"Blackbird" is a catchall term for songbirds that appear black in the field. These birds are not necessarily related; they're grouped here for identification purposes.

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Author: Author: Trisha Shears. Creative  Commons Attribution-Noncommercial 2.0

• Aggressive bird that displaces our native species
• Related to mynahs; song includes squeaky imitations of other birds and human-related sounds
• Breeding adults have iridescent plumage
• Immature and winter birds show heavy speckling
• A large flock of starlings is called a “murmuration”

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Author: Mdf.  GNU Free Documentation License 1.2, no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts

• Smaller than American Crow; about the size of a robin but with longer tail and beak.
• Male has glossy, iridescent plumage; female has drabber plumage
• Vocalizations are metallic-sounding
• Easy to confuse with Brewer’s Blackbird

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Author: DickDaniels. Creative Commons Attribution-Share Alike 3.0 Unported

• Easily confused with Common Grackle: note the tail and beak which are shorter than a grackle's. Voice also differs.
• Males are glossy iridescent black; females are dark gray-brown.
• Well-adapted to life around humans in rural, suburban and urban areas.

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Author: Alan Wilson. Creative Commons Attribution-Share Alike 3.0 Unported

• Male has brown head and iridescent body; female is drab brown
• Parasitic species which lays its eggs in the nests of other birds
• Song is liquid; female chatters

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Author: J. P. McKenna.  Creative Commons Attribution-Noncommercial 2.0

• Larger than other commonly-seen songbirds
• Most common vocalization is the “caw”; but crows make a variety of sounds including a low rattle. Immature birds make a higher-pitched caw
• Motion of wings in flight resemble swimming
• Often seen in small family groups much of the year; may congregate in large flocks ("murders") in winter.

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Author:  Rick Leche. Creative  Commons Attribution-Noncommercial-No Derivative Works 2.0 Generic

• Larger than American Crow, with larger beak and wedge-shaped tail
• Acrobatic flier; superior in flight to American Crows and Red-tailed Hawks, with which it often contests
• Call is a throaty croak, more resonant than the caw of a crow
• Male is larger than female. Frequently seen in pairs; they often display affection by touching each others' beaks.
• Usually displays confident stance, in contrast to American Crow which often shows nervous, twitchy body language

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Author: Alan D. Wilson. Public Domain, Creative Commons Attribution-Share Alike 2.5

• Male has distinctive epaulets which are displayed from exposed perches
• Preferred habitat is cattails and other vegetation in marshy areas
• Female looks very different from male: streaky brown all over, with a white eye stripe. Skulks in vegetation and does not show itself flashily like the male.