Thistle seeds are an ideal wild bird food for several North American species. The seeds are small and packed with nutrients, fat and protein and especially hearty for winter feeding. The best way to feed thistle seed is with a tube feeder or a thistle sock, both of which feature very small holes through which the birds can extract the seeds.
Finches may be tiny birds, averaging less than 6 inches tall, but they are big eaters of thistle seed. Those that particularly enjoy thistle are goldfinches, Cassin's finches, house and purple finches, pine siskins and redpolls. Finches are squatty, colorful birds with short, stout beaks and a wide range of hues. Goldfinches, as their name suggests, are a dull gold and green color, with the males turning bright yellow to attract the females during mating season. Cassin's finches and purple finches are similar, both with soft purple and red colorings. House finches feature bright reddish orange on their upper chests, shoulders and heads. Pine siskins are one of the less colorful finches, with mottled brown patterns all over its body and white and yellow marking on its wings. Redpolls, as you may guess, feature a bright red chest and cap, with brownish grey stripes and markings on the rest of its body.
Juncos, which are a type of sparrow, are another prime consumer of thistle seed. Two types of thistle-loving Juncos include the dark-eyed Junco and the yellow-eyed Junco, both of which are medium-sized sparrows no more than 8 inches tall. The dark-eyed Junco has a pink bill, white belly and a range of different regional colors of black, brown and gray. Yellow-eyed Juncos are pale gray with a dark face and a sharp set of contrasting yellow eyes. Both have stubby, short beaks.
Mourning doves also enjoy thistle seeds. These birds are larger than sparrows and finches, about 12 inches tall, and are fairly dull in color. Their backs are a grayish brown while their bellies and chest are brown with pink undertones. They have thin, black beaks and a small dot beneath their black eyes.