Birds migrate for a variety of reasons, usually to find more favorable environments and food sources as seasons change. Some species migrate only short distances while others embark on epic journeys spanning thousands of miles. When it comes to the longest migratory routes, small birds punch well above their weight class and undertake some of the most incredible migrations in the animal kingdom.
What factors enable small birds to migrate long distances?
Many small bird species, like warblers, sandpipers, and plovers, are capable of migrating enormous distances despite their tiny size. So what enables them to pull off such feats?
- Light body weight – Small birds can fly long distances efficiently because they don’t have to generate as much lift or thrust to stay airborne compared to larger, heavier birds.
- High metabolism – Small migratory birds have very fast metabolic rates and can refuel quickly during stopovers to power their journeys.
- Strong flight muscles – Long distance migrants often have large pectoral muscles relative to their body size to sustain prolonged flight.
- Built-in navigation – Many migratory birds have innate biological compasses and map senses that guide them on their journeys.
- Favorable wind patterns – Small birds often strategically plan migration to capitalize on seasonal tailwinds that help push them along.
Thanks to these adaptations, diminutive birds can achieve awe-inspiring migratory feats across immense distances.
Which small bird species makes the longest migration?>
Here are some of the smallest birds that take on the longest migrations each year:
1. Arctic Tern
- Total migration distance: Up to 49,700 miles roundtrip
- Route: Arctic breeding grounds to Antarctic and back
- Length: 8 inches
- Wingspan: 20 inches
- Weight: 2-4 oz
The Arctic tern makes the longest migration of any bird species. After breeding in the Arctic summer, the Arctic tern embarks on a journey spanning some 49,700 miles to reach its wintering grounds in the Antarctic seas. In the process, this epic migration takes the birds through nearly every longitude on Earth. The total distance traveled during an Arctic tern’s lifetime adds up to an astonishing 1.5 million miles.
2. Bar-tailed Godwit
- Total migration distance: 6,800-9,000 miles one way
- Route: Alaska and Canada to New Zealand
- Length: 15-16 inches
- Wingspan: 26-29 inches
- Weight: 10-14 oz
After breeding in Alaska and northern Canada, the bar-tailed godwit makes a nonstop trans-Pacific flight across the ocean to reach its wintering grounds in New Zealand and eastern Australia. Spanning 6,800-9,000 miles, it’s recognized as the longest nonstop flight of any bird. Bar-tailed godwits make this journey in a single bound without pausing to rest or refuel. Satellite tracking has clocked nonstop flight durations of over seven days for this epic journey across the Pacific.
3. Great Snipe
- Total migration distance: 4,970 miles one way
- Route: Northern Europe/Western Siberia to Sub-Saharan Africa
- Length: 10-12 inches
- Wingspan: 17-20 inches
- Weight: 4-7 oz
The great snipe migrates from its breeding grounds in northern Europe and western Siberia all the way down to Africa south of the equator. Their migration route passes through eastern and central Europe before crossing the Mediterranean Sea and Sahara Desert. Total migration distances can exceed 4,970 miles as the birds make this tremendous journey between continents.
4. Red Knot
- Total migration distance: 9,300 miles one way
- Route: Canadian Arctic to southern South America
- Length: 9-11 inches
- Wingspan: 20-24 inches
- Weight: 4-6 oz
The red knot is a sandpiper species that breeds in the far north of Canada and Alaska. Come winter, it migrates down to the very tip of South America, reaching key wintering sites in Tierra del Fuego at the southern end of Chile and Argentina. Red knots fly as far as 9,300 miles between their Arctic breeding grounds and winter homes off South America’s southern coast.
5. Northern Wheatear
- Total migration distance: 9,000 miles one way
- Route: Alaska/Canada to eastern and southern Africa
- Length: 6 inches
- Wingspan: 12 inches
- Weight: 1 oz
Northern wheatears nest in Alaska and Canada before heading off on an epic transoceanic journey to reach their winter quarters in Africa. Their route takes them across the Atlantic, including a nonstop flight of at least 2,100 miles over open ocean. Total migration distances can add up to 9,000 miles as the birds wing their way between the continents.
What are the longest overwater migration routes?
Since most small birds migrate north and south between continents, some of the longest overwater migration routes include:
- Alaska to New Zealand – Bar-tailed godwit (6,800+ miles)
- Northeastern North America to South America – Semipalmated sandpiper (3,700 miles)
- Northeastern Asia to Southeast Asia – Eastern curlew (2,800 miles)
- Alaska to Hawaii and South Pacific – Bristle-thighed curlew (2,000+ miles)
- Northeastern North America to northern South America – Sanderling (1,800 miles)
These marathon transoceanic flights require extensive fat reserves and navigational precision. By timing departures, catching helpful tailwinds, and using innate programs to maintain direction, small birds manage nonstop journeys of thousands of miles over open water between stopover sites.
How do small birds physically complete such long migrations?
Completing migrations of many thousands of miles is an astonishing feat for any animal, let alone tiny birds weighing just a few ounces. So how do they pull it off?
- Make short hops – While some migratory legs involve long ocean crossings, most small birds cover large distances via a succession of much shorter flights interspersed with stopovers to rest and feed. This allows them to refuel and complete journeys of thousands of miles via manageable hops.
- Fatten up pre-migration – Small migratory birds put on substantial fat reserves before migration commences. This extra body fat provides the fuel needed to fly long distances without food.
- Fly in efficient V-formations – migrating in V-shaped flocks takes advantage of aerodynamic factors that reduce energy expenditure for trailing birds.
- Utilize helpful tailwinds – Small birds often strategically time migrations to occur when seasonal winds are blowing in the same direction as their travel, providing an extra push.
- Use innate programming – Migratory birds rely on innate biological compasses, star maps, and mental maps to travel accurately between seasonal sites, often the same ones each year.
Thanks to these physical and behavioral adaptations, tiny birds can achieve migratory journeys spanning thousands of miles between hemispheres.
Do smaller birds migrate faster than larger birds?
Research shows that smaller migratory bird species do tend to travel faster than larger birds during migration flights. There are a few key reasons behind this:
- Lower body drag – The smaller frontal profile of tiny birds reduces aerodynamic drag compared to larger birds, letting them fly faster relative to their power output.
- Lower energy requirements – Small birds need less energy for propulsion during sustained flights due to their lighter body weight.
- Faster wingbeats – Smaller birds flap their wings more quickly, enabling faster forward propulsion compared to larger birds with slower wingbeats.
- More efficient fliers – The flight styles and aerodynamics of many small birds are extremely efficient, further boosting airspeed.
However, while small birds can fly faster over a given distance, larger birds can often cover more total distance in a single migratory flight due to greater fuel reserves. The differences in speed depend greatly on the exact species being compared.
Conclusion
The exceptional migratory capabilities of tiny birds are one of the great wonders of the natural world. By making the most of innate advantages like their light weight and advanced navigation systems, small birds complete some of the longest and most arduous migrations on Earth. Champions of endurance like the Arctic tern and bar-tailed godwit fly incredible distances up to tens of thousands of miles between hemispheres as they chase favorable habitat and resources with the seasons. Carefully tailored adaptations enable these birds to achieve such feats and migrate farther than many much larger species.
