Larus crassirostris
Silhouette: Sharon Wegner-Larsen · PhyloPic
In 3 days ~10% in a week ~30%
The black-tailed gull (Larus crassirostris) is a gull native to shorelines of East Asia. The black-tailed gull is medium-sized (46 cm or 18.1 in), with a wingspan of 126–128 cm (49.6–50.4 in). It has yellow legs and a red and black spot at the end of the bill. Males and females have identical plumage and features, although males are larger in size than females. This gull takes four years to reach full adult plumage. As the name suggests, it has a black tail. The bird has a cat-like call, giving it its Japanese name — umineko (海猫, 'sea cat'), and Korean name — gwaeng-yi gull, which means 'cat' gull. In Hachinohe their calls are one of the 100 Soundscapes of Japan.
The species is resident to coastlines of the East China Sea, Japan, Manchuria and the Kuril Islands. It is a vagrant to Alaska and North America and has been found in the Philippines. The bird is common in Japan, nesting from Hokkaido to Western Kyushu. It has caused flights to be delayed at Haneda Airport in Tokyo.
An enormous gathering of black-tailed gulls can be found at Kabushima, a peninsula (formerly an island) in Hachinohe, Aomori, Japan. A Shinto shrine... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Zhuhai Chimelong Ocean Kingdom | 🇨🇳 China | |
| 2 | Chimelong Spaceship | 🇨🇳 China | |
| 3 | Tierpark Berlin | 🇩🇪 Germany | |
| 4 | Zoorasia | 🇯🇵 Japan | |
| 5 | Walsrode World Bird Park | 🇩🇪 Germany | |
| 6 | Beijing Zoo | 🇨🇳 China | |
| 7 | Beijing Aquarium | 🇨🇳 China |
Rare
Under 5% of wildlife watchers report a Black-tailed Gull sighting in Osaka on a given day, based on 316 verified sightings from GBIF citizen-science data. It is the 65th most-seen of the 180 birds we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
August
In that month about 20% of wildlife watchers report a Black-tailed Gull in Osaka on a given day, against under 5% in November to June, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Black-tailed Gull sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
12th of 20
Of the 20 cities where we can rate Black-tailed Gull sightings, Osaka ranks 12th at under 5%. The best odds are in Busan (South Korea, about 60%), Dalian (China, about 40%) and Qingdao (China, about 20%).
GBIF citizen-science records
It is estimated from how often the Black-tailed Gull is recorded against all the birds logged in Osaka (316 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.
