eyed Vireos.

These vireos arrive in Chicago during the first week of May after migrating from their wintering grounds in South America. They breed in mature deciduous forests, building cup-shaped nests suspended from forked branches in the mid-canopy.

Fall migration occurs from late August through September, with birds departing for their long journey to Amazonian forests where they spend the winter. During migration, they’re often found in mixed-species foraging flocks with warblers and other songbirds, though their deliberate feeding style distinguishes them from the more frenetic warblers.

13. Warbling Vireo

The Warbling Vireo (Vireo gilvus) is a common summer resident in Chicago’s parks and forest preserves, arriving in late April and remaining through September. These plain-looking vireos display pale olive-gray upperparts, whitish underparts with a subtle yellow wash on the flanks, and a relatively unmarked face with a faint whitish eyebrow stripe. Their overall appearance is much plainer than the Red-eyed Vireo, lacking bold facial markings.

These small vireos measure 4.5-5.5 inches long with relatively thick bills and a somewhat round-headed appearance. Their plumage is notably plain—grayish-olive above and pale below with very subtle markings. The faint whitish eyebrow stripe is much less distinct than in Red-eyed Vireos, and the face appears relatively unmarked. This plain appearance can make them challenging to identify visually, but their distinctive song makes them easy to detect.

Warbling Vireos prefer open deciduous woodlands, particularly areas with tall cottonwoods, willows, and other riverside trees. They’re commonly found along the Chicago River, in Lincoln Park, and throughout forest preserves with mature deciduous trees. Unlike Red-eyed Vireos that forage in dense forest canopy, Warbling Vireos often feed in more open situations with scattered tall trees.

These vireos feed primarily on insects gleaned from foliage in the upper canopy, moving deliberately along branches as they search for caterpillars, beetles, and other prey. They occasionally hover briefly to snatch insects from leaf surfaces or make short flights to catch flying insects. Their foraging style is methodical and deliberate, similar to other vireo species but slower-paced than warblers.

The song of the Warbling Vireo is distinctive—a long, rambling, musical warble that flows continuously without distinct pauses, quite different from the short, broken phrases of the Red-eyed Vireo. The song has been described as sounding like “if I sees you, I will seize you, and I’ll squeeze you till you squirt.”

This persistent singing from high in the canopy is often the best way to locate these otherwise inconspicuous birds. They sing throughout the day from arrival in late April through July, making them one of the most frequently heard birds in appropriate habitat.

Warbling Vireos build cup-shaped nests suspended from forked branches high in deciduous trees, often over water or near forest edges. They typically raise one brood per season, with both parents participating in nest building, incubation, and feeding young.

Fall migration occurs from late August through September, with birds departing for wintering grounds in Mexico and Central America. During migration, they’re less conspicuous than during breeding season, as singing decreases and they often join mixed-species foraging flocks with other migratory songbirds.

14. Philadelphia Vireo

The Philadelphia Vireo (Vireo philadelphicus) is an uncommon but regular migrant through Chicago during spring and fall. These small vireos display olive-green upperparts, distinctive yellow underparts (brightest on the throat and breast), and a bold white eyebrow stripe with a dark eye line. They’re the only vireo in the Chicago area with consistently yellow underparts, making them easier to identify than other vireo species when seen well.

These vireos measure 4.5-5 inches long—slightly smaller than Red-eyed Vireos and about the same size as Warbling Vireos. The bright yellow throat and breast are diagnostic, though the intensity of yellow coloring varies individually and by season.

Fall birds show paler yellow than spring adults. The facial pattern is similar to Red-eyed Vireo with a white eyebrow stripe bordered by dark lines, but the overall appearance is more compact and the bill appears slightly shorter.

Philadelphia Vireos migrate through Chicago primarily in May during spring and from late August through September during fall. They’re significantly less common than Red-eyed or Warbling Vireos, making them a prized sighting for local birders. During migration, they forage in the mid to upper canopy of deciduous trees, often joining mixed-species flocks with warblers and other vireos.

Pro Tip: Philadelphia Vireos are most easily found during spring migration at known migrant traps like Montrose Point and the Magic Hedge, where they occasionally descend to eye level in shrubby vegetation, offering excellent viewing opportunities.

These vireos feed on insects gleaned from foliage, using the same deliberate, methodical foraging style characteristic of all vireo species. They move slowly along branches, carefully inspecting leaves and twigs for caterpillars, beetles, and other prey. Their song is similar to Red-eyed Vireo but typically higher-pitched and slower-paced, though migrants rarely sing in the Chicago area.

Philadelphia Vireos breed in young deciduous and mixed forests across Canada and the northeastern United States, preferring edge habitats and regenerating woodlands. They winter in Central America, making Chicago an important stopover site during their long migrations. The species was named by pioneering ornithologist John James Audubon, who first collected a specimen near Philadelphia.

During migration, careful observation is needed to distinguish them from the more common Warbling Vireo—look for the Philadelphia’s brighter yellow underparts, more contrasting facial pattern, and darker lores (the area between eye and bill). They’re most often detected by experienced birders who carefully check vireo flocks during peak migration periods in early to mid-May and again in early September.

15. Green-winged Teal

The Green-winged Teal (Anas crecca) is North America’s smallest dabbling duck and a common migrant through Chicago during spring and fall, with some individuals wintering in the area when open water persists.

Breeding males display chestnut-colored heads with distinctive iridescent green patches extending from the eye to the back of the head, while their bodies show intricate gray vermiculation and a vertical white stripe on the side. The green wing patch (speculum) that gives them their name is visible in flight and when the wing is extended.

These compact ducks measure 12-15 inches long with a wingspan of about 23 inches. Males in breeding plumage are unmistakable with their chestnut and green head pattern, though they molt into drab “eclipse” plumage during summer that resembles females. Females and eclipse males show mottled brown plumage with a distinctive green speculum bordered by white. Both sexes have relatively small bills compared to other dabbling ducks.

Green-winged Teal are found on ponds, marshes, and shallow wetlands throughout the Chicago area during migration, with peak numbers occurring in March-April during spring and October-November during fall. They prefer shallow water with muddy bottoms where they can dabble for seeds, aquatic invertebrates, and plant material. Unlike larger ducks, they can take flight almost vertically from the water’s surface, making them highly maneuverable in confined spaces.

These ducks feed by tipping forward in shallow water to reach submerged vegetation and invertebrates, rarely diving completely underwater. They’re often found in small flocks, sometimes mixed with other dabbling duck species. Their flight is swift and erratic, with flocks twisting and turning in tight formation. The male’s call is a distinctive, high-pitched whistle, while females produce soft quacks.

Green-winged Teal breed across Alaska, Canada, and the northern United States in prairie potholes and boreal wetlands. Most individuals migrate south for winter, though some remain in the Chicago area as long as open water persists. They’re among the most abundant ducks during migration, with thousands passing through the region each spring and fall.

Look for them in shallow wetlands at forest preserves, particularly areas with mudflats and emergent vegetation. They often associate with other dabbling ducks like Mallards and American Wigeon, making careful observation necessary to pick them out from larger, more obvious species.

16. Mallard

The Mallard (Anas platyrhynchos) is Chicago’s most familiar and abundant duck, present year-round in parks, forest preserves, and urban waterways. Breeding males (drakes) display the iconic iridescent green head that makes them instantly recognizable, along with a white neck ring, chestnut breast, and gray body. This green head coloration is what qualifies them for this list, though the green is limited to the male’s head and neck during breeding season.

These large dabbling ducks measure 20-26 inches long with a wingspan of 32-39 inches. Males in breeding plumage are unmistakable with their glossy green heads, yellow bills, and distinctive coloring.

The iridescent green appears almost black in poor light but shimmers brilliantly in sunlight. Females show mottled brown plumage with orange and black bills. Males molt into drab “eclipse” plumage during summer that resembles females but retain their yellow bills.

Mallards are found on virtually every body of water in the Chicago area, from small park ponds to Lake Michigan’s shoreline. They’ve adapted remarkably well to urban environments and readily accept food from humans, though feeding bread to waterfowl is discouraged by wildlife experts. These ducks are year-round residents, with local populations supplemented by migrants from farther north during fall and winter.

Important Note: While Mallards are common and approachable, feeding them bread can cause serious health problems and environmental issues. If you want to feed ducks, use appropriate foods like cracked corn, oats, or specialized waterfowl feed.

Mallards are dabbling ducks that feed by tipping forward in shallow water to reach submerged vegetation, seeds, and aquatic invertebrates. They also graze on land, particularly in parks and golf courses where they feed on grass and grain. Their diet is omnivorous, including plant material, insects, small fish, and crustaceans. They’re social birds often found in flocks, particularly during winter when northern migrants join resident populations.

These ducks are the ancestors of most domestic duck breeds and readily hybridize with other dabbling duck species, sometimes creating identification challenges. The male’s courtship display includes head-bobbing, tail-wagging, and a distinctive raspy call quite different from the female’s familiar quack.

Mallards nest in a variety of locations from ground nests near water to elevated sites in trees or buildings. They’re highly successful urban adapters, thriving in environments ranging from natural wetlands to city parks and residential neighborhoods. Their abundance and familiarity make them an excellent species for beginning birdwatchers to observe waterfowl behavior and seasonal plumage changes.

17. Wood Duck

The Wood Duck (Aix sponsa) is one of North America’s most stunningly beautiful waterfowl and a regular breeding resident in the Chicago area. Males display spectacular plumage including an iridescent green and purple head with distinctive white facial markings, a red eye and bill base, and intricate patterns of green, purple, and bronze throughout the body. The iridescent green on the head and crest qualifies them as one of Chicago’s most spectacular green birds.

These medium-sized ducks measure 18-21 inches long with a wingspan of 26-29 inches. Breeding males are unmistakable with their elaborate plumage and swept-back crest that creates a distinctive head shape. Females show more subdued coloring with grayish-brown bodies, white eye rings, and distinctive white teardrop-shaped patches around the eyes. Both sexes have relatively long tails and large heads compared to other duck species.

Wood Ducks inhabit wooded swamps, forested wetlands, and tree-lined ponds throughout the Chicago area from March through October, with some individuals occasionally wintering in areas with open water.

Unlike most ducks that nest on the ground, Wood Ducks are cavity nesters, using natural tree cavities or nest boxes placed near water. This unique nesting habit makes them particularly responsive to nest box programs, and many forest preserves maintain active Wood Duck nest box trails.

These ducks feed on acorns, seeds, aquatic plants, and invertebrates, often foraging in shallow water or on land beneath oak trees. They’re highly maneuverable fliers capable of navigating through dense forest canopy—an unusual ability among waterfowl.

Females lead newly hatched ducklings from nest cavities to water, with the day-old ducklings making impressive leaps of 50 feet or more from elevated nest sites to the ground below.

Wood Ducks were nearly hunted to extinction in the early 1900s but have made a remarkable recovery thanks to hunting regulations and widespread nest box programs. They’re now common breeding birds throughout the Chicago area, particularly in forest preserves with suitable wetland habitat. The male’s call is a distinctive, rising whistle—”jeeeeee”—while females produce a loud, squealing “oo-eek” when alarmed.

During breeding season, males are highly territorial and engage in elaborate courtship displays including head-bobbing, wing-flapping, and preening. After breeding, males molt into drab “eclipse” plumage and become secretive, hiding in dense vegetation during their flightless period.

Fall migration brings additional birds from farther north, with flocks gathering on larger wetlands before departing for southern wintering grounds. Wood Ducks are among the most rewarding species to observe in Chicago, combining spectacular beauty with interesting behavior and successful conservation history.

Their preference for wooded wetlands means they’re often found in more natural settings than the ubiquitous Mallard, offering glimpses into less disturbed aquatic ecosystems within the urban landscape.