The Royal Society for the Protection of Birds Northern Ireland (RSPB NI) is asking local people for their support in helping the organisation to build a clearer picture of the population of Swifts in the country.
Swifts travel for around 12,000 miles between Ireland and Africa every single year to feed and breed and are characterised by an acrobatic flying pattern.
They can be seen swooping high through the skies with distinctive scythe-shaped wings - and they even eat and sleep while in flight. They only touch down when they are nesting and have very short feet that allow them to climb up vertical surfaces like walls. Having such short feet combined with extremely long wings means they are unable to take off from the ground so a Swift that is found at ground level will need to be taken into specialist care
Cracks and crevices in high buildings are typically made homes of by Swifts - and the birds usually pair with a mate for life. After migrating, the birds reunite with their mate at the same nest, which they reuse year after year.
However, these sites can be lost as old buildings are renovated or demolished, which can make it very difficult for a displaced pair of birds to find a suitable new home to lay eggs and raise chicks before heading back to Africa in August.
Concerns have been raised by RSPB NI that the Swift population is in decline, with the species being raised to amber-listed status - or of medium conservation concern. The wildlife charity is aiming to help them by learning where they can be spotted and where they are nesting.
The best time to look for them is usually around dusk on a warm evening, or early morning. They can often be seen entering a roof or hole in a building at low-level roof height. If they can be heard screaming it means they are breeding nearby.