Apus apus
Silhouette: Ferran Sayol · PhyloPic
In 3 days ~40% in a week ~70%
The common swift (Apus apus) is a medium-sized bird, superficially similar to the barn swallow or house martin but somewhat larger, though not stemming from those passerine species, being in the order Apodiformes. The resemblances between the groups are due to convergent evolution, reflecting similar contextual development. The swifts' nearest relatives are the New World hummingbirds and the Southeast Asian treeswifts.
Its scientific name Apus is Latin for a swift, thought by the ancients to be a type of swallow with no feet (from Ancient Greek α, a, "without", and πούς, pous, "foot"). Swifts have very short legs which they use primarily for clinging to vertical surfaces (hence the German name Mauersegler, literally meaning "wall-glider"). They never settle voluntarily on the ground where they would be vulnerable to accidents and predation, and non-breeding individuals may spend up to ten months in continuous flight.
The common swift was one of the many 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 erected by the Italian naturalist... Wikipedia →
Possible
About 20% of wildlife watchers report a Common Swift sighting in Belgrade on a given day, based on 623 verified sightings from GBIF citizen-science data. It is the 36th most-seen of the 144 birds we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
June
In that month about 70% of wildlife watchers report a Common Swift in Belgrade on a given day, against under 5% in September to March, the lowest months. That is one of Belgrade's wettest months, with about 85 mm of rain against 45 mm in February.
Between 5 and 8 pm
Across all the parks we cover, that three-hour window holds the most Common Swift sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
56th of 103
Of the 103 cities where we can rate Common Swift sightings, Belgrade ranks 56th at about 20%. The best odds are in Tashkent (Uzbekistan, about 70%), Amman (Jordan, about 60%) and Yerevan (Armenia, about 50%).
GBIF citizen-science records
It is estimated from how often the Common Swift is recorded against all the birds logged in Belgrade (623 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
