Birds are an incredibly diverse animal group. This is certainly reflected in their flying abilities, as you can see in this short list of facts about bird flight.
Fastest bird: Peregrine Falcon diving at 117 mph (188 km/h). It is believed this bird may even reach speeds of up to 150 mph (240 km/hr). This makes the Peregrine Falcon the fastest animal on earth.
Fastest level flight: Red-breasted Merganser at 100 mph (161 km/h).
Fastest wingbeat: Hummingbirds (e.g., Amethyst Woodstar) at 90 beats per second.
Slowest wingbeat: Vultures at 1 beat per second.
Most aerial bird: Sooty Terns, who can spend 3 to 10 years in the air without landing.
Most aerial landbird: Common Swift, who can remain in the air for 3 years without landing.
Highest flying bird: Ruppell’s Griffon Vulture at 7 miles, or 37,000 feet (11,274 m).
Longest two-way annual migration: Arctic Tern at 25,000 miles (40,200 km).
Source of these facts: The Bird Almanac, by Dr. David M. Bird