Larus cachinnans
Silhouette: Sharon Wegner-Larsen · PhyloPic
In 3 days ~10% in a week ~20%
The Caspian gull (Larus cachinnans) is a large gull and a member of the herring and lesser black-backed gull complex. The scientific name is from Latin. Larus appears to have referred to a gull or other large seabird, and cachinnans means 'laughing', from cachinnare 'to laugh'.
It is a large gull at 56–68 cm (22–27 in) long, with a 137 to 155 cm (54 to 61 in) wingspan and a body mass of 680–1,590 g (1.50–3.51 lb). Among standard measurements, the wing chord is 38.5 to 48 cm (15.2 to 18.9 in), the bill is 4.6 to 6.4 cm (1.8 to 2.5 in) and the tarsus is 5.8 to 7.7 cm (2.3 to 3.0 in). The Caspian gull has a long, slender bill, accentuated by the sloping forehead. The legs, wings, and neck are longer than those of the herring gull and yellow-legged gull. The eye is small and often dark, and the legs vary from pale pink to a pale yellowish colour. The back and wings are a slightly darker shade of grey than the herring gull, but slightly paler than the yellow-legged gull. The outermost primary feather has a large white tip and a white tongue running up the inner web.
First-winter birds have a pale head with dark streaking on the back of the neck. The underparts are pale... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Hortobágy National Park | 🇭🇺 Hungary | |
| 2 | Kiskunság National Park | 🇭🇺 Hungary | |
| 3 | Fertő-Hanság National Park | 🇭🇺 Hungary | |
| 4 | Białowieża National Park | 🇵🇱 Poland | |
| 5 | Biebrza National Park | 🇵🇱 Poland | |
| 6 | Wadden Sea National Park | 🇩🇪 Germany | |
| 7 | Bavarian Forest National Park | 🇩🇪 Germany |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Kharkiv Zoo | 🇺🇦 Ukraine | |
| 2 | Kharkiv Dolphinarium | 🇺🇦 Ukraine |
Rare
Under 5% of wildlife watchers report a Caspian Gull sighting in Białowieża National Park on a given day, based on 31 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 137th most-seen of the 182 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.
June and August–November
In those months about 10% of wildlife watchers report a Caspian Gull in Białowieża National Park on a given day, against under 5% in July and December–May, the lowest months.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Caspian 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.
4th of 7
Of the 7 parks where we can rate Caspian Gull sightings, Białowieża National Park ranks 4th at under 5%. The best odds are in Hortobágy National Park (Hungary, about 50%), Kiskunság National Park (Hungary, about 40%) and Fertő-Hanság National Park (Hungary, about 10%).
GBIF citizen-science records
It is estimated from how often the Caspian Gull is recorded against all the birds logged in Białowieża National Park (31 verified sightings from 2019 to 2026), 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.
