Mongolian Gull
Larus mongolicus
蒙古银鸥
Introduction
A large gull species in the Larus complex native to interior eastern Asia. Taxonomically raised to separate species rank in 2024 based on distinct morphology and vocal repertoire. Breeds primarily on large inland lakes, both fresh and saline, from the Altai Republic to Lake Baikal, across northern Mongolia, and at Lake Khanka in northeast China. A small population also breeds on islands in the Yellow Sea west of South Korea. In winter, migrates southeast to the coasts of Japan, the Korean Peninsula, eastern and southern China, Taiwan, and northern Vietnam. Identification requires careful examination of wing pattern and moult, and in juveniles, the wing and tail patterns, due to close similarity with Caspian gull, Vega gull, and European herring gull.
Description
A large gull closely similar to its relatives Caspian gull, Vega gull, and European herring gull. Males weigh 1.15–1.58 kg and females 0.85–1.1 kg, making it somewhat heavier than Caspian gull but similar to Vega gull and nominate European herring gull. The mantle and wings are mid-grey with black primary tips, distinctly darker than European herring gull and slightly darker than Caspian gull, though similar to Vega gull. There is geographic variation: birds from northwest Mongolia are darker grey, while those from Lake Baikal are paler, approaching the coloration of European herring gull L. a. argenteus. Most individuals have pink legs, though some show yellow to bright yellow tinges. Eyes are dull yellowish, sometimes brownish. The bill is stout, similar to European herring gull and Vega gull, and stouter than Caspian gull.
Distribution & Habitat
Breeding range extends from the Altai Republic to Lake Baikal in central southern Russia, across northern Mongolia, and at Lake Khanka in northeast China. A small population breeds on islands in the Yellow Sea west of South Korea within the normal wintering area. In winter, migrates southeast to the coasts of Japan, the Korean Peninsula, eastern and southern China, Taiwan, and northern Vietnam. Prefers large inland lakes, both fresh and saline, during the breeding season. Reports from the Indian Ocean region including India, Pakistan, and the Persian Gulf are considered unlikely and unreliable, with no ringing recoveries from that area.
Behavior & Ecology
Diet and detailed breeding behavior are not described in available sources. However, the species possesses a distinct vocal repertoire, which contributed to its 2024 taxonomic elevation to species rank. Social behavior patterns require additional study.
Culture
No cultural information available.
Source: Wikipedia · CC BY-SA 3.0
Taxonomy
- Order
- Charadriiformes
- Family
- Laridae
- Genus
- Larus
- eBird Code
- casgul4
Distribution
breeds Altai Republic to Lake Baikal (south-central Russia) and Mongolia, Lake Khanka (Heilongjiang, northeastern China), and Yellow Sea islands (western Korean Peninsula); winters mostly to coastal wetlands of Japan, Korean Peninsula, eastern China, and Taiwan
Data Sources
Species description from Wikipedia, licensed under CC BY-SA 3.0.
Taxonomy data from AviList 2025.