Swifts are aerial birds, spending up to ten months of each year on the wing. Summers are spent in Europe and the far north of Africa, followed by a long migration flight that ends in southern Africa.
But what do they eat to power such extensive flight periods? And do swifts ever feed on the ground? Read on to learn more about the dietary habits of these graceful sickle-winged birds.
Common swifts (Apus apus) survive on a diet of flying insects, caught and eaten mid-air. Their legs and feet are not adapted for walking on the ground, and they would never feed at a garden bird feeder. Insects up to around 12 mm (0.5 in) are taken, caught at speeds of up to 25 mph.
Flying at altitudes of 2300 m (7550 ft) on clear days, swifts take advantage of reaching heights that other insect-eating birds cannot access, and eat a wide range of flying insects, with one survey counting 312 different species of small insects and spiders in their diet.
Weather affects their ability to fly and hunt for food, and in summer swifts are known to fly around storms to reach clear skies, in order to safely forage. On their wintering grounds, the reverse is true, as wet weather brings with it an increase in insects, which means an abundance of insect life in the air.
To learn more about the feeding habits of swifts, scroll down, as we answer all the questions you might have on this fascinating topic.
Swifts mainly consume flying insects, which they catch in the air
Swifts are insectivores, feasting on insects and small spiders they catch on the wing. They never feed on land, and are not equipped with sharp talons for catching or gripping prey, so are limited to eating flying insects and aerial spiders.
They are not particularly fussy, which helps when they are feeding young and need to catch up to 10,000 insects in a day! According to a report, hoverflies are the most commonly eaten prey.
Swifts do not eat any seeds or plant-based foods, or fruits. They catch their prey while in flight and never land, so you won’t ever see one checking out your bird feeders or berry bushes.
Swifts forage while flying, and have been recorded to eat a wide and varied diet, with more than 300 insect and spider species identified. Observations show that they avoid insects with stings, such as female bees and all wasps. However, they are known to prey on stingless male bees, so they instinctively know which individuals to avoid.
Insects commonly eaten by swifts include dragonflies, flies, flying ants and beetles, aphids, moths, and mosquitoes.
Common Swift hunting for insects in the air
Swifts constantly eat, particularly during the breeding season when they need to collect thousands of insects each day to feed their young. During migration flights, swifts are known to fly solidly for up to four days without food or water.
Swifts never visit bird feeders; they are not physically built to walk on land and have no interest in any food typically offered in back gardens.
Swifts spend their days on the wing, and feed opportunistically. They sleep in flight, and can be seen and heard screeching across the sky at dusk or soaring at great heights at first light.
On summer days they are frequently seen soaring at high altitudes at the warmest part of the day, often in groups of a dozen or more – what we cannot see from below is that as they fly, they are catching and eating tiny insects.
Swifts feast on insects that they find while flying, hunting at speeds of up to 25 miles per hour at heights of between 50 and 100 m (165 ft to 330 ft) in the air.
In wet weather, it’s common to see swifts at lower altitudes, often around ponds, lakes and reservoirs, where they feed off aquatic insects and low-flying bugs that are easier to catch because of the poor flying conditions.
Swifts hunt insects in the air at up to 25 miles per hour, up to 100 meters (330 ft) high
All swifts leave their summer breeding grounds in Europe and North Africa in late summer, heading to southern Africa where they spend their winters.
European climates do not support sufficient insect life once the temperatures start to fall, so migrating south is the only option for their survival.
When swifts arrive in southern Africa, temperatures there are warming up, and locally spring is beginning. The diet of a swift on its African wintering grounds is virtually identical to its summer European one, with mosquitoes, hoverflies, aphids, and moths in abundance.
Swifts spend summers breeding, and keeping up with the demands of their hungry nestlings is quite a task. On a typical summer day, nesting swifts will catch upwards of 10,000 tiny insects to bring to their young.
Insects such as mosquitoes, hoverflies, moths, flying ants and aerial spiders are abundant in summer months, offering swifts an abundance of foraging opportunities.
Food caught on the wing by adult swifts is stored in a ‘bolus’, a kind of ball-shaped mass bound together by saliva, and kept in the back of the throat until they return to the nest site. Up to 1,000 insects at a time can be stored in this way.
Young swifts need a lot of food until they are ready to fledge, and up to 20,000 insects may be brought to the nest on a single day.
A small flock of Swifts in flight together
Swifts will not be attracted to any food that may be on offer in your back garden, so if you’re hoping to catch sight of one on your feeders or bird table, you’ll be out of luck. However, on the rare occasion that you come across a grounded swift, you should not attempt to feed it.
Instead, seek advice on how best to help it get airborne again, or if it is young, malnourished or injured, specialist wildlife rescue organizations will be able to help.
If you do find an injured, traumatized or grounded swift, it is important to seek an expert’s advice and not attempt to feed it yourself. Foods such as grains, mealworms, bread and earthworms are highly unsuitable for swifts and should never be offered.
Swifts will not be attracted by humans leaving out food for them, but they may be tempted to raise their young in a specially designed swift nesting box, mounted high on the roof or side of a house.
Natural nesting sites used by swifts are in decline, due to modern construction techniques, but environmental campaigners are seeking to encourage swift numbers by popularizing the use of swift bricks in new homes that are built.
Swifts are opportunists, and spend most of the day foraging for flying insects
Like the vast majority of bird species, swifts do need to drink water regularly in order to survive. They seek hydration from lakes, ponds, reservoirs, and streams.
Similar to their approach to eating, swifts do not pause to drink, and any water is taken on the wing. They fly over lakes and reservoirs, scooping a beak full of water as they skim the surface.
Swifts are a natural form of pest control, due to the sheer number of insects they consume on a daily basis. They are also no threat to gardens or pets, and do not destroy agricultural crops or damage any property or habitats. Swifts are also an absolute delight to watch in summer skies.
Close up of an adult Common Swift taking a drink of water
Swifts are known to avoid stinging insects, but have been recorded to eat male, stingless drone bees.
It is believed that swifts avoid eating wasps and other stinging insects. Their diet may include gall wasps, which do not have a sting.
Mosquitoes are among the chief insect prey of swifts, particularly as they migrate across the humid savannah landscapes on their way to their southern African wintering grounds.
Swifts are a delight to watch in the sky
Dragonflies are frequently eaten by swifts. They are often caught near lakes and reservoirs when swifts swoop down to drink from the water’s surface and take advantage of the aquatic insects commonly found in such environments.
Butterflies may sometimes be eaten by swifts, although they are at the larger end of the scale of prey that they target. Most insects caught by swifts are a maximum of 12 mm (0.5 in), so the larger butterfly species may be too big for them to manage.
Swifts do eat smaller moths caught in flight, but will not eat their larvae or caterpillars.
Flying ants are common prey of swifts and will readily be caught and eaten on the wing. Terrestrial ants, however, are not eaten, as swifts do not forage on land.
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