HOME >> BIOLOGY >> NEWS
Winning by a neck -- Giraffes avoid competing with shorter browsers

The giraffe's elongated neck has long been used in textbooks as an illustration of evolution by natural selection, but this common example has received very little experimental attention. In the January issue of the American Naturalist, researchers at the Mammal Research Institute in the Department of Zoology and Entomology at the University of Pretoria tested whether foraging competition with shorter herbivores could explain why giraffes feed mostly on leaves high in trees, despite being able to feed at lower levels as well.

"This [study] provides the first real experimental evidence that the long neck of the giraffe might have evolved as a consequence of competition, which provides support for a previously untested textbook example of natural selection," says Elissa Cameron (University of Pretoria), who coauthored the study with Johan du Toit (University of Pretoria and Utah State University).

Giraffes are well known for their unusual height, and they generally feed high in the tree canopy, above the height other herbivores can reach. Giraffes receive more leaves per bite by foraging high in the tree, but it's unclear whether this is caused by competition -- smaller browsers eating some of the leaves at lower heights -- or if more leaves grow at higher levels.

The researchers built low fences around trees in greater Kruger National Park to stop smaller browsers from eating leaves. After a complete growing season they found that the number of leaves on the fenced trees was roughly the same, revealing that small browsers are responsible for most of the foraging. Therefore, the researchers argue, it is competition from other herbivores, such as kudu, that appears to drive giraffes to eat leaves high in the trees.


'"/>

Contact: Patricia Morse
amnat@press.uchicago.edu
773-702-0446
University of Chicago Press Journals
22-Dec-2006


Page: 1

Related biology news :

1. Winning the oil endgame in America to be discussed at NJIT forum
2. Desertification: UN experts prescribe global policy overhaul to avoid looming mass migrations
3. The eyes have it! How box jellyfish avoid banging into things
4. Embryonic selection of sex avoids conceiving blind children
5. How to avoid a bat
6. Define precautionary principle to avoid clashes over biotechnology under World Trade rules
7. Elephants avoid costly mountaineering
8. How plants avoid feeling the burn
9. Heal thyself: Systems biology model reveals how cells avoid becoming cancerous
10. Female guppies risk their lives to avoid too much male attention
11. Altering genetic blueprint of receptors in brain could help stroke victims avoid brain damage

Post Your Comments:
*Name:
*Comment:
*Email:
TAG: Winning neck Giraffes avoid competing with shorter browsers

(Date:5/11/2015)... 11, 2015 Curemark LLC, a privately held ... a new Phase III double blind, randomized, placebo-controlled clinical ... CM-AT, on all children ages 3-8 with Autism. Previously, ... III double blinded clinical trial for CM-AT in children ... the digestive enzyme chymotrypsin. This new trial will help ...
(Date:5/8/2015)... Synaptics Inc. (NASDAQ: SYNA ), the leading ... the executive management team will present at the following investor ... Telecom Conference Date: May 18, 2015 Time: 10:40am ... Cowen and Company Technology, Media & ... The New York Palace Hotel, New York, NY ...
(Date:5/6/2015)... 2015 LifeBEAM, a developer of bio-sensing technology, ... today that they will expand their partnership in bio-sensing ... cycling helmet and the first joint project between the ... in order to give cyclists more style choices and ... and Lazer announced their plan to release a new ...
Breaking Biology News(10 mins):Curemark, LLC, Launches New Phase III Trial in Expanded Population of Children with Autism 2Synaptics to Present at Upcoming Investor Conferences 2LifeBEAM and Lazer Announce Expanded Partnership in Bio-Sensing Sports Gear 2LifeBEAM and Lazer Announce Expanded Partnership in Bio-Sensing Sports Gear 3
(Date:5/21/2015)... NEW YORK , May 21, 2015  Prima ... biotechnology company that is striving to become a leader ... of cancer, recently announced that the final CVac data ... has shown a clear trend for a clinically meaningful ... ("SOC") in second remission patients. In the ...
(Date:5/21/2015)... W. R. Grace & Co. ... Worms, Germany has received good manufacturing practice (GMP) ... International Pharmaceutical Excipient Council (IPEC) Foundation. ... SYLOID® FP brand of pharmaceutical grade excipient silica ... Curtis Bay, Maryland (USA) and Sorocaba, Brazil locations. ...
(Date:5/21/2015)... DUBLIN , May 20, 2015 Research ... announced the addition of the "2015 Global ... to their offering. The primary goal ... of flow cytometry instruments and reagents. Key information ... drive the selection of flow cytometers, predominantly used ...
(Date:5/20/2015)... , May 20, 2015 ... presented preliminary data demonstrating the ability of the ... fibrosis (IPF) from other interstitial lung diseases (ILDs) ... the classifier,s potential to help thousands of patients ... ambiguity in IPF diagnosis – a frequent challenge ...
Breaking Biology Technology:Correction Continues after Big Move - BrokerBank Securities, Inc. 2Grace European Facility Receives GMP Excipient Certification for SYLOID® FP Silica Gel 2Global Survey on Flow Cytometry Adoption Trends 2015 2Veracyte Presents Preliminary Data Demonstrating Ability of Molecular Classifier to Improve Non-Surgical IPF Diagnosis Using Bronchoscopy Samples 2Veracyte Presents Preliminary Data Demonstrating Ability of Molecular Classifier to Improve Non-Surgical IPF Diagnosis Using Bronchoscopy Samples 3Veracyte Presents Preliminary Data Demonstrating Ability of Molecular Classifier to Improve Non-Surgical IPF Diagnosis Using Bronchoscopy Samples 4Veracyte Presents Preliminary Data Demonstrating Ability of Molecular Classifier to Improve Non-Surgical IPF Diagnosis Using Bronchoscopy Samples 5
Cached News: