Tuesday 2 February 2010

The Peregrine Falcon

by Vishesh Jain

Comments by Asyncritus

I was astonished to read the following blog article today, and take the liberty of reproducing it in its entirety.

The author Vishesh Jain is connected to Harker, which publishes a blog here:harkerbio.blogspot.com/ from which this article is copied in full. It is a marvellous description of this wonderful bird, and gives full rein to the inquirer's questions about just how this creature could have obtained the instinct package which powers its fantastic behaviour.

harkerbio.blogspot.com/

The Peregrine Falcon: Fastest Animal on the Planet
Peregrine Falcons are raptors with keen eyes, strong wings, powerful beaks, and tremendous speed. Outside their nesting season, peregrine falcons earn their name by traveling extensively, as much as 15,500 miles a year. Once endangered by DDT and human development, they have rebounded and are now found all over the world. Though they prefer open spaces such as plains and sea coasts, they live everywhere from tundra to desert to cityscape.

Peregrine falcons are known for their speed. When they plummet to catch an unsuspecting pigeon below them, they can reach velocities over 200 miles per hour (320 km/h). That's over a fourth of the speed of sound. Zoom. But what's also fascinating about these remarkable birds are the adaptations that allow them to use such power.

The Eyes:
If a peregrine falcon is flying or perched over a kilometer in the air, as they often are, it would be useful, perhaps, to be able to see what it's trying to strike. While they're no mantis shrimp in terms of spectral range, they do indeed have some of the keenest eyes on the planet. With full color vision and rapidly focusing lenses, their eyes have a resolving power up to 8 times greater than humans, enabling them to spot prey miles away and keep track of it while approaching at breakneck speed.

The Shape:
To achieve 70 mph speeds in pursuit of prey and 200 mph plummets to attack those below, the peregrine falcon has one of the most streamlined bodies in the air. The curved wings create an air foil effect in multiple dimensions, maximizing maneuverability, lift, and speed.

The Wings:
Besides the streamlined structure of the wings themselves, peregrine falcons maximize speed in every way possible. In pursuit, it can flap its wings up to four times a second, and in its dive it is able to let gravity pull it down with negligible air resistance, locking its wings in place to create minimum drag. The feathers themselves are stiff, slim, and unslotted, allowing them to literally slip through the air as they attack. As in all birds, their wings are hollow, enhancing flight and maneuverability in the air.

The Power:
Small tubercles and bones in the nose prevent the immense air pressure from flowing into and rupturing their respiratory system. In addition to tons of strong red muscle fibers, peregrine falcons have one-way lungs, like most birds, to maximize oxygen intake. To achieve torpedo-like speed both horizontally and vertically, peregrine falcons have an enormous keel, part of the sternum. As the attachment site for flight muscles, the larger the keel, the more powerful the flight, and this makes these birds some of the fastest in the world.

The Attack:
Now, if you were to drop a couple hundred stories, you'd probably be going pretty fast too. The question, then, is whether you'd be able to catch something, halt your dive, and be in a medical condition to eat it. From the muscle, to the talons, to the beak, these raptors are serious predators. When their keen eyes finish guiding their dive into their prey, if the impact of 200mph razor-sharp talons hitting a poor pigeon's back doesn't kill it, the tomial tooth of their strong beak can break the stunned bird's spine in a second. Then the falcon can leisurely eat it in the air or on the ground, after plucking its feathers, of course.

A National Geographic video tracking a peregrine falcon's flight speeds from the air.


-Vishesh Jain
Image Sources and Cool Links:

Speed and Strike:
Extreme Science - Fastest on Earth
HowStuffWorks - How Do Peregrine Falcons Fly So Fast?
National Geographic - High-Velocity Falcons

Endangered:
Science Daily: Peregrine Falcons May Face New Environmental Threat
Royal Belgian Institute of Natural Sciences: The Return of the Peregrine Falcons
Texas Parks and Wildlife: Peregrine Falcon

General:
Cornell Lab of Ornithology - Peregrine Falcon
National Geographic - Peregrine Falcon
University of Wisconsin - BioWeb: Peregrine Falcon

Images:
U.S. Fish and Wildlife Service - Ozzie
Raptor Guide Gallery - Peregrine Falcon
TreeHugger - DDT Redux
Jerry Ting - Peregrine Falcon
Audubon - Signature Species: Peregrine Falcon
Posted by Harker Bio at 10:45 PM

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