Ant Wars and a Whistling Tree
By Chelsie Vandaveer
February 6, 2002
killerPlants Tendrils: ~~1~~2~~3~~4~~5~~
Shop the National Geographic Store—>Click here.
Suggested Reading—>Click here.
Assorted Killer Savings Garden Links—>Click here.
Killer Picks: Wollemi Pine, greatest living fossils discovered in the 20th century—>Click here.
Travel Vest, Broad-brimmed Tilley Airflo Hat, Atomic Clip Watch—>Click here.
Weather Station, Earth Explorer Shoulder Bag, Men's Leather Travel Shoes—>Click here.
On the Serengeti Plain in Kenya and Tanzania are whistling-thorn acacias (Acacia drepanolobium Sjostedt). The paired thorns are actually spines, modified leaves that serve as protection against mammalian herbivory. One in every five pairs of spines is swollen at the base into a globe that serves as a domatium (communal nest) for ants. When the ants have made holes into the swollen base, the structure whistles in the wind.
Acacia drepanolobium serves as host for four obligate species of ants, Crematogaster mimosae, C. sjostedti, C. nigriceps, and Tetraponera penzigi. The ants are mutually exclusive, only one species per tree.
The whistling-thorn acacias have extrafloral nectaries near the base of the leaves, but unlike many of the New World acacias, they do not have Beltian bodies on the tips of the leaflets to feed the ants. The ants forage for their proteins in the form of insects. Two of the species, Crematogaster sjostedti and C. mimosae tend scale insects on the acacias.
The ants war among themselves for possession of the acacias. Of the four obligate ants, Crematogaster nigriceps are usually the losers in the ant wars. In eight out of ten invasions by the other ant species, C. nigriceps were routed from their acacia. The ants have had to develop another method of survival. C. nigriceps cheat their host tree.
The acacia provides the ants with lodging and nectar. C. nigriceps prune the acacia especially if surrounding acacias are host to other ant species. The terminal buds are removed preventing the acacia branches from touching other trees. This prevents other ant species breaching their tree.
The ants' pruning produces acacias which are small and densely branched in comparison to trees with the other ant species. But the pruning is detrimental to the acacias. The trees can never flower and produce seed when occupied by Crematogaster nigriceps.
Mark Olson of the Missouri Botanical Garden has photographs of the Acacia drepanolobium. To view the photographs, click on the link:
http://www.mobot.org/gradstudents/olson/legume.html
Then click to enlarge photographs 6 through 8 to view the whistling-thorn. Photograph 9 on this page shows the Beltian bodies seen on New World acacias.
killerPlants Tendrils: ~~1~~2~~3~~4~~5~~
Suggested Reading:
Bull's-horn Acacia (Acacia sphaerocephala) Plant of the Week - February 4, 2002
Sweet Acacia (Acacia farnesiana) Plant of the Week - February 2, 2004
What is the mystery of acacia? What's in a Name? - February 8, 2002
What is khaki? Herbal Folklore - May 26, 2003
What is shellac? Renfield's Garden - May 28, 2003
What is cassie? Herbal Folklore - February 9, 2004
What is henna? Herbal Folklore - October 6, 2003
Killer Savings Links:
Breck's Bulbs -$25 off—>Click here.
Gurney's Seed and Nursery -$20 off—>Click here.
Henry Fields Seed and Nursery -$20 off—>Click here.
Spring Hill Nursery -$20 off—>Click here.
Gardens Alive! -$20 off—>Click here.
Michigan Bulb -$20 off—>Click here.
Unique Professionally Designed Gardens
Springhill Nursery®
Spring Hill Nursery has unique gardens professionally designed by experts to take the guesswork out of gardening. Whether you are looking for a three season garden, foundation garden, or a garden to attract hummingbirds and butterflies, Spring Hill Nursery has created a step-by-step design just for you.
Click here - $20 off your first order at Spring Hill Nursery!
|
|
|
|
Travel Vest
National Geographic®
In an earlier era of heavy fiber travel clothing, Society expedition teams surely dreamed of gear like this. Made from a remarkably airy, cottonlike nylon with advanced performance characteristics and Teflon® protection, it's a quick-drying wrinkle-, stain-, and water-resistant wonder that keeps necessities close and packs away into almost nothing.
|
|
Nineteen separate pockets (including a secret security pocket) can hold a water bottle, passport, travel tickets, cell phone, maps, film, and personal stereo. Complemented by camera and binocular epaulets with slip-resistant grips, adjustable side cinches, and padded shoulders. Machine wash. Imported. 13 oz. Unisex sizes. Tan.
Click here for price and to view other exciting National Geographic products.
Shop the National Geographic Store. All purchases support research and education.
|
|
|
Broad-brimmed Tilley Airflo Hat
National Geographic®
A hat is a highly recommended accesory when traveling or exploring, and this adventure-ready hat features a special airflow mesh that provides unparalleled cooling ventilation. Rated UPF 50+, it also blocks 98% of UV rays for solid sun protection. The lightweight, water- repellent Supplex® nylon surface keeps you dry in the rain, and resists mildew.
|
|
Comes with a lifetime guarantee and two-year all peril insurance policy against loss, theft, or other untimely demise. Wind strap. Made in Canada.
Click here for price and to view other exciting National Geographic products.
Shop the National Geographic Store. All purchases support research and education.
|
|
|
National Geographic Atomic Clip Watch
National Geographic®
Keep highly accurate time while sightseeing or on the trail with this sturdy carabiner clip watch. Clips onto a backpack or belt loop for quick and easy access. With rugged styling and a classic leather strap and backing, this analog watch syncs to signals from the U.S. atomic clock for maintenance-free use.
|
|
Displays both 12-hour and 24-hour military time, day of the week, and digital date and seconds. Batteries included. 1 3/4''W x 5 1/2''L. 2 oz.
Click here for price and to view other exciting National Geographic products.
Shop the National Geographic Store. All purchases support research and education.
|
|
|
Altitech Adventure Weather Station
National Geographic®
Stay on course and on time with this water-resistant data center with clock that provides quick altitude, barometric pressure, temperature, and compass readings as well as alarm clock, chronograph, and calendar functions. Clips onto your bag, pack, or belt via the built-in carabiner, which also folds to serve as a handy stand.
|
|
It keeps a 24-hour barometric history to track the weather and as many as 20 date-stamped altitude log entries that create a record of your travels above sea level.
Click here for price and to view other exciting National Geographic products.
Shop the National Geographic Store. All purchases support research and education.
|
|
|
Earth Explorer Shoulder Bag
National Geographic®
The Earth Explorer shoulder bag, designed by Bogen for National Geographic, holds all your personal gear, including laptop, camera, or camcorder. Protective padded safety zones keep delicate gear stable and safe. Modular detachable bottom padding lets you choose between extra protection and a larger storage area.
|
|
Generous external pockets and pouches, plus a read concealed flat pocket store cell phones, mp3 players, passports, and travel documents. Exterior gear loops let you carry accessories with ease.
Click here for price and to view other exciting National Geographic products.
Shop the National Geographic Store. All purchases support research and education.
|
|
|
Men's Leather Travel Shoes
National Geographic®
Travelers can often find themselves in situations where looking appropriate is just as important as being physically comfortable. These advanced shoes are designed with double-density, dual-foam foot beds and EVA midsoles that cushion every step to reduce foot and leg fatigue, allowing you to walk farther in your travels. A special moisture-wicking leather lining keeps feet dryer and fresher while full-grain leather uppers maintain the sophisticated look that many destinations require.
|
|
Rubber outsoles dependably grab terrain both urban and rural. Metal-free design aids passage at security points. Velcro® closure. Imported.
Click here for price and to view other exciting National Geographic products.
Shop the National Geographic Store. All purchases support research and education.
|
|
|
Wollemi Pine
National Geographic®
This survivor from the age of the dinosaurs is one of the greatest living fossils discovered in the 20th century. The Wollemi pine is one of the world's oldest and rarest tree species, belonging to a 200-million-year-old plant family thought to have been extinct for more than two million years.
|
|
Previously known only from fossil records, it was presumed extinct until a single tree was found in the Wollemi National Park, Australia, in 1994. Subsequent research discovered 100 adult trees that have survived in a single canyon in this wild and rugged area.
Click here to view canyon, trees and fossil record.
You can assist in the conservation effort and enjoy the unique opportunity to ensure the continued survival of this rare species by giving the tree as a gift or growing your own. Suitable for indoor container gardening. Can also be used as a landscape tree in USDA hardiness zones 2 through 7, which includes New England, the Midatlantic states, and much of the Midwest.
Comes with a care manual with the full story about the discovery and fascinating history of the Wollemi pine. Tree will be approximately 8"H when shipped. A portion of the proceeds from the sale of these plants will fund ongoing conservation research.
Click here to get your Wollemi Pine and assist in the conservation effort.
|
National Geographic Magazine
National Geographic®
|
|
You are invited to roam the world in the pages of National Geographic magazine. Explore the diversity of our planet's lands and inhabitants in compelling stories covering topics such as animals, nature, science, technology, culture, history, travel, adventure, exploration, and geography. The monthly National Geographic magazine is your key benefit of membership.
Additional benefits include:
- As many as five wall map supplements throughout the year in issues of the magazine
- A personalized Membership Certificate
- Special discounts on selected products
- The opportunity to examine special Society products free in your home before deciding to purchase
- The privilege of traveling the world with the Society's educational travel tour programs
- The satisfaction of supporting important research, conservation, education, and exploration projects
|
|
Join the Society and bring the adventure of National Geographic into your home!
Click here for price and more info...
|
| |
killerplants Recommended Smart Stores
|
|
|
|
|
|
|
 BACK TO TOP
|
|
