Arctic Tern vs Common Tern: Key Differences & Complete Comparison
When comparing Arctic Tern vs Common Tern, several key differences emerge despite their similar appearance. The Arctic Tern (Sterna paradisaea) holds the record for the longest animal migration, traveling up to 44,000 miles annually, while the Common Tern (Sterna hirundo) typically migrates 12,000-15,000 miles per year. These remarkable seabirds share many characteristics but differ in crucial ways.
Understanding these differences helps birders and researchers distinguish between these elegant species. From their distinctive calls to their preferred habitats, each species has evolved unique adaptations that set them apart. Let’s explore their key differences and similarities in detail.
© Kristian Pikner / CC BY-SA 4.0
The Arctic Tern exhibits distinctive features that set it apart from its cousin, the Common Tern. Note the shorter bill, more streamlined body shape, and translucent wing appearance in flight.
© Charles J. Sharp / CC BY-SA 4.0
The Common Tern shows its characteristic longer bill and darker wingtips. These features, along with its slightly larger size, help distinguish it from the Arctic Tern.
Key Differences: Arctic Tern vs Common Tern
| Feature | Arctic Tern | Common Tern |
|---|---|---|
| Size | 13-15 inches (33-38 cm) | 14-17 inches (35-43 cm) |
| Wingspan | 29-33 inches (74-84 cm) | 31-35 inches (79-89 cm) |
| Bill Length | Shorter, blood-red | Longer, orange-red with black tip |
| Migration Distance | Up to 44,000 miles annually | 12,000-15,000 miles annually |
| Breeding Range | Arctic regions | Temperate regions |
| Lifespan | Up to 30 years | Up to 25 years |
Habitat and Distribution
Arctic Terns breed in coastal areas and tundra regions of the Arctic Circle, while Common Terns prefer temperate coastlines and inland waterways across North America, Europe, and Asia. During winter, Arctic Terns travel to Antarctic waters, making them true pole-to-pole migrants. Common Terns generally winter along tropical and subtropical coastlines.
Behavior and Feeding
Both species are accomplished hunters, diving for small fish and marine invertebrates. Arctic Terns typically dive from higher altitudes (30-50 feet), while Common Terns hunt from lower heights (20-40 feet). Their fishing success rates are similar, with both species catching prey on about 60% of attempts.
Breeding and Reproduction
Nesting Habits
- Arctic Terns: Simple ground scrapes on tundra or rocky outcrops
- Common Terns: More substantial nests, often with vegetation
- Both species: Highly territorial during breeding season
Clutch Size and Incubation
- Arctic Terns: 1-3 eggs, 21-24 days incubation
- Common Terns: 2-4 eggs, 21-22 days incubation
Conservation Status
Both species face similar challenges from climate change and habitat loss. While neither is currently endangered, their populations are monitored closely due to their role as indicator species for marine ecosystem health. Arctic Terns are particularly vulnerable to changes in polar environments, while Common Terns face pressures from coastal development.
Who Would Win in a Confrontation?
While direct confrontations are rare outside of breeding territory disputes, Common Terns generally have a slight advantage due to their larger size and more robust bill. However, Arctic Terns are known for their aggressive defense of breeding territories, even against much larger birds. In most cases, these encounters end in aerial displays rather than physical contact.
Identification Tips for Birdwatchers
To distinguish between Arctic Tern vs Common Tern, focus on these key features:
- Bill color and length
- Wing pattern in flight
- Tail streamers length
- Call differences (Arctic Terns have a higher-pitched call)
- Breeding location and timing
These remarkable seabirds continue to captivate researchers and nature enthusiasts alike, each species representing unique adaptations to their respective niches in marine ecosystems.
