Chroicocephalus genei
Silhouette: Michael Scroggie · PhyloPic
In 3 days ~10% in a week ~20%
The slender-billed gull (Chroicocephalus genei) is a mid-sized gull which breeds very locally around the Mediterranean and the north of the western Indian Ocean (e.g. Pakistan) on islands and coastal lagoons. Most of the population is somewhat migratory, wintering further south to as far as North Africa and India. A few birds have wandered to western Europe. A vagrant individual was reportedly seen on Antigua, April 24, 1976 (AOU, 2000).
The genus name Chroicocephalus is from Ancient Greek khroizo, "to colour", and kephale, "head". The specific genei commemorates Italian naturalist Giuseppe Gené. This species is 37 to 40 cm (14.6 to 15.7 in) long with a 90 to 102 cm (35.4 to 40.2 in) wingspan. It is therefore slightly larger than the black-headed gull, which it resembles, although it does not have a black hood in summer. It has a pale grey body, white head and breast and black tips to the primary wing feathers. The head and dark red bill have an elongated tapering appearance, and this bird also appears long-necked. The legs are dark red, and the iris is yellow. In summer, the breast has a faint pink colouration. This bird takes two years to reach maturity, as is... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Camargue | 🇫🇷 France | |
| 2 | Doñana National Park | 🇪🇸 Spain | |
| 3 | Murchison Falls National Park | 🇺🇬 Uganda | |
| 4 | Lake Nakuru National Park | 🇰🇪 Kenya |
Rare
Under 5% of wildlife watchers report a Slender-billed Gull sighting in Mumbai on a given day, based on 228 verified sightings from GBIF citizen-science data. It is the 119th most-seen of the 283 birds we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
December to February
In those months about 10% of wildlife watchers report a Slender-billed Gull in Mumbai on a given day, against under 5% in March to November, the lowest months. Those are among Mumbai's driest months, with almost no rain against 830 mm in July.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Slender-billed Gull sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
17th of 26
Of the 26 cities where we can rate Slender-billed Gull sightings, Mumbai ranks 17th at under 5%. The best odds are in Kuwait City (Kuwait, about 60%), Manama (Bahrain, about 60%) and Karachi (Pakistan, about 40%).
Same genus: Chroicocephalus
The closest relatives of the Slender-billed Gull that you can see in Mumbai (genus Chroicocephalus, Masked Gulls and allies) are Brown-headed Gull (about 10%) and Black-headed Gull (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Slender-billed Gull is recorded against all the birds logged in Mumbai (228 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.
