Swallow

Cliff or Barn Swallow


These slender, sleek birds are well known for their long migration and nesting habits. Cliff and barn swallows spend their winters in South America and summers in North America. They arrive around March in the southern part of the country, reaching the northern states in April. They are very territorial and will always come back to the same nesting site. 
These swallows have made a very successful switch from cliffs and caves to man made structures for placement of their mud pellet nests. Increased insect populations from modern agriculture and shelter created by man made structures are two reasons given for this transition. Unfortunately, this success has often been at the expense of a frustrated homeowner. The swallow now faces strong competition from the introduced house sparrow for food and shelter. This may be why their numbers appear to be dwindling. Swallows are a protected species and their arrival is a sign of spring for many. The return of the swallows to San Juan Capistrano in California is a well-noted annual festival.

Swallows have about 8 members of the Hirundinidae Family living in the North American Region. Of the 8, only 2 regularly build mud nests attached to buildings, and other structures. The Cliff Swallow (Hirundo pyrrhonota) and the Barn Swallow (Hirundo rustica) are most often in conflict with humans the most.
 Cliff swallows will live in colonies of up to several hundred pairs. Barn swallows usually nest as a single pair or a few pairs in one structure. "The cliff swallow, 5 to 6 inches in length, is the only squared-tailed swallow in most of North America." It has a "pale, orange-brown rump, white forehead, dark, rust colored throat, and steel-blue crown and back. The barn swallow, 5.75 to 7.75 inches long, is the only swallow in the United States with a long, deeply forked tail. Barn swallows have steel-blue plumage on the crown, wings, back, and tail. The forehead, throat, breast, and abdomen are rust colored." The females are usually duller in color than the males.

Habitat: Four basic conditions are found near most cliff and barn swallow nest sites: (1) an open habitat for foraging, (2) a suitable surface for nest attachment beneath an overhang or ledge, (3) a supply of mud of the proper consistency for nest building, and (4) a body of fresh water for drinking."

 General Biology: Both cliff and barn swallows migrate to South America for the winter. They will begin their return north in late winter and early spring. Swallows travel during the day and catch flying insects along the way. The migratory route of a swallow will always have an abundant level of flying insects. Swallows have a tendency to return to the same nest year after year, under suitable conditions.

Most swallow nests are inhabited by hematophagous (bloodsucking) insects and mites. Swallow bugs (Oeciacus vicarius), most common in cliff swallow nests, can spread rapidly from nest to nest. Swallow bugs reduce nestling growth rates and cause up to half of all nestling deaths." These bugs are able to survive in unoccupied nest for up to 3 years. When swallows are picking out a nest, they will asses which nesting sites have a large infestation of swallow bugs and they will avoid nesting there.

Cliff swallow nests are gourd-shaped, enclosed structures with an entrance tunnel that opens downward. The mud pellets used by the swallows consist of sand, silt, and clay. The inside is lined with grass, hair, and feathers. "The nest is cemented with mud under the eave or overhang of a building, bridge, or other vertical surface."

Barn swallow nests are cup-shaped. The mud pellets "contain coarse organic matter such as grass stems, horse hairs, and feathers. The nest cup is profusely lined with grasses and feathers. Both male and female swallows help build the nest. They have to take their time, allowing the mud to dry and harden. Depending on the climate, nest construction could take up to 2 weeks. "A typical cliff swallow's nest contains about 900 - 1400 mud pellets. 

Swallows lay their eggs during early spring. Male and female swallows help incubate the eggs. Incubation usually occurs before the last egg is laid. "Whitewash on the ground below the nest or on the rim of the nest entrance is a sign of newly hatched nestlings inside the nest. Juvenile swallows will leave the nest approximately 24 days after hatching. After leaving the nest, swallows can stay near the nest, but normally they will start migrating south around late summer.

Damage: Cliff swallows nest in colonies and often live in close association with humans." Because of cliff swallows nature to build clustered mud nests, they can do a lot of damage to a structure aesthetically. They also cause a health hazard around humans because of the heavy infestation of swallow bugs, mites, and ticks. Even though barn swallows live in smaller numbers, they cause the same amount of damage.

Control
   All swallows enjoy special protection under the law. You can not disturb them once the nest is completely built and they lay their eggs in the nest.

   The only way to eliminate cliff and barn swallow problems is to take down the nests in the winter after they are gone and exclude them from returning by using 3/4” StealthNet. The netting needs to be angled across the eaves to prevent access to any sharp building angles. Several strands of Birdwire can also be run under eaves in strategic patterns at angles to prevent nest build up as well. A new product called Bird slide can be installed in the corner to break up the angle and keep swallows from building a nest in that location.

Legal Status: In the United States, all swallows are classified as migratory insectivorous birds under the Migratory Bird Treaty Act of 1918." All states offer swallows the same protection. One must obtain permission from local, state, and federal officials to treat for swallows. As a general rule, if eggs or nestlings are present in a nest, a permit authorizing nest removal must be obtained. A permit for swallow nest removal can only be issued if very compelling reasons exist.