Swifts live in small groups. There are about 100 species, usually grouped into two subfamilies and four tribes. This is the fastest bird in the world, which is dependent on weather conditions. The swift was created for air and freedom. They are found on all continents, with the exception of Antarctica and distant islands, where they have not yet been able to reach. In European folklore, swifts were known as “Devil's Birds” — probably due to their inaccessibility and, like owls, they attract more attention.
Origin of the species and description
Swift – medium size, looks like a swallow, but a little larger. The similarities between these groups are due to convergent evolution, reflecting similar lifestyles based on catching insects in flight. However, their paths diverged in the distant past. Their closest relatives are New World hummingbirds. The ancients considered them to be a swallow without legs. The scientific name Apus comes from the ancient Greek α – “without” and πούς – “leg”. The tradition of depicting swifts without legs continued into the Middle Ages, as can be seen from heraldic images.
Fun Fact: Swift taxonomy is complex, with generic and specific boundaries often contested. The analysis of behavior and vocalizations is complicated by the general parallel evolution, while the analysis of various morphological characters and DNA sequences has given ambiguous and partially contradictory results.
The common swift was one of the species described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae. He introduced the binomial name Hirundo apus. The current genus Apus was formed by the Italian naturalist Giovanni Antonio Scopoli in 1777. The predecessor of the Central European subspecies that lived during the last ice age has been described as Apus palapus.
Swifts have very short legs, which are used primarily for grasping vertical surfaces. They never voluntarily land on the ground where they may be in a vulnerable position. During periods of non-breeding, some individuals can spend up to ten months in continuous flight.
Appearance and Features
Swifts have a length of 16 to 17 cm and a wingspan of 42 to 48 cm, depending on the age of the specimen. They are black-brown except for the chin and throat, which can be white to cream. Other than that, the upper parts of the flight feathers are pale brown-black compared to the rest of the body. Swifts can also be distinguished by moderately forked tail feathers, narrow sickle-shaped wings, and shrill screaming sounds. They are very often mistaken for swallows. The swift is larger, has a completely different wing shape and flight diagonal than the swallows.
All species in the family Apodidae (swifts) have a unique morphological characteristic, a lateral “grasping foot” in which toes one and two oppose toes three and four. This allows regular shears to attach to areas such as stone walls, chimneys, and other vertical surfaces that other birds cannot reach. Males and females look the same.
Individuals show no seasonal or geographic variation. However, it is possible to distinguish young chicks from adults by a slight difference in saturation and uniformity of coloration, since juveniles are usually more black in color, as well as feathers with white fringe on their foreheads and a white spot under the beak. These differences are best observed at close range. They have a short forked tail and very long lowered wings resembling a crescent moon.
Swifts produce a loud call in two different tones, the highest of which comes from females. They often form “scream parties” on summer evenings when 10-20 individuals gather in flight around their nesting site. Large screaming groups form at high altitudes, especially towards the end of the breeding season. The purpose of these parties is unclear.
Where does the swift live?
Swifts live on all continents except Antarctica, but not in the far north, in large deserts or on oceanic islands. Common swifts (Apus apus) can be found in almost every region from Western Europe to East Asia and from northern Scandinavia and Siberia to North Africa, the Himalayas and central China. They live throughout this range during the breeding season, and then migrate during the winter months in southern Africa, from Zaire and Tanzania south to Zimbabwe and Mozambique. The summer distribution range extends from Portugal and Ireland in the west to China and Siberia in the east.
They breed in countries such as:
Germany and other European countries.
Common swifts do not breed in the Indian subcontinent. Most nesting habitat is located in temperate zones, where there are suitable trees for nesting and enough open spaces in which to forage. However, swifts' habitat becomes tropical for several months after migrating to Africa. These birds prefer areas with trees or buildings with open spaces, as they are able to use vertical surfaces such as stone walls and chimneys due to their unique physical adaptation.
What does the swift eat?
Common swifts are insectivorous birds and feed exclusively on aerial insects and spiders, which they capture with their beaks during flight. Insects are brought together in the throat with a salivary gland product to form a food ball or bolus. Swifts are attracted to swarms of insects, as they help to quickly collect enough food. It is estimated that there are an average of 300 insects per bolus. These numbers may vary depending on the abundance and size of prey.
The most commonly used insects:
Birds fly with their beaks open, catching prey using quick maneuvers or simply fast flight. One of the species of swifts can reach a speed of 320 km/h. They often fly near the surface of the water to catch insects flying there. When gathering food for newly hatched chicks, adults deposit beetles in their elastic throat pouch. After the pouch is filled, the swift returns to the nest and feeds the young. Young nesting swifts are able to survive days without food by lowering their body temperature and metabolic rate.
Interesting fact: With the exception of the nesting period, swifts spend most of their lives in the air, living on the energy they receive from insects caught in flight. They drink, eat, sleep on the wing.
Some individuals fly for 10 months without landing. No other bird spends so much of its life in flight. Their maximum horizontal flight speed is 111.6 km/h. In a lifetime they can cover millions of kilometers.
Character and lifestyle features
Swifts — very sociable bird species. They typically nest, live, migrate, and hunt for food in groups throughout the year. In addition, these birds are unique in their ability to stay aloft for long periods of time. It is not uncommon for them to spend all day on the wing, only landing to feed young chicks or to roost. It is estimated that common swifts fly at least 560 km per day during the nesting season, which is a testament to their endurance and strength, as well as incredible aerial abilities.
Swifts can also mate and forage while in the air. Birds prefer to fly in lower airspace when the weather is bad (cold, windy and/or high humidity), and move to higher airspace when the weather is favorable for sustained aerial activity.
Interesting fact: In August and September, swifts leave Europe and begin their journey to Africa. Sharp claws are extremely useful during this flight. Although the chicks hatch before the start of the migration, observations show that many juveniles do not survive the long journey.
Swifts can nest in former woodpecker hollows found in forests, for example about 600 nesting birds in Belovezhskaya Pushcha. In addition, swifts have adapted to nesting in artificial areas. They build their nests from airborne material captured in flight and combined with their saliva, in building voids, in gaps under window sills and under eaves and inside gables.
Social structure and reproduction
Swifts start breeding at the age of two and form pairs that can join for years and return to the same nest and partner year after year. The age of first breeding may vary depending on the availability of nesting sites. The nest consists of grass, leaves, hay, straw and flower petals. Swift colonies include 30 to 40 nests, reflecting the gregarious nature of the birds.
Common swifts breed from late April to early May and until mid-September when juveniles fledge. One of the bird's most unique characteristics is its ability to mate in flight, although they can also mate in the nest. Mating takes place every few days after the onset of suitable weather. After successful copulation, the female lays one to four white eggs, but the most common clutch size is two eggs. Incubation lasts for 19-20 days. Both parents participate in incubation. After hatching, it can take another 27 to 45 days before fledging occurs.
During the first week after hatching, the clutch is heated all day long. During the second week, parents keep the chicks warm for about half the day. The rest of the time, they rarely heat the masonry during the day, but almost always cover it at night. Both parents are equally involved in all aspects of raising the chicks.
Fun fact: If bad weather persists or food sources become scarce, hatchlings have the ability to become semi-torpid , as if going into hibernation, thus reducing the energy requirement of their rapidly growing body. This helps them survive on a small amount of food for 10-15 days.
Nestlings are fed food pellets consisting of insects collected by the parents during flight and held together by the salivary gland, creating a food bolus. Small chicks share a food bolus, but as they get bigger they can swallow a whole food bolus on their own.
Natural enemies of swifts
Adult black swifts have few natural enemies due to their extreme flight speeds. There are few documented cases of attacks on these birds. The strategic placement of nests helps swifts to prevent attacks from land-based predators. Placement of nests in recesses provides cover from above, and in combination with dark skin and down feathers that camouflage the chicks from above, protection from air attacks is provided. In some cases, nests that are easy to see have been devastated by humans.
The swifts' unique, centuries-old defensive adaptations allow birds to avoid most of their natural predators, including:
- Hawk (Falco Subbuteo);
- Hawk (Accipiter);
- Common Buzzard (Buteo buteo).
The choice of nesting sites on vertical surfaces, such as rock walls and chimneys, also makes hunting common swifts difficult due to the difficulty of accessing the nest area. The simple coloration also helps to avoid predators, as they are difficult to see when they are not in the air. The vast majority of cases of attacks on swifts are associated with their eggs collected by people before the 21st century.
The black swift is more prone to mortality due to harsh environmental conditions. The typical location of the nest in wet areas poses a potential hazard to the chicks. If the baby falls out of the nest prematurely or flies out before it can sustain a long flight, or they may be washed away by water or their feathers become weighted with moisture. Nests can be lost due to flash floods.
Population and species status
Monitoring populations of swifts is hampered by the difficulty of detecting the nests they occupy, and sometimes by the large distances from the nest where they can breed, and often by a significant midsummer influx of non-breeding individuals in the vicinity of breeding colonies. Since swifts usually do not start breeding until they are at least two years old, the number of non-breeding individuals can be large.
Some international organizations are concerned to facilitate the provision of nesting sites for swifts, as so many suitable places are constantly shrinking. They are also collecting information on populations to try to ascertain the breeding status of each species.
This species has an extremely large range and therefore does not approach the Vulnerable species thresholds in terms of range size. The population is extremely large and therefore does not approach the thresholds for the vulnerable in terms of population size. For these reasons, the species is rated as Least Endangered.
Although the swift population has disappeared in some places, they can still be seen in fairly large numbers in cities and many other areas. Since they are not disturbed by the presence of a human, it can be expected that swifts will not be endangered anytime soon. However, twelve species do not have enough data for classification.