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Woodpeckers belong to the Picidae family of birds. Woodpeckers spend a great deal of their time pecking wood and chiseling bark off trees. They do this for several reasons—to search for their principal food of wood-boring arthropods, to excavate their nesting and roosting cavities, and to proclaim their territory and impress potential mates by loud drumming. Woodpeckers accomplish these tasks by hammering vigorously at softer, fungal-rotted parts of living and dead trees, using their chisel-shaped bill. In their territorial drumming, however, woodpeckers tend to choose more resonant, unrotted trees. Some woodpeckers habitually use telephone poles and tin roofs as their sonorous drumming posts. Both males and females engage in drumming displays, which may be supplemented by loud, raucous, laughing calls. Woodpeckers use their cavities for both nesting and roosting. Although both sexes participate in brooding the eggs and young, only the male bird spends the night in the nesting cavity. Woodpeckers have a number of adaptations that permit the vigorous hammering of wood without damaging the bird. Their skull is thick-walled and the brain is cushioned by absorbent tissue, which helps withstand the physical shocks of their head blows. The tongue of the woodpecker is long, barbed, and sticky to help extract insects from crevices, and the organ is supported by an extended hyoid bone and its muscles. The bill of woodpeckers is stout and pointed, and it grows continuously because of the wear to which it is subjected. As an adaptation for gripping vertical bark surfaces, woodpeckers have feet in which two toes point forward and two backward. The stiff, downward-propping tail feathers of woodpeckers also provide mechanical support while they are pecking.
Most woodpeckers live in forests, eating arthropods in or on trees, but a few species occur in more open habitats, where they often forage on the ground for arthropods. Some species are at least partly herbivorous, seasonally eating soft fruits and nuts. Many species of woodpeckers are migratory, while others are resident throughout the year in or near their territories. All of the true woodpeckers nest in cavities that they excavate in the soft, rotted interior of living or dead trees. However, some birds in the family use natural cavities or are secondary users of the abandoned excavations of other birds. About 21 species of woodpeckers regularly breed in North America, of those 21 there are 3 main species that live in Minnesota and Wisconsin: the Hairy Woodpecker, the Downey Woodpecker and the flicker.
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The Cliff Swallow is somewhat similar in appearance to the Barn Swallow. The back, wings, and crown of the adult is a deep blue like the Barn Swallow, but the Cliff Swallow has a light belly, chestnut-colored face, dark throat, and pale gray nape. Three field marks especially useful in distinguishing the Cliff Swallow from the Barn Swallow are the white forehead, buff rump, and short, squared-off tail. The Cliff Swallow also has two white streaks down its back. Juveniles are brown above, buff below, and have varying numbers of small white spots on their foreheads and throats.
Cliff Swallows originally inhabited open canyons and river valleys with rocky cliffs for nesting. Many still nest in these habitats, but others have adapted to nesting on man-made structures, especially under bridges and freeways. Cliff Swallows can be seen in farmland, wetlands, prairies, residential areas, road cuts and over open water. They require a source of mud for their nests, and they apparently have specific nesting requirements that are as yet unknown, as their distribution is patchy, and there are many areas that appear to be suitable habitat that host no Cliff Swallows.
Cliff Swallows forage high in the air, soaring in circles. This is one of the most social land-birds of North America, generally nesting in large colonies (of up to 3,500 nests!) During nesting season Cliff Swallows gather at mud puddles to collect mud that they carry to their nests in their bills. While at these puddles, both males and females flutter their wings up high, which appears to prevent attempts at forced copulation. Extra-pair copulations are common, as is brood parasitism. Females will lay eggs in other females' nests and will also carry eggs in their beaks from their own nests to the nests of others.
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The pigeon—also known as the rock dove—is a European immigrant. Early settlers brought pigeons to North America, where they soon flourished. You can now find them in almost any city, town, or suburb on the continent.
The pigeon's diet consists primarily of grains and seeds, along with insects and some greens. They aren't terribly picky though, and they'll happily accept human food scraps and leftovers when available.
Pigeons live in groups called flocks, and show a strong affinity for human-built structures. A courting male pursues his intended mate on the ground, circling her with neck feathers inflated and tail spread, bowing and cooing all the while. Pigeons mate for life, but if one partner dies, the survivor generally will attempt to find another mate. Pigeons breed throughout the year, even during winter, and can raise four or five broods annually. Haphazard nests of twigs, leaves, and a few feathers are built on window ledges, behind signs, and under bridges.
Parents take turns incubating the clutch of one or two white eggs for between 16 and 19 days. Both parents feed the newly hatched young—called squabs—a secretion known as "crop milk." Produced from the lining of the crop—a sac-like food-storage organ unique to birds—crop milk is highly nutritious. Squabs can fly at four to six weeks of age, but remain dependent on their parents for as long as the adults will tolerate them—generally another one or two weeks.
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Starlings are now among the continent’s most numerous songbirds. They are stocky black birds with short tails, triangular wings, and long, pointed bills. Covered in white spots during winter, they turn dark and glossy in summer. For much of the year, they wheel through the sky and mob lawns in big, noisy flocks.
Starlings typically live around people, using mowed lawns, city streets, and agricultural fields for feeding; and trees, buildings, and other structures for nesting. Their main requirements are open, grassy areas in which to forage, a water source, and trees or buildings that contain suitable cavities or niches for nesting. They avoid large, unbroken stretches of forest, chaparral, and desert.
Starlings will eat nearly anything, but they focus on insects and other invertebrates when they’re available. Common prey include grasshoppers, beetles, flies, caterpillars, snails, earthworms, millipedes, and spiders. They also eat fruits including wild and cultivated cherries, holly berries, hackberries, mulberries, tupelo, Virginia creeper, sumac, and blackberries; as well as grains, seeds, nectar, livestock feed, and garbage.
Males choose the nest site and use it to attract females. The nests are virtually always in a cavity, typically in a building or other structure (look for them in streetlights and traffic signal supports), an old woodpecker hole, or a nest box. Starlings also occasionally nest in burrows and cliffs. Nest holes are typically 10-25 feet off the ground but can be up to 60 feet high.
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The House Sparrow is a chunky bird, ranging from 14–18 centimetres (5.5–7.1 in) in length, and from 24–39.5 grams (0.85–1.4 oz) in mass, depending on sex, subspecies, and environment. Females average smaller than males, and southern birds are smaller than their northern counterparts, though altitude may be equally important.
Like most of the members of its genus, the House Sparrow is sexually dimorphic. The male's mantle and upper back are a warm brown, broadly streaked with black, while the lower back, rump and uppertail coverts are a greyish-brown. The crown, cheeks and underparts are pale grey, with black on the throat, upper breast and between the bill and eyes. The bill in summer is blue-black, and the legs are brown. In winter the plumage is dulled by pale edgings, and the bill is yellowish brown. The black throat patch on the males is variable in size, and the size of that patch or badge may be correlated with the aggressiveness, suggesting that it is a signal to show dominance in a social situation. The female has no black on head or throat, nor a grey crown; her upperparts are streaked with brown. The juveniles are deeper brown, and the white is replaced by buff; the beak is pink to dull yellow. The House Sparrow's range overlaps extensively with that of the smaller and more slender Eurasian Tree Sparrow, which has a chestnut and not grey crown, two distinct wing bars, and a black patch on each cheek.[
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