A Little Bit More
Two of the most beautiful and interesting of North America’s mammals, are also among the least known. Both the Northern and Southern Flying Squirrels are similar in appearance and habits, making identification difficult in areas where the two species’ ranges overlap. Their strictly nocturnal activities have made them difficult to study for students trying to learn more about these animals. More often than not, a person’s introduction to flying squirrels comes when an attic is invaded by squirrels intent on storing nuts or preparing a nest.
Undoubtedly, their most impressive characteristic is their ability to glide from tree to tree in search of food or escape an enemy. When the front and hind limbs are fully extended, a loose fold of skin, called the patagium (pah-TAG-ee-um) acts as a gliding surface; a cartilage spur stiffens the forward edge of the patagium, improving the squirrel’s aerodynamics.
The densely furred tail is flat on the bottom and rounded on top, providing additional lift. The tail takes an active role in the squirrel’s maneuverability, serving as both elevator (up and down movement) and rudder (side to side movement). Once in flight, a flying squirrel is capable of complex turns and even abrupt directional reversals. In flight, the squirrel constantly monitors its progress, using its tail to direct and maintain the flight path. The average glide ratio is 3-4 feet of forward motion for each one foot of drop, but they’re capable of as much as a 6:1 ratio at times. Just before landing, the tail is pointed skyward, causing the head and front quarters to rise vertically. At this point the squirrel makes a four-point landing on feet that have specially thickened toe pads that help cushion its impact. If you have a bird feeder at your home and find that it’s being “raided” each night, your nighttime visitors may be flying squirrels!
Activities
Gliders
Objectives: Experience the aerodynamics of a glider
Materials: Access to internet
No doubt, many of your students have created their own paper glider and tried flying them. With some attention to detail and close observation, your students should be able to get a “feel” for the basics of a glider. Granted, flight is a complex subject but just being able to make simple adjustments to their paper gliders to achieve various results will impress everyone. In fact, it might be instructional to allow students to make their own paper glider BEFORE trying some other examples online. They’ll quickly find that their glider doesn’t fly as well as one that has had more thought and “engineering” incorporated into its design.
Variety of paper airplane designs for (easy, medium, complex)
Making a simple paper airplane glider
NASA Beginner’s guide to aerodynamics
Some good basics of flight ( nice illustrations)
The best paper airplane in the world (instructions to build your own)
Key Concepts
Adaptations and Diversity, Identification, Structures and Functions
Questions
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Posted by john rankin on February 13, 2006 at 12:28 PM
Q: i got a nighttime flash picture of a mountain lion. as it was looking directly at the camera, its eyes reflected the flash. one eye in the photo is yellow and the other is distinctly greenish yellow.
what is the true color of this mammals eyes when reflecting headlights, flashlights or camera flash ?
A: Wow, I'm impressed and a bit envious! There are people who go a lifetime without ever seeing a Mountain Lion, let alone photograph one. I really can't tell you the "true" color of its eyeshine since so few people ever get to see it. I'm guessing that the one eye got a rather direct hit by the flash while the other did not and that is why the difference in color. Which is the actual color is anyone's guess. Thanks for sharing.
Posted by john rankin on February 13, 2006 at 12:28 PM
Q: i got a nighttime flash picture of a mountain lion. as it was looking directly at the camera, its eyes reflected the flash. one eye in the photo is yellow and the other is distinctly greenish yellow.
what is the true color of this mammals eyes when reflecting headlights, flashlights or camera flash ?
A: My apologies. I was checking out my "questions sent" info and it seems your answer never went. I really did send one earlier!
First off, I think the fact that you got a picture of a Mountain Lion is really incredible. How many people ever get to see one in the wild? Very impressive!!!
I'm not at all sure what the "true" color of their eyeshine would be. I'm guessing that the flash from your camera hit one eye at enough of a different angle that it caused this difference in color. Different animals do indeed have different eyeshine colors depending on the makeup of the tapedum lucidum but I can't say what a Mountain Lion's would be. Thanks for the question and I hope you get many more shots in the future.