Youve probably seen swallows darting back and forth on fluttering wings, plucking insects out of the air to eat. Swallows members of the bird family Hirundinidae, which includes 86 species worldwide are part of a broader category of birds called aerial insectivores, meaning they catch insects on the wing.
Swallows are small birds with slender, pointed wings and small beaks and feet. They typically live in open habitats, often near water. Although the specifics of their nesting habitats vary from species to species, most swallows are socially monogamous, meaning one male and one female pair off to raise young, and both parents contribute to caring for their young.
Swallows and other aerial insectivores are of special interest to scientists and conservationists because populations of many birds in this group are declining across North America and Europe. The reasons why arent yet fully understood. One major factor is probably agricultural pesticides used in habitats frequented by swallows: You cant have healthy aerial insectivore populations without lots of insects for them to eat, and our attempts to eliminate agricultural pests may be inadvertently harming birds that hunt for flying insects over fields and farms.
Below, weve profiled each of the eight swallow species found in the United States. Keep an eye out for these tiny insect-eaters the next time you go for a walk!
This plain, dusty-brown swallow with telltale smoky sides breeds across the lower 48 U.S. states and in southern Canada, then winters in the far-southern U.S., Mexico, and Central America. Another population breeds in Mexico. The unusual name comes from the stiff barbs on males leading flight feathers. These birds nest in natural crevices or burrows left by other species and also in human-made structures: Northern Rough-winged Swallow nests have been found in gutters, drainpipes, and holes in walls. This species ability to make use of these nest sites helps it adapt to areas modified by human activities. Look for Northern Rough-winged Swallows flying low over water to snatch up insects.
Both the Bank Swallows common name and its scientific name, Riparia riparia, give a clue to a preferred habitat: streamsides, where this bird nests colonially in burrows excavated in sandy banks. The Bank Swallow breeds across a large portion of North America and migrates to South America, but this species also nests across Eurasia, wintering in Africa and parts of tropical Asia; there, it is known as the Sand Martin, or Collared Sand Martin. Bank Swallows are brown above and white below, with a distinctive dark band across the chest. Theyre hard to survey accurately thanks to their ever-shifting colony sites, but Partners in Flight considers them a common species in steep decline, meaning action may be needed to keep populations healthy.
Like Bank Swallows, Barn Swallows have a worldwide distribution, and they are simply called Swallows in Europe. They can be recognized by their long, forked tails, and are blue above with orangey underparts and brick-red foreheads and throats. They build nests of mud, located primarily on human-made structures including bridges and culverts, as well as in barns. Their long association with humans has led to appearances in the folktales and superstitions of many cultures. North Americas Barn Swallow populations have declined by approximately 38 percent since 1970, likely due to the effects of climate change and agricultural pesticides.
The largest and darkest swallows in North America, Purple Martins breed mostly in the eastern U.S. and southern Canada, with scattered populations in the West. They migrate to South America to winter. Males are a deep blue-black, and females are duller with gray napes. Eastern birds probably nested historically in old woodpecker holes, but today they almost exclusively use apartment-style birdhouses provided by humans; western Purple Martins nest in natural cavities as well as birdhouses. Purple Martin populations have declined by about 23 percent since 1970. Threats to this species include agricultural pesticides, collisions with human-made structures, and competition for nest sites from introduced House Sparrows and European Starlings.
Male Tree Swallows are iridescent blue-green above and white below, and females are similar but duller overall. They often nest in old woodpecker cavities, and competition for nest sites can be intense, but they also eagerly move into nest boxes. Tree Swallows breed in much of the U.S. and Canada, winter from the southern U.S. south to Central America, and they are typically found in open habitats near water. They have been gradually expanding their breeding range southward, but overall their populations have declined by about 40 percent since 1970. Tree Swallows affinity for wetland habitats makes them vulnerable to exposure to mercury and other aquatic contaminants.
The most colorful of North Americas swallows, Violet-green Swallows have iridescent green and purplish backs, white undersides, and distinctive white patches on their rumps and faces. They are the only United States swallow found only in the West, breeding in the western U.S. and Canada and northern Mexico and wintering across much of Mexico, and in parts of Central America. Violet-green Swallows are close relatives of Tree Swallows and nest in rock crevices and old woodpecker cavities in open coniferous forests. Their populations are relatively stable overall, but some bird surveys suggest that they, like other aerial insectivores, are experiencing a gradual long-term decline.
Cliff Swallows once nested primarily in the mountains of western North America, but theyve expanded east as theyve adapted to nesting on human structures in addition to natural cliffs. Their populations are stable to increasing. Today, Cliff Swallows breed throughout much of the U.S., Canada, and Mexico, forming colonies of up to 6,000 nests. In winter, they migrate to South America. Like several other swallows on this list, Cliff Swallows are primarily blue above and whitish underneath, but theyre set apart by chestnut throats, white forehead patches (in most U.S. and all Canadian populations), square tails, and pale rumps.
In the U.S., the Cave Swallow nests mainly in Texas and South Florida, though there are also some places in New Mexico and Oklahoma where they breed. They are widespread in Mexico and the Caribbean. Cave Swallows are similar in appearance to their close relatives the Cliff Swallows, but with paler throats and no white forehead patch. Their natural nesting habitat is caves, as their name suggests, where their colonies may share space with bats. However, as with many other swallow species, the Cave Swallow has adapted to nesting on human-made structures. In fact, Cave Swallows expanded their range into the U.S. since the beginning of the 20th century largely by using highway overpasses and bridges as colony sites. Their population has increased significantly in recent decades.
Cliff Swallows used to nest mostly in the mountains of western North America, but as they adapted to nesting on man-made structures as well as natural cliffs, their range has expanded eastward. Their populations are stable to increasing. Today, Cliff Swallows breed throughout much of the U. S. , Mexico, and Canada, creating colonies with up to 6,000 nests each In winter, they migrate to South America. Cliff Swallows are mainly blue above and whitish underneath, like several other swallows on this list, but they are distinguished by chestnut throats, white forehead patches (in most U.S. S. and all Canadian populations), square tails, and pale rumps.
Swallows are small birds with small feet and beaks, and slender, pointed wings. They typically live in open habitats, often near water. While the specifics of their nesting sites differ among species, most swallows are socially monogamous, meaning that both parents help raise their young when a male and a female pair off to raise offspring.
Breeds throughout the lower 48 U.S. states, this plain, dusty-brown swallow with telltale smoky sides. S. states and southern Canada, spending the winter in the extreme south of the S. , Mexico, and Central America. Another population breeds in Mexico. The male’s leading flight feathers have stiff barbs, which give rise to the unusual name. These birds build their nests in man-made structures such as gutters, drainpipes, and wall holes, as well as in natural cracks or burrows abandoned by other species. Because it can use these nest sites, this species is better able to adapt to areas where human activity has caused changes. Seek out Northern Rough-winged Swallows as they soar low over bodies of water, capturing insects.
Similar to bank swallows, barn swallows are found all over the world and are simply referred to as “Swallows” in Europe. They are blue above, with orangey underparts and brick-red foreheads and throats; they are distinguished by their long, forked tails. They construct mud nests, which are mostly found in barns and on man-made structures like culverts and bridges. Due to their long history of human association, they can be found in many cultures’ folktales and superstitions. Since 1970, the number of barn swallows in North America has decreased by about 38%, most likely as a result of agricultural pesticides and the effects of climate change.
It’s likely that you have witnessed swallows swooping back and forth on quivering wings, catching insects in the air to consume. Swallows belong to a larger group of birds known as aerial insectivores, which means they capture insects on the wing. Swallows are members of the Hirundinidae family of birds, which has 86 species worldwide.
Calls edit Song of the
Swallows can make a wide variety of calls or songs, which they use to communicate with other members of their species, to show excitement, to court potential mates, or to warn of approaching predators. Male bird songs are associated with the physical state of the bird, and females likely use them to assess a male’s suitability for mating based on his physical attributes. [41] Young people use begging calls to ask their parents for food. Swallows typically twitter in a simple, occasionally melodious manner.
Status and conservation edit The
The loss of habitat is typically the cause of hirundine species that face extinction. This is thought to be the cause of the critically endangered white-eyed river martin’s decline; the species is only known from a small number of specimens that were collected in Thailand. The species most likely breeds along riverbanks, which are a severely reduced habitat in Southeast Asia. The species might already be extinct because it hasn’t been observed consistently since 1980. [42] Due to forest loss and competition from introduced species like starlings and sparrows, which vie with these swallows for nesting sites, two insular species, the Bahama swallow and golden swallow, have declined. The island of Hispaniola is now home to the golden swallow, which was last observed breeding on the island of Jamaica in 1989. [43].
FAQ
What bird is called a swallow?
Is a swallow a type of sparrow?
Is a swallow a songbird?
What kind of swallows are in the US?