The Common Blackbird, Turdus merula, is a widespread and familiar species across Europe, Asia, and other introduced regions. While the adult male is immediately recognizable by his striking, uniform black plumage, identifying the female can be challenging for the casual observer. Her appearance lacks the dramatic contrast that makes the male stand out in a garden or park setting. This difference in coloration is a classic example of sexual dimorphism. Accurately identifying the female involves focusing on her specific, nuanced features rather than just the absence of black.
Plumage and Physical Characteristics
The female Common Blackbird is characterized by a generally dull, earthy coloration. Her overall plumage is a sooty-brown or grayish-brown, often with a slightly reddish-brown tinge, particularly noticeable on the wings and tail feathers. This uniform brown body color is broken up by subtle patterns across her front, which are key identification markers.
She typically displays light streaking or faint mottling on her breast and a distinctly paler patch on her throat. The female is a medium-sized bird, measuring about 24 to 27 centimeters in length, possessing the typical upright posture and relatively long tail of a true thrush.
The soft parts of the female blackbird also lack the brilliance of her male counterpart. Her beak is a dull yellowish-brown or dark brown, often with a darker base. Similarly, the eye-ring is present but is a duller, less prominent yellow or brown color, blending easily into her facial feathers. Her legs are typically a dark brown or blackish-brown color.
Differentiating Her from the Male
The difference between the sexes in the Common Blackbird is stark, illustrating a clear case of sexual dimorphism. The adult male possesses glossy, uniform black feathers across his entire body, instantly distinguishing him in the field. This solid black plumage sharply contrasts with the female’s brown and mottled appearance.
A primary point of comparison is the coloration of the bill and eye-ring. The male’s bill is a vivid orange-yellow during the breeding season, complemented by a bright yellow eye-ring. The female lacks this bright ornamentation, instead having a duller, yellowish-brown beak and a less conspicuous eye-ring.
The male’s plumage is almost entirely unpatterned, presenting a sleek, solid color. The female’s breast, in contrast, retains subtle streaking or mottling. This difference means that a bird that is clearly black with a bright yellow bill is an adult male, while a bird of similar size that is brown with a duller bill is the female.
Confusion with Similar Species and Juveniles
The female blackbird’s brown plumage can easily lead to confusion with other similar-looking thrushes and her own young. Juvenile blackbirds, regardless of sex, share a general brown coloration with the adult female, but they are typically even streakier. Juveniles often exhibit more pronounced speckling and buff-colored streaks, making their patterning more extreme than the adult female’s subtle mottling.
The female is also frequently mistaken for other brown thrush species, such as the Song Thrush or the Mistle Thrush, which are common in the same habitats. The Song Thrush is smaller and has a distinct pattern of dark, arrowhead-shaped spots on a pale breast, unlike the female blackbird’s weaker, more diffuse mottling. The Mistle Thrush is a significantly larger bird with a paler, greyer plumage and rounder, bolder spots on its underparts.
Proper identification relies on observing the combination of features, not just the color. While the brown body and streaked breast might suggest another thrush, the female blackbird’s overall size, relatively long tail, and the specific dull coloration of her bill and eye-ring help confirm her identity. Paying attention to these details helps distinguish the female blackbird from both her young and other brown birds.