www.swallowconservation.org/enhancing-cliff-swallow-habitat, Here is an Audubon article on artificial nests at SJC for further reading. Swallows will not penetrate regions unless flying insects are available for food, which usually occurs after a few days of relatively warm weather (70°F or more). Clusters of their intricate mud nests cling to vertical walls, and when a Cliff Swallow is home you can see its bright forehead glowing from the dim entrance. to cliffs each year. The extremely social American cliff swallow's life revolves around its flock: it forages, preens, gathers mud, sunbathes, nests, migrates and winters in large groups. # Cliff swallows often trespass into each other's nests. American cliff swallows never have a problem sharing their food sources. They will not. Basic Description. Site Selection . We still do not understand completely why cliff swallows choose (or do not choose) particular places to live. Cliff swallows are federally protected, migratory songbirds, and it is a violation of state and federal laws to harm them or interfere with their nests while they are breeding. The breeding season for swallows lasts from March through September. Though the cliff swallow still settles along the cliffs and canyons of western North America, it has adapted to alternative nesting sites across the U.S.: many bridges, dams or buildings offer protective overhangs and suitable vertical surfaces on which to attach a nest. The American cliff swallow feeds entirely on insects caught in flight. We are often asked if the swallow bug parasites in cliff swallow nests on buildings will come into a home and infest humans. The cliff swallow generally nests in dense colonies on cliffs, banks, dams and bridges; groups of several thousand nests have been observed. Construction can cause nest loss or abandonment due to vibration, noise, or obstruction of the birds’ access. Cliff swallows arrive at their breeding areas by May.The birds are more comfortable in flight; on land, they shuffle along when gathering mud to build their mud nests. We are working with the Mission to try to restore cliff swallows to the site. Attempts to entice them to settle at a particular site by providing wet mud have not been successful. Busy flocks of Cliff Swallows often swarm around bridges and overpasses in summer, offering passers-by a chance to admire avian architecture and family life at once. American cliff swallows are abundant throughout their range and are currently not threatened.Their adaptability in nesting sites has led to the expansion of their range across the United States. Efforts to reduce conflicts include re-scheduling highway construction to non-breeding times of the year, using plastic netting or barriers, broadcasting alarm calls to prevent settlement during construction, and installing Teflon sheeting to nest-attachment areas to block the birds' access. The female swallow incubates the 4-5 eggs for up to 16 days; after hatching, the chicks are able to fly by 24 days, but still rely on their parents for food.The juveniles gather to form large crèches and depart with their parents for wintering grounds from July to September. Most measures have had only mixed success at discouraging nesting, and we do not recommend enacting any of these methods once birds are present at a colony site. The plaster nests have not yet been occupied, but in 2017 two pairs of cliff swallows nested elsewhere at the Mission. To discourage them from nesting at a site, old nests can be removed during the non-breeding season (that is, only in winter when no cliff swallows are present). In this damp and dreary climate, the bird tends to forage alone. The birds preen their feathers and sunbathe together at their daytime perches on wires, small twigs and rooftops, and they roost together at night, clinging to reeds and tall grasses. the nests at the edges of a colony are more vulnerable to attack. ^ Dense colony Hundreds of nests are packed close together. Foraging in large groups of up to 2,000 birds, the cliff swallow searches for swarms of insects.The birds tend to focus on areas of relatively high altitudes; however; in cool and cloudy weather the cliff swallows feed just above the ground or water surface due to lack of visibility and decreased availability of swarming insects. Central nests are sought after; because i». There are occasional reports of swallow bugs coming into a building, usually because of a disturbance to the birds' nests where the bugs reside or because of unusually warm spring weather that brings the bugs out of diapause early before cliff swallows return. A dedicated cliff swallow nesting structure was built at Thunder Valley Casino in Lincoln, California, which attracted birds in large numbers, . Cliff swallows arrive at nest colonies in successive waves. Previous attempts to attract swallows with playbacks of vocalizations, a project begun in 2012. , were unsuccessful.