Arctic Tern vs Harpy Eagle
Sterna paradisaea compared with Harpia harpyja
Side-by-Side Comparison
| Attribute | Arctic Tern | Harpy Eagle |
|---|---|---|
| Scientific Name | Sterna paradisaea | Harpia harpyja |
| Order | Charadriiformes | Accipitriformes |
| Family | Laridae | Accipitridae |
| Conservation Status | Least Concern | Vulnerable |
| Length | 34.0 cm (13.4 in) | 100.0 cm (39.4 in) |
| Wingspan | 80.0 cm (31.5 in) | 200.0 cm (78.7 in) |
| Weight | 110.0 g (3.88 oz) | 7500.0 g (264.55 oz) |
| Diet | Small fish and crustaceans caught by plunge-diving from the air. Hovers briefly before diving. | Arboreal mammals including sloths, monkeys, and opossums, which make up over 70% of the diet. … |
| Clutch Size | 2-3 | 2-3 |
| Population Trend | — | — |
Size Comparison
Habitat Comparison
Arctic Tern
Breeds on coastal and tundra habitats. Spends most of its life at sea over the open ocean. Nests in colonies on beaches and rocky shores.
Harpy Eagle
Tropical lowland rainforests, requiring large tracts of continuous forest with tall emergent trees for nesting.
Song & Call Comparison
Arctic Tern
A sharp, grating 'kree-yah' alarm call. Also gives 'kik-kik-kik' near the nest. Highly aggressive vocally during the Arctic breeding season. Calls are harsh and insistent.
Harpy Eagle
Rarely heard; emits mournful whistled screams 'wheee-oo' and low croaking grunts near the nest. Vocalizations poorly documented given its remote Amazonian habitat.
Geographic Range & Migration
Arctic Tern
Breeds in the Arctic and sub-Arctic. Migrates to the Antarctic, experiencing two summers per year. Found on every ocean.
Harpy Eagle
Central and South America from southern Mexico through Brazil and northern Argentina. Range is shrinking due to deforestation.
Conservation Status
Arctic Tern
Harpy Eagle
How to Tell Them Apart
Arctic Tern
Pale grey upperparts, white underparts with a black cap. Blood-red bill and short red legs. Deeply forked tail streamers. Winter adults lose the full black cap.
Slender, pointed, bright red bill
Harpy Eagle
Slate-black upperparts and head with a pale grey breast and white underparts with black barring. A distinctive split grey crest rises when the bird is alarmed.
Massive dark hooked bill, one of the largest of any eagle
About These Birds
Arctic Tern
The Arctic tern holds the record for the longest known migration of any animal, traveling roughly 70,000 km annually from Arctic to Antarctic and back. Over its 30-year lifespan, it may fly the equivalent of three round trips to the Moon. This remarkable bird experiences more daylight than any other creature on Earth.
Harpy Eagle
The harpy eagle is among the most powerful raptors in the world, with talons as large as a grizzly bear's claws. It is the national bird of Panama. Deforestation poses the greatest threat to this species, as each breeding pair requires a vast territory of undisturbed forest.