How High and How Fast Do Birds Fly? In general, birds fly in accordance with the teasing advice that pilots frequently receive: “fly low and slow.” The average cruise speed is between 20 and 30 mph, and the fastest accurately recorded air speed is about 47 mph for an eider duck. But during a chase, things pick up speed. Ducks, for instance, can fly 60 mph or more, and reports suggest that a Peregrine Falcon can reach 200 mph (though 100 mph may be more typical). It’s interesting to note that a bird’s speed and size don’t really correlate. The maximum speeds that geese and hummingbirds can travel are comparable. Naturally, there is a significant difference between a bird’s maximum speed and its typical flying speed. One might anticipate that when the bird is “around home,” it will either minimize its metabolic rate—that is, use less energy per unit of time—or maximize the distance it travels for each unit of energy used. Similar to an observation aircraft pilot, a vulture searching for prey might maximize endurance, and a seabird flying to far-off feeding grounds might maximize range, akin to a Concorde facing headwinds during a transoceanic flight. Staying up longest does not necessarily mean going farthest. A bird’s maximum endurance in the air is six hours at 15 mph, or 90 miles, or five hours at 20 mph, or 100 miles, maximum range. As they race to defend a territory or are being pursued by a predator, birds can also opt to fly as fast as possible. Or they can choose some compromise between speed and range. Gary Schnell and Jenna Hellack of the University of Oklahoma measured the ground speeds of a dozen species of seabirds (gulls, terns, and a skimmer) close to their colony using Doppler radar, a tool akin to that used by police to apprehend speeders, in order to ascertain what the birds typically did. They also used an anemometer to measure the wind speed, which they then used to calculate the birds’ airspeeds. (Since surface friction slows air movements near the ground, some estimation errors resulted from measuring wind speeds generally closer to the ground than the birds did.) The majority of airspeeds were observed to be between 10 and 40 mph. It was possible to determine each bird’s power requirements at each speed, and using that data, it was determined that the birds were typically compromising between increasing their range and lowering their metabolic rates, with a greater focus on the former. Although airspeeds varied greatly, significant variations in airspeed did not necessitate sharp increases in energy consumption when the airspeed was close to the minimum metabolic rate. For instance, a gull that could fly at any speed between 15 and 28 mph without increasing its metabolic rate by more than 15 percent would be able to maintain its most efficient loiter airspeed of 22 mph. Most birds fly below 500 feet except during migration. There is no need to use the energy to go higher, and doing so could put you in danger from things like exposure to stronger winds or hawks’ keen vision. However, birds frequently soar to relatively high altitudes during migration, perhaps to evade dehydration in the warmer air near the ground. In the Caribbean, migratory birds are typically seen at elevations of 10,000 feet, though some are found at elevations of half or even twice that. Long-distance migrants typically begin their journey at 5,000 feet and gradually ascend to 20,000 feet. Similar to jet aircraft, migrants’ ideal cruise altitude rises as their “fuel” runs out and their weight decreases. In order to search wider areas for food and to observe the behavior of distant vultures for clues as to the location of a feast, vultures will occasionally soar above 10,000 feet. An airline pilot visually identified a flock of Whooper Swans at 29,000 feet after they were spotted on radar arriving over Northern Ireland during their migration, which is arguably the most impressive altitude record. Since bird lungs can extract a larger fraction of oxygen from the air than can mammal lungs, birds are able to fly at altitudes that would be impossible for bats to reach. SEE: Flight and Wing Shapes; Soaring; Vee Formation Flight; Flight Adaptations Copyright ® 1988 by Paul R. Ehrlich, David S. Dobkin, and Darryl Wheye.
Yellow warbler migration is another example of rapidity. The average temperature in New Orleans on April 5 is 65°F, which is when this species arrives from its wintering grounds in the Tropics. This warbler moves north far more quickly than the spring does, arriving at its breeding grounds in Manitoba in late May, when the average high is only 47° F. Throughout their entire journey, they experience progressively colder weather, and in the 15 days from May 11 to 25, they cross a region of the country that typically takes 35 days to traverse in the spring. Most northern species that winter in the Gulf States, as well as those that spend the winter south of the United States, are accustomed to “catching up” with spring. The Canada goose, mallard, pintail, common crow, red-winged blackbird, and robin seem to be the only six exceptions to this rule.
A remarkable illustration of a late but extremely quick spring migration is provided by the snow goose. Most of these geese spend the winter in Louisiana’s vast coastal marshes, where over 400,000 of them do so each year. Congregations of 50,000 or more of these birds can be seen grazing in the “pastures” or soaring overhead in a variety of sizes. Their primary breeding grounds are the northern Hudson Bay islands of Baffin and Southampton, where extreme cold is the norm save for a few weeks every year. Even though the season is quickly approaching in their winter quarters and their nesting grounds are still heavily covered in ice and snow, the birds are not encouraged to migrate. This suggests that an internal mechanism, such as gonad development, regulates the stimulus for spring departure. As a result, blue geese stay in the coastal marshes until the end of March or the beginning of April, at which point the local birds have already begun their busy breeding season. As far as the United States is concerned, the birds are moving quickly and practically nonstop northward; while occasional reports of large flocks of birds have been made in the Mississippi Valley, eastern South Dakota, and southeast Manitoba, there are few reports along the path of the massive flocks that spend the winter in Louisiana. The birds appear to take a long break after arriving in the James Bay region because they are not spotted close to their breeding grounds until the first of June. They arrive on the Arctic tundra in their thousands during the first two weeks of that month, and each pair immediately gets to work raising their brood.
It has been noted that the American robin is a slow migrant; as a species, it takes 78 days to travel the 3,000 miles from Iowa to Alaska, a distance that advancing spring crosses in 68 days. But in this instance, that doesn’t always imply that robins are sluggish as individuals. The species’ northward migration is most likely dependent on birds continuing to advance from behind, meaning that the first birds to arrive in a suitable location are the ones that establish a nest there, and the remaining birds continue the species’ northward migration.
Given that this would best preserve the birds’ strength, it appears likely that the majority of migratory flights are made at little more than the typical, unforced rate of flight. When migrating birds fly past lightships and lighthouses or across the moon, they are seen to do so without hurrying or showing any signs of straining to fly quickly. Thus, the duration of flights and tail wind velocity would be the primary determinants of the speed or rate of migration.
Few species migrate in such a leisurely manner; many wait until spring is well on its way before rushing to their breeding grounds. Sometimes this advance happens so quickly that species that have been moving slowly but steadily northward for a month or longer are actually caught up by late migrants. The following several examples of well-known migrants illustrate this.
FAQ
How many miles can birds fly without stopping?
Do birds fly non-stop when migrating?
How far can birds fly nonstop?