Soaring For Survival - Unveiling Swifts

30th June 2024

Swifts feed on small flying insects, capturing them mid-flight. These insects accumulate in a specialised pouch located at the back of the swift's throat, where they are bound together by saliva, forming a pellet or bolus. This bolus can be regurgitated and fed to their chicks. A single bolus can contain as many as 1,000 insects, which equates to a substantial number of midges.

Swifts are unique in their nesting choices. Unlike many birds that prefer trees or ground-level locations, swifts predominantly nest in cavities. In urban areas, they favour old buildings, using crevices, eaves, and holes to establish their nests. They exhibit strong site fidelity, often returning to the same nesting site year after year to raise their young. This behaviour means we need to preserve their nesting habitats and educate others as to why they cannot be relocated easily.

Swift Awareness Week
Swifts, along with their relatives, swallows and house martins, are some of the most captivating birds to grace our skies. Their remarkable aerial prowess, long migratory journeys, and unique nesting habits make them a focal point for bird lovers across the UK and beyond.

Each year, nature enthusiasts and conservationists come together for the RSPB's Swift Awareness Week, a crucial initiative aimed at raising awareness and promoting efforts to protect these remarkable birds. Swift Awareness Week events are organised by various independent local groups within the Swifts Local Network, as well as by RSPB local groups and RSPB nature reserves.

Common swifts (Apus apus) are renowned for their extraordinary flight capabilities. Spending almost their entire lives on the wing, they eat, sleep, and even mate in the air. Swifts are easily recognisable by their scythe-like wings and rapid, screaming sound and flight patterns, often seen darting through urban landscapes during the summer months. They can fly up to 70mph! Imagine!

Migratory Routes and Overwintering
The migratory journey of swifts is a marvel of nature. Each year, swifts travel from their breeding grounds in the UK to wintering sites in sub-Saharan Africa. This migration covers thousands of miles, with swifts typically departing the UK in late July and returning by late April or early May.

Their journey is not a direct one. Swifts follow a route that takes them through various countries in Europe and across the Mediterranean Sea. From there, they traverse the Sahara Desert, continuing down to Central and Southern Africa. Specific overwintering sites are spread across countries like Congo, Gabon, and parts of East Africa, where they find the insects they need to survive the winter months.

For those with an interested in the evolution of long distance migration patterns, I stumbled across this interesting paper on the subject: https://academic.oup.com/evolut/article/74/10/2377/6727314

Aerial Cousins
Let's not us forget the swallows and house martins, who are close relatives of swifts, sharing similar migratory patterns and aerial lifestyles.

Swallows (Hirundo rustica) are known for their long, forked tails and fluid flight. They often nest in barns and under eaves, creating mud nests lined with feathers.

House Martins (Delichon urbicum) have a distinctive white rump and build nests from mud pellets under the eaves of buildings. Like swifts, they are excellent flyers and spend much of their time in the air catching insects.

Both swallows and house martins also migrate to sub-Saharan Africa for the winter, making incredible journeys similar to those of swifts.

Swifts, Swallows and House Martins are currently experiencing a dramatic 40% decline in population according to the citizen science project the Breeding Bird Survey, which raises serious concerns about their future. https://www.theguardian.com/environment/article/2024/may/16/swallows-swifts-house-martins-decline-uk-bird-survey-aoe

The primary factors contributing to this decline include:

Loss of Nesting Sites: Modern building practices often eliminate the cavities these birds rely on for nesting.

Insect Declines: Less flying insects - mean less food!

Habitat Destruction: The destruction of habitats along migratory routes and in wintering grounds impact populations.

Due to these threats, swifts are classified as Red on the UK's Birds of Conservation Concern list, indicating that they are a high conservation priority.

For much more on this topic go to Highland Highlife HERE