SUBSCRIBE | NEWSLETTERS | MAPS | VIDEOS | BLOGS | MARKETPLACE | CONTESTS
TRY BACKPACKER FREE!
SUBSCRIBE NOW and get
2 Free Issues and 3 Free Gifts!
Full Name:
Address 1:
Address 2:
City:
State:
Zip Code:
Email: (required)
If I like it and decide to continue, I'll pay just $12.00, and receive a full one-year subscription (9 issues in all), a 73% savings off the newsstand price! If for any reason I decide not to continue, I'll write "cancel" on the invoice and owe nothing.
Your subscription includes 3 FREE downloadable booklets.
Or click here to pay now and get 2 extra issues
Offer valid in US only.

Also on Backpacker.com


Enter Zip Code

Backpacker Magazine – May 1998

Why Do Fireflies Glow?

Plus 24 other round-the-campfire brain stumpers every nature buff should know.

by: Phillip Manning

PAGE 1 2 3 4

21. How can crickets tell the temperature, and what other creatures are weather forecasters?

The Weather Channel is more reliable than any critter, but the male snowy tree cricket (Oecanthus fultoni), found in all United States regions except the Southeast, does vary its chirping according to the temperature. Adding 40 to the number of chirps made in 15 seconds provides a close measure of the temperature in degrees Fahrenheit. Evidence is spotty for other creatures, but owls hooting throughout an autumn night are said to be harbingers of a storm, waterfowl usually fly higher in clear weather and lower in stormy weather, and woolly bear caterpillars are supposedly blacker before severe winters.

22. What do tree rings mean, and how do I count them?

In temperate zones, including North America, most trees add a ring every year, making a tree the only organism whose age can be precisely determined. Tree rings enable scientists called dendrochronologists to not only date specimens, but also "interpret how these trees have been treated by mother nature and human activity," explains Dr. D.W. Larson, a professor of botany at Guelph University in Ontario, Canada. "Each of these long chronologies, as they are called, is a living clock whose ticks are louder or softer as a function of drought, cold, heat, and disturbance." Certain tree species' rings are easily identifiable, such as oak, ash, hickory, tamarack, fir, or northern white cedar. Each annual ring actually consists of two rings: a light-colored ring (earlywood) and a dark-colored ring (latewood).

23. Can snakes spit venom?

Yes, but thankfully not the ones in this hemisphere, Fellows says. The spitting cobras of Africa have a propensity for defending themselves by squirting a thin stream of venom toward the eyes of an attacker.

24. Why do leaves change color?

The green pigments known as chlorophyll, which capture energy from the sun, dissipate as the days grow shorter and the nights colder. This lets the yellow, brown, and orange pigments, called carotenoids, already present in the leaf shine through. Red and purple come from anthocyanin pigments, which are produced in sap cells beginning in late summer.

25. Do opossums really play dead or hang by their tails?

They'll play "possum" when confronted by an aggressor and are known to secrete a foul-smelling substance like skunks do. As for hanging, young ones do but mature opossums are unable to support themselves by their tails, although they use them while climbing.

Matt Purdue hoards his Reese's Pieces in the Southern California backcountry.


PAGE 1 2 3 4

Subscribe to Backpacker magazine
Sign up for our free weekly e-newsletter
Name:
Address 1:
Address 2:
City:
State:
Zip:
Email (req):
Reader Rating: -

ADD A COMMENT

Your rating:
Your Name:

Comment:

My Profile Join Now

Most recent threads

Gear
I am in so much trouble
Posted On: Aug 22, 2014
Submitted By: hikerjer
The Political Arena
At what age did you come back....
Posted On: Aug 22, 2014
Submitted By: hikerjer

Go
View all Gear
Find a retailer

Special sections - Expert handbooks for key trails, techniques and gear

Check out Montana in Warren Miller's Ticket to Ride
Warren Miller athletes charge hard and reflect on Big Sky country, their love for this space and the immense energy allotted to the people who reside in Montana.

Boost Your Apps
Add powerful tools and exclusive maps to your BACKPACKER apps through our partnership with Trimble Outdoors.

Carry the Best Maps
With BACKPACKER PRO Maps, get life-list destinations and local trips on adventure-ready waterproof myTopo paper.

FREE Rocky Mountain Trip Planner
Sign up for a free Rocky Mountain National Park trip planning kit from our sister site MyRockyMountainPark.com.

Follow BackpackerMag on Twitter Follow Backpacker on Facebook
Get 2 FREE Trial Issues and 3 FREE GIFTS
Survival Skills 101 • Eat Better
The Best Trails in America
YES! Please send me my FREE trial issues of Backpacker
and my 3 FREE downloadable booklets.
Full Name:
City:
Address 1:
Zip Code:
State:
Address 2:
Email (required):
Free trial offer valid for US subscribers only. Canadian subscriptions | International subscriptions