Tachymarptis melba
Silhouette: Andy Wilson · PhyloPic
In 3 days ~70% in a week ~90%
The alpine swift (Tachymarptis melba) is a species of swift found in Africa, southern Europe, and Asia. They breed in mountains from southern Europe to the Himalayas. Like common swifts, they are migratory; the southern European population winters further south in southern Africa. They have very short legs which are used for clinging to vertical surfaces. Like most swifts, they never settle voluntarily on the ground, spending most of their lives in the air living on the insects they catch in their beaks.
The alpine swift was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae. He placed it with the swifts in the genus Hirundo and coined the binomial name Hirundo melba. Linnaeus specified the type locality as Gibraltar. Linnaeus based his account on "The greatest martin or swift" that had been described and illustrated in 1743 by the English naturalist George Edwards in his book A Natural History of Uncommon Birds. Edwards's specimen had been shot on the rock of Gibraltar. The alpine swift is now placed together with the mottled swift in the genus Tachymarptis that was introduced in 1922 by the South African zoologist... Wikipedia →
Possible
About 30% of wildlife watchers report an Alpine Swift sighting in Sofia on a given day, based on 1,208 verified sightings from GBIF citizen-science data. It is the 19th most-seen of the 99 birds we can rate there. Over three days the chance rises to about 70%, and over a week to about 90%, if each day is a fresh chance.
June to August
In those months about 70% of wildlife watchers report an Alpine Swift in Sofia on a given day, against under 5% in November to February, the lowest months.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Alpine Swift sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is most active around dawn and dusk.
4th of 40
Of the 40 cities where we can rate Alpine Swift sightings, Sofia ranks 4th at about 30%. The best odds are in Fez (Morocco, about 70%), Istanbul (Turkey, about 40%) and Athens (Greece, about 30%).
GBIF citizen-science records
It is estimated from how often the Alpine Swift is recorded against all the birds logged in Sofia (1,208 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.
