Heermann's Gull vs South American Tern
Larus heermanni compared with Sterna hirundinacea
Side-by-Side Comparison
| Attribute | Heermann's Gull | South American Tern |
|---|---|---|
| Scientific Name | Larus heermanni | Sterna hirundinacea |
| Order | Charadriiformes | Charadriiformes |
| Family | Laridae | Laridae |
| Conservation Status | Near Threatened | Least Concern |
| Length | — | — |
| Wingspan | 67.2 cm (26.5 in) | 59.3 cm (23.3 in) |
| Weight | 448.26666666666665 g (15.81 oz) | 190.25 g (6.71 oz) |
| Diet | -- | -- |
| Clutch Size | 1-2 | 1-3 |
| Population Trend | — | — |
Habitat Comparison
Conservation Status
Near Threatened
Heermann's Gull
Least Concern
South American Tern
About These Birds
Heermann's Gull
Heermann's Gull, 46–51 cm, is distinctive — dark grey body, white head (breeding), red bill. Breeds almost entirely on Isla Rasa in the Gulf of California, then disperses north along the Pacific coast to British Columbia. Kleptoparasite; steals fish from Brown Pelicans. Near Threatened; range highly restricted.
South American Tern
South American Tern, 40–44 cm, is the largest South American tern, breeding from Peru around Cape Horn to southeastern Brazil. Red bill, grey mantle, black cap. Pelagic and coastal piscivore; strong plunge-diver. Movements poorly known; some populations may migrate north along both coasts.