Lesser Crested Tern vs Chinese Crested Tern

In short

The most reliable field mark to separate Lesser Crested Tern from Chinese Crested Tern is the bill: Lesser Crested Tern has a long, sharp orange bill, while Chinese Crested Tern shows a stouter yellow bill with a distinct black tip. In flight, check the rump color—Lesser Crested Tern has a grey rump, whereas Chinese Crested Tern has a white rump. Both are medium-large terns with similar black caps and pale grey upperparts, but careful attention to bill pattern and rump color will separate them at all ages. Juvenile and nonbreeding birds are especially tricky, so focus on these structural and color differences.

Identification tips

1. Bill color and shape (all ages): Lesser Crested Tern has a long, sharp orange bill; Chinese Crested Tern has a stouter yellow bill with a distinct black tip (sometimes with a white point at the very tip). This is the most reliable field mark at any distance where bill color is visible.
2. Rump color in flight (all ages): Lesser Crested Tern shows a grey rump and central tail feathers; Chinese Crested Tern has a white rump and tail. This is especially useful for birds in flight or distant perched birds with the rump exposed.
3. Mantle shade (adults): Chinese Crested Tern has a paler grey mantle compared to Lesser Crested Tern, but this difference is subtle and best used in direct comparison.
4. Juvenile plumage: Juvenile Lesser Crested Terns are paler overall with only faint dark crescents on the mantle and a yellow-orange bill. Juvenile Chinese Crested Terns are not described in detail, but should show the stouter yellow bill with black tip, following the adult pattern.
5. Leg color: Both species have black legs, so this is not helpful for separation.
6. Crown pattern (breeding): Both have a full black cap in breeding plumage; this does not separate them.
7. Forehead (nonbreeding): Both species develop a white forehead in nonbreeding plumage, so this is not a separator.
8. Primary feather darkness (summer): Lesser Crested Tern's primary flight feathers darken in summer, but this is not contrasted for Chinese Crested Tern and may not be reliable.
9. Bill structure: Chinese Crested Tern's bill is not only different in color but also noticeably stouter than the long, slender bill of Lesser Crested Tern. This is visible at close range or in photos.
10. Size and structure: Both are very similar in size and general proportions; do not rely on overall size or jizz for separation.
11. Tail and central tail feathers: Lesser Crested Tern has grey central tail feathers, while Chinese Crested Tern's tail is white; this is best seen in flight or when the tail is fanned.
12. Context and range: Both species can overlap in wintering areas, so do not use location alone for identification.
13. Voice: Lesser Crested Tern has a loud, grating call similar to Sandwich Tern, but no vocal information is available for Chinese Crested Tern; do not use voice as a separator unless familiar with both.
14. Pitfalls: Beware of confusing Lesser Crested Tern with Greater Crested or West African Crested Terns, which are larger and have different bill and rump colors; Chinese Crested Tern is best separated from Lesser Crested by bill tip and rump color.
15. When in doubt: Focus on the bill (color and shape) and rump (grey vs white) as the two most consistent and visible field marks, especially in mixed flocks or distant views.

Size

Both species are medium-large terns and very close in size, with Lesser Crested Tern measuring 35–43 cm in length and Chinese Crested Tern 38–43 cm. The mass for Lesser Crested Tern averages around 209 g [wikidata], but no specific mass is given for Chinese Crested Tern. In the field, size is not a reliable separator between these two, as their dimensions overlap almost completely.

Plumage

Juvenile and immature birds of both species are similar, but Lesser Crested Tern juveniles are paler overall with only faint dark crescents on the mantle and a yellow-orange bill, while Chinese Crested Tern juveniles (not described in detail in the notes) should follow the adult pattern of a stouter yellow bill with a black tip. For adults in breeding plumage, both have a full black crown, pale silvery-grey back and wings, and white underparts. The key difference is the bill: Lesser Crested Tern's is long, sharp, and orange, while Chinese Crested Tern's is stouter, yellow with a black tip (sometimes with a white point at the very tip). In flight, Lesser Crested Tern shows a grey rump and central tail feathers, while Chinese Crested Tern has a white rump and tail. The mantle is also paler grey in Chinese Crested Tern. In nonbreeding (winter) plumage, both species develop a white forehead, but the bill and rump differences persist and remain diagnostic.

Behaviour

Both species feed by plunge-diving for fish, typically in saline environments. Lesser Crested Tern is noted for diving directly rather than using the 'stepped-hover' technique of Arctic Tern, but this is not contrasted for Chinese Crested Tern. Courtship in Lesser Crested Tern includes fish-offering by the male. Both species breed in dense colonies on coasts and islands, with similar nesting behavior. Behavioral differences are subtle and not reliably diagnostic in the field.

Habitat

Both species occur in similar coastal and island habitats, often overlapping in wintering distribution. There is no strong habitat separation in the notes; both are found in saline environments and breed on coasts or islands, usually in dense colonies.

Voice

Lesser Crested Tern gives a loud, grating call similar to Sandwich Tern. No vocal description is provided for Chinese Crested Tern, so voice is not a reliable field separator based on the available notes.