Communication between Apus apus occurs almost exclusively through the use of different vocalizations, or calls, and by changes in body language. The types of calls used by A. apus are largely dependent upon its age. There are different calls used by the adults than by the young. The most common call during flight, a long, shrill ‘sreee’, is used in innumerable contexts by adults. Also among the vocalizations of the adults are those given during allopreening (nest-call), those following defeat in a fight (piping-call), as well as those preceding copulation (pre-copulatory call). The most common call used by young is the food-call, used to beg for food from a parent upon its return.
Communication Channels: visual ; tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Apus apus is neither threatened nor endangered.
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Common swifts have no notable negative impacts upon humans, with the exception of the occasional nuisance of having them nest in the eaves and open spaces in the rooftops of many cities and villages across Europe.
Negative Impacts: household pest
Besides the fact that the common swift frequently nests in close association with humans, A. apus has no significant economical impact on humans. Apus apus may offer a slight benefit to humans by consuming pest insects such as mosquitos. However, it is unlikely that A. apus itself would have a significant impact on these pest populations. In some places common swifts are encouraged to nest in manmade structures so that the young can be harvested for food, however, this practice is not very common. Also the nests of some swifts are used by indigenous peoples of Asia as the key ingredient in bird’s nest soup.
Positive Impacts: food ; controls pest population
As a predator, A. apus contributes to the control of the insect population.
Commensal/Parasitic Species:
Common swifts are insectivorous, feeding solely on aerial insects and spiders that it gathers in its mouth as it glides through the air. The insects are gathered together inside the throat through the use of a product from the salivary glands, to form a food-ball or bolus. Apus apus is commonly attracted to swarms of insects, as it aides in the ease of collecting sufficient food. It has been estimated that there are an average of 300 insects per bolus, and that each nest of young may receive 3000 food-balls per day. These numbers may vary based upon the abundance of prey. Among some of the most commonly consumed insects are aphids (Hemiptera), wasps, bees, and ants (Hymenoptera), beetles (Coleoptera), and flies (Diptera).
Animal Foods: insects; terrestrial non-insect arthropods
Primary Diet: carnivore (Insectivore )
Common swifts, Apus apus, can be found in almost any region from western Europe to eastern Asia and from northern Scandanavia and northern Siberia to North Africa, Himalayas, and central China. Apus apus can be found throughout this range during the breeding season and, following migration, spends the winter months in Southern Africa, from Zaire and Tanzania south to Zimbabwe and Mozambique.
Biogeographic Regions: palearctic (Native ); ethiopian (Native )
The majority of the breeding habitat of A. apus is located in temperate zones, where there are suitable trees for nesting and sufficient open spaces in which to fly to gather food. The habitat of Apus apus during the months following migration into Africa, however, is tropical. Common swifts have been observed breeding from sea level to several thousand meters in elevation. Apus apus prefers areas with trees, or buildings with open spaces, and is able to use vertical surfaces such as rock walls and chimneys for nesting due to a unique physical adaptation possessed by all swifts (Apodidae).
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: forest
Other Habitat Features: urban ; suburban
Apus apus is typically long-lived. A common swift banded in Sweden was re-trapped at the age of 17. The annual survival rate for the adults is 65-83%.
Range lifespan
Status: wild: 21 (high) years.
Average lifespan
Status: captivity: 21.0 years.
Common swifts are 16-17 cm in length with a wingspan of 42-48 cm, depending upon the age of the individual. Common swifts are black-brown in color with the exception of a white to cream colored chin and throat (located directly underneath the beak). In addition, the topside of the flight feathers is a paler brown-black color in comparison to the rest of the body. Apus apus can also be distinguished by its moderately forked tail feathers, its narrow, sickle-shaped wings, as well as its shrill, screaming call. Apus apus is frequently mistaken for a swallow or a hummingbird. Apus apus is larger and has very a different wing shape and flight pattern than do hummingbirds or swallows. All members of the family Apodidae possess a unique morphological characteristic, a lateral “grasping foot” in which toes one and two are opposed by toes three and four. This allows the common swift to occupy areas such as walls of rock, chimneys, and other vertical surfaces that would be difficult for other types of birds to inhabit. Apus apus is a sexually monomorphic species, meaning that the males and females look alike. There has been no seasonal or geographical variation reported in the appearance. However, it is possible to distinguish juveniles from adults in the slight difference in richness and uniformity of their coloration, as it is common for juveniles to be blacker in color, as well as to have a pale forehead, white-fringed feathers, and a starker white patch under the beak. This distinction is best observed at close range.
Average length: 16-17 cm.
Range wingspan: 42 to 48 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
Average mass: 44.9 g.
Average basal metabolic rate: 0.4372 W.
Most notable among the anti-predator adaptations of A. apus is its aerial mastery, allowing these birds to avoid most of their natural predators, including Eurasian hobbies (Falco subbuteo), sparrowhawks (Accipiter nisus), and buzzards (Buteo buteo), by taking to the air. In addition, the choice of nesting sites on vertical surfaces such as rock walls and chimneys makes it difficult for common swifts to be preyed upon because of the level of difficulty associated with accessing the nest area. The plain coloration of Apus apus also is advantageous for predator evasion as it makes them difficult to see when they are not in the air.
Known Predators:
Apus apus usually first breeds at two years of age, but the age of the first breeding can vary based upon the availability of nesting sites. The common swift is a monogamous species, meaning that it typically has one partner in a lifetime, and that the bond between the pair is maintained from year to year. The male A. apus typically chooses the nest site. Upon the arrival of the female shortly thereafter (usually within a period of days), the nesting site is protected by the pair. The nest is typically composed of grass, leaves, hay, straw, and flower petals (among other things). The nesting site usually includes the nest itself and the areas directly surrounding the nest. Courtship, some copulation, and the rearing of the chicks all occur at this site. Colonies of A. apus typically include 30-40 nest sites, reflecting the gregarious nature of the common swift mating system. Apus apus is more likely to fight to defend a nesting site than it is to defend a mate. Males attract their female partners through attainment of a good nesting site prior to their meeting. Upon their first meeting it is not unusual for the initial responses of the potential mates, both male and female, to be hostile. If interested and unpaired, the female will enter the nest site tentatively, thereby inviting her potential partner to stroke her chin with its bill. If this encounter is successful, the female may also invite her potential partner to allopreen. Allopreening is the process by which birds smooth or clean each others feathers with their beak or bill. This mutual action begins the pair-bonding process.
Mating System: monogamous
Common swifts typically breed from late April to early May through mid-September when the young are fledged. One of the most unique characteristics of A. apus is its ability to mate while in flight, although they also can mate while perched. Mating occurs every few days following the arrival of suitable weather, until a few days after the young have fledged. Following a successful copulation, anywhere from one to four white eggs may be laid, however a clutch size of two is most common. Eggs must then be dutifully incubated for 19-20 days while the embryos develop. Both parents participate in the incubation of the clutch. After the young hatch, it can take an additional 27-45 days before fledging occurs.
Breeding interval: Apus apus breeds once yearly.
Breeding season: Common swifts breed from late April to early May through mid-September
Average eggs per season: 2.
Range time to hatching: 19 to 20 days.
Range fledging age: 27 to 45 days.
Average age at sexual or reproductive maturity (female): 2 years.
Average age at sexual or reproductive maturity (male): 2 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Both parents take turns incubating the clutch following fertilization and prior to hatching. For the duration of the first week following hatching, the clutch is typically brooded all day long. During the second week, the young are brooded for approximately half of the day. For the remainder of the time, until the clutch is fledged, they are rarely brooded during the day, but are almost always covered at night. Both parents participate equally in all aspects of the raising of the young. In the event that unusually bad weather persists or food sources become scarce during the time shortly after the hatching of the young, the young possess the ability to become semi-torpid, a hibernation-like state, thereby reducing the energy demands of their rapidly growing bodies. This adaptation allows young A. apus to survive with little food for 10-15 days. During the time from hatching until fledging, the young are fed almost exclusively in the nest. The young are fed food-balls consisting of insects gathered by the parents during flight and held together with a salivary gland product, creating the food bolus. While the young are smaller, they will share a food bolus among them. However, once young are larger they become able to swallow an entire food bolus on their own.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female)
