On warm summer days, it is not unusual to spot birds of prey circling effortlessly high overhead in the clear skies with outstretched wings. But why do these birds fly in circles? And is this technique of soaring in circular flight limited to birds of prey? If you want to find out more about how birds use air currents when flying, then please read on.
Birds take advantage of warm, rising air currents, called thermals, to lift themselves into the air, enabling them to soar at great heights. Soaring birds cover vast distances, while expending a minimal amount of energy, as the lift from the thermals does much of the hard work for them.
Birds carried by thermals can fly without the need for flapping their wings. Warm air from the Earth’s surface rises in a ‘bubble-like’ form, and when birds tap into these thermal updrafts, they are effectively lifted into the air to fly around the edge of the ‘bubble’, in what we see in the skies above us as circling flight.
Birds of prey flying in a circle
“Normal” sustained flight can be a huge drain on a bird’s energy reserves, with flapping of wings becoming tiring very quickly, especially for birds with wider wingspans. Using thermal currents to rise to great heights allows them to circle high in the air until they find another updraft to move to, gradually traveling through the air relatively effortlessly.
Migratory birds may be seen temporarily flying in circles during their migration journeys. The reason behind this is thought to be energy conservation, taking a brief chance to enjoy the benefits of the thermals to effectively rest mid-air before resuming their onward migration. This practice uses less energy than landing and taking off again, and is an adaptation to prolonging their reserves while on the wing.
As well as the benefit of using less energy, flying high above the ground in a circle gives soaring birds a wider field of vision over the land below to scan for prey or in some cases carcasses to feast on.
Birds of prey, such as hawks, which have highly developed eyesight, even from such heights, will circle prey from above, until the opportune moment to strike arises.
Spectacular exhibitions of circling flight of flocks of birds seen at sunset are known as murmurations. Safety in numbers may hold the key to these acrobatic en-masse movements, aerodynamically swirling across the sky, with birds being better protected against predators when flying as part of a larger group.
Read on to find out more about the types of birds that fly in circles, and discover what spiritual meanings circular bird flight may have in different cultures.
A red-tailed hawk circling in the sky
Circling flight is commonly associated with vultures, condors, and large soaring birds of prey, including buzzards, eagles, and hawks. These predators can be seen at high altitudes, effortlessly cruising the skies without the presence of even the slightest breeze.
The wider field of vision that circular flight provides enables scavenging birds such as vultures and condors to scan vast areas of land for carcasses and potential feeding sites.
Flocks of feeding pigeons may take flight when startled, circling overhead until they consider it safe to land again, either on the ground or in nearby trees.
Circular flight formations In starlings, these impressive formations are known as murmurations, but other species, such as wagtails and blackbirds fly together in large flocks, engaging in synchronized flight, which can follow circular or elliptical patterns.
Pelicans take advantage of thermals during their lengthy migration flights, using their vast wingspans to reach speeds of up to 56 km/h (35 mph) at heights of up to 3000 m (9850 ft). Periods of circular soaring allow them to rest their wings and scan wide areas of ocean for fish.
A large flock of vultures circling in the sky
Murmurations of large flocks of birds, commonly starlings and sparrows, may be seen undulating across the skies at sunset in impressive displays or circular or elliptical flight. It’s thought that these flocks form and fly together in such patterns to protect themselves against predation as they head towards their nightly roosts.
Another common time when you might catch sight of circling birds overhead is ahead of a storm. As with many animals, birds have the ability to sense changes in air pressure ahead of a thunderstorm, and will often take to the skies in circling flight before the storm breaks.
One explanation is that they use this calm before the storm to circle over land while assessing the best options for where to shelter if the rain is heavy or prolonged.
An impressive murmuration of Starlings
Flying in a group is thought to bring more protection from predators than flying as a solitary bird. Birds that fly alone stand a greater chance of being picked off or targeted by a bird of prey.
Large groups of birds flying together, moving in somewhat unpredictable circular or elliptical swirling motion have greater potential to confuse a predator, lowering their chances of a successful kill.
Linked to this concept of safety in numbers, another explanation for circular group flight is to swell the numbers of an existing flock. Murmurations, often seen at dusk, may start with a handful of birds, and gradually build up to dozens or even hundreds of birds, with the ultimate aim of survival – the chances of which are increased by flying en-masse.
Birds of prey, such as hawks, buzzards and eagles are less likely to be spotted engaged in circular group flights, tending instead to be solitary hunters enjoying the thermal currents – and the benefits they bring – alone.
In the UK, common buzzards can frequently be spotted circling throughout the countryside
The circular flight of birds has a range of associated spiritual meanings, both positive and cautionary, depending on the species.
Vultures circling overhead is considered an omen of impending doom, and a warning to take precaution to protect yourself and those you care about.
In Native American culture, birds flying in circles around a person can be interpreted as a spiritual sign, often thought to symbolize a visit from a deceased loved one or a message from a spirit guide.
Do you have a question about this topic that we haven't answered? Submit it below, and one of our experts will answer as soon as they can.
Get the latest BirdFacts delivered straight to your inbox