Identification
Swallows have slender, streamlined bodies and wings that are long and pointed. Their bodies are evolutionarily conservative to allow for endurance and maneuverability. Swallows have short bills with wide gaps and strong jaws. The length of the body ranges from 3.9 to 9.4 inches, and the average body weight is between 0.35 and 2.1 ounces. Swallows have long tails with 12 feathers that are typically either deeply forked or slightly indented.
Types
Swallows, saw-wings and martins fall into the same family, but each is distinctive in color or shape. The biggest difference between species and subspecies is in the tail. Common swallows include the tree swallow, golden swallow, white-winged swallow, Chilean swallow, violet-green swallow, bank swallow, barn swallow and northern rough-winged swallow. Saw-wings also fall into the swallow family, including the square-tailed saw-wing, fanti saw-wing, black saw-wing and mountain saw-wing.
Geography
Swallows can be found throughout the world. Swallows live and breed on six of the seven continents, the only exception being Antarctica. The greatest distribution of swallow species is found in Africa, which is where swallows are believed to have originated. Swallows are also commonly found across many oceanic islands. Many swallow species in North America and Europe are long-distance migrants, while species in Africa tend not to be migratory at all.
Feeding
Swallows are primarily insectivorous and do their hunting in the air. Each species has a primary group of insects that it hunts. Diet will also vary depending on time of year. Many swallow species also consume plant matter and fruits. Some African swallow species eat Acacia tree seeds. Swallows forage for prey primarily on the wing, though they will also hunt insects on the ground and from tree branches. Swallows primarily hunt slower-moving insects, taking advantage of their own speed and maneuverability to attack insects in the air.
Communication
Swallows are known for their ability to produce a variety of different songs and calls. They use these calls and songs to express excitement as well as to communicate with other swallows to warn of predators or attract attention during courtship. The songs and calls that a male communicates tell females whether or not he is suitable for mating.